Patients with hip or knee osteoarthritis who report frequent physical activity demonstrate improved health-related quality of life and physical function over a period of 5 years, according to data published in Arthritis Care & Research.
“Little epidemiological research has followed people with [hip and knee osteoarthritis (HKOA)] long-term and analyzed the effect of exercise frequency on function and quality of life using longitudinal modeling,” David G. Lopes, MD, of Nova University, in Lisbon, Portugal, and colleagues wrote. “Analysis of variance (ANOVA) is commonly used in prospective studies wherein several measures are taken over time from the same participants.
Patients with hip or knee OA who report frequent physical activity demonstrate improved health-related quality of life and physical function over a period of 5 years, according to data.
“However, repeated ANOVA measures collapse observations across individuals or items, which leads to loss of information and thus statistical power,” they added. “Multilevel modeling approaches, such as mixed-effects regression modeling, can overcome this problem. In contrast to ANOVA, multilevel models are well adapted to handling variability within and across individuals, and they assume that missing observations are missing completely at random so as not to lose information.”
To examine the impact regular physical activity on physical function and health-related quality of life in patients with hip or knee OA, Lopes and colleagues conducted a prospective study of data from the Portuguese Epidemiology of Chronic Diseases cohort. According to the researchers, this cohort includes a representative sample of Portuguese adults enrolled between 2011 and 2013, who underwent four evaluations, including a face-to-face interview, a structured examination by a rheumatologist and phone interviews. The analysis included patients who had validated diagnoses of hip or knee OA.
For the current analysis, the researchers excluded participants who failed to report their level of physical activity, or reported low levels of activity. Main outcomes included physical function, assessed using the Health Assessment Questionnaire, and health-related quality of life, evaluated through the Portuguese validated version of the EQ-5D-3L questionnaire. The survey included five factors — mobility, self-care, usual activities, pain or discomfort, and anxiety or depression.
The currently analysis included 1,086 patients, of whom 6.3%reported “frequent physical activity,” while 14.9% reported “very frequent physical activity.” According to the researchers, frequent (=–0.101; 95% CI, –0.187 to–0.016) and very frequent (=–0.061; 95% CI, –0.118 to–0.004) physical activity were associated with improved physical function over time, compared with non-frequent exercise. Meanwhile, frequent (=0.039; 95% CI, –0.002 to 0.08) and very frequent (=0.057; 95% CI, 0.029-0.084) physical activity were associated with improved health-related quality of life over the same period.
The researchers adjusted the data for years to baseline, sex, age, years of education, BMI, multimorbidity, hospitalizations, clinical severity, and unmanageable pain levels.
“The findings of this study raise awareness on the importance of maintaining physical activity in people with HKOA to optimize physical function and [health-related quality of life] and calls for future research on the need to understand the barriers, and develop strategies that can be effective in promoting long-term adherence, to physical activity in the population with HKOA,” they wrote. “Physical activity-based programs should be implemented early on as a core intervention for the management of HKOA and to prevent the clinical progression of the disease.”