Effect of age-related premium readjustment on health insurance cancellation in Brazil: Regression discontinuity approach.

Age is one of the most relevant observable risk attributes in determining the value of health insurance premiums. Empirical evidence indicates that the cost of health insurance is the leading cause of contract switching, which can compromise access to healthcare services and potentially result in treatment discontinuities. Using data from a Health Maintenance Organization in the Southern region of Brazil, we examined the effect of health plan price readjustment resulting from changes in the beneficiary's age group on disenrollment or switches to a more limited coverage plan. The estimates were obtained using the method of regression discontinuity. The main findings indicate that for age group transitions at 59 years old, the price readjustment effect led to an increase in contract cancellations and switching to cheaper plans. These findings highlight that an important consequence of the difference in premium sensitivity among age groups is that the exit of individuals from the health insurance sector is selective in age. The results of this paper can support policymaking to improve access to health insurance.