Development of Motivation to Exercise in Patients with Parkinson's Disease: An Application of Self Determination Theory

Abstract

A patient's response to receiving a diagnosis of a chronic progressive disease is critical, as is the approach to the intervention that the patient receives. Parkinson's disease (PD) exemplifies chronic disease with the additional complication of being progressively degenerative and therefore increasingly debilitating. Many of the patients with PD suffer from a decrease in motivation. While physical therapy and individual independent exercise may benefit these patients with PD, the lack of motivation to exercise often presents a significant barrier to this beneficial behavior. Self-determination Theory (SDT) has been used successfully in other health paradigms to improve motivation. Motivation is achieved by satisfying the three psychological needs of competence, autonomy and relatedness of the individual. Physical therapy intervention may facilitate motivation through the development of relatedness to the health care professional (HCP). The purpose of this study was to determine if SDT may be effectively applied to increase motivation in patients with PD, determine the factors that facilitate the motivation, and quantify the effect on the patient's quality of life. This study utilized a within subject design consisting of 8 weekly sessions. At screening, demographics and baseline assessments for cognitive impairment (SLUMS), severity of PD ( Hoehn and Yahr), quality of life (PDQ-8 a questionnaire validated for the PD patient), and evaluation of physical impairments (Tinetti gait and balance test and Timed Up and Go Test[TUG]) were collected. Each weekly session included motivational interviewing designed to implement SDT strategies promoting satisfaction of the three psychological needs. Additionally, at each weekly physical therapy session, additional physical assessments were completed as well as the SRQ-E, a Likert scale SDT questionnaire designed to determine the motivation to exercise (extrinsic regulation, introjected regulation, identified regulation and intrinsic motivation.). Ten patients were consented and enrolled in this study at a physician-owned clinic in the Philadelphia suburbs. All patients completed the 8-week study, with 6 of the patients opting to continue in physical therapy after the study. At baseline, patients exhibited mild to moderate impairment in physical activity as assessed by the Hoehn and Yahr average score of 2.9 (range 1-4). The average age of the patient was 68.4 (range 50-84) years with an average SLUMS score of 26.3 (range 20-30), indicating mild cognitive impairment. The data from the SRQ-E did not demonstrate significance for change in motivation. Both the Tinetti gait and balance test and the TUG average scores improved, with a change of 4.9, 1.8, and 7.1, respectively. The PDQ-8 average change improved 0.118, indicating improvement in the quality of life. Results from both the Tinetti and PDQ-8 demonstrated improvements that were statistically significant (p=.0007 and p=.008 respectively). Qualitative analysis of the motivational interviews showed the most common themes as a decrease in pain, increase in strength and function as well as independently initiating a novel exercise. Correlative analysis was inconclusive. While motivational interviewing is qualitative, a positive effect was indirectly assessed by the patient's self-reports of increased exercise and the development of relatedness to the HCP as evidenced by the patient's 100% completion rate of the study and 60% continuation on physical therapy. Further study is warranted to determine the factors that facilitated this improvement and evaluate the benefit of motivation in these patients with Parkinson's disease.