- Email: [email protected]
Effects of Pedometer Use in Veterans With Chronic Heart Failure
BRIEF REPORT
Effects of Pedometer Use in Veterans With Chronic Heart Failure Vicky M. Chang, DNP, APRN, Mary I. Dallas, PhD, PT, Tammy M. Lampley, PhD, RN, and Kerry A. Milner, DNSc, RN ABSTRACT
Routine physical activity can improve exercise tolerance in individuals with chronic heart failure (HF). Lack of exercise can lead to worsening of HF. This study examined the effect of a pedometer on exercise tolerance in veterans with chronic HF. Although both pedometer and routine exercise groups improved 6-minute walk test distance, the use of a pedometer was not better than routine exercise in improvement in exercise tolerance after 6 weeks. Factors that may have impacted the effectiveness of pedometer use include pedometer malfunction, low pedometer compliance, and severe wintery weather. Keywords: 6-minute walk test, chronic heart failure, exercise tolerance, pedometer Published by Elsevier, Inc.
E
xercise intolerance, fatigue, and dyspnea are the most common complaints among patients with chronic heart failure (HF). These symptoms have a substantial impact on patients’ activity of daily living and overall sense of well-being. Consequently, the lack of physical activity fosters further deconditioning of general health leading to worsening of HF. It is often assumed that dyspnea is the main factor causing exercise intolerance in patients with HF. However, approximately 50% of HF individuals reported leg fatigue, not dyspnea, being the main reason for their exercise intolerance.1 A number of previous studies have discovered relationships among pedometer use, exercise tolerance, and health outcomes. Evangelista et al2 found significant functional improvement in New York Heart Association (NYHA) class II-IV HF patients with greater distance walked measured by a pedometer. Additionally, patients with severe chronic obstructive pulmonary disease (COPD) in a home-based pulmonary rehabilitation program using pedometers showed significant improvements in exercise tolerance, dyspnea score, and quality of life score after 6-12 weeks.3 Studies have also identified pedometers as a motivational tool to increase physical activity and functional measurements.4,5 The purpose of this study was to evaluate the impact of pedometer use on exercise tolerance among www.npjournal.org
veterans with chronic HF. Specifically, we sought to evaluate the effect of a home-based nonsupervised exercise regimen using a pedometer compared with verbal instructions in veterans with chronic HF. THEORETICAL FRAMEWORK
The Health Promotion Model is a middle-range nursing theory that was used to guide this study. The foundation of Health Promotion Model focuses on factors that influence an individual’s ability to achieve health-promoting behaviors.6 METHODS Design
A prospective randomized controlled design was used in this study. Using permuted block randomization, veterans were assigned to either the control (routine exercise) group or the pedometer (exercise with a pedometer) group. Setting and Sample
Veterans were recruited from the Veterans Administration Connecticut Healthcare System. Veterans with NYHA class II-III HF symptoms and confirmed ejection fraction 45% were eligible to participate. Exclusion criteria included unstable angina, untreated cardiac dysrhythmias, COPD, severe lower back pain, peripheral neuropathy, peripheral artery disease, dementia, blindness, and admission within 6 weeks before enrollment. The Journal for Nurse Practitioners - JNP
819
Twelve veterans (46.2%) were randomized into the pedometer exercise group, whereas 14 (53.8%) were randomized to the routine exercise group. All participants continued to receive optimized medical treatment during the study.
Figure 1. Patient selection process.
