Research paper · RP01

Reps Before Results

Does the number of completed practice sessions predict wellbeing gains better than programme length or format? Across the trials that reported sessions or modules completed, a pooled estimate of change in g per extra completed session could not be computed: mean completed dose was almost never published, and the two largest digital tests disagreed. The largest self-help app trial (Kloos and colleagues, 2022; n = 849) found a weak dose–response (modules finished versus wellbeing change r = 0.21). The best-guided self-help trial (Schotanus-Dijkstra and colleagues, 2017; n = 275) found no meaningful dose–response for adherence, while still producing a medium-to-large wellbeing gain versus wait-list (d = 0.66). Prior reviews that pooled assigned length, not completed reps, report small-to-medium wellbeing effects (Bolier 2013, d = 0.34; Carr 2021, g = 0.39; Hendriks 2020 multi-component programmes, g = 0.34). Eight adult non-clinical or mixed-community randomised trials reported completed sessions or a defined adherence rule and a wellbeing outcome. Narrative synthesis shows three consistent facts: people complete far fewer reps than the protocol assigns; people who keep practising after the assigned week tend to hold their gains longer; and a working plateau, not a pooled plateau, sits around four to six modules in two Dutch app trials. No Indian office-professional trial yet reports completed-session dose against wellbeing. Certainty of the dose–response claim is very low on GRADE. The practical case for counting reps remains stronger than the statistical case for a single slope.