Segmentation and fragmentation of health systems and the quest for universal health coverage: conceptual clarifications from the Mexican case.

Health systems are complex entities. The Mexican health system includes the private and public sectors, and subsystems that target different populations based on corporatist criteria. Lack of unity and its consequences can be better understood using two concepts, segmentation and fragmentation. These reveal mechanisms and strategies that impede progress toward universality and equity in Mexico and other low- and middle-income countries. Segmentation refers to separation of the population by position in the labour market. Fragmentation refers to institutions, and to financial aspects, health care levels, states' systems of care, and organizational models. These elements explain inequitable allocation of resources and packages of health services offered by each institution to its population. Overcoming segmentation will require a shift from employment to citizenship as the basis for eligibility for public health care. Shortcomings of fragmentation can be avoided by establishing a common package of guaranteed benefits. Mexico illustrates how these two concepts characterize a common reality in low- and middle-income countries.