Using Motivational Interviewing to Promote Adherence to Antiretroviral Medications: A Pilot Study

JANAC Vol. 14, No. 2, March/April 2003 ARTICLE 10.1177/1055329002250996 DiIorio et al. / Motivational Interviewing

Using Motivational Interviewing to Promote Adherence to Antiretroviral Medications: A Pilot Study Colleen DiIorio, PhD, RN, FAAN Ken Resnicow, PhD Marcia McDonnell, DSN, RN, C, FNP Johanna Soet, MA Frances McCarty, PhD Katherine Yeager, MS, RN

People prescribed highly active antiretroviral theraThis report describes a pilot study of a nursing intervention to increase adherence to combination therapy. The intervention was based on motivational interviewing (MI). Participants completed a baseline assessment using the computer-administered selfinterview with audio (ACASI) data collection method and then were randomly assigned to the MI intervention or control condition. Nurse counselors met with participants in the MI intervention group for three adherence sessions. Two months following baseline, participants completed a follow-up assessment. Mean scores on ratings of missed medications were lower for participants in the intervention group than those in the control group. Although there were no significant differences in the number of medications missed during the past 4 days, participants in the MI group reported being more likely to follow the medication regimen as prescribed by their health care provider. The pilot study provided useful information about the acceptability of ACASI and the adequacy of intervention procedures. The results of this pilot study show promise for the use of MI as an intervention to promote adherence to antiretroviral medications. Key words: HIV/AIDS, adherence, motivational interviewing, intervention

pies (HAART) to treat HIV are confronted with taking multiple pills and following complex medication schedules. To reduce both viral suppression and the chance of developing resistant mutations, HAART must be ingested as prescribed, that is, taking the correct number of pills at the correct times each day under the appropriate conditions (Panel on Clinical Practices, 2002). Failure to do so can lead to progression of the disease or the development of medication-resistant strains of HIV (Panel on Clinical Practices, 2002; Paterson et al., 2000). Because of the importance of strict adherence, clinicians are particularly concerned that people taking combination therapy receive adherence education. To promote adherence, nurses teach patients about HIV and combination therapy using Colleen DiIorio, PhD, RN, FAAN, and Ken Resnicow, PhD, are professors in the Department of Behavioral Sciences and Health Education, Rollins School of Public Health, Emory University, Atlanta, Georgia. Marcia McDonnell, DSN, RN, C, FNP, is an assistant professor in the Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia. Johanna Soet, MA, is a senior faculty associate; Frances McCarty, PhD, is a statistician; and Katherine Yeager, MS, RN, is a senior research nurse for the Department of Behavioral Sciences and Health Education, Rollins School of Public Health, Emory University, Atlanta, Georgia.

JOURNAL OF THE ASSOCIATION OF NURSES IN AIDS CARE, Vol. 14, No. 2, March/April 2003, 52-62 DOI: 10.1177/1055329002250996 Copyright © 2003 Association of Nurses in AIDS Care

DiIorio et al. / Motivational Interviewing

educational materials developed by themselves or obtained from sources such as pharmaceutical companies. Nurses also tailor medication schedules to each person’s lifestyle and encourage people to adopt reminder strategies such as beepers, timers, and pillboxes. Despite teaching and skill building, some patients struggle to achieve an acceptable level of medication adherence. Thus, new approaches to promoting adherence are needed. This article describes a pilot study of a nursing intervention to increase adherence to combination therapy. The purpose of the pilot study was twofold: to gather preliminary data on the outcome measures following a test of the intervention and to evaluate assessment and intervention procedures.

