- Email: [email protected]
Self-Monitoring Dietary Intake: Current and Future Practices
REVIEW
Self-Monitoring Dietary Intake: Current and Future Practices Lora E. Burke, PhD, MPH, RN,* Melanie Warziski, BSN, RN,† Terry Starrett, BS, MA, MSN, RN,‡ Jina Choo, PhD, RN,§ Edvin Music, MSIS,¶ Susan Sereika, PhD,㛳 Susan Stark, MS, RD, CSR, LDN,# and Mary Ann Sevick, ScD, RN** This article reviews the literature on the use of paper diaries for self-monitoring food intake, identifies the strengths and limitations of paper-and-pencil diaries and their new counterpart, the electronic diary or personal digital assistant (PDA), and reports how participants were trained to use a PDA with dietary software in two pilot studies— one with hemodialysis patients and the other with participants in a weight loss study. The report of the pilot studies focuses on the practical issues encountered in training participants in the use of a PDA and addresses the pros and cons of different dietary software programs. Six hemodialysis patients were trained in the first study and seven participants attempting to lose or maintain their weight were trained in the second pilot study. The training focused on how to use a PDA and how to navigate the dietary software to self-monitor food intake. The goals of using the PDA were to improve adherence to the therapeutic diets and to self-monitoring. Lessons learned from the pilot studies are shared. © 2005 by the National Kidney Foundation, Inc.
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ELF-REPORT DIARIES have been the mainstay of researchers for the collection of numerous subjective and behavioral variables relevant to research and clinical practice. For exam*Associate Professor of Nursing and Epidemiology, †Graduate Student Researcher, PREFER Trial, ‡Project Manager, the ENHANCE Trial, §Postdoctoral Scholar, ¶Systems Analyst/Data Manager, PREFER Trial, and 㛳Associate Professor of Nursing, Biostatistics and Epidemiology, Department of Health & Community Systems, University of Pittsburgh School of Nursing, Pittsburgh, PA. #Dietitian Specialist, University of Pittsburgh Medical Center, Pittsburgh, PA. **Associate Professor, Department of Health & Community Systems, University of Pittsburgh School of Nursing, Pittsburgh, PA. Support was provided by NIH, NIDDK, RO1-DK58631; support for the hemodialysis pilot study was received from the Obesity and Nutrition Research Center NIH-NIDDK No. DK046204; the General Clinical Research Center NIH-NCRRGCRC No. 5M01-RR00056; and the Center for Research in Chronic Disorders, NIH-NINR No. P30-NR03924. Address reprint requests to Lora E. Burke, PhD, MPH, RN, University of Pittsburgh School of Nursing, Department of Health and Community Systems, 415 Victoria Building, Pittsburgh, PA 15261. E-mail: [email protected] © 2005 by the National Kidney Foundation, Inc. 1051-2276/05/1503-0001$30.00/0 doi:10.1016/j.jrn.2005.04.002
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ple, diaries have been used to measure pain,1 sleep,2 coping with smoking urges,3 illness or injury and health care use,4 medication taking,5 and exercise.6 Diaries are also used in the assessment of eating-related behaviors, eg, episodes of binge eating,7 energy intake and expenditure in weight loss treatment,8 –10 fat and dietary cholesterol intake in the management of dyslipidemia,11 blood glucose levels in diabetes management,12 and nutrient intake in patients with end-stage renal disease (ESRD).13 There are two indications for using diaries to record food intake: first, to self-monitor one’s eating behavior and food consumption on a daily basis as part of an intervention, and second, to record in detail all foods consumed for a computerized nutrient analysis for outcome assessment. The latter is usually done periodically with a 3- to 5-day food diary in a research setting. Unfortunately, the majority of the diaries used today for either purpose are in the paper-and-pencil format, which has inherent limitations.14,15 This article focuses on diaries used for the first indication—to self-monitor food intake in the self-management of chronic disorders. 281
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The purpose of this article is multifold: to review the use of paper diaries for self-monitoring food intake; to identify the strengths and limitations of paper-and-pencil diaries and their new counterpart, the electronic diary or personal digital assistant (PDA); and to report on the issues encountered when training individuals to use a PDA for dietary self-monitoring.
Review of the Literature Use of Self-Monitoring in Making Dietary and Eating Behavior Changes Self-monitoring food intake is considered the cornerstone of behavioral treatment of obesity and other chronic disorders that can be managed by dietary modification and control, such as ESRD, diabetes, and dyslipidemia.11,13,16 Selfmonitoring is conducted as a systematic observation and recording for the purpose of increasing the individual’s awareness of eating behaviors and food consumed. The individual is instructed to record all food intake (energy consumption or target nutrients) and, in cases in which calorie expenditure is an issue, to also record exercise (energy expenditure). This recording may be extended to include the location of where one is when eating (home versus away), time of day, quantity eaten, and the target nutrient values (eg, sodium, potassium, fat grams). Ideally, when using this approach, the individual records the food intake as it occurs. Recording in an ongoing manner permits individuals to alter their food intake so they do not exceed their daily target values (eg, calories, fat, carbohydrates, sodium, cholesterol, or potassium). Dietary self-monitoring has been given limited attention in the literature. Most reports on selfmonitoring involve paper diaries and weight loss interventions.8 –10 Baker and Kirschenbaum showed that self-monitoring was positively correlated with weight loss, and that the more consistently the monitoring occurred, the better the weight loss.8 Similarly, Milas et al,13 in the Modification of Diet in Renal Disease Study, found that the participants who engaged in more frequent self-monitoring were more likely to achieve their dietary goals. However, the selfmonitoring protocol is seldom followed adequately. One study reported that only 66% of the participants self-monitored for the entire day for
more than 50% of the days, and approximately 25% did not self-monitor on most days.8 Although it is not known why the participants failed to self-monitor, it is clear that it is a tedious and time-consuming process that is difficult to carry out in some situations.
Strengths and Limitations of Paper Diaries for Self-Monitoring Although paper diaries are inexpensive and readily available in several formats, their limitations are numerous. The first requirement for the use of any diary is literacy. The simplest paper diary challenges individuals who have limited literacy skills or illegible handwriting. Having the time to complete daily diaries is another issue. Regardless of the condition for which an individual is self-monitoring food intake, the need to look up foods in a nutrient guide and calculate and record the content of foods eaten is time consuming. There is also the issue of the social acceptability of self-monitoring in public situations, which may create uneasiness. Moreover, using the paper-and-pencil format makes it nearly impossible for the clinician or researcher to determine when the diary was completed. Observations of study participants provide evidence showing that often they record in the diaries long after the fact, also referred to as back-fill.17 The longer the delay in recording dietary intake (eg, weekly or monthly), the greater is the risk of recall bias. See Table 1 for a summary of the negative and positive aspects of using paper diaries. Research focused on human memory reveals that memory recall is unreliable and that each step in the process of recalling information has the potential to introduce inaccuracy and bias.14 Autobiographic memory includes four key processes: encoding the event or experience, storage of the event’s memory, retrieval of the event or experience from memory, and reconstructing the event.14,18,19 Encoding is often less than complete, imperfect, and influenced by the saliency of the event, which in turn is influenced by the individual’s subjective and mental state at the time of the event. Thus, memory does not start as an objective record of events. When an individual is asked to recall a previously encoded eating or exercise experience, active reconstruction of that experience is required, which can introduce biases and inaccuracies. Several factors may work
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Table 1. The Positive and Negative Aspects of Using Paper Diaries and Handheld Computers for Dietary Self-Monitoring Positive Aspects Paper diaries Simple to use, require little training Readily available in several formats Inexpensive
Handheld electronic diaries May be learned by individuals without prior computer experience Illegible handwriting is not an issue Know when the recording was done Able to detect adherence to self-monitoring Can protect data by use of personal digital assistant password Are able to summarize and analyze data Provides immediate feedback because user sees current intake next to the daily goals Automatically calculates subtotals and total May be able to send data via phone modem to provider or researcher Cost of devices is continually decreasing
to introduce biases, such as how recent and important that event was, the positive or negative nature of the event, and20 the mood or state of the individual at the time of recall. For example, individuals are more likely to retrieve negatively valenced information when in a negative mood.21 When a food questionnaire is used that asks for a report of foods consumed over the past 6 or 12 months, the issue of recall bias is known. An investigator attempts to avoid this bias when using a food record to obtain a report of foods consumed in the present time. If participants do not complete their diaries in a timely way and back-fill the reports after the time of the intended recording, the diary data are subject to the very recall biases that were the rationale for choosing the diary format. Although it is likely that individuals can recall singular and prominent events such as having a migraine headache, recall over the interval of a day is subject to the same cognitive processes that bias autobiographic memory over longer periods.14 Thus, even over 1 day, individuals may find it difficult to recall details of specific activities that seem continuous or occur frequently. Eating behaviors are frequent, may not be consciously
Negative Aspects
Requires user to be literate Need to look up the nutrient values in a book Need to calculate the subtotals and total for each nutrient being monitored Unable to detect when the recording was done Delayed recording is subject to recall bias Illegible handwriting is a problem Requires some training and practice Requires user to be literate Requires user to recharge battery regularly Loss of device may be an issue If battery is not charged, data are lost Is available at moderate price
thought about, and may not be salient. These characteristics make it more difficult to recall episodes of eating, whether it is eating a piece of candy, a snack, or a full meal. Unfortunately, food consumption is difficult to measure, but short of direct observation, we are reliant on self-report measures. Fortunately, technological advances now permit us to determine whether the diary data were recorded at the time of eating (referred to as real time) or in a delayed period.
