Physical activity level and association with behavioral factors in knee osteoarthritis

Abstract

Background: The effects of physical activity (PA) in disease prevention and therapy have well-known effects on lower-limb osteoarthritis (OA), decreasing pain and improving function.

Objective: We aimed to describe the level and factors affecting PA practices of people with knee OA.

Design: Prospective epidemiological study.

Setting: In all, 548 people with knee OA were interviewed by use of self-administered anonymous questionnaires.

Main outcome measurement: The main outcome was physical activity level evaluated by the International physical activity questionnaire (IPAQ) (short version). Secondary outcomes included sociodemographic and clinical data, comorbidities, and barriers to and facilitators of practicing regular PA evaluated by 24 specific elements.

Results: The mean (SD) age of the study population was 67.6 (7.9) years; 73.9% were women and 30.9% had obesity (mean [SD] body mass index [BMI] 28.2 [5.7] kg/m2). Multi-joint OA affected 92% of the population, and 71.6% had comorbidities. The mean (SD) visual analog scale score for pain intensity was 4.5/10 (2.5), which was 51.4% better than the patient acceptable symptom state (PASS). The mean (SD) Western Ontario and McMaster Universities Osteoarthritis Index function score was 36.6/100 (20.7), which was 57.5% better than the PASS. In total, 67% of patients used analgesics, half of them at least once a week. According to the IPAQ, 42.6% of patients reported high, 38.6% moderate, and 18.8% low PA level; the median IPAQ total activity score was 2628 metabolic equivalent of task (MET)-min/week and time spent sitting was 257.1min/day. Only one third of participants received non-pharmacological treatment corresponding to the latest recommendations. Variables significantly related to inactive or minimally active PA levels were BMI (P=0.0294), sex (P=0.0008), and biomedical barriers, related to self-efficacy (P=0.0118).

Conclusions: The OA study population was less active, more sedentary, and had more comorbidities and more barriers to PA practice than the overall population.

Keywords: Behavior; Epidemiology; Exercise; Knee osteoarthritis; Physical activity.