100,000 [bed] nets distributed will lead to a reduction of about 900 under-age-five malaria inpatients, and to a reduction of approximately 100 child deaths.
Since 2003, Zambia has been engaged in a large-scale, centrally coordinated national anti-malaria campaign which has become a model in sub-Saharan Africa. This program -- which involved mass distribution of insecticide-treated mosquito nets, intermittent preventive treatment for pregnant women, indoor residual spraying, rapid diagnostic tests, and artemisinin-based combination therapy -- contributed to decreasing the death rate from malaria in Zambia by 60 percent.
In Evaluating the Effect of Large Scale Health Interventions in Developing Countries: The Zambian Malaria Initiative (NBER Working Paper No. 16069), co-authors Nava Ashraf, Günther Fink, and David Weil jointly analyze data on inputs and health outcomes to measure the program's impact on overall population health. To estimate the health benefits associated with the program, they use both population-based morbidity measures and health-facility based mortality data. Specifically, they study data for children under the age of 5 and concentrate on two fundamental strategies of the anti-malaria initiative: spraying houses, and encouraging the distribution and use of bed nets in high-malaria, rural areas. They find that the rollout of bed nets varied significantly year by year, and that utilization rates of nets were well below the 85 percent program goal. Overall bed net use did, however, more than double over the period studied, reaching 43 percent. The researchers find that a distribution of one net per person in a district lowers fever prevalence by between 10 and 20 percentage points.
The authors conclude that full coverage with bed nets (one net per capita) in the years prior to the surveys lowers child mortality by 4.4 percentage points. Using their health facility data, they conclude that 100,000 nets distributed will lead to a reduction of about 900 under-age-five malaria inpatients, and to a reduction of approximately 100 child deaths.
The results on spraying suggest smaller health effects. Providing full spraying coverage has about half the effect of providing full net coverage.
-- Claire Brunel