Strengths and Limitations of Electronic Devices for Dietary Self-Monitoring The use of an electronic device, such as a PDA, for self-monitoring food intake represents an improvement over paper diaries. Although both paper and electronic diaries provide the individual (and those providing dietary counseling) with the ability to conveniently track the type, frequency, and portion size of foods consumed, the use of an electronic device with a dietary software program facilitates the recording process. Most dietary software programs that use the United States Department of Agriculture as the source database have a database of approximately 5,000 to 6,000 food items (eg, BalanceLog or Diet Mate Pro). With these programs, individuals can log
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foods without the labor of maintaining handwritten records, searching for the nutrient content of foods in pocket manuals, and calculating the totals for nutritional intake. These programs provide individuals with immediate feedback about their nutrient intake in comparison to a daily target for nutrient intake. If self-monitoring is done throughout the day, individuals can make real-time modifications in their energy intake and expenditure. With the use of PDA monitoring, the issue of illegible handwriting is eliminated.22 Moreover, some programs permit the data on the PDA to be uploaded, either directly or via a modem connection, to a personal computer (PC) for review by the clinician or researcher.12,23 These innovations make dietary self-monitoring easier than is the case with paper diaries, and thus individuals are likely to be more adherent in recording their food intake. Although there are no comparative data on dietary self-monitoring with paper diaries versus with PDAs, studies reporting on the self-monitoring of pain1,24 and of peak flow among asthma patients 25 report better adherence to the use of electronic methods than to the paper diary. Finally, a factor that is important to the clinician, adherence cannot be manipulated or falsified because ideally the PDA dateand time-stamps every entry. Therefore, providers know the extent to which they can rely on the diary data to make treatment decisions, which can improve clinical management.12 Not unlike the paper diary, the limitations of electronic devices for self-monitoring also include literacy because an individual needs to read the list of foods displayed on the screen of the PDA, or knowhow to spell a food when using the search option. Other limitations include cost; however, the price of these devices is rapidly declining. Acceptability by older or less-educated individuals is often raised as an issue. However, in the pilot study we describe later in this article, we found that a group of older ESRD patients with no prior computer experience readily accepted and learned how to use a PDA for self-monitoring. Others have reported similar findings.12 See Table 1 for the positive and negatives features of using electronic diaries.
Current Application of Electronic Food Diaries As mentioned previously, there are few reports of PDA use for dietary self-monitoring. Two
studies reported the use of electronic diaries in the management of diabetes. Tsang et al showed a significant decrease in hemoglobin A1c over a 3-month period among patients who used PDAs to track meal portions and blood glucose readings compared with the patients who used a paperand-pencil diary.23 A Canadian study combined the use of PDAs and a web-based site where adolescent participants could upload the data, which were accessed by the health care providers, who could monitor the information and assist participants in their diabetes management.12 In both of these studies, participants thought it was easy to use the electronic devices and found it useful, and noteworthy for adherence concerns, the adolescent participants reported that using the PDA to report their data in public places made it less conspicuous than a paper diary and easy to complete. Glanz et al described a pilot study that used PDA-based self-monitoring to reduce dietary fat intake in postmenopausal women.26 Compared with women receiving a dietary counseling intervention alone, women who selfmonitored using the PDA were found to meet their dietary goals more often, and to consume fewer total calories and fewer calories from fat. Using healthy volunteers, Beasley et al assessed the accuracy of food recorded on a PDA with Diet MatePro software compared with 24-hour recall and observation and found no significant difference between the PDA data and the other sources.27 No studies were found in the literature evaluating PDA-based self-monitoring for individuals with ESRD or those engaged in weight management.
Report of Experience Training Individuals in the Use of a PDA in Two Pilot Studies One of the goals of the pilot studies was to examine the feasibility of teaching hemodialysis (HD) patients and individuals in a weight loss study to use PDA devices for self-monitoring. The full report of the HD pilot study, the accompanying behavior intervention, and clinical outcomes are reported in a companion article in this issue.28 This article focuses on the PDA training in these two pilot studies. The protocols for the studies were approved by the University of Pittsburgh Institutional Review Board.
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Pilot Study Participants The six participants on HD were, on average, 64 years old (range, 55 to 70 years). Five of the six participants were African American, four were women; four had a high school education or less, and two had some college education. None had prior experience with computerized devices of any sort. The seven participants in the weight loss study were, on average, 46.96 ⫾ 8.85 years old (range, 28.20 to 55.68 years). One of the seven was African American, and one was male. The mean education for the group was 15.28 ⫾ 2.56 years; all had prior experience with computers but not with PDAs. These seven participants were enrolled in the pilot study after completion of an 18-month behavioral and nutrition intervention program. Some individuals had lost a significant amount of weight and were trying to maintain that loss, whereas others were still trying to lose weight. PDA Training Different software and hardware, as well as and different teaching approaches, were used for the training in the two studies. Participants in the HD study used the Visor Neo, a PDA that uses nonrechargeable batteries. The dietary self-monitoring software was BalanceLog, which provided a meal-by-meal and day-by-day breakdown of total calories, calories from fat, saturated fat, protein, carbohydrates, sodium, and other nutrients. BalanceLog contains a food database of more than 4,300 foods, including over 1,700 major brand names. BalanceLog software uses the most recent nutrient composition data from the United States Department of Agriculture (USDA), and also monitors brand name and restaurant data to ensure that the program uses the most current data. BalanceLog was programmed with the individual participants’ daily dietary goals. The investigators developed a PowerPoint module to instruct participants in the use of these devices for recording their dietary intake, which was shown on a laptop computer while the participant was receiving the dialysis treatment; the participant followed along with his or her own PDA. Hard copies of the PowerPoint slides were provided for the individual to use and also take home. Initial training in the use of the PDA required 45 to 90 minutes of individualized instruction. After the initial training, the participants were encouraged to log their meals into BalanceLog, starting with one meal,
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progressing to all meals in 1 day, and then gradually increasing this activity until they were recording all meals consumed. Participants received 1:1 dietary counseling during the dialysis session, during which time they could obtain additional assistance in using the program. BalanceLog also permits the user to monitor weight loss/gain and energy expenditure from exercise. However, these programs were not taught to participants in the HD study. The seven participants in the weight loss study used a different PDA, the Palm Pilot Zire31, a PDA that permits recharging, and the software program was Diet Mate Pro, a program that is based on the USDA nutrient database and includes 6,000 food items in the PDA database, including brand names and restaurant foods. Similar to the HD study, a PowerPoint module was developed that focused on basic PDA functions and the Diet Mate Pro software. The training in this study was conducted in group sessions with all seven participants in attendance, and the slides were presented on a screen while the participants followed along with the PDA. The training session included the use of a Palm Pilot emulator so that the instructor could demonstrate the use of the PDA functions on the screen before having the participants perform them. Several staff members were present so that they could walk around the room and assist individual participants in practicing the exercises on their PDA. Participants attended three sessions; the first one focused on the use of a PDA, the second one introduced the dietary software and had participants practice looking up foods and entering what they ate, and the third addressed problems that participants had been experiencing and included more practice. Participants were given a print out of the slides to take with them. A telephone number was provided for participants to call when there were questions or troubleshooting was needed.