Background Like other people taking medications for chronic illnesses, people prescribed HAART report less than perfect adherence. Reported nonadherence rates in persons with HIV have varied from 10% to 60% of individuals surveyed (Gifford et al., 2000; Weidle et al., 1999; Wenger et al., 1999). Chesney (1997) found that 12% of 179 people taking regimens with protease inhibitors skipped at least one dose within the previous 24 hours. In a study of 75 patients prescribed combination therapy, Chesney and colleagues (2000) found similar reports of missing a dose within the previous 24 hours (11%). This team of researchers also reported that 17% of participants missed at least one dose in the previous 48 hours, and 36% missed at least one dose in the previous 2 weeks. In other studies, investigators have found similar rates of nonadherence (Gifford et al., 2000; Holzemer, Henry, Portillo, & Miramontes, 2000; Laine et al., 2000; McDonnell, Pace, De, & Ura, 2001; Mostashari, Riley, Selwyn, & Altice, 1998; Singh et al., 1999). Reasons for skipping medications are varied and include forgetting, being asleep, being away from home, changing routines, being occupied with other things, feeling too sick, having side effects, and feeling depressed (Chesney, 1997; Holzemer et al., 2000). People might also skip medications to control side effects or alter medication schedules because of concerns about toxicity and efficacy or

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the difficulties of taking medications on a regular basis (Fogarty et al., 2002). Psychosocial factors also play a role in medication adherence. Investigators have shown that people who are depressed or have poor coping skills, alcohol or drug problems, and/or a history of psychiatric problems have more difficulty following a regular medication schedule (Chesney et al., 2000; Ferrando, Wall, Batki, & Sorensen, 1996; Gordillo, del Amo, Soriano, & Gonzalez-Lahoz, 1999; Singh et al., 1996, 1999). Lack of social support and lack of material resources such as stable housing also have been found to be related to nonadherence (Brown et al., 1998; Gordillo et al., 1999; Singh et al., 1999; Williams, Wolf, Yu, & Singh, 1998). In addition to personal factors, research has highlighted the importance of the health care provider in HAART adherence. Poor patient-provider communication and poor quality interactions often lead to negative attitudes toward the provider and the treatment. Studies assessing the patient-provider relationship indicate that a supportive provider can enhance treatment adherence (Bakken et al., 2000; Mostashari et al., 1998). A major factor in treatment with HAART medications that has been explored in several studies is the complexity of the medical regimens. Stone et al. (2001) found that patients were more likely to miss doses of medications if they were taking medications three or more times per day or if they were required to take medications on an empty stomach. However, Singh et al. (1999) observed no relationship between number of medications or doses and adherence. Although Gifford et al. (2000) found no association between complexity of regimen and adherence, these researchers did find that perceived convenience of the regimen was associated with better adherence.

Interventions to Promote Antiretroviral Medication Adherence Because not all persons on HAART take medications exactly as ordered, clinicians and researchers are interested in implementing strategies to improve

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adherence. Investigators assessing interventions to enhance adherence with antiretroviral medications have demonstrated the potential effectiveness of a variety of interventions including directly observing the patient take the medication (Greenberg et al., 1999), peer counseling (Broadhead, Heckathorn, Altice, van Hulst, & Carbone, 2001), telephone counseling (Byrd et al., 1998), and personalized memory cues (Rigsby et al., 2000). Nursing interventions have also been successful in enhancing adherence. Holzemer et al. (2000) noted a drop in the number of missed HAART doses in a pilot study to test the feasibility and efficacy of CAP-IT, a nursing intervention that includes standardized detailed assessments and tailored care planning for clients on HAART. Imbriano and Grindel (1999) used a strong patient/nurse therapeutic alliance as the basis of their 6-month individually tailored education and counseling intervention for 30 persons with AIDS. Eighty-seven percent of the participants were adherent at the end of the study. These studies demonstrate that adherence can be improved and that different modalities, particularly those that provide tailored regimens and support, can be used to promote adherence.

Overview of Motivational Interviewing In the present study, we used a counseling strategy called motivational interviewing (MI) as a basis for the adherence intervention. MI was developed in the early 1980s as a therapy to promote behavioral change in individuals who were problem drinkers (Miller, 1983, 1996). Since then, the technique has been applied to a variety of behaviors including smoking cessation, diabetes self-management, fruit and vegetable intake, and, to a limited extent, medication adherence (Colby et al., 1998; Kemp, Hayward, Applewhaite, Everitt, & David, 1996; Resnicow et al., 2001; Smith, Heckemeyer, Kratt, & Mason, 1997). MI is a client-centered approach that draws heavily on the work of Carl Rogers (1986, 1987). Counseling is tailored to the client’s needs and readiness to change behavior. In an MI session, the counselor creates a nonjudgmental and supportive environment within which the client can be an active partner and can feel free to express both motivation for and reluctance to

