Reporting dose in complex self-management support interventions for long-term conditions: is it defined by researchers and received by participants? A systematic review

BACKGROUND: The minimum clinically effective dose, and whether this is received in randomised controlled trials (RCTs) of complex self-management interventions in long-term conditions (LTCs), can be unclear. The Template for Intervention Description and Replication (TIDieR) checklist states that dose should be clearly reported to ensure validity and reliable implementation. OBJECTIVES: To identify whether the expected minimum clinically effective dose, and the dose participants received is reported within research articles and if reporting has improved since the TIDieR checklist was published. METHODS: Four databases were systematically searched (MEDLINE, PsycINFO, AMED and CINAHL) to identify published reports between 2008 and 2022 for RCTs investigating complex self-management interventions in LTCs. Data on reporting of dose were extracted and synthesised from the eligible articles. RESULTS: 94 articles covering various LTCs including diabetes, stroke and arthritis were included. Most complex interventions involved behaviour change combined with education and/or exercise. The maximum dose was usually reported (n=90; 97.8%), but the expected minimum clinically effective dose and the dose received were reported in only 28 (30.4%) and 62 (67.4%) articles, respectively. Reporting of the expected minimum clinically effective dose and the dose participants received did not improve following the publication of the TIDieR checklist in 2014. CONCLUSIONS: Interpreting results and implementing effective complex self-management interventions is difficult when researchers’ reporting of dose is not in line with guidelines. If trial findings indicate benefit from the intervention, clear reporting of dose ensures reliable implementation to standard care. If the results are non-significant, detailed reporting enables better interpretation of results, that is, differentiating between poor implementation and lack of effectiveness. This ensures quality of interventions and validity and generalisability of trial findings. Therefore, wider adoption of reporting the TIDieR checklist dose aspects is strongly recommended. Alternatively, customised guidelines for reporting dose in complex self-management interventions could be developed. PROSPERO REGISTRATION NUMBER: CRD42020180988.