Data Collection
Baseline blood pressure, weight, serum B-type natriuretic peptide, and 6-minute walk test (6MWT) results were collected on the initial visit and at the end of 6 weeks. Veterans in both groups were given verbal instructions to exercise for at least 30 minutes 5 times a week. Although veterans in the control group exercised on their own merits and recorded the total minutes walked daily, veterans in the experimental group were provided a spring-levered pedometer and asked to keep a daily recording of the number of steps taken and asked to maintain or increase their daily steps taken. The exact number of steps taken daily was not used for the primary data analysis; it was used as a means to monitor compliance and to assess if veterans were able to maintain or exceed the number of steps each day. Differences in the number of meters walked in 6 minutes between baseline and postexperiment were recorded and analyzed. Statistical Analysis
Descriptive statistics were used to describe demographic characteristics. Inferential statistics were used to compare demographic and baseline clinical characteristics between the 2 groups. One-sample t-tests were applied to each group to test for 6MWT improvements within each group. Finally, a 2-sample t test was used to assess improvement in 6MWT between the groups. Data were analyzed using SPSS software version 18.0 (SPSS Inc, Chicago, IL). A P value .05 was considered statistically significant. A minimal clinically importance difference (MCID) in an outcome is the smallest difference that is considered to be clinically meaningful. Sample sizes were calculated to have good power to detect the MCID in 6MWT scores at a significance level of .05. The MCID for HF was found to be in the range of 54 to 80 m.7 Dallas et al3 studied changes in 6MWT scores and provided a standard deviation of 59 m in those changes. Although this study was done 820
The Journal for Nurse Practitioners - JNP
in patients with COPD, it has been recognized that patients with COPD and HF have similar levels of exercise capacity and health status.8 With this standard deviation of 59 m, the range of MCID values from 54 to 80 corresponds to a range of effect sizes from 0.92 to 1.36. Using Monte Carlo simulations, for MCID ¼ 80 and MCID ¼ 54, the sample sizes required to achieve power over 0.8 (80%) are n ¼ 8 and n ¼ 16, respectively, per group. Therefore, the target sample size for this study was a total of 16 to 32 subjects. RESULTS
A total of 102 veterans meeting the criteria were identified. Seventy-four veterans declined to Volume 11, Issue 8, September 2015
Table 1. Comparison of Demographic Characteristics Variables
Pedometer (n ¼ 12)
Control (n ¼ 14)
P Value
Age (mean SD)
71.6 7.7
70.4 13.4
.80
White
10
8
Black
2
6
11
14
1
0
207 43.1
194.4 35.0
164-301
138-249
Figure 2. Improvements in 6MWT.
Race
.15
Sex Male Female
.27
Baseline weight Mean SD Range Baseline SBP
121.8 11.8 121.8 11.3
Mean SD Baseline DBP
.99 73.7 8.6
75.4 10.2
Mean SD LVEF
.42
.64 37.9 5.4
33.9 9.0
(mean SD)
.19
ICM
8
10
.79
ICD
5
9
.25
Class II
12
8
Class III
0
6
.01*
2
4
.47
Hypertension
11
13
.91
Sleep apnea
4
4
.79
COPD
2
3
.76
Beta-blocker
10
13
.45
ACE inhibitor
10
10
.47
Diuretics
6
10
.26
Spironolactone
1
4
.19
NYHA
Diabetes
ACE ¼ angiotensin-converting-enzyme; COPD ¼ chronic obstructive pulmonary disease; DBP ¼ diastolic blood pressure; ICD ¼ implantable cardioverter defibrillator; ICM ¼ ischemic cardiomyopathy; LVEF ¼ left ventricular ejection fraction; SBP ¼ systolic blood pressure; SD ¼ standard deviation. * p < 0.05.
