TY - JOUR T1 - Randomised controlled trials for complex physiotherapy interventions are perfectly possible JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 950 LP - 951 DO - 10.1136/bjsports-2017-098612 VL - 52 IS - 15 AU - Leonardo Oliveira Pena Costa Y1 - 2018/08/01 UR - http://bjsm.bmj.com/content/52/15/950.abstract N2 - Randomised controlled trials (RCTs) are widely recognised as the strongest scientific approach to measuring the effects of interventions. If a clinician chooses to ignore evidence from RCTs to make clinical decisions and rely only on clinical observation, overestimation of treatment effects is very likely to occur. The latter occurs because changes in outcomes and the effects of interventions are completely different constructs.Change in a given outcome is all a clinician can observe in clinical practice, and is basically the difference between an outcome measured after the intervention compared with the baseline assessment (ie, within-group difference). However, there are a number of factors that play a key role on the changes in outcomes. These factors are scientifically known as confounders and include (1) natural history, (2) regression to the mean, (3) placebo effect, (4) polite patients and (5) recall bias. Improvements observed in patients in clinical practice are contaminated with these … ER -