PITCH: A systematic review to investigate the effectiveness of physical activity interventions for people with osteoarthritis and comorbidity
Osteoarthritis (OA) is one of the diseases with the highest prevalence of comorbidity with other long-term chronic conditions. Clinical guidelines recommend physical activity (PA) in the form of general aerobic and strengthening exercises for people with OA irrespective of comorbidity. However, there is a gap in the literature for a systematic review specifically investigating the effectiveness of PA interventions in OA populations with comorbidity. Objective: To synthesise existing evidence investigating the effectiveness of PA interventions in adults with OA and obesity.
A systematic review with meta-analysis was conducted (PROSPERO Registration: CRD42017055582). Six electronic databases; MEDLINE, EMBASE, AMED, CINAHL, SportDiscus and CENTRAL were searched for studies from their inception until March 2017 (29.03.17). Inclusion criteria were randomised controlled trials (RCTs) comparing the effectiveness of any PA intervention to non-PA control group; including adults aged 45 years old and over with clinical or radiographic OA at any site; at least one of the comorbidities of interest (COPD, depression, diabetes, hypertension, obesity, T2DM); and measuring pain, physical function, quality of life, global health post intervention and adverse events. Included study risk of bias (ROB) was assessed using the Cochrane risk of bias tool. Two reviewers screened titles and abstracts then full text articles, checked data extraction, and carried out ROB assessment. Random-effects model meta-analysis was used to pool outcomes from sufficiently homogeneous studies to calculate effect sizes (Standardized Mean Difference (SMD) with 95% confidence interval (CI)). For this abstract we report meta-analysis findings of the OA and obesity subgroup.
The literature search retrieved 8171 citations of which 14 studies (n=4224 participants) were included in the full review, with 9 (n=1382 participants) analysed in the OA and obesity subgroup. PA interventions included: aquatic, aerobic, strengthening and functional activity; of 1 - 18 months in duration.
Four studies of OA and obesity measuring either Western Ontario Osteoarthritis Index (WOMAC) pain, WOMAC function or Six Minute Walking Test (6MWT) and were included in three meta-analyses. Best estimates showed PA to improve WOMAC pain (n=3 studies; n=547 participants; SMD = -0.09 (95% CI) -0.65, 0.47), improve WOMAC function (n=3 studies, n=415 participants; SMD = -0.35 (95% CI) -0.89, 0.18) and the 6MWT (n=4 studies, n=573 participants; SMD =-0.93 (95% CI) -0.49, 2.35). However, results were not statistically significant. There was substantial between-trial outcome heterogeneity (I² = 89.4% (p=0.000); 77.5% (p=0.012); 97.8% (p=0.000); respectively); results should be interpreted with caution.
Best estimates suggest small beneficial effects of physical activity on WOMAC pain, WOMAC function and the 6MWT. Mixed effectiveness among individual RCTs was likely due to heterogeneous intervention types, intensity and duration.