Inactivity is a major risk factor for a multitude of illnesses and is also a mediator of dyspnea, fatigue, and other symptoms in chronic pulmonary disease. Although pulmonary rehabilitation (PR) is an integral part of optimal care for patients with chronic pulmonary disease, little is known about strategies to support adherence to exercise following PR over time.
1. To evaluate the effectiveness of an exercise adherence intervention following a pulmonary rehabilitation program to maintain daily activity (primary objective) ,exercise, functional capacity, (secondary objectives), symptom experiences, muscle strength, quality of life, health status, and walking self-efficacy. 2. To determine personal predictors of post-program daily activity and exercise. Personal predictors are individual characteristics present at entry to the study that support post-intervention adherence to activity and exercise. 3. To determine associations between intensity of daily activity and exercise and other outcome variables. 4. To describe the dollar cost of administering an exercise adherence intervention.
A two-group, experimental design was used with randomization into a usual care control or intervention group occurring following the PR program. Measures completed and data collected at Time 1 (T1-pre-PR), Time 2 (T2-last week PR, just prior to randomization), Time 3 (T3-short-term adherence- 12 weeks post PR), Time 4 (T4-long-term adherence-36 weeks post PR) were: Charlson Comorbidity Index (T1 and T4 only), daily activity (accelerometer), daily exercise (self-report, Daily Activity Diary), muscle strength, life quality (Seattle Obstructive Lung Disease Questionnaire), functional capacity (spirometry, 6-minute walk, muscle strength), symptom experiences (Multidimensional Assessment of Fatigue scale, Dyspnea Scale), health status (Medical Outcomes Short Form-36V), and walking self-efficacy (Walking Self-Efficacy Questionnaire).
Objective 1: A rank-based ANCOVA of the primary outcome variable, daily activity at T3 as measured by accelerometer, showed no statistically significant difference between intervention and control groups though there was a trend in favor of the intervention (median change from T2 to T3 of 10 versus -12). However, the secondary outcomes of 6- minute walk distance and self-reported daily exercise were significant at T3 with the intervention group showing less decline from immediately post PR to 3 months later (6-minute walk, median change -42 versus 105, p=.016; daily activity, median change 0 versus 11, p= .034). At T4, there were no differences between intervention and control groups in these secondary outcomes although the trend favoring the intervention group was still there. Objective 2: Personal predictors of daily activity and self-reported exercise (short-term adherence) (intervention group only): Spearman correlations between daily activity at Time 3 were significant for Time 1 daily activity (0.74), 6-minute walk (0.44), age (-.48), spirometry (.40), and walking self-efficacy (0.53); Spearman correlations between daily exercise at Time 3 were significant for Time 1 daily activity (.32), age, (-.26), Charlson Comorbidity Index (-.31) and walking self-efficacy (.41). No significant correlations were evident with personal variables for long-term adherence measures. Objective 3: Associations between intensity of daily activity and exercise with other outcomes (intervention group only): At Time 3 daily activity was correlated with 6-minute walk (.47), self-efficacy (.45), and emotional function (SOLQ- -.32). Self-reported exercise at Time 3 was correlated with self-efficacy (.44), and 6-minute walk (.32) Time 4 results were similar but somewhat weaker. Objective 4. Cost of exercise intervention: The exercise intervention was carried out by a physical therapist. For each subject in the adherence intervention group, the mean (sd) cost of the intervention was $134 (36); range of costs was between $76-$221.
The identification of effective exercise/activity adherence intervention strategies for pulmonary patients may contribute to improved treatment outcomes, including fewer illnesses and costly hospitalizations and improved functioning and life quality. This study demonstrated good short-term benefit for the secondary outcomes of self-reported of exercise and functional capacity as measured by in terms of six-minute walk distance, which were significant at 3 months, but were not statistically significant at 9 months. The intervention was low in cost, feasible for clinical applications, and accepted by study participants. Successful interventions fashioned for this group will be readily applicable to other high-risk populations, including veterans with heart failure, malignancies, and the frail elderly.
External Links for this Project
- Belza B, Steele BG, Hunziker J, Lakshminaryan S, Holt L, Buchner DM. Correlates of physical activity in chronic obstructive pulmonary disease. Nursing Research. 2001 Jul 1; 50(4):195-202. [view]
- Steele BG, Belza B, Hunziker J, Holt L, Legro M, Coppersmith J, Buchner D, Lakshminaryan S. Monitoring daily activity during pulmonary rehabilitation using a triaxial accelerometer. Journal of Cardiopulmonary Rehabilitation. 2003 Mar 1; 23(2):139-42. [view]
- Belza B, Steele BG, Cain K, Coppersmith J, Howard J, Lakshminarayan S. Seattle Obstructive Lung Disease Questionnaire: sensitivity to outcomes in pulmonary rehabilitation in severe pulmonary illness. Journal of Cardiopulmonary Rehabilitation. 2005 Mar 1; 25(2):107-14. [view]
- Steele BG, Belza B, Cain K, Coppersmith J, Howard J, Lakshminarayan S. Does self-reported non-ventilatory limitation to six-minute walk distance (6MWD) contribute to change in 6MWD following pulmonary rehabilitation. Paper presented at: American Thoracic Society Annual International Conference; 2005 May 1; San Diego, CA. [view]
- Steele BG, Coppersmith J, Belza B, Cain K, Howard J, Lakshminarayan S. Promoting activity and exercise in chronic lung disease: An intervention study. Paper presented at: American Thoracic Society Annual International Conference; 2005 May 1; San Diego, CA. [view]
- Steele BG, Belza B, Cain K, Coppersmith J, Howard J, Lakshminarayan S. The impact of chronic obstructive pulmonary disease exacerbation on pulmonary rehabilitation participation and function outcomes. Presented at: American Thoracic Society Annual International Conference; 2006 May 21; San Diego, CA. [view]
Behavior (patient), Functional status, Nursing