change. The counselor uses a set of techniques that include involving the client in setting the agenda for each session, listening and reflecting back on what the client said, and pointing out discrepancies between the client’s current and desired behavior. These and other techniques are used to help the client express and resolve ambivalence about the behavior, to identify factors that prevent him or her from embracing the behavior, and to assist the client in solving issues that interfere with adoption of the behavior. During this process, the client is encouraged to process and interpret information. In this role, clients are encouraged to describe their own situation, their reasons for and against change, and their own ideas for resolving barriers to initiating change. Thus, the client rather than the counselor does most of the work of identifying barriers to change, understanding the reasons for successes and failures, and devising strategies to promote change. Clients are also encouraged to consider what health means to them and how their current behavior might interfere with their core values or achieving their life goals. Techniques used in the more authoritarian practitioner-focused model of adherence education such as persuasion, providing unsolicited advice, and confrontation are rarely used. In a series of studies conducted between 1995 and 1998, Kemp and colleagues used MI techniques to promote medication adherence among people with psychosis. In their first study, the investigators designed and tested an MI-based compliance therapy to encourage medication adherence among patients prescribed neuroleptic drugs (Hayward, Chan, Kemp, Youle, & David, 1995). Although the findings revealed no differences between the treatment and control groups in attitudes toward medication, insight, or adherence, the changes in the treatment group were in the expected direction. Based on these findings, the intervention was modified and lengthened from three to six sessions and tested in two subsequent studies. In each of these studies, participants receiving the MIbased intervention showed significantly greater improvements in attitudes to drug treatment, greater insight into their illness, and more adherence with their treatment than did participants in the supportive counseling group (Kemp et al., 1996; Kemp, Kirov, Everitt, Hayward, & David, 1998).

DiIorio et al. / Motivational Interviewing

Method Procedures In the present study, we evaluated a nursing intervention based on MI. The purpose of the intervention is to foster and support medication adherence among individuals who are starting or changing HAART. The study, which is called “Get Busy Living,” is being conducted at a clinic devoted to the care of persons with HIV. The clinic is located in a large southeastern metropolitan area and serves approximately 4,000 clients who are diagnosed with HIV and have a CD4+ count of 200 or less at the time of entry to the clinic. About 73% of clients served at the clinic are African Americans, and 76% are male. Most (75%) clients are between 30 and 50 years of age. Prior to the study, the protocol was reviewed and approved by the Institutional Review Board at the investigators’ institution and by the research committees of the clinic. Individuals meeting study criteria were randomly assigned to the intervention and control group. For the pilot study, individuals in the intervention group received three sessions, 2 weeks apart, with the nurse counselor. The participants in the intervention group also received motivational materials for their use. These included a motivational videotape, a journal for recording thoughts and feelings about medication taking, a motivational calendar, and educational materials related to their particular medication regimen. Participants in the control group received the usual adherence education provided by the clinic. All participants completed a screening assessment (to determine eligibility), a baseline assessment, and one follow-up assessment. The follow-up assessment was completed approximately 2 weeks after completing the last MI session for those in the intervention group (8 weeks postbaseline) and 8 weeks after the baseline assessment for those in the control group. The baseline and follow-up assessments were completed using the computer-administered self-interview, with audio (ACASI) data collection method. Nurse Counselor Training Nurses conducting the adherence counseling sessions received training in MI techniques. The three

