Does Higher Compliance With American College of Sports Medicine Exercise Prescription Guidelines Influence Exercise Outcomes in Knee Osteoarthritis? A Systematic Review With Meta‐Analysis

Objective We wanted to determine if higher compliance with American College of Sports Medicine (ACSM) exercise prescription guidelines influences exercise outcomes in knee osteoarthritis (OA). Methods We conducted a systematic review. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase up to January 4, 2024, for randomized controlled trials evaluating resistance and/or aerobic exercise for knee OA. Interventions were classified as higher compliance (meeting ≥60% of ACSM guideline recommendations for frequency, intensity, and duration) or lower compliance (meeting <60% of recommendations). Effects on pain and function were evaluated via meta‐analysis, stratified by compliance. Results Twenty‐five trials (3,290 participants) evaluated combined resistance and aerobic programs, with no differences in outcomes between those with higher and lower compliance (standardized mean difference [SMD] pain: −0.38 [95% confidence interval (CI) −0.59 to −0.17] vs −0.31 [95% CI −0.45 to −0.16], respectively; SMD function: −0.43 [95% CI −0.64 to −0.21] vs −0.36 [95% CI −0.58 to −0.14]). Sixty‐six trials (5,231 participants) evaluated resistance exercise, with no differences between interventions with higher and lower compliance (SMD pain: −0.60 [95% CI −0.81 to −0.39] vs −0.93 [95% CI −1.27 to −0.59]; SMD function: −0.64 [95% CI −0.83 to −0.44] vs −0.85 [95% CI −1.20 to −0.49]). Twelve trials (958 participants) evaluated aerobic exercise, with no differences between interventions with higher and lower compliance (SMD pain: −0.79 [95% CI −1.20 to −0.38] vs −1.00 [95% CI −2.52 to 0.53]; SMD function: −0.83 [95% CI −1.27 to −0.38] vs −0.76 [95% CI −2.02 to 0.50]). Conclusion Higher or lower compliance with ACSM exercise prescription guidelines did not influence exercise outcomes. Given there was substantial heterogeneity and many publications were at risk of bias, our results should be interpreted with caution.