Access to the PDA Dietary Data Participants in the HD study had the data from their PDA uploaded to the laptop computer at each intervention session, and the data were stored on the hard drive. The data were in the same format as appeared on the PDA screen. The weight loss study participants brought in their PDAs at a monthly visit, at which time, using the synchronization cable, the data were uploaded via a PC to the web site of the company that devel-
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Figure 1. PDA screen showing “search” option with list of food categories, BalanceLog.
oped the software, PICS, Inc. At a later time, the data were sent back to the weight loss study center in ASCII format. The nutrient variables that are included in the uploaded BalanceLog software data included calories, total fat, saturated fat, protein, carbohydrates, cholesterol, sodium, fiber, sugar, vitamins A and C, iron, and calcium. The HD study focused primarily on calories, calories from protein, and sodium, because protein energy malnutrition and fluid retention were predominant problems in the participants. Diet Mate Pro was configured for this study to include only two variables, calories and fat grams, on the PDA screen because that is what weight loss study participants traditionally record in paper diaries. However, the program permits one to monitor five variables (calories and nutrients) without scrolling. In the current version, the program matches the food intake to the full USDA nutrient database, so any nutrient available in the USDA database is available to the researcher for analysis. Therefore, when the data from our pilot study were uploaded to the PC, several more nutrients were displayed on the PC.
Software Issues Some initial difficulties were encountered in the use of the software. Figure 1 shows the search categories for foods in the BalanceLog software program. The HD participants began by selecting a major food group, and then within the group, searching for specific foods. However, some participants had difficulty identifying the appropriate food group to search. Thus, an alternative search strategy was taught in which the “find” option was used to list all foods in the database alphabetically. This approach allowed the participant to scroll through the list to find the foods they had
eaten. Another problem was that portion size was expressed in decimals, which was unfamiliar to several participants. Other minor problems encountered were the lack of ethnic foods, lowsodium foods (commonly eaten by HD patients, who must limit sodium intake), and dietary supplements (such as Boost, Glucerna, and Breeze) that are commonly consumed by HD patients. However, the BalanceLog software had the ability to allow the user to enter new foods and even recipes into the database. When participants encountered missing foods, they were instructed to write down what they had eaten (including nutritional content if available) or to bring the food labels to the dialysis center, and the interventionist added the foods to the database at the next encounter. Because dietary habits tend to follow a pattern, this problem diminished in frequency over time. The users of the Diet Mate Pro software found similar problems, although decimals are not used in that program. In the search function, one can write in the first few letters of a food and it will present the foods beginning with those letters. Refer to Table 2 for a summary of the software and features that are available.
Hardware Issues As previously noted, the PDA used for the HD study was the Visor Neo, chosen because it had sufficient memory to load and use BalanceLog and because it was economical. However, the Visor Neo is battery operated, and BalanceLog apparently consumed a lot of battery power. During the initial study period, the investigators learned that the batteries lasted approximately 2 weeks. and moreover, that when battery power was lost, all dietary data stored in BalanceLog were also lost. Thus, in subsequent studies the investigators will use PDAs with batteries that can be recharged via a direct current cable, and the participants will be trained to charge the PDA nightly to prevent loss of data. The PDA used in the weight loss study had a rechargeable battery, but two participants who were not highly adherent did not plug in the PDA for recharging as often as instructed and brought in the PDA when the battery status showed very little remaining energy. No participant let the battery run down to the point that the data were lost. On one occasion, a participant caused the PDA to freeze its functions, which
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SELF-MONITORING DIETARY INTAKE Table 2. Positive and Negative Features of Currently Available Software for Food Diaries Software
Positive Features
BalanceLog
Uses the USDA database with 4,300 items. When a food is selected, the PDA shows the USDA food labeling information. Serving size may be adjusted upward or downward, and nutritional content automatically adjusts accordingly. One may use the program for planning meals and may alter food choices based on feedback received (eg, may remove a food from the electronic log if, for example, the patient would exceed the calorie target by consuming it). Includes eating and physical activity self-monitoring as well as weight tracking. Provides a summary “calorie budget” that displays total calories consumed and whether the individual is over or under the budget. Provides colorful bar graphs illustrating the percent of target consumed for a variety of nutrients. Allows the user to track weight and display weight graphs. Monitors 13 nutrients (total calories, calories from fat, calories from saturated fat, calories from protein, calories from carbohydrates, cholesterol, sodium, sugar, vitamins A and C, fiber, iron, and calcium).
Permits the user to add food items and recipes to the database.
DietMate Pro
User maneuvers through the program easily using colorful icons. PDA version may be downloaded from the internet for only $29.00 May receive an aggregate report of intake via electronic file (Access or ASCII) or a printed copy by contacting health-e-tech. Uses the USDA database with 6,000 food items; includes brand names and restaurant foods. Monitors up to five foods on the PDA screen, which can be programmed. Patients can monitor five nutrients (calories, total and saturated fats, cholesterol, sodium, calcium) on the PDA screen without scrolling. When uploaded to the PC, the program matches the food intake to the full USDA nutrient database, so any nutrient available in the USDA is available for analysis. Set records the date and time of each entry. Portion sizes are in fractions of a cup or serving. Screen displays the actual amount consumed next to the target (goal). Preprogrammed diets are available, eg, the Ornish diet. Patients are able to download the data in an ASCII or Access format. Software license is available from PICS, Inc, for research use; it will be available commercially in the future.
Negative Features Portion sizes are in decimals.
Flexibility of removing foods from the electronic log may result in patients sanitizing their food record. Does not date- and time-stamp the entry.
Cannot limit the number of nutrients tracked to those that are of particular importance to the therapeutic diet. Must teach the participant to focus on important nutrients. Lacks many ethnic specialty foods, low-sodium foods, and dietary supplements (eg, Glucerna).
Unable to search for a food to determine nutrient values without entering it as eaten. Unable to enter a recipe directly into the PDA. Need to upload the data to the PICS, Inc, web site and then download it to the project computer.
Abbreviations: USDA, United States Department of Agriculture; PDA, personal digital assistant; ASCII, American Standard Code for Information Interchange; PICS, Personal Improvement Computer Systems.
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required the staff do a hard reset, which deleted all software programs and the data. It was not clear what precipitated the PDA to freeze. The Palm Zire31 was used for the weight loss study, which seemed to have adequate power to support this program; however, the next pilot study to further test the Diet Mate Pro and an exercise software program (CalCu Fit) will go to the next level of Palm Pilot and use the Palm Tungsten/E, which will have increased battery capacity and speed in executing the self-monitoring functions. An important feature of the software program for both the clinician and the researcher is the capability to monitor not only what the participant is eating, but also when the participant is recording: whether the participant is recording in such a delayed manner as to depend on recall of several hours or days to record what was eaten, or if the participant is recording in a timely manner and able to make corrections as the participant sees the current intake in relation to the daily goal or restriction. Currently, BalanceLog does not date- and time-stamp when the entry was made. Diet Mate Pro does record the date and time of every entry, and if the individual returns to a previous day’s recording and edits the original entry, it records the date and time of the editing and also leaves the original entry intact.
