Strengths and Limitations
The pragmatic cluster RCT design with a follow-up period of 12 months is an important strength of this study. Such a design is acknowledged as the best setup for evaluating the effectiveness and cost-effectiveness of interventions in a real-world setting. The pragmatic approach and the involvement of 42 physiotherapy practices and 68 physiotherapists across the Netherlands improve the generalizability of the results to daily physiotherapy practice in the Netherlands [This study also has some limitations. An important limitation is that incomplete cases had—on average—higher levels of physical functioning, lower utility scores, and higher aggregate and disaggregate costs than complete cases. This suggests that the results of the complete-case analysis are likely biased to some extent by the self-selection of patients. To address this limitation, multiple imputation, which is considered an appropriate method for imputing data that are related to observed data (ie, missing at random) and simultaneously accounts for uncertainty about the missing data by creating several imputed data sets and pooling their results, was used to handle missing data [