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nurses attended 25 hours of classroom training that included lectures and supervised practice sessions. A psychologist trained in MI techniques conducted the training sessions. These sessions also included instruction on adherence, antiretroviral medication regimens, and referral procedures within the clinic presented by a nurse practitioner. The counseling skills of the nurses were evaluated prior to beginning the pilot study using a standardized patient approach. Using this method, the nurses conducted a counseling session with actors trained to take on the role of a patient taking antiretroviral medications. Each nurse conducted two in-person and two telephone sessions with standardized patients. The sessions were either videotaped or audiotaped. The trainer reviewed each tape and gave the nurse counselors feedback on their use of MI skills. During the pilot study, each counseling session was audiotaped and reviewed by the psychologist to assess MI counseling skills and fidelity to the intervention. Sample Participants for the pilot study were recruited through health care providers and written advertisements posted in the clinic. To participate, clients infected with HIV had to be currently prescribed HAART with at least one protease inhibitor. Volunteers were also required to be 18 years of age or older, speak and understand English, have a telephone and VCR (or access to them), be mentally stable as determined by a screening assessment, and be willing to participate. Participation included the completion of preassessments and postassessments, random assignment to the intervention or control group, and, if selected for the intervention group, three sessions with a nurse counselor. In response to the posted recruitment signs and health care provider referrals, 22 people expressed interest in the study, and all 22 signed consent forms and completed screening and baseline assessments. Following random assignment, 2 individuals withdrew from the study noting lack of interest, leaving 10 participants in each group. Nine participants in the control group completed the follow-up assessment. In the intervention group, 8 participants completed the three MI sessions, 1 completed two sessions, and 1

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completed one session. Eight participants in the intervention group completed the follow-up assessment. The reasons for those who did not complete the assessments were: relocation, time constraints, and inability to locate. Participants ranged in age from 26 to 53, with a mean age of 42.4 years (SD = 7.9; see Table 1). Most (87.5%) participants were African American and male (52.9%), 82.4% were currently single, and 94.1% had at least a high school education. In regard to HIV diagnosis and treatment, the average time since diagnosis of HIV was 11.2 years (SD = 3.5), and the average number of antiretroviral medications prescribed was three. A comparison between participants in the intervention and control groups showed no significant differences on these variables except for age. Participants in the intervention group were on average 8 years older than those in the control group. Study Measures The UCSF Adherence Questionnaire. Three sections of the UCSF Adherence Questionnaire (Chesney et al., 2000) were used—reasons for not taking medications, number of medications missed during the past 4 days, and length of time since missing a medication. Reasons for not taking medications within the past 30 days were assessed using a 14-item measure. The response options for each item were 0 = never, 1 = rarely, 2 = sometimes, and 3 = often. A total score was computed by summing the responses across the 14 items, resulting in a possible score range of 0 to 42, with lower scores representing fewer reasons for missing medications. To measure the number of medication doses missed during the past 4 days, for each HAART medication, participants were asked if they missed any dose of medication yesterday, the day before yesterday, 3 days ago, and 4 days ago. The interviewer recorded all missing doses for each medication during the past 4 days. A total score was computed by adding all missed doses over all medications. And a percentage of missing doses was calculated by dividing the number of missed doses by the number prescribed for each of the past 4 days. In addition to these items, a single item from the UCSF Adherence Questionnaire asking, “When was

Table 1. Descriptive Statistics for Personal Characteristics of Participants in the Intervention and Control Groups Variable Age 18 to 29 years (%) 30 to 39 years (%) 40 to 49 years (%) 50 or >50 years (%) M SD Range Gender Male, n (%) Female, n (%) Race (%) African American White Other Marital status (%) Never married Separated/divorced/ widowed Married/committed relationship Education (%) Less than high school High school More than high school Years since HIV diagnosis M SD Range Number of drugs M SD Range

Intervention Control p Value 0.0 0.0 75.0 25.0 46.8 4.3 41-53

11.1 44.4 44.4 0.0 38.4 8.4 26-49

.061

5 (62.5) 3 (37.5)

4 (44.4) 5 (55.6)

.457

87.5 12.5 0.0

77.8 11.1 11.1

.624

50.0

44.4

.164

50.0

22.2

0.0

33.3

12.5 37.5 50.0

0.0 66.7 33.3

.352

12.13 4.19 8-20

10.33 2.83 6-15

.313

2.63 0.74 2-4

3.00 0.76 2-4

.334

.024*

NOTE: Significance indicated with an asterisk.

the last time you missed taking any of your medications?” also served as an outcome. The response categories for this item were: within the past week, 1 to 2 weeks ago, 2 to 4 weeks ago, 1 to 3 months ago, more than 3 months ago, and never skip medications (or not applicable). The first two response categories, (within the past week, 1 to 2 weeks ago), the middle two categories (2 to 4 weeks ago, 1 to 3 months ago), and the last two categories (more than 3 months ago, never skip medications) were combined for analysis due to the small number of participants.

