Assessing the effect of a complex psychosocial intervention: a methodological note on determining measurement intervals

Aim Guidelines describing how to carry out a randomised controlled trial (RCT) provide no advice concerning when to measure an intervention effect. Possibly as a result, most papers give no rationales for the time frames chosen for data collection. This paper discusses four general strategies to identify when to collect data. Furthermore, an additional individual strategy concerning the current German young carers project is presented.

Background The first German young carers project is being implemented and evaluated in a pilot study’s RCT. Organisational difficulties as well as problems accessing the field led to a delay in the research and ended with a change to the overall timeframe for data assessment. This process resulted in a discussion by the research team about whether the shorter timeframe would lead to biased data.

Discussion The authors discuss how they reviewed the literature and decided how to determine the best point to conduct follow ups with their study participants.

Conclusion The authors conclude that the standard three-month intervals used in RCTs are not necessarily applicable to psychosocial interventions and researchers should determine more appropriate intervals where possible.