In recent decades, global attention to the harrowing state of health in sub-Saharan Africa has increased dramatically. Funding to combat the major health problems there has reached unprecedented levels, and marked improvements have been made. In Zanzibar (Tanzania), for example, malaria deaths have been cut substantially. And in Uganda, maternal mortality has dropped by more than half.

Despite these improvements, the health of the vast majority of people in sub-Saharan Africa remains in jeopardy. From 1990 to 2005, life expectancy slid by more than 2 years, to 47.1 years. What’s more, millions of Africans still suffer from diseases that are relatively simple to prevent or treat.

As the region’s health systems struggle to meet basic standards of care, many experts have come to believe that systemwide barriers to its delivery are preventing greater progress. A comprehensive approach is required to overcome these barriers. But how can systemwide changes occur in countries that struggle to provide even basic care? To address this issue, the Touch Foundation, a nonprofit organization active in Tanzania, and McKinsey recently conducted an intensive investigation of the health system in the Lake Zone, in the northwest part of the country. This area was chosen because it is small enough to be studied in detail but large enough to serve as a suitable geographic proxy for Tanzania as a whole and, potentially, for the entire sub-Saharan region.

These initiatives will require new investments, and we do not underestimate the difficulty in finding the necessary funds. But because the initiatives are targeted, their impact would be disproportionate to their cost. The diagnostic approach we used in the Lake Zone provides a way to move past the debate about whether countries in sub-Saharan Africa should pursue “vertical” programs targeted to specific disease outcomes or “horizontal” efforts to strengthen health systems. Any health system, in sub-Saharan Africa or elsewhere, could adapt this approach.