A functional model for monitoring equity and effectiveness in purchasing health insurance premiums for the poor: evidence from Cambodia and the Lao PDR.

Objectives: To assess the impact on equity and effectiveness of introducing targeted subsidies for the poor into existing voluntary health insurance schemes in Low Income Countries with special reference to cross-subsidisation.

Methods: A functional model was constructed using routine collected financial data to analyse changes in financial flows and resulting shifts in cross-subsidization between poor and non-poor. Data were collected from two sites, in Cambodia at Kampot operational health district and in the Lao People's Democratic Republic at Nambak district.

Results: Six key variables were identified as determining the financial flows between the subsidy and the insurance schemes and with health providers: population coverage, premium rate, facility contact rate, capitation rate, cost of treatment and changes in administration costs. Negative cross-subsidization was revealed where capitation was used as the payment mechanism and where utilisation rates of the poor were significantly below the non-poor. The same level of access for the poor could have been achieved with a lower Health Equity Fund subsidy if used as a direct reimbursement of user charges by the Health Equity Fund to the provider rather than through the Community Based Health Insurance scheme.

Conclusions: Purchasing premiums for the poor under these conditions is more costly than direct reimbursement to the provider for the same level of service delivery. Negative cross-subsidization is a serious risk that must be managed appropriately and the benefits of a larger risk pool (cross-subsidization of the poor) are not evident. Benefits from combined coverage may accrue in the longer term with an expanded base of voluntary payers or when those with subsidized premiums are lifted out of poverty.