Feasibility and Acceptability of Using PDA The HD study participants were requested to log all foods consumed for 16 weeks. Four of the six participants used the dietary monitoring program for 16 weeks. The five who continued with the study self-monitored their dietary intake an average of 86% of the observation days, a rate significantly higher than what is usually found with self-monitoring.1,8 Not only was adherence to self-monitoring excellent, with the exception of one individual, participants showed a pattern of steady or increasing selfmonitoring. The participants in the weight loss study were requested to use the PDA as much as possible and to determine whether this was something that would help them self-monitor their eating. In this group, adherence ranged from 10.6% to 65.4%. It must be pointed out that the goal in this pilot study was to determine the feasibility of participants using the PDA, and an intensive interven-
tion was not part of this study, as in the study of HD patients. Having used simple paper diaries during the 18-month study that they had just completed, most participants displayed a learning curve in navigating the dietary software program with some learning it faster than others, which was not related to education. Those who were less adherent in the original study using paper diaries were also less adherent in the pilot study. The issue seemed more to be giving priority and time to the exercise of self-monitoring rather than capability to use the electronic device. No participant in either study withdrew because they had difficulty with PDA training or because they perceived the PDA to be too complicated or daily monitoring to be too burdensome. Some participants had a very low level of self-monitoring; however, this is also the case when paper diaries are used.1,29 In future studies, individuals who are highly nonadherent to selfmonitoring would be eliminated by a 5-day “run-in” of self-monitoring with a paper diary, which would be conducted to screen individuals who were incapable or unwilling to self-monitor their dietary intake.
Discussion As a tool to self-monitor dietary intake, BalanceLog and Diet Mate Pro provide some real advantages over the use of paper diaries and the traditional methods of dietary counseling with HD patients or individuals prescribed a therapeutic diet. In managing patients with ESRD treated with HD, renal dieticians typically examine dry weight and serum albumin levels to assess whether or not their patient is consuming sufficient calories and protein. They also review serum laboratory data to assess whether or not their patients are sufficiently limiting intake potassium and phosphorus, and interdialytic weight gain to determine whether sodium restrictions are being followed. Laboratory data are generally obtained on a monthly basis, leaving large gaps during which the patient may have dietary indiscretions that go undetected. When abnormalities are detected, the dietician must resort to dietary recalls to identify problem behaviors. However, it would not be unusual for patients to forget what foods they had eaten, or to report consuming foods that are consistent with what they believe is expected of them or will please the interviewer.
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Consistent with the literature, the study of HD patients showed that these patients consumed far fewer calories than required, and less high-quality protein than recommended. When shown print outs of their dietary patterns, several patients expressed surprise that they were eating so little. A graphic display provided by BalanceLog of percent of nutrient consumed was a powerful motivator, and a useful tool for setting and evaluating short-term dietary goals. Finally, it is important to note that although BalanceLog may be a useful self-monitoring or intervention tool, there are some limitations in using this technology as a measurement instrument. First, BalanceLog does not currently contain a date- and time-stamp, and thus it is not possible to know when diet data were entered. It is possible that participants were not entering their meals in real time, which would increase the likelihood of respondent bias. It is important to note that other programs include a date- and time-stamp (Diet Mate Pro) and that BalanceLog is planning to add this feature to future versions of the program. Second, as people become more adherent to self-monitoring, one will see improvements in calorie and protein intake as an artifact of making greater use of the PDA. Thus it is not possible to tease out improvements in nutrition from improvements in self-monitoring. Therefore, any studies that use similar PDA-based programs as an intervention component must obtain independent measures of nutritional adherence (eg, food frequencies, food diaries, or changes in biophysiologic measures over time).
New Software Capabilities An attractive and useful feature of the available dietary software programs is the provision of feedback regarding current dietary intake compared with their daily dietary goal or allotment of nutrients (eg, percent of target consumed). Another advancement that is taking place is the development of software that permits tracking of multiple behaviors (eating and exercise) and multiple components of diabetes management (eg, GlucoPilot, Diabetes Pilot, and ezManager Diabetic Software) and devices that combine glucometer and PDA functionality, which currently are not available but may be again in the future. A program that is undergoing final development and testing is a configurable electronic real-time assessment system (CERTAS) that will permit
feedback messages to the participant to be programmed in the PDA (PICS, Inc). A computerized educational module was developed for instructing participants in the use of the PDA and two software programs, BalanceLog and Diet Mate Pro, and were pilot tested in two studies, one involving six HD patients and one involving seven participants in a weight management study. The pilot studies showed that the participants easily learned to use the PDA and the software programs. Rates of self-monitoring among the two study groups were good to excellent. In summary, there are numerous limitations to using a paper diary for self-monitoring dietary intake, in particular, patient burden and delayed recording. The technology available today reduces the burden of actually recording food intake as well as the inaccuracy that occurs with delayed recording. The two pilot studies, although limited in size, add to the small body of existing literature that shows the acceptability and feasibility of having patients use electronic devices to self-monitor and self-manage therapeutic dietary regimens, as well as the improved adherence that results from the use of these devices.
References 1. Stone AA, Shiffman S, Schwartz JE, et al: Patient compliance with paper and electronic diaries. Control Clin Trials 24:182-199, 2003 2. Rogers AE, Caruso CC, Aldrich MS: Reliability of sleep diaries for assessment of sleep/wake patterns. Nursing Res 42: 368-372, 1993 3. O’Connell KA et al: Coping in real time: Using ecological momentary assessment techniques to assess coping with the urge to smoke. Res Nurs Health 21:487-497, 1998 4. Verbrugge LM: Health diaries. Med Care 18:73-95, 1980 5. Dunbar-Jacob J, Burke LE, Puczynski S: Clinical assessment and management of adherence to medical regimens, in Nicassio P, Smith TManaging Chronic Illness: A Biopsychosocial Perspective. Washington, DC, American Psychological Association, 1995, pp313-349 6. Jakicic JM, Winters C, Lang W, et al: Effects of intermittent exercise and use of home exercise equipment on adherence, weight loss, and fitness in overweight women: A randomized trial. JAMA 282:1554-1560, 1999 7. Latner JD, Wilson GT: Self-Monitoring and the Assessment of Binge Eating. Behav Ther 33:456-477, 2002 8. Baker RC, Kirschenbaum DS: Self-monitoring may be necessary for successful weight control. Behav Ther 24:377-394, 1993 9. Baker RC, Kirschenbaum DS: Weight control during the holidays: Highly consistent self-monitoring as a potentially useful coping mechanism. Health Psychol 17:367-370, 1998 10. Sperduto WA, Thompson HS, O’Brien RM: The effect of target behavior monitoring on weight loss and completion rate