participate in the study. Twenty-eight veterans were recruited, but 2 veterans dropped out, making the final sample size 26. Twelve veterans (46.2%) were randomized into the pedometer group and 14 (53.8%) into the control group (Figure 1). www.npjournal.org
Demographic characteristics of both groups are displayed in Table 1. The only significant difference between the 2 groups was that veterans in the control group were more likely to have more advanced NYHA classification (P ¼ .01). Figure 2 displays the 6MWT improvements of the participants grouped by study assignments. There was no significant difference in baseline 6MWT between the 2 groups (P ¼ .52). Both groups increased their 6MWT after the 6-week study period (Table 2). The pedometer group had a mean increase of 15.7 9.2 m (P ¼ .19), whereas the control group had a statistically significant increase of 29.8 38.2 m (P ¼ .01) after 6 weeks. The 6MWT improvement was not statistically different within the pedometer group initially. However, the withingroup improvement in the pedometer group reached statistical significance of P ¼ .005 when an outlier was excluded from analysis. This outlier corresponded to a veteran in the pedometer group who decided to stop walking after only 4 minutes during the follow-up 6MWT to conserve energy for walking in the mall later that day. This incomplete 6WMT was not an accurate measurement of the veteran’s actual exercise tolerance level, and, therefore, the data were excluded. Only 50% of veterans in the pedometer group completed their daily logs compared with 71.4% in the control group (Table 3). In the pedometer group, only 1 veteran came close to maintaining the level of activity measured by the pedometer throughout the study. The Journal for Nurse Practitioners - JNP
821
Table 2. Comparison of 6MWT Within and Between Groups (Meters) Pedometer Variables
Total No (n ¼ 12)
Outlier (n ¼ 11)
Control (n ¼ 14)
Total (n ¼ 26)
Bivariate Analysis
344.5 87.6
t24 ¼ 0.66
P Value
Pre-6MWT Mean SD
356.8 79.1
370.5 66.5
333.9 95.8
Range
206.6-472.4
274.3-472.4
178.6-514.5
Mean SD
372.5 11.0
395.5 8.2
363.6 93.2
Range
120.1-508.4
269.8-508.4
231.6-505.4
.52
Post-6MWT 367.8 99.8
t24 ¼ 0.22 .83
6MWT Differences Mean SD Range
15.7 9.2
29.8 38.2
23.3 38.5
86.6 to 81.4
42.7 to 84.7
86.6 to 84.7
P ¼ .19
P ¼ .01
t24 ¼ 0.93 .36
a
25.0 23.4 4.9 81.4
27.7 32.56
P ¼ .005
t23 ¼ 0.365
.72
42.7 to 84.7
a
6MWT ¼ 6-minute walk test; SD ¼ standard deviation. a
Statistically significant.
DISCUSSION
Among the veterans who completed the pre- and post6MWT in the experimental group, pedometer use significantly improved their exercise tolerance after 6 weeks of exercise (P ¼ .005). This finding is consistent with previous studies reporting that pedometer use was associated with increased exercise tolerance.2-5 Veterans in the control group also experienced statistically significant improvement in their exercise tolerance (P ¼ .01). However, there was no significant difference in the improvement of exercise Table 3. Daily Log Returned and Completed Total Number of Patients N ¼ 26 Pedometer
Control
12
Number of patients in each group
14
11
Number of returned logs at the end of study
10
6 (50%)
Number of patients completed logs on a daily basis
822
The Journal for Nurse Practitioners - JNP
8 (71.4%)
tolerance between the pedometer and control groups (P ¼ .72) (ie, although walking improved exercise tolerance in both groups, the use of pedometers was not better than routine exercise to improve exercise tolerance in this study of veterans with chronic HF). Veteran compliance with pedometer use was an issue in this study. Only 6 of 12 veterans (50%) in the pedometer group completed daily logs. The veterans who did not return complete logs admitted that they were not compliant with wearing their pedometers. This lack of compliance was also found by Zoellner et al9; their study found that participants had low pedometer compliance despite having trained coaches to encourage them to complete their diaries. Furthermore, pedometer malfunctioning was also a major obstacle in the current study and may have contributed to the low compliance rate. Jehn et al9 found that in patients with chronic HF, the highest pedometer error occurred in those with greater functional limitation and 6MWT < 400 m. Seven (58.3%) of the 12 veterans using pedometers in this study walked less than 400 meters at their baseline 6MWT, and this may have contributed to higher pedometer misregistration leading to the low compliance rate. Volume 11, Issue 8, September 2015
Finally, this study was conducted in the winter of 2013 during a time that the Northeastern US experienced 2 “storms of the century” and in general had a harsh winter. Hamilton et al10 found study participants had statistically significant greater daily steps in the summer season when compared with the winter season. In fact, cold weather was cited by many qualified veterans as a reason to decline in this study.
the improvement may not have reached MCID (Figure 2), this positive trend is encouraging. Pedometers provide specific numbers of steps walked daily and can be easily tracked by telehealth nursing services. A select group of veterans with HF may experience increased health benefits by tracking their daily or weekly steps via a pedometer and reporting this information to their provider.
