Comparison of BMI changes in Japanese adults receiving face-to-face versus online counseling for specific health guidance: a noninferiority prospective observational study.

Objectives: This study aimed to evaluate the noninferiority of online counseling over face-to-face counseling for specific health guidance (SHG).

Methods: This prospective observational study was conducted using specific health checkup (SHC) and SHG data of individuals with health insurance in Japan. We analyzed data from 1431 participants who met the inclusion criteria, including those who underwent online or face-to-face counseling between April 1, 2020 and March 31, 2021, and received an SHC in the following year but no earlier than 90 days after their first counseling session. Assessed variables comprised demographics, counseling methods, and SHC results, including baseline questionnaire findings and body mass index (BMI) at follow-up. We performed inverse probability of treatment weighting (IPTW) using propensity scores, with changes in BMI as the objective variable and the counseling method as the explanatory variable. We set the noninferiority margin to 0.175, based on a previous study.

Results: The online and face-to-face counseling groups comprised 455 (31.8%) and 976 (68.2%) participants, respectively. The number of men and mean age were 214 (47.0%) and 49.9 years (SD: 6.9 years), respectively, in the online counseling group, and 491 (50.3%) and 51.1 years (SD: 7.6 years), respectively, in the face-to-face counseling group. IPTW using propensity scores revealed a regression coefficient of -0.014 (95% CI: -0.157 to 0.129) for the online group compared with the face-to-face group (P = .847). The CI was within the noninferiority margin.

Conclusions: The effects of online counseling on BMI are likely noninferior to those of face-to-face counseling.