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in a behavior modification program for weight reduction. Addict Behav 11:337-340, 1986 11. Burke LE, Dunbar-Jacob J, Orchard TJ, et al: Improving adherence to a cholesterol-lowering diet: A behavioral intervention study. Patient Educ Counseling 57:134 –142, 2005 12. Kerkenbush NL, Lasome CME: The emerging role of electronic diaries in the management of diabetes mellitus. AACN Clinical Issues 14:371-378, 2003 13. Milas NC, Norwalk MP, Akpele L, et al: Factors associated with adherence to the dietary protein intervention in the Modification of Diet in Renal Disease study. J Am Diet Assoc 95:1295-1300, 1995 14. Hufford MR, Shiffman S: Assessment methods for patient-reported outcomes. Pract Dis Manag 11:77-86, 2003 15. Stone AA, Schwartz JE, Neale JM, et al: A comparison of coping assessed by ecological momentary assessment and retrospective recall (personality processes and individual differences). J Pers Soc Psychol 74:1670-1680, 1998 16. Wadden TA: The treatment of obesity, in Stunkard AJ, Wadden TAObesity: Theory and Therapy. New York, Raven Press, 1993, pp 197-217 17. Stone AA, Shiffman S: Capturing momentary, self-report data: A proposal for reporting guidelines. Ann Behav Med 24:236-243, 2002 18. Jobe JB: Cognitive process in self-report, in Stone AA, Turkkan JS, Bachrach CA, et al (eds): The Science of SelfReport: Implication for Research and Practice. Mahwah, NJ, Lawrence Erlbaum Associates, 2000 19. Tourangeau R: Remembering what happened: Memory errors and survey reports, in Stone AA, Turkkan JS, Bachrach CA, et al (eds): The Science of Self-Report: Implication for
Research and Practice. Mahwah, NJ, Lawrence Erlbaum Associates, 2000, pp 29-48 20. Fisher EBJ, Lowe JR, Jeffery C, et al: Reinforcement and structural support of maintained risk reduction , in Adherence, Compliance and Generalization in Behavioral Medicine. New York, Bruner/Mazel, 1982 21. Teasdale JD, Fogarty SJ: Differential effects of induced mood on retrieval of pleasant and unpleasant events from episodic memory. J Abnorm Psychol 88:248-257, 1979 22. Johannes C, et al: Electronic versus paper instruments for daily data collection. Ann Epidemiol 10:457, 2000 23. Tsang MW, et al: Improvement in diabetes control with a monitoring system based on a hand-held, touch-screen electronic diary. J Telemedicine Telecare 7:47-50, 2001 24. Jamison RN, et al: Electronic diaries for monitoring chronic pain: 1-year validation study. Pain 91:277-285, 2001 25. Hyland ME, et al: Diary keeping in asthma: Comparison of written and electronic methods. Br Med J 306:487-489, 1993 26. Glanz K, et al: Improving dietary self-monitoring and adherence with hand-held computers: A pilot study. Ann Behav Med 27(suppl):S111, 2004 27. Beasley J, Riley WT, Jeran-Mary J: Accuracy of a PDAbased dietary assessment program. Nutrition: The International Journal of Applied and Basic Nutritional Sciences, June 2005. 28. Sevick MA, et al: A preliminary study of PDA-based dietary self-monitoring in hemodialysis patients. J Ren Nutr 15:304-311, 2005 29. Burke LE, et al: Using technology to document actual patterns of self-monitoring among subjects in a weight loss study. Washington, DC, Conference Proceedings, National Congress on the State of the Science in Nursing Research, 2004 October
Self-Monitoring Dietary Intake: Current and Future Practices Lora E. Burke, PhD, MPH, RN,* Melanie Warziski, BSN, RN,† Terry Starrett, BS, MA, MSN, RN,‡ Jina Choo, PhD, RN,§ Edvin Music, MSIS,¶ Susan Sereika, PhD,㛳 Susan Stark, MS, RD, CSR, LDN,# and Mary Ann Sevick, ScD, RN** This article reviews the literature on the use of paper diaries for self-monitoring food intake, identifies the strengths and limitations of paper-and-pencil diaries and their new counterpart, the electronic diary or personal digital assistant (PDA), and reports how participants were trained to use a PDA with dietary software in two pilot studies— one with hemodialysis patients and the other with participants in a weight loss study. The report of the pilot studies focuses on the practical issues encountered in training participants in the use of a PDA and addresses the pros and cons of different dietary software programs. Six hemodialysis patients were trained in the first study and seven participants attempting to lose or maintain their weight were trained in the second pilot study. The training focused on how to use a PDA and how to navigate the dietary software to self-monitor food intake. The goals of using the PDA were to improve adherence to the therapeutic diets and to self-monitoring. Lessons learned from the pilot studies are shared. © 2005 by the National Kidney Foundation, Inc.
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ELF-REPORT DIARIES have been the mainstay of researchers for the collection of numerous subjective and behavioral variables relevant to research and clinical practice. For exam*Associate Professor of Nursing and Epidemiology, †Graduate Student Researcher, PREFER Trial, ‡Project Manager, the ENHANCE Trial, §Postdoctoral Scholar, ¶Systems Analyst/Data Manager, PREFER Trial, and 㛳Associate Professor of Nursing, Biostatistics and Epidemiology, Department of Health & Community Systems, University of Pittsburgh School of Nursing, Pittsburgh, PA. #Dietitian Specialist, University of Pittsburgh Medical Center, Pittsburgh, PA. **Associate Professor, Department of Health & Community Systems, University of Pittsburgh School of Nursing, Pittsburgh, PA. Support was provided by NIH, NIDDK, RO1-DK58631; support for the hemodialysis pilot study was received from the Obesity and Nutrition Research Center NIH-NIDDK No. DK046204; the General Clinical Research Center NIH-NCRRGCRC No. 5M01-RR00056; and the Center for Research in Chronic Disorders, NIH-NINR No. P30-NR03924. Address reprint requests to Lora E. Burke, PhD, MPH, RN, University of Pittsburgh School of Nursing, Department of Health and Community Systems, 415 Victoria Building, Pittsburgh, PA 15261. E-mail: [email protected] © 2005 by the National Kidney Foundation, Inc. 1051-2276/05/1503-0001$30.00/0 doi:10.1016/j.jrn.2005.04.002
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ple, diaries have been used to measure pain,1 sleep,2 coping with smoking urges,3 illness or injury and health care use,4 medication taking,5 and exercise.6 Diaries are also used in the assessment of eating-related behaviors, eg, episodes of binge eating,7 energy intake and expenditure in weight loss treatment,8 –10 fat and dietary cholesterol intake in the management of dyslipidemia,11 blood glucose levels in diabetes management,12 and nutrient intake in patients with end-stage renal disease (ESRD).13 There are two indications for using diaries to record food intake: first, to self-monitor one’s eating behavior and food consumption on a daily basis as part of an intervention, and second, to record in detail all foods consumed for a computerized nutrient analysis for outcome assessment. The latter is usually done periodically with a 3- to 5-day food diary in a research setting. Unfortunately, the majority of the diaries used today for either purpose are in the paper-and-pencil format, which has inherent limitations.14,15 This article focuses on diaries used for the first indication—to self-monitor food intake in the self-management of chronic disorders. 281
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The purpose of this article is multifold: to review the use of paper diaries for self-monitoring food intake; to identify the strengths and limitations of paper-and-pencil diaries and their new counterpart, the electronic diary or personal digital assistant (PDA); and to report on the issues encountered when training individuals to use a PDA for dietary self-monitoring.
Review of the Literature Use of Self-Monitoring in Making Dietary and Eating Behavior Changes Self-monitoring food intake is considered the cornerstone of behavioral treatment of obesity and other chronic disorders that can be managed by dietary modification and control, such as ESRD, diabetes, and dyslipidemia.11,13,16 Selfmonitoring is conducted as a systematic observation and recording for the purpose of increasing the individual’s awareness of eating behaviors and food consumed. The individual is instructed to record all food intake (energy consumption or target nutrients) and, in cases in which calorie expenditure is an issue, to also record exercise (energy expenditure). This recording may be extended to include the location of where one is when eating (home versus away), time of day, quantity eaten, and the target nutrient values (eg, sodium, potassium, fat grams). Ideally, when using this approach, the individual records the food intake as it occurs. Recording in an ongoing manner permits individuals to alter their food intake so they do not exceed their daily target values (eg, calories, fat, carbohydrates, sodium, cholesterol, or potassium). Dietary self-monitoring has been given limited attention in the literature. Most reports on selfmonitoring involve paper diaries and weight loss interventions.8 –10 Baker and Kirschenbaum showed that self-monitoring was positively correlated with weight loss, and that the more consistently the monitoring occurred, the better the weight loss.8 Similarly, Milas et al,13 in the Modification of Diet in Renal Disease Study, found that the participants who engaged in more frequent self-monitoring were more likely to achieve their dietary goals. However, the selfmonitoring protocol is seldom followed adequately. One study reported that only 66% of the participants self-monitored for the entire day for
more than 50% of the days, and approximately 25% did not self-monitor on most days.8 Although it is not known why the participants failed to self-monitor, it is clear that it is a tedious and time-consuming process that is difficult to carry out in some situations.