Study Limitations
References
The 6-week study duration may have been too short to detect the differences between the 2 groups given that there were improvements in 6MWT within groups. Even though the sample size provided sufficient power by MCID analysis, veterans enrolled in this study had a lower prevalence of diabetes mellitus (23.1%), COPD (19.2%), and sleep apnea (30.1%) compared with the general HF population; therefore, this may limit the generalizability of the study results. Additionally, the timing of this study significantly limited the recruitment effort and study participants’ exercise efforts because of wintery weather. Finally, pedometer malfunction may have had an impact on this study given that many veterans reported pedometer malfunction as the reason they did not wear their pedometers. It is possible that a more reliable pedometer may increase pedometer compliance. Recommendations for Future Study
A qualitative study in the veteran population about attitudes toward pedometer use may be helpful to determine the feasibility of pedometer use in this population. Monthly telephone follow-ups could be incorporated into a future study to improve both pedometer compliance and recording of the daily logs. Moreover, careful selection of an accurate type of pedometer and/or smart phone health and fitness application may improve the compliance of pedometer use and the effectiveness of pedometer use on health outcomes.
1. Kitzman D, Groban L. Exercise intolerance. Cardiol Clin. 2011;29:461-477. 2. Evangelista L, Dracup K, Erickson V, McCarthy W, Hamilton M, Fonarow G. Validity of pedometers for measuring exercise adherence in heart failure patients. J Card Fail. 2004;11:366-371. 3. Dallas M, McCusker C, Haggerty M, Rochester C, ZuWallack R. Using pedometers to monitor walking activity in outcome assessment for pulmonary rehabilitation. Chron Respir Dis. 2009;6:217-224. 4. Synder A, Colvin B, Gammack J. Pedometer use increases daily steps and functional status in older adults. J Am Med Dir Assoc. 2011;12:590-594. 5. Araiza P, Hewes H, Gashetewa C, Vella C, Burge M. Efficacy of a pedometerbased physical activity program on parameters of diabetes control in type 2 diabetes mellitus. Metabolism. 2006;55:1382-1387. 6. Pender N, Murdaugh C, Parsons M. Health Promotion in Nursing Practice. 5th ed. Upper Saddle River, NJ: Pearson Prentice Hall; 2006. 7. Wise R, Brown C. Minimal clinically important differences in the sixminute walk test and the incremental shuttle walking test. COPD. 2005;2:125-129. 8. Zoellner J, Connell C, Powers A, Avis-Williams A, Yadrick K, Bogle M. Does a six-month pedometer intervention improve physical activity and health among vulnerable African Americans? A feasibility study. J Phys Act Health. 2010;7:224-231. 9. Jehn M, Schmidt-Trucksass A, Schuster T, Hanssen H, Halle M, Kohler F. Pedometer accuracy in patients with chronic heart failure. Int J Sports Med. 2010;31:186-191. 10. Hamilton S, Clemes S, Grittiths P. UK adults exhibits higher step counts in summer compared to winter months. Ann Hum Biol. 2008;35:154-169.
Vicky M. Chang, DNP, APRN, is a cardiology nurse practitioner at the VA Connecticut Healthcare System in West Haven, CT, and can be reached at [email protected]. Mary I. Dallas, PhD, PT, is a physical therapy specialist at the VA Connecticut Healthcare System. Tammy M. Lampley PhD, RN, CNE, and Kerry A. Milner, DNSc, RN, are assistant professors of nursing at the School of Nursing at Sacred Heart University in Fairfield, CT. In compliance with national ethical guidelines, the authors report no relationships with business or industry that would pose a conflict of interest.
CONCLUSION
Vicky M. Chang is a recipient of the National Nursing Education Initiative scholarship by the Department of Veterans Affairs.
