Research paper · RP05

The Half-Life of a Wellness Programme

Every published workplace wellbeing trial reports the post-test. Far fewer report what is left when the last session has ended. Across published follow-up pools, about 70 per cent of the post-test wellbeing effect remains at one to three months; at six months, programmes with continued practice still hold roughly 85 per cent, while universal one-shot programmes hold about a quarter. This PRISMA-2020-structured evidence synthesis asked how much of a workplace wellbeing or stress-management gain survives at one, three and six months, and what slows the fade. Eligible evidence was randomised or controlled trials of employed adults, 2000-2026, with a wellbeing or stress outcome at post-test and at least one later follow-up. Search covered PubMed, PsycINFO, Scopus, Web of Science, Google Scholar, CTRI, ClinicalTrials.gov and OSF preprints. Decay was modelled as the ratio of follow-up Hedges g (or Cohen's d) to post-test g. Prior syntheses already pooled time-stratified effects: Vanhove and colleagues found resilience-building programmes dropped from d = 0.26 within a month to d = 0.07 later; Vonderlin and Michaelsen found mindfulness-based workplace programmes held most of the wellbeing effect to twelve weeks and lost more of it after that. Primary trials with continued digital access or coaching (Heber 2016; Ebert 2016; Radin 2025; Aikens 2014) held or grew the stress effect at four to six months. Self-guided delivery of a similar programme retained about two-thirds. One large worksite trial found a null at six and twelve months. Certainty is low to moderate: follow-up samples shrink, wait-list arms contaminate later comparisons, heterogeneity is high, and corporate India has almost no decay-tracked randomised trial. The practical implication is not mysterious. A programme is not a day. It is a practice that has to be repeated after the facilitator leaves the building.