Strengths and Limitations of Paper Diaries for Self-Monitoring Although paper diaries are inexpensive and readily available in several formats, their limitations are numerous. The first requirement for the use of any diary is literacy. The simplest paper diary challenges individuals who have limited literacy skills or illegible handwriting. Having the time to complete daily diaries is another issue. Regardless of the condition for which an individual is self-monitoring food intake, the need to look up foods in a nutrient guide and calculate and record the content of foods eaten is time consuming. There is also the issue of the social acceptability of self-monitoring in public situations, which may create uneasiness. Moreover, using the paper-and-pencil format makes it nearly impossible for the clinician or researcher to determine when the diary was completed. Observations of study participants provide evidence showing that often they record in the diaries long after the fact, also referred to as back-fill.17 The longer the delay in recording dietary intake (eg, weekly or monthly), the greater is the risk of recall bias. See Table 1 for a summary of the negative and positive aspects of using paper diaries. Research focused on human memory reveals that memory recall is unreliable and that each step in the process of recalling information has the potential to introduce inaccuracy and bias.14 Autobiographic memory includes four key processes: encoding the event or experience, storage of the event’s memory, retrieval of the event or experience from memory, and reconstructing the event.14,18,19 Encoding is often less than complete, imperfect, and influenced by the saliency of the event, which in turn is influenced by the individual’s subjective and mental state at the time of the event. Thus, memory does not start as an objective record of events. When an individual is asked to recall a previously encoded eating or exercise experience, active reconstruction of that experience is required, which can introduce biases and inaccuracies. Several factors may work
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Table 1. The Positive and Negative Aspects of Using Paper Diaries and Handheld Computers for Dietary Self-Monitoring Positive Aspects Paper diaries Simple to use, require little training Readily available in several formats Inexpensive
Handheld electronic diaries May be learned by individuals without prior computer experience Illegible handwriting is not an issue Know when the recording was done Able to detect adherence to self-monitoring Can protect data by use of personal digital assistant password Are able to summarize and analyze data Provides immediate feedback because user sees current intake next to the daily goals Automatically calculates subtotals and total May be able to send data via phone modem to provider or researcher Cost of devices is continually decreasing
to introduce biases, such as how recent and important that event was, the positive or negative nature of the event, and20 the mood or state of the individual at the time of recall. For example, individuals are more likely to retrieve negatively valenced information when in a negative mood.21 When a food questionnaire is used that asks for a report of foods consumed over the past 6 or 12 months, the issue of recall bias is known. An investigator attempts to avoid this bias when using a food record to obtain a report of foods consumed in the present time. If participants do not complete their diaries in a timely way and back-fill the reports after the time of the intended recording, the diary data are subject to the very recall biases that were the rationale for choosing the diary format. Although it is likely that individuals can recall singular and prominent events such as having a migraine headache, recall over the interval of a day is subject to the same cognitive processes that bias autobiographic memory over longer periods.14 Thus, even over 1 day, individuals may find it difficult to recall details of specific activities that seem continuous or occur frequently. Eating behaviors are frequent, may not be consciously
Negative Aspects
Requires user to be literate Need to look up the nutrient values in a book Need to calculate the subtotals and total for each nutrient being monitored Unable to detect when the recording was done Delayed recording is subject to recall bias Illegible handwriting is a problem Requires some training and practice Requires user to be literate Requires user to recharge battery regularly Loss of device may be an issue If battery is not charged, data are lost Is available at moderate price
thought about, and may not be salient. These characteristics make it more difficult to recall episodes of eating, whether it is eating a piece of candy, a snack, or a full meal. Unfortunately, food consumption is difficult to measure, but short of direct observation, we are reliant on self-report measures. Fortunately, technological advances now permit us to determine whether the diary data were recorded at the time of eating (referred to as real time) or in a delayed period.
Strengths and Limitations of Electronic Devices for Dietary Self-Monitoring The use of an electronic device, such as a PDA, for self-monitoring food intake represents an improvement over paper diaries. Although both paper and electronic diaries provide the individual (and those providing dietary counseling) with the ability to conveniently track the type, frequency, and portion size of foods consumed, the use of an electronic device with a dietary software program facilitates the recording process. Most dietary software programs that use the United States Department of Agriculture as the source database have a database of approximately 5,000 to 6,000 food items (eg, BalanceLog or Diet Mate Pro). With these programs, individuals can log
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foods without the labor of maintaining handwritten records, searching for the nutrient content of foods in pocket manuals, and calculating the totals for nutritional intake. These programs provide individuals with immediate feedback about their nutrient intake in comparison to a daily target for nutrient intake. If self-monitoring is done throughout the day, individuals can make real-time modifications in their energy intake and expenditure. With the use of PDA monitoring, the issue of illegible handwriting is eliminated.22 Moreover, some programs permit the data on the PDA to be uploaded, either directly or via a modem connection, to a personal computer (PC) for review by the clinician or researcher.12,23 These innovations make dietary self-monitoring easier than is the case with paper diaries, and thus individuals are likely to be more adherent in recording their food intake. Although there are no comparative data on dietary self-monitoring with paper diaries versus with PDAs, studies reporting on the self-monitoring of pain1,24 and of peak flow among asthma patients 25 report better adherence to the use of electronic methods than to the paper diary. Finally, a factor that is important to the clinician, adherence cannot be manipulated or falsified because ideally the PDA dateand time-stamps every entry. Therefore, providers know the extent to which they can rely on the diary data to make treatment decisions, which can improve clinical management.12 Not unlike the paper diary, the limitations of electronic devices for self-monitoring also include literacy because an individual needs to read the list of foods displayed on the screen of the PDA, or knowhow to spell a food when using the search option. Other limitations include cost; however, the price of these devices is rapidly declining. Acceptability by older or less-educated individuals is often raised as an issue. However, in the pilot study we describe later in this article, we found that a group of older ESRD patients with no prior computer experience readily accepted and learned how to use a PDA for self-monitoring. Others have reported similar findings.12 See Table 1 for the positive and negatives features of using electronic diaries.
Current Application of Electronic Food Diaries As mentioned previously, there are few reports of PDA use for dietary self-monitoring. Two
studies reported the use of electronic diaries in the management of diabetes. Tsang et al showed a significant decrease in hemoglobin A1c over a 3-month period among patients who used PDAs to track meal portions and blood glucose readings compared with the patients who used a paperand-pencil diary.23 A Canadian study combined the use of PDAs and a web-based site where adolescent participants could upload the data, which were accessed by the health care providers, who could monitor the information and assist participants in their diabetes management.12 In both of these studies, participants thought it was easy to use the electronic devices and found it useful, and noteworthy for adherence concerns, the adolescent participants reported that using the PDA to report their data in public places made it less conspicuous than a paper diary and easy to complete. Glanz et al described a pilot study that used PDA-based self-monitoring to reduce dietary fat intake in postmenopausal women.26 Compared with women receiving a dietary counseling intervention alone, women who selfmonitored using the PDA were found to meet their dietary goals more often, and to consume fewer total calories and fewer calories from fat. Using healthy volunteers, Beasley et al assessed the accuracy of food recorded on a PDA with Diet MatePro software compared with 24-hour recall and observation and found no significant difference between the PDA data and the other sources.27 No studies were found in the literature evaluating PDA-based self-monitoring for individuals with ESRD or those engaged in weight management.