Routine mild to moderate exercise motivated by either pedometer use or verbal instruction improved exercise tolerance in veterans with HF. Although
1555-4155/15/$ see front matter Published by Elsevier, Inc. http://dx.doi.org/10.1016/j.nurpra.2015.04.027
www.npjournal.org
The Journal for Nurse Practitioners - JNP
823
Effects of Pedometer Use in Veterans With Chronic Heart Failure Vicky M. Chang, DNP, APRN, Mary I. Dallas, PhD, PT, Tammy M. Lampley, PhD, RN, and Kerry A. Milner, DNSc, RN ABSTRACT
Routine physical activity can improve exercise tolerance in individuals with chronic heart failure (HF). Lack of exercise can lead to worsening of HF. This study examined the effect of a pedometer on exercise tolerance in veterans with chronic HF. Although both pedometer and routine exercise groups improved 6-minute walk test distance, the use of a pedometer was not better than routine exercise in improvement in exercise tolerance after 6 weeks. Factors that may have impacted the effectiveness of pedometer use include pedometer malfunction, low pedometer compliance, and severe wintery weather. Keywords: 6-minute walk test, chronic heart failure, exercise tolerance, pedometer Published by Elsevier, Inc.
E
xercise intolerance, fatigue, and dyspnea are the most common complaints among patients with chronic heart failure (HF). These symptoms have a substantial impact on patients’ activity of daily living and overall sense of well-being. Consequently, the lack of physical activity fosters further deconditioning of general health leading to worsening of HF. It is often assumed that dyspnea is the main factor causing exercise intolerance in patients with HF. However, approximately 50% of HF individuals reported leg fatigue, not dyspnea, being the main reason for their exercise intolerance.1 A number of previous studies have discovered relationships among pedometer use, exercise tolerance, and health outcomes. Evangelista et al2 found significant functional improvement in New York Heart Association (NYHA) class II-IV HF patients with greater distance walked measured by a pedometer. Additionally, patients with severe chronic obstructive pulmonary disease (COPD) in a home-based pulmonary rehabilitation program using pedometers showed significant improvements in exercise tolerance, dyspnea score, and quality of life score after 6-12 weeks.3 Studies have also identified pedometers as a motivational tool to increase physical activity and functional measurements.4,5 The purpose of this study was to evaluate the impact of pedometer use on exercise tolerance among www.npjournal.org
veterans with chronic HF. Specifically, we sought to evaluate the effect of a home-based nonsupervised exercise regimen using a pedometer compared with verbal instructions in veterans with chronic HF. THEORETICAL FRAMEWORK
The Health Promotion Model is a middle-range nursing theory that was used to guide this study. The foundation of Health Promotion Model focuses on factors that influence an individual’s ability to achieve health-promoting behaviors.6 METHODS Design
A prospective randomized controlled design was used in this study. Using permuted block randomization, veterans were assigned to either the control (routine exercise) group or the pedometer (exercise with a pedometer) group. Setting and Sample
Veterans were recruited from the Veterans Administration Connecticut Healthcare System. Veterans with NYHA class II-III HF symptoms and confirmed ejection fraction 45% were eligible to participate. Exclusion criteria included unstable angina, untreated cardiac dysrhythmias, COPD, severe lower back pain, peripheral neuropathy, peripheral artery disease, dementia, blindness, and admission within 6 weeks before enrollment. The Journal for Nurse Practitioners - JNP
819
Twelve veterans (46.2%) were randomized into the pedometer exercise group, whereas 14 (53.8%) were randomized to the routine exercise group. All participants continued to receive optimized medical treatment during the study.
Figure 1. Patient selection process.
