Which Survey Questions Change Behavior? Randomized Controlled Trial of Mere Measurement Interventions

Objective: Evidence indicates that receiving a questionnaire about a behavior increases the likelihood that the person will perform that behavior-a phenomenon termed the mere measurement effect. This research tested the role of (a) the type of questions, and (b) questionnaire completion in optimizing the impact of mere measurement interventions designed to retain novice blood donors. Design: Novice blood donors (N = 4391) were randomly allocated to four conditions that varied the content of a questionnaire about blood donation (behavioral intention-only, behavioral intention plus regret, implementation intention-only, implementation intention plus regret) or to a no-questionnaire control condition. Main Outcome Measures: Objective measures of registration at blood drives were obtained at 6 and 12 months postbaseline. Results: Participants in the implementation intention-only condition donated more frequently at 6 months compared to participants in each of the other conditions. At 12 months both implementation intention conditions outperformed the other conditions. Implementation intentions increased the frequency of donations over 1 year by 12%. Measuring anticipated regret did not augment the impact of interventions whereas questionnaire completion had an important impact on donation behavior. Conclusion: Questions about implementation intentions but not behavioral intentions promote retention of novice blood donors.