Report of Experience Training Individuals in the Use of a PDA in Two Pilot Studies One of the goals of the pilot studies was to examine the feasibility of teaching hemodialysis (HD) patients and individuals in a weight loss study to use PDA devices for self-monitoring. The full report of the HD pilot study, the accompanying behavior intervention, and clinical outcomes are reported in a companion article in this issue.28 This article focuses on the PDA training in these two pilot studies. The protocols for the studies were approved by the University of Pittsburgh Institutional Review Board.
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Pilot Study Participants The six participants on HD were, on average, 64 years old (range, 55 to 70 years). Five of the six participants were African American, four were women; four had a high school education or less, and two had some college education. None had prior experience with computerized devices of any sort. The seven participants in the weight loss study were, on average, 46.96 ⫾ 8.85 years old (range, 28.20 to 55.68 years). One of the seven was African American, and one was male. The mean education for the group was 15.28 ⫾ 2.56 years; all had prior experience with computers but not with PDAs. These seven participants were enrolled in the pilot study after completion of an 18-month behavioral and nutrition intervention program. Some individuals had lost a significant amount of weight and were trying to maintain that loss, whereas others were still trying to lose weight. PDA Training Different software and hardware, as well as and different teaching approaches, were used for the training in the two studies. Participants in the HD study used the Visor Neo, a PDA that uses nonrechargeable batteries. The dietary self-monitoring software was BalanceLog, which provided a meal-by-meal and day-by-day breakdown of total calories, calories from fat, saturated fat, protein, carbohydrates, sodium, and other nutrients. BalanceLog contains a food database of more than 4,300 foods, including over 1,700 major brand names. BalanceLog software uses the most recent nutrient composition data from the United States Department of Agriculture (USDA), and also monitors brand name and restaurant data to ensure that the program uses the most current data. BalanceLog was programmed with the individual participants’ daily dietary goals. The investigators developed a PowerPoint module to instruct participants in the use of these devices for recording their dietary intake, which was shown on a laptop computer while the participant was receiving the dialysis treatment; the participant followed along with his or her own PDA. Hard copies of the PowerPoint slides were provided for the individual to use and also take home. Initial training in the use of the PDA required 45 to 90 minutes of individualized instruction. After the initial training, the participants were encouraged to log their meals into BalanceLog, starting with one meal,
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progressing to all meals in 1 day, and then gradually increasing this activity until they were recording all meals consumed. Participants received 1:1 dietary counseling during the dialysis session, during which time they could obtain additional assistance in using the program. BalanceLog also permits the user to monitor weight loss/gain and energy expenditure from exercise. However, these programs were not taught to participants in the HD study. The seven participants in the weight loss study used a different PDA, the Palm Pilot Zire31, a PDA that permits recharging, and the software program was Diet Mate Pro, a program that is based on the USDA nutrient database and includes 6,000 food items in the PDA database, including brand names and restaurant foods. Similar to the HD study, a PowerPoint module was developed that focused on basic PDA functions and the Diet Mate Pro software. The training in this study was conducted in group sessions with all seven participants in attendance, and the slides were presented on a screen while the participants followed along with the PDA. The training session included the use of a Palm Pilot emulator so that the instructor could demonstrate the use of the PDA functions on the screen before having the participants perform them. Several staff members were present so that they could walk around the room and assist individual participants in practicing the exercises on their PDA. Participants attended three sessions; the first one focused on the use of a PDA, the second one introduced the dietary software and had participants practice looking up foods and entering what they ate, and the third addressed problems that participants had been experiencing and included more practice. Participants were given a print out of the slides to take with them. A telephone number was provided for participants to call when there were questions or troubleshooting was needed.
Access to the PDA Dietary Data Participants in the HD study had the data from their PDA uploaded to the laptop computer at each intervention session, and the data were stored on the hard drive. The data were in the same format as appeared on the PDA screen. The weight loss study participants brought in their PDAs at a monthly visit, at which time, using the synchronization cable, the data were uploaded via a PC to the web site of the company that devel-
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Figure 1. PDA screen showing “search” option with list of food categories, BalanceLog.
oped the software, PICS, Inc. At a later time, the data were sent back to the weight loss study center in ASCII format. The nutrient variables that are included in the uploaded BalanceLog software data included calories, total fat, saturated fat, protein, carbohydrates, cholesterol, sodium, fiber, sugar, vitamins A and C, iron, and calcium. The HD study focused primarily on calories, calories from protein, and sodium, because protein energy malnutrition and fluid retention were predominant problems in the participants. Diet Mate Pro was configured for this study to include only two variables, calories and fat grams, on the PDA screen because that is what weight loss study participants traditionally record in paper diaries. However, the program permits one to monitor five variables (calories and nutrients) without scrolling. In the current version, the program matches the food intake to the full USDA nutrient database, so any nutrient available in the USDA database is available to the researcher for analysis. Therefore, when the data from our pilot study were uploaded to the PC, several more nutrients were displayed on the PC.
Software Issues Some initial difficulties were encountered in the use of the software. Figure 1 shows the search categories for foods in the BalanceLog software program. The HD participants began by selecting a major food group, and then within the group, searching for specific foods. However, some participants had difficulty identifying the appropriate food group to search. Thus, an alternative search strategy was taught in which the “find” option was used to list all foods in the database alphabetically. This approach allowed the participant to scroll through the list to find the foods they had
eaten. Another problem was that portion size was expressed in decimals, which was unfamiliar to several participants. Other minor problems encountered were the lack of ethnic foods, lowsodium foods (commonly eaten by HD patients, who must limit sodium intake), and dietary supplements (such as Boost, Glucerna, and Breeze) that are commonly consumed by HD patients. However, the BalanceLog software had the ability to allow the user to enter new foods and even recipes into the database. When participants encountered missing foods, they were instructed to write down what they had eaten (including nutritional content if available) or to bring the food labels to the dialysis center, and the interventionist added the foods to the database at the next encounter. Because dietary habits tend to follow a pattern, this problem diminished in frequency over time. The users of the Diet Mate Pro software found similar problems, although decimals are not used in that program. In the search function, one can write in the first few letters of a food and it will present the foods beginning with those letters. Refer to Table 2 for a summary of the software and features that are available.
Hardware Issues As previously noted, the PDA used for the HD study was the Visor Neo, chosen because it had sufficient memory to load and use BalanceLog and because it was economical. However, the Visor Neo is battery operated, and BalanceLog apparently consumed a lot of battery power. During the initial study period, the investigators learned that the batteries lasted approximately 2 weeks. and moreover, that when battery power was lost, all dietary data stored in BalanceLog were also lost. Thus, in subsequent studies the investigators will use PDAs with batteries that can be recharged via a direct current cable, and the participants will be trained to charge the PDA nightly to prevent loss of data. The PDA used in the weight loss study had a rechargeable battery, but two participants who were not highly adherent did not plug in the PDA for recharging as often as instructed and brought in the PDA when the battery status showed very little remaining energy. No participant let the battery run down to the point that the data were lost. On one occasion, a participant caused the PDA to freeze its functions, which
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SELF-MONITORING DIETARY INTAKE Table 2. Positive and Negative Features of Currently Available Software for Food Diaries Software
Positive Features
BalanceLog
Uses the USDA database with 4,300 items. When a food is selected, the PDA shows the USDA food labeling information. Serving size may be adjusted upward or downward, and nutritional content automatically adjusts accordingly. One may use the program for planning meals and may alter food choices based on feedback received (eg, may remove a food from the electronic log if, for example, the patient would exceed the calorie target by consuming it). Includes eating and physical activity self-monitoring as well as weight tracking. Provides a summary “calorie budget” that displays total calories consumed and whether the individual is over or under the budget. Provides colorful bar graphs illustrating the percent of target consumed for a variety of nutrients. Allows the user to track weight and display weight graphs. Monitors 13 nutrients (total calories, calories from fat, calories from saturated fat, calories from protein, calories from carbohydrates, cholesterol, sodium, sugar, vitamins A and C, fiber, iron, and calcium).