DiIorio et al. / Motivational Interviewing

The Antiretroviral General Adherence Scale (AGAS). The AGAS (McDonnell et al., 2001) was used to assess the ease and ability of participants to take HAART according to the health care providers’ recommendations during the past 30 days. This scale consists of five items, each rated according to six categories ranging from 1 = none of the time to 6 = all of the time. A total score was computed by summing across the five items after recoding the two negatively worded items, resulting in a possible score range of 5 to 30. The alpha coefficient for responses for the current sample of participants was .70. In addition to the total score, the last item was analyzed separately because it provides a single, general assessment of how often the individual was able to take his or her medications according to health care provider advice during the past 30 days. Responses were collapsed into two categories (none of the time and a little to all of the time) due to the small number of responses in some categories. Other adherence measures. The final two outcome measures were based on the participants’ responses to two items asking how often in the past 2 weeks and how often in the past 30 days they had missed taking each of their medications. The response options for these two items were 1 = none, 2 = 1 to 2 times, 3 = 3 to 5 times, and 4 = more than 5 times. These items were completed for each medication taken. A mean score was created for each time frame (2 weeks, 30 days) by summing the ratings across all of a participant’s medications and dividing by the number of medications. This score provided a general measure of adherence across all medications. Participant evaluation forms. After completing the follow-up interview, participants were asked to evaluate their experience. Participants in the control group were asked to respond to 11 items assessing their experience with staff members, the project office, and computer assessments. The 11 items were rated on a 4point scale ranging from strongly disagree to strongly agree. An example of an item is, “I enjoyed using the computer.” Participants in the intervention condition completed this form as well as a form assessing their experience with the intervention. This second form consisted of 19 items, each rated on a 4-point agree/

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disagree scale. An example of an item is, “The counseling sessions helped me take an active role in my care.” Analysis Using SPSS 10.0 (SPSS, 2000), frequencies and percentages were calculated for personal characteristic variables, individual reasons for missing medications, and medications missed during the past 4 days. Analysis of outcome measures was conducted using data from the follow-up assessment only. Independent samples t tests were used to assess the differences between the intervention and control groups on the total scores for reasons for missing medications and the AGAS and for the two single-item measures. To provide more information regarding group differences, Hedges and Olkin’s (1985) unbiased effect size was computed for these measures. The computation of this effect size involves dividing the difference between two means by a pooled (intervention group and control group) standard deviation and then multiplying by a correction factor to arrive at an unbiased estimate of the effect size. Finally, chi-square tests comparing the responses for the intervention and control groups at follow-up assessment were computed for the item assessing the last time medications were missed and the item assessing the frequency of being unable to take medications during the past 30 days.

Results At the follow-up assessment, participants were asked to report for each antiretroviral medication the number of times they missed taking medication for each of the past 4 days. All participants in the intervention group reported taking all doses of their medications during the past 4 days. In the control group, 1 participant reported missing at least one dose 1, 2, and 4 days ago. Three participants reported missing at least one dose 3 days ago. These differences between the intervention and control groups were not statistically significant. Table 2 displays the means, standard deviations, and t-test results for comparisons of differences at the follow-up assessment in AGAS total scores and the

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Table 2.

Ranges, Means, Standard Deviations, t-Test Results, and Effect Sizes for Adherence Measures Obtained at Follow-Up

Outcome Antiretroviral General Adherence Scale Intervention Control Missed medications in the past 2 weeks Intervention Control Missed medications in the past 30 days Intervention Control Reasons for missed medications Intervention Control

Table 3.

Range

M

18-30 16-30

26.50 23.44

0-0.5 0-3.67

SD

t

df

p

Effect Size

4.78 5.10

–1.27

15

.224

.59

0.06 0.70

0.18 1.26

1.42

14

.198

.67

0-1 0-3.67

.13 0.98

0.35 1.48

1.59

14

.152

.75

0-10 0-27

3.13 6.67

3.44 8.15

1.14

15

.273

.53

Percentages and Chi-Square Analysis Results for Adherence Measures Obtained at Follow-Up

When was the last time you missed taking any of your medications? Never/more than 3 months ago 1 to 3 months ago/2 to 4 weeks ago 1 to 2 weeks ago/within past week Generally speaking, how often in the past 30 days were you unable to take your medication as your health care provider advised? None of the time A little to all of the time