Data Collection
Baseline blood pressure, weight, serum B-type natriuretic peptide, and 6-minute walk test (6MWT) results were collected on the initial visit and at the end of 6 weeks. Veterans in both groups were given verbal instructions to exercise for at least 30 minutes 5 times a week. Although veterans in the control group exercised on their own merits and recorded the total minutes walked daily, veterans in the experimental group were provided a spring-levered pedometer and asked to keep a daily recording of the number of steps taken and asked to maintain or increase their daily steps taken. The exact number of steps taken daily was not used for the primary data analysis; it was used as a means to monitor compliance and to assess if veterans were able to maintain or exceed the number of steps each day. Differences in the number of meters walked in 6 minutes between baseline and postexperiment were recorded and analyzed. Statistical Analysis
Descriptive statistics were used to describe demographic characteristics. Inferential statistics were used to compare demographic and baseline clinical characteristics between the 2 groups. One-sample t-tests were applied to each group to test for 6MWT improvements within each group. Finally, a 2-sample t test was used to assess improvement in 6MWT between the groups. Data were analyzed using SPSS software version 18.0 (SPSS Inc, Chicago, IL). A P value .05 was considered statistically significant. A minimal clinically importance difference (MCID) in an outcome is the smallest difference that is considered to be clinically meaningful. Sample sizes were calculated to have good power to detect the MCID in 6MWT scores at a significance level of .05. The MCID for HF was found to be in the range of 54 to 80 m.7 Dallas et al3 studied changes in 6MWT scores and provided a standard deviation of 59 m in those changes. Although this study was done 820
The Journal for Nurse Practitioners - JNP
in patients with COPD, it has been recognized that patients with COPD and HF have similar levels of exercise capacity and health status.8 With this standard deviation of 59 m, the range of MCID values from 54 to 80 corresponds to a range of effect sizes from 0.92 to 1.36. Using Monte Carlo simulations, for MCID ¼ 80 and MCID ¼ 54, the sample sizes required to achieve power over 0.8 (80%) are n ¼ 8 and n ¼ 16, respectively, per group. Therefore, the target sample size for this study was a total of 16 to 32 subjects. RESULTS
A total of 102 veterans meeting the criteria were identified. Seventy-four veterans declined to Volume 11, Issue 8, September 2015
Table 1. Comparison of Demographic Characteristics Variables
Pedometer (n ¼ 12)
Control (n ¼ 14)
P Value
Age (mean SD)
71.6 7.7
70.4 13.4
.80
White
10
8
Black
2
6
11
14
1
0
207 43.1
194.4 35.0
164-301
138-249
Figure 2. Improvements in 6MWT.
Race
.15
Sex Male Female
.27
Baseline weight Mean SD Range Baseline SBP
121.8 11.8 121.8 11.3
Mean SD Baseline DBP
.99 73.7 8.6
75.4 10.2
Mean SD LVEF
.42
.64 37.9 5.4
33.9 9.0
(mean SD)
.19
ICM
8
10
.79
ICD
5
9
.25
Class II
12
8
Class III
0
6
.01*
2
4
.47
Hypertension
11
13
.91
Sleep apnea
4
4
.79
COPD
2
3
.76
Beta-blocker
10
13
.45
ACE inhibitor
10
10
.47
Diuretics
6
10
.26
Spironolactone
1
4
.19
NYHA
Diabetes
ACE ¼ angiotensin-converting-enzyme; COPD ¼ chronic obstructive pulmonary disease; DBP ¼ diastolic blood pressure; ICD ¼ implantable cardioverter defibrillator; ICM ¼ ischemic cardiomyopathy; LVEF ¼ left ventricular ejection fraction; SBP ¼ systolic blood pressure; SD ¼ standard deviation. * p < 0.05.