Permits the user to add food items and recipes to the database.
DietMate Pro
User maneuvers through the program easily using colorful icons. PDA version may be downloaded from the internet for only $29.00 May receive an aggregate report of intake via electronic file (Access or ASCII) or a printed copy by contacting health-e-tech. Uses the USDA database with 6,000 food items; includes brand names and restaurant foods. Monitors up to five foods on the PDA screen, which can be programmed. Patients can monitor five nutrients (calories, total and saturated fats, cholesterol, sodium, calcium) on the PDA screen without scrolling. When uploaded to the PC, the program matches the food intake to the full USDA nutrient database, so any nutrient available in the USDA is available for analysis. Set records the date and time of each entry. Portion sizes are in fractions of a cup or serving. Screen displays the actual amount consumed next to the target (goal). Preprogrammed diets are available, eg, the Ornish diet. Patients are able to download the data in an ASCII or Access format. Software license is available from PICS, Inc, for research use; it will be available commercially in the future.
Negative Features Portion sizes are in decimals.
Flexibility of removing foods from the electronic log may result in patients sanitizing their food record. Does not date- and time-stamp the entry.
Cannot limit the number of nutrients tracked to those that are of particular importance to the therapeutic diet. Must teach the participant to focus on important nutrients. Lacks many ethnic specialty foods, low-sodium foods, and dietary supplements (eg, Glucerna).
Unable to search for a food to determine nutrient values without entering it as eaten. Unable to enter a recipe directly into the PDA. Need to upload the data to the PICS, Inc, web site and then download it to the project computer.
Abbreviations: USDA, United States Department of Agriculture; PDA, personal digital assistant; ASCII, American Standard Code for Information Interchange; PICS, Personal Improvement Computer Systems.
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required the staff do a hard reset, which deleted all software programs and the data. It was not clear what precipitated the PDA to freeze. The Palm Zire31 was used for the weight loss study, which seemed to have adequate power to support this program; however, the next pilot study to further test the Diet Mate Pro and an exercise software program (CalCu Fit) will go to the next level of Palm Pilot and use the Palm Tungsten/E, which will have increased battery capacity and speed in executing the self-monitoring functions. An important feature of the software program for both the clinician and the researcher is the capability to monitor not only what the participant is eating, but also when the participant is recording: whether the participant is recording in such a delayed manner as to depend on recall of several hours or days to record what was eaten, or if the participant is recording in a timely manner and able to make corrections as the participant sees the current intake in relation to the daily goal or restriction. Currently, BalanceLog does not date- and time-stamp when the entry was made. Diet Mate Pro does record the date and time of every entry, and if the individual returns to a previous day’s recording and edits the original entry, it records the date and time of the editing and also leaves the original entry intact.
Feasibility and Acceptability of Using PDA The HD study participants were requested to log all foods consumed for 16 weeks. Four of the six participants used the dietary monitoring program for 16 weeks. The five who continued with the study self-monitored their dietary intake an average of 86% of the observation days, a rate significantly higher than what is usually found with self-monitoring.1,8 Not only was adherence to self-monitoring excellent, with the exception of one individual, participants showed a pattern of steady or increasing selfmonitoring. The participants in the weight loss study were requested to use the PDA as much as possible and to determine whether this was something that would help them self-monitor their eating. In this group, adherence ranged from 10.6% to 65.4%. It must be pointed out that the goal in this pilot study was to determine the feasibility of participants using the PDA, and an intensive interven-
tion was not part of this study, as in the study of HD patients. Having used simple paper diaries during the 18-month study that they had just completed, most participants displayed a learning curve in navigating the dietary software program with some learning it faster than others, which was not related to education. Those who were less adherent in the original study using paper diaries were also less adherent in the pilot study. The issue seemed more to be giving priority and time to the exercise of self-monitoring rather than capability to use the electronic device. No participant in either study withdrew because they had difficulty with PDA training or because they perceived the PDA to be too complicated or daily monitoring to be too burdensome. Some participants had a very low level of self-monitoring; however, this is also the case when paper diaries are used.1,29 In future studies, individuals who are highly nonadherent to selfmonitoring would be eliminated by a 5-day “run-in” of self-monitoring with a paper diary, which would be conducted to screen individuals who were incapable or unwilling to self-monitor their dietary intake.
Discussion As a tool to self-monitor dietary intake, BalanceLog and Diet Mate Pro provide some real advantages over the use of paper diaries and the traditional methods of dietary counseling with HD patients or individuals prescribed a therapeutic diet. In managing patients with ESRD treated with HD, renal dieticians typically examine dry weight and serum albumin levels to assess whether or not their patient is consuming sufficient calories and protein. They also review serum laboratory data to assess whether or not their patients are sufficiently limiting intake potassium and phosphorus, and interdialytic weight gain to determine whether sodium restrictions are being followed. Laboratory data are generally obtained on a monthly basis, leaving large gaps during which the patient may have dietary indiscretions that go undetected. When abnormalities are detected, the dietician must resort to dietary recalls to identify problem behaviors. However, it would not be unusual for patients to forget what foods they had eaten, or to report consuming foods that are consistent with what they believe is expected of them or will please the interviewer.
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Consistent with the literature, the study of HD patients showed that these patients consumed far fewer calories than required, and less high-quality protein than recommended. When shown print outs of their dietary patterns, several patients expressed surprise that they were eating so little. A graphic display provided by BalanceLog of percent of nutrient consumed was a powerful motivator, and a useful tool for setting and evaluating short-term dietary goals. Finally, it is important to note that although BalanceLog may be a useful self-monitoring or intervention tool, there are some limitations in using this technology as a measurement instrument. First, BalanceLog does not currently contain a date- and time-stamp, and thus it is not possible to know when diet data were entered. It is possible that participants were not entering their meals in real time, which would increase the likelihood of respondent bias. It is important to note that other programs include a date- and time-stamp (Diet Mate Pro) and that BalanceLog is planning to add this feature to future versions of the program. Second, as people become more adherent to self-monitoring, one will see improvements in calorie and protein intake as an artifact of making greater use of the PDA. Thus it is not possible to tease out improvements in nutrition from improvements in self-monitoring. Therefore, any studies that use similar PDA-based programs as an intervention component must obtain independent measures of nutritional adherence (eg, food frequencies, food diaries, or changes in biophysiologic measures over time).
New Software Capabilities An attractive and useful feature of the available dietary software programs is the provision of feedback regarding current dietary intake compared with their daily dietary goal or allotment of nutrients (eg, percent of target consumed). Another advancement that is taking place is the development of software that permits tracking of multiple behaviors (eating and exercise) and multiple components of diabetes management (eg, GlucoPilot, Diabetes Pilot, and ezManager Diabetic Software) and devices that combine glucometer and PDA functionality, which currently are not available but may be again in the future. A program that is undergoing final development and testing is a configurable electronic real-time assessment system (CERTAS) that will permit
feedback messages to the participant to be programmed in the PDA (PICS, Inc). A computerized educational module was developed for instructing participants in the use of the PDA and two software programs, BalanceLog and Diet Mate Pro, and were pilot tested in two studies, one involving six HD patients and one involving seven participants in a weight management study. The pilot studies showed that the participants easily learned to use the PDA and the software programs. Rates of self-monitoring among the two study groups were good to excellent. In summary, there are numerous limitations to using a paper diary for self-monitoring dietary intake, in particular, patient burden and delayed recording. The technology available today reduces the burden of actually recording food intake as well as the inaccuracy that occurs with delayed recording. The two pilot studies, although limited in size, add to the small body of existing literature that shows the acceptability and feasibility of having patients use electronic devices to self-monitor and self-manage therapeutic dietary regimens, as well as the improved adherence that results from the use of these devices.
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