Several individual RCTs demonstrated clinical ly important improvements in pain and disability with aerobic exercise .
Other PT interventions demonstrated no sustained benefit .
Individual RCTs showed similar benefits with aerobic , aquatic , and strengthening exercise .
Adverse events were uncommon and did not deter participants from continuing treatment .
Low-strength evidence suggested that only a few PT interventions were effective .
BACKGROUND Osteoarthritis is a leading cause of disability .
Nonsurgical treatment is a key first step .
PURPOSE Systematic literature review of physical therapy ( PT ) interventions for community-dwelling adults with knee osteoarthritis .
Smallest detectable and minimal clinically important differences of rehabilitation intervention with their implications for required sample sizes using WOMAC and SF-36 quality of life measurement instruments in patients with osteoarthritis of the lower extremities.
OBJECTIVE To discuss the concepts of the minimal clinical ly important difference ( MCID ) and the smallest detectable difference ( SDD ) and to examine their relation to required sample sizes for future studies using concrete data of the condition-specific Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) and the generic Medical Outcomes Study 36-Item Short Form ( SF-36 ) in patients with osteoarthritis of the lower extremities undergoing a comprehensive inpatient rehabilitation intervention . METHODS  SDD and MCID  were determined in a prospect i ve study of 122 patients before a comprehensive inpatient rehabilitation intervention  and at the 3-month followup .  MCID was assessed by the transition method . Required SDD and sample sizes were determined by applying normal approximation and taking into account the calculation of power . RESULTS In the WOMAC sections the SDD and MCID ranged from 0.51 to 1.33 points ( scale 0 to 10 ) , and in the SF-36 sections the SDD and MCID ranged from 2.0 to 7.8 points ( scale 0 to 100 ) . Both question naires showed 2 moderately responsive sections that led to required sample sizes of 40 to 325 per treatment arm for a clinical study with unpaired data or total for paired followup data . CONCLUSION In rehabilitation intervention , effects larger than 12 % of baseline score ( 6 % of maximal score ) can be attained and detected as MCID by the transition method in both the WOMAC and the SF-36 . Effects of this size lead to reasonable sample sizes for future studies lying below n = 300 . The same holds true for moderately responsive question naire sections with effect sizes higher than 0.25 . When design ing studies , assumed effects below the MCID may be detectable but are clinical ly meaningless
Several individual RCTs demonstrated clinical ly important improvements in pain and disability with aerobic exercise .
Other PT interventions demonstrated no sustained benefit .
Individual RCTs showed similar benefits with aerobic , aquatic , and strengthening exercise .
Adverse events were uncommon and did not deter participants from continuing treatment .
Low-strength evidence suggested that only a few PT interventions were effective .
BACKGROUND Osteoarthritis is a leading cause of disability .
Nonsurgical treatment is a key first step .
PURPOSE Systematic literature review of physical therapy ( PT ) interventions for community-dwelling adults with knee osteoarthritis .