Optimal design of financial rebates to encourage dental visits

The study seeks to assess the extent to which various levels of financial rebates affect the uptake of dental services.

A total of 4400 adults from the Singapore Population Health Study were invited by mail to participate in a four-group experimental study. Each group was invited to complete a survey and offered a rebate (SGD $10, $20, $30, $50) for visiting a dental professional. The effect of rebates on dental uptake was assessed through modified Poisson regression and by tabulating average marginal effects. Subgroup analyses were carried out by sociodemographic factors. Log-log regression was carried out to assess rebate elasticity.

The overall survey response rate was 25.7 % (n = 1132). Dental uptake rates varied from 25.5 % (n = 65) for a $10 rebate to 35.4 % (n = 111) for a $50 rebate. Compared to a $10 rebate, $30 and $50 rebates were associated with a higher likelihood of dental uptake (Adjusted Prevalence Ratio (Adj. PR) 1.33 (95 % confidence interval (CI) 1.04 - 1.71) and 1.38 (95 % CI 1.08 - 1.76) respectively), and higher predicted probabilities of dental uptake by 9.0 and 10.3 percentage points respectively. Rebates of $30 and above were associated with higher uptake rates among irregular dental attendees (Adj. PR 1.72 (95 % CI 1.08 - 2.74) and those staying in smaller public housing flats (Adj. PR 1.68 (95 % CI 1.07 - 2.66). The rebate elasticity was 0.36 (95 % CI 0.22 - 0.49).

Financial rebates have a positive impact on the uptake of dental services, particularly among irregular dental attendees and socioeconomically disadvantaged groups.