Maintenance of Exercise Adherence Among Older Adults with Osteoarthritis

Principal Investigator: Susan L. Hughes, DSW

University of Illinois

Abstract:

Osteoarthritis (OA) is the most common condition affecting older people today. It is the leading cause of disability among older people and its impact is projected to increase substantially with the aging of the U.S population (CDC, 1999; CDC, 2003). To date, 10 randomized trials of exercise interventions have been conducted among persons with OA. Although most report positive short-term outcomes at three months or less, only two have reported mixed findings on longer term adherence and related outcomes at 12 or 18 months. This paucity of data on the maintenance of long-term exercise behavior among persons with OA indicates an urgent need for additional studies of issue. This study will use a multi-site randomized controlled trial with repeated measures to assess the comparative effects of two different ways of enhancing long-term adherence to and benefits associated with participation in the evidence-based, Fit and Strong multi-component exercise intervention for older persons with lower extremity OA (Hughes et al., in press). We will recruit 600 persons to participate in the 8-week Fit and Strong program. At the conclusion of Fit and Strong, participants will be stratified by arthritis severity and randomized to either Negotiated Maintenance, in which individualized tailored adherence plans will be developed, or Mainstreamed Maintenance, in which participants will be mainstreamed into an ongoing facility-based program at each of four participating study sites. In addition, half of the participants in both maintenance arms will be randomly assigned to receive telephone reinforcement. We will use generalized estimating equations and random effects models to test the hypotheses that Negotiated maintenance participants will experience significantly greater levels of adherence to exercise at 2, 6, 12, 18, and 24 months, and significant improvements in self-efficacy for exercise, self-efficacy for exercise adherence, self reported and observed functional status, and psychosocial measures compared to Mainstreamed maintenance participants at 2, 6, 12, and 18 months.

Specific aims:

1. Train instructors to implement the multiple component (strength training, aerobic walking and health education for behavior change) Fit and Strong intervention at 4 Senior Centers in Chicago;
   
   
2. Screen 2000 older adults with OA in order to identify 600 persons who are similar to our original cohort to participate in Fit and Strong. Prior to the conclusion of Fit and Strong participants will be stratified and randomly assigned to one of two follow-up maintenance arms. Treatment Arm A will develop tailored/negotiated contracts to maintain post intervention exercise adherence at home or in the community. Half of the participants in this “negotiated maintenance” arm will be randomly assigned to receive telephone calls to reinforce adherence and half will be assigned to a no telephone calls group. Treatment Arm B will be mainstreamed into an ongoing facility-based exercise program for post intervention exercise adherence. Persons in this “mainstream follow up” arm will be randomly assigned such that half will receive regular telephone reinforcement follow up and half will not. Taken together, these two comparisons will constitute a two by two factorial design based on a negotiated vs. mainstream and a phone vs. no-phone effect;
   
   
3. Obtain baseline, 2, 6, 12, 18, and 24-month adherence data on all participants; as well as secondary outcome measures at 2, 6, 12, and 18 months;
   
   
4. Obtain repeated self-efficacy and decisional balance and other mediators on all participants at 2, 6, 12, and 18 months and analyze their relationship to exercise adherence, cessation, and reactivation;
   
   
5. Use generalized estimating equations and random effect models to test whether persons in the negotiated maintenance arm show significantly higher exercise rates over time vis a vis the mainstreamed maintenance arm, and whether higher maintenance levels will be accompanied by significant improvements in self-efficacy for exercise, self efficacy for exercise adherence, and functional status;
   
   
6. Use the same analytic techniques to test whether, in both arms, persons who receive telephone reinforcement will have superior adherence rates and attendant outcomes to those who do not.