participate in the study. Twenty-eight veterans were recruited, but 2 veterans dropped out, making the final sample size 26. Twelve veterans (46.2%) were randomized into the pedometer group and 14 (53.8%) into the control group (Figure 1). www.npjournal.org
Demographic characteristics of both groups are displayed in Table 1. The only significant difference between the 2 groups was that veterans in the control group were more likely to have more advanced NYHA classification (P ¼ .01). Figure 2 displays the 6MWT improvements of the participants grouped by study assignments. There was no significant difference in baseline 6MWT between the 2 groups (P ¼ .52). Both groups increased their 6MWT after the 6-week study period (Table 2). The pedometer group had a mean increase of 15.7 9.2 m (P ¼ .19), whereas the control group had a statistically significant increase of 29.8 38.2 m (P ¼ .01) after 6 weeks. The 6MWT improvement was not statistically different within the pedometer group initially. However, the withingroup improvement in the pedometer group reached statistical significance of P ¼ .005 when an outlier was excluded from analysis. This outlier corresponded to a veteran in the pedometer group who decided to stop walking after only 4 minutes during the follow-up 6MWT to conserve energy for walking in the mall later that day. This incomplete 6WMT was not an accurate measurement of the veteran’s actual exercise tolerance level, and, therefore, the data were excluded. Only 50% of veterans in the pedometer group completed their daily logs compared with 71.4% in the control group (Table 3). In the pedometer group, only 1 veteran came close to maintaining the level of activity measured by the pedometer throughout the study. The Journal for Nurse Practitioners - JNP
821
Table 2. Comparison of 6MWT Within and Between Groups (Meters) Pedometer Variables
Total No (n ¼ 12)
Outlier (n ¼ 11)
Control (n ¼ 14)
Total (n ¼ 26)
Bivariate Analysis
344.5 87.6
t24 ¼ 0.66
P Value
Pre-6MWT Mean SD
356.8 79.1
370.5 66.5
333.9 95.8
Range
206.6-472.4
274.3-472.4
178.6-514.5
Mean SD
372.5 11.0
395.5 8.2
363.6 93.2
Range
120.1-508.4
269.8-508.4
231.6-505.4
.52
Post-6MWT 367.8 99.8
t24 ¼ 0.22 .83
6MWT Differences Mean SD Range
15.7 9.2
29.8 38.2
23.3 38.5
86.6 to 81.4
42.7 to 84.7
86.6 to 84.7
P ¼ .19
P ¼ .01
t24 ¼ 0.93 .36
a
25.0 23.4 4.9 81.4
27.7 32.56
P ¼ .005
t23 ¼ 0.365
.72
42.7 to 84.7
a
6MWT ¼ 6-minute walk test; SD ¼ standard deviation. a
Statistically significant.
DISCUSSION
Among the veterans who completed the pre- and post6MWT in the experimental group, pedometer use significantly improved their exercise tolerance after 6 weeks of exercise (P ¼ .005). This finding is consistent with previous studies reporting that pedometer use was associated with increased exercise tolerance.2-5 Veterans in the control group also experienced statistically significant improvement in their exercise tolerance (P ¼ .01). However, there was no significant difference in the improvement of exercise Table 3. Daily Log Returned and Completed Total Number of Patients N ¼ 26 Pedometer
Control
12
Number of patients in each group
14
11
Number of returned logs at the end of study
10
6 (50%)
Number of patients completed logs on a daily basis
822
The Journal for Nurse Practitioners - JNP
8 (71.4%)
tolerance between the pedometer and control groups (P ¼ .72) (ie, although walking improved exercise tolerance in both groups, the use of pedometers was not better than routine exercise to improve exercise tolerance in this study of veterans with chronic HF). Veteran compliance with pedometer use was an issue in this study. Only 6 of 12 veterans (50%) in the pedometer group completed daily logs. The veterans who did not return complete logs admitted that they were not compliant with wearing their pedometers. This lack of compliance was also found by Zoellner et al9; their study found that participants had low pedometer compliance despite having trained coaches to encourage them to complete their diaries. Furthermore, pedometer malfunctioning was also a major obstacle in the current study and may have contributed to the low compliance rate. Jehn et al9 found that in patients with chronic HF, the highest pedometer error occurred in those with greater functional limitation and 6MWT < 400 m. Seven (58.3%) of the 12 veterans using pedometers in this study walked less than 400 meters at their baseline 6MWT, and this may have contributed to higher pedometer misregistration leading to the low compliance rate. Volume 11, Issue 8, September 2015
Finally, this study was conducted in the winter of 2013 during a time that the Northeastern US experienced 2 “storms of the century” and in general had a harsh winter. Hamilton et al10 found study participants had statistically significant greater daily steps in the summer season when compared with the winter season. In fact, cold weather was cited by many qualified veterans as a reason to decline in this study.
the improvement may not have reached MCID (Figure 2), this positive trend is encouraging. Pedometers provide specific numbers of steps walked daily and can be easily tracked by telehealth nursing services. A select group of veterans with HF may experience increased health benefits by tracking their daily or weekly steps via a pedometer and reporting this information to their provider.
