Effectiveness of a targeted primary preventive intervention in a high-risk group identified using an efficiency score from data envelopment analysis: a randomised controlled trial of local residents in Japan

OBJECTIVE: To determine whether a minimal intervention based on the data envelopment analysis (DEA)-identified efficiency score effectively prevents hypertension. DESIGN: Randomised controlled trial. SETTING: Takahata town (Yamagata, Japan). PARTICIPANTS: Residents aged 40–74 years belonged to the information provision group for specific health guidance. Participants with a blood pressure ≥140/90 mm Hg, those taking antihypertensive medication, or those with a history of cardiac diseases were excluded. Participants were consecutively assigned based on their health check-up visit at a single centre from September 2019 to November 2020 and were followed up at the check-up in the following year, until 3 December 2021. INTERVENTION: A targeted approach using minimal intervention. Target was identified using DEA and 50% of participants with higher risk were targeted. The intervention was notifying the results of their risk of hypertension according to the efficiency score obtained by the DEA. PRIMARY OUTCOME MEASURES: A reduction in the proportion of participants who developed hypertension (≥140/90 mm Hg or taking antihypertensive medication). RESULTS: A total of 495 eligible participants were randomised, and follow-up data were available for 218 and 227 participants in the intervention and control groups, respectively. The risk difference for the primary outcome was 0.2% (95% CI −7.3 to 6.9) with 38/218 (17.4%) and 40/227 (17.6%) events in the intervention and control group, respectively (Pearson’s χ(2) test, p=0.880). The adjusted OR of the effect of the intervention was 0.95 (95% CI 0.56 to 1.61, p=0.843), and that of the efficiency score (10-rank increase) was 0.81 (95% CI 0.74 to 0.89, p<0.0001). CONCLUSIONS: Minimal intervention to a high-risk population stratified by DEA was not effective in reducing the onset of hypertension in 1 year. The efficiency score could predict the risk of hypertension. TRIAL REGISTRATION NUMBER: UMIN000037883