Many health care systems in low income settings define essential health packages (EHP) to concentrate scarce resources on key health interventions to which their populations can have free access at the point of delivery. Malawi has used EHPs since 2004 but they have generally included unaffordable interventions that have not been fully delivered. To guide decisions about the 2016 EHP in Malawi, an analytical framework is proposed that identifies interventions which, based on currently available evidence, offer the most gains in population health. The framework uses existing estimates of what the Malawian health care system is currently able to afford to generate gains in health – a measure of health opportunity costs. This facilitates an initial quantification of an appropriate budget for the EHP, and of the interventions that might be included which can then be prioritised on the basis of their expected impact on population health assuming 100% implementation. In practice, lower levels of implementation will be achieved by interventions due to various constraints operating on the demand or supply side, and which apply to specific interventions or the system more generally. The framework provides an analytical basis to consider the implications for population health of these different types of constraints. It uses this as a basis of assessing how the underspend on the EHP due to the ‘implementation gap’ can be used. The framework estimates the potential impacts on health outcomes of intervention-specific implementation activities and system strengthening. These potential impacts are compared with the health outcomes offered by extending the package to include additional interventions. The analytical framework can also assess the implications for population health of the types of constraints that donors may impose on their funding schemes in health care. These constraints can include requiring that particular interventions are included in the EHP when the funding could have a bigger impact on health if spent elsewhere; offers to expand the package but restricted to particular interventions and forgoing greater health outcomes elsewhere; and offers to provide additional funding as long as these are matched by government. In negotiating with donors and communicating with relevant stakeholders, policy makers will benefit from understanding the implications for population health of such constraints