Intervention (%)

Control (%)

2

62.5 25.0 12.5

33.3 11.1 55.6

3.45, p = .178

87.5 12.5

33.3 66.7

5.13, p = .024*

NOTE: Significance indicated with an asterisk.

ratings of number of medications missed during the past 2 weeks and 30 days. Self-reported adherence scores on the AGAS were higher for participants in the intervention group (26.5 vs. 23.4), indicating more adherence to taking medications according to the health care provider’s recommendations. Mean scores on ratings of missed medications during the past 2 weeks and 30 days were lower for participants in the intervention group, indicating overall fewer missed doses of medications. Although none of these differences were significant, the effect sizes ranged from .59 to .75. Table 3 displays the chi-square analysis results for two indicators of missing medications. The first item provides an indication of when the last time the participants missed a medication, and the second item gives an indication of how often in the past 30 days medications were not taken according to the health care provider’s directions. The results of chi-square analysis showed that a smaller percentage of those in the

intervention group reported missing a medication in the past week. And a smaller percentage of participants in the intervention group also reported being unable to take their medications according to their health care provider’s recommendations. This latter finding was statistically significant (χ2 = 5.13, p = .024). In regard to reasons for not taking medications, participants in the control group reported more reasons for missing medications than did those in the intervention group (see Table 2). The mean frequency of occurrence of reasons for the control group was 6.67 (SD = 8.15), and for the intervention group, 3.13 (SD = 3.44). The t test showed no significant difference between the groups. An examination of individual items showed that the most common reasons for missing medications were being away from home (47%) and being too busy with other things (47%). Simply forgetting (35%) and falling asleep (35%) were also common reasons for not taking medications. The least

DiIorio et al. / Motivational Interviewing

likely reasons for missing medications included feeling good (6%), feeling that the drugs were toxic (12%), and running out of pills (18%). The second aim of this pilot study was to assess the feasibility of the assessment and intervention procedures. Responses to the participant evaluation form indicated that participants were generally satisfied with their experience. Most participants either agreed or strongly agreed that the staff treated them with respect and that the office was pleasant. In addition, 86% indicated that they enjoyed using the computer. Most also believed that both the computer and the mouse were easy to use, that the computer voice was easy to listen to, and that the computer questionnaire was about the right length. Two participants had difficulty using the mouse to select responses. Of these 2 respondents, 1 was able to successfully complete the follow-up assessment using the computer, whereas the second person elected a paper-and-pencil follow-up assessment. Participants in the intervention group were generally positive about their experience with the counseling sessions. Five of the 6 participants who completed the evaluation form rated the nurse counselors high on all personal characteristics assessed including knowledge, respect, and organization. In regard to MI skills, most (83%) participants believed that the nurse counselor encouraged the participant to come up with their own ways to take medications, and 50% believed that the nurse counselor did more talking than they did. (In MI, the client is encouraged to do most of the talking.) Most participants agreed that the nurse counselor offered a lot of advice, which is an approach not advocated in MI. Generally, the participants were comfortable with the sessions and believed that the sessions were helpful. Most participants (83%) also agreed that talking about motivation, confidence, and values— three components of MI included in this intervention—was helpful. Each intervention session was tape recorded, and a psychologist trained in MI reviewed each tape and provided feedback to each nurse counselor. The nurse counselors found the evaluations helpful in identifying areas for continued improvement. Although some opportunities were missed for the use of MI skills in the sessions, overall the nurse counselors used the MI skills in addressing the adherence needs of the study participants. Information from these qualitative

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evaluations of the MI sessions was used to create an evaluation form for the ongoing assessment of MI counseling sessions during the main study. For each MI session, the nurse counselors followed a written script that broadly identified areas for discussion and prompted them to elicit the participants’ levels of motivation and confidence in maintaining adherence to medications. During the pilot study, the nurse counselors were able to identify several areas on the script that were problematic. They noted that sometimes the script was difficult to follow and lacked some information that they thought would be helpful to them. Their suggestions were incorporated into the revised scripts. The nurse counselors also were asked to record information during each session with the participants. They were asked to record the name of each medication, degree of adherence for each medication, levels of motivation and confidence, and personal values that support adherence. Following the pilot sessions, the nurse counselors offered several suggestions for improvement in the recording forms, and their suggestions were used to revise these forms.