Study Limitations
References
The 6-week study duration may have been too short to detect the differences between the 2 groups given that there were improvements in 6MWT within groups. Even though the sample size provided sufficient power by MCID analysis, veterans enrolled in this study had a lower prevalence of diabetes mellitus (23.1%), COPD (19.2%), and sleep apnea (30.1%) compared with the general HF population; therefore, this may limit the generalizability of the study results. Additionally, the timing of this study significantly limited the recruitment effort and study participants’ exercise efforts because of wintery weather. Finally, pedometer malfunction may have had an impact on this study given that many veterans reported pedometer malfunction as the reason they did not wear their pedometers. It is possible that a more reliable pedometer may increase pedometer compliance. Recommendations for Future Study
A qualitative study in the veteran population about attitudes toward pedometer use may be helpful to determine the feasibility of pedometer use in this population. Monthly telephone follow-ups could be incorporated into a future study to improve both pedometer compliance and recording of the daily logs. Moreover, careful selection of an accurate type of pedometer and/or smart phone health and fitness application may improve the compliance of pedometer use and the effectiveness of pedometer use on health outcomes.
1. Kitzman D, Groban L. Exercise intolerance. Cardiol Clin. 2011;29:461-477. 2. Evangelista L, Dracup K, Erickson V, McCarthy W, Hamilton M, Fonarow G. Validity of pedometers for measuring exercise adherence in heart failure patients. J Card Fail. 2004;11:366-371. 3. Dallas M, McCusker C, Haggerty M, Rochester C, ZuWallack R. Using pedometers to monitor walking activity in outcome assessment for pulmonary rehabilitation. Chron Respir Dis. 2009;6:217-224. 4. Synder A, Colvin B, Gammack J. Pedometer use increases daily steps and functional status in older adults. J Am Med Dir Assoc. 2011;12:590-594. 5. Araiza P, Hewes H, Gashetewa C, Vella C, Burge M. Efficacy of a pedometerbased physical activity program on parameters of diabetes control in type 2 diabetes mellitus. Metabolism. 2006;55:1382-1387. 6. Pender N, Murdaugh C, Parsons M. Health Promotion in Nursing Practice. 5th ed. Upper Saddle River, NJ: Pearson Prentice Hall; 2006. 7. Wise R, Brown C. Minimal clinically important differences in the sixminute walk test and the incremental shuttle walking test. COPD. 2005;2:125-129. 8. Zoellner J, Connell C, Powers A, Avis-Williams A, Yadrick K, Bogle M. Does a six-month pedometer intervention improve physical activity and health among vulnerable African Americans? A feasibility study. J Phys Act Health. 2010;7:224-231. 9. Jehn M, Schmidt-Trucksass A, Schuster T, Hanssen H, Halle M, Kohler F. Pedometer accuracy in patients with chronic heart failure. Int J Sports Med. 2010;31:186-191. 10. Hamilton S, Clemes S, Grittiths P. UK adults exhibits higher step counts in summer compared to winter months. Ann Hum Biol. 2008;35:154-169.
Vicky M. Chang, DNP, APRN, is a cardiology nurse practitioner at the VA Connecticut Healthcare System in West Haven, CT, and can be reached at [email protected]. Mary I. Dallas, PhD, PT, is a physical therapy specialist at the VA Connecticut Healthcare System. Tammy M. Lampley PhD, RN, CNE, and Kerry A. Milner, DNSc, RN, are assistant professors of nursing at the School of Nursing at Sacred Heart University in Fairfield, CT. In compliance with national ethical guidelines, the authors report no relationships with business or industry that would pose a conflict of interest.
CONCLUSION
Vicky M. Chang is a recipient of the National Nursing Education Initiative scholarship by the Department of Veterans Affairs.
Routine mild to moderate exercise motivated by either pedometer use or verbal instruction improved exercise tolerance in veterans with HF. Although
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