Sensitivity Analyses
LBP
In total, 3 sensitivity analyses were conducted as part of the economic evaluation. In the first sensitivity analysis, only data from complete cases on the primary clinical and cost outcome measures were included. In the second sensitivity analysis, absenteeism costs were estimated using the human capital approach assuming that productivity losses are generated for the entire duration of absence. In the third sensitivity analysis, the analysis was performed per risk group for developing persistent LBP (low, medium, and high) separately as this proved to be an effect modifier of the between-group differences between stratified blended physiotherapy and face-to-face physiotherapy in the short term [