Discussion The purpose of this study was to assess the use of MI in enhancing adherence to antiretroviral medication. Overall, participants in the intervention group as compared to those in the control group had higher selfreported adherence scores and missed fewer doses of medication within the past 2 weeks and 30 days. Statistical significance was reached for only one measure of adherence. Participants in the intervention group were less likely to report that they were unable to take their medications as recommended within the past 30 days. Although the differences for most adherence measures were not statistically significant, participants in the intervention scored higher on the AGAS, and their mean scores on ratings of missed medications during the past 2 weeks and 30 days were lower than for participants in the control group, indicating overall fewer missed doses of medications. Because the small number of participants in this study can be a reason for failure to achieve statistical significance, we calculated effect sizes. Effect size is a standardized or scale-free indication of the mean difference between groups and is commonly used to

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represent the magnitude of an effect and to compare effects across outcome measures. According to Cohen (1988), an effect size of at least .8 represents a large effect and an effect size of at least .5 represents a moderate effect. The effect sizes for the adherence measures ranged from .59 to .75. These results are encouraging as they suggest that with the larger sample size proposed in the main study, significant differences between the groups are possible. If these effect sizes hold for the main study, MI techniques could prove useful for promoting antiretroviral medication adherence. The findings from the pilot study were also useful in evaluating the feasibility and acceptability of using ACASI for self-report assessments and MI techniques for promoting medication adherence. Based on comments from the participants, we purchased a touchscreen monitor to aid participants who had difficulty using a mouse to select responses. The research assistants were also trained to conduct an in-person interview in the event that a participant lacks confidence in using a computer or if the computer malfunctions. Based on the nurse counselors’ comments, we revised the MI scripts and included more guidance to ensure that all aspects of the MI session were covered. Participants completed evaluation forms and reported that they liked to talk with the nurse counselor. From the participants’ and psychologist’s evaluations of the nurse counselors’ techniques, we were able to identify areas for additional training and monitoring. In addition to the 25 hours of MI training, we include biweekly meetings to discuss issues, individual sessions with the psychologist to discuss specific areas for improvement, and booster sessions approximately every 3 months. We also developed a form to record the evaluation of MI counseling techniques. This form will be used by our MI experts, who will review the tapes from the MI sessions and record the extent to which the nurse counselors are able to use MI techniques during the session. These data will be helpful in the ongoing evaluation of nurse counselors and will provide information for training and support needs. There are several limitations of this study. First, the sample size was small, limiting the use and interpretation of statistical tests. Second, at pretest, most participants indicated that they were adherent to their medication regimens. Thus, most participants had already

addressed and resolved issues around adherence. The differences noted between the intervention and control might have been greater for individuals who were known to have more difficulty taking their medications. A third limitation was the use of only one method to measure adherence. In the main study, we will use an electronic monitoring device to record openings of the bottle that contains one antiretroviral medication. We also plan to use pharmacy refill information that will give us a gross measure of adherence. These additional measures will provide a more complete description of medication adherence. Another factor that might have had a bearing on the results is the length of the intervention. In the pilot study, participants received three MI sessions. In the main study, participants will receive five sessions over a 3-month period. In their work, Kemp and colleagues found that adherence rates increased after increasing the number of compliance counseling sessions from three to six (Hayward et al., 1995; Kemp et al., 1998). The findings from the study support the feasibility and acceptability of using MI techniques for promoting medication adherence. Participants completed evaluation forms and reported that they liked to talk with the nurse counselor. From this pilot study, we have gathered information to refine the MI techniques for adherence promotion, improve nurse counselor skills, and refine training techniques for nurse counselors. We are currently recruiting participants for the main study to test the effectiveness of a five-session adherence-counseling program that includes MI techniques and the adaptation of these techniques for antiretroviral medication adherence. The results of this full-scale study will be helpful in determining the long-term usefulness of this technique as a nursing intervention.

Acknowledgment This study was funded by a grant from the National Institute of Nursing Research (R01 NR04857).

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