The 2019 Family Planning Data Sheet presents survey estimates of contraceptive prevalence, one of two methods of estimating national contraceptive prevalence widely used today. To calculate these estimates, surveys are conducted that ask a nationally representative sample of women of reproductive age about their use of contraceptive methods. Such surveys include the Demographic and Health Surveys (DHS), Multiple Indicator Cluster Surveys (MICS), Performance Monitoring and Accountability 2020 (PMA2020) surveys, and others national surveys.
A second method of estimating contraceptive use, modeled estimates, come from statistical models developed using a set of available data points and assumptions relevant to contraceptive use. Modeled estimates of contraceptive use for countries around the world are produced using a modeling program called the Family Planning Estimation Tool (FPET) developed as part of a collaboration between the United Nations Population Division, the University of Massachusetts at Amherst, and Track20. FPET determines long-term trends in contraceptive use for countries based on all available survey estimates of contraceptive use and then produces current estimates and future projections. It can assign different weights to different sources of survey estimates, so the estimates from more reliable sources have a greater impact in the model. For some countries, FPET also incorporates service statistics to inform trends in contraceptive use. The model can also indicate the levels of uncertainty around their estimates. The accuracy of the FPET estimates therefore improves with the number of survey estimates available, the reliability of those estimates, the length of the period they cover, and the timeliness of the latest available estimates.
When a country has had a survey in a recent year, the modeled estimate for the current year should be similar to the latest survey estimate available. Modeled estimates are particularly valuable when no recent survey estimates are available. They may also provide insight when there are multiple estimates from different surveys that cover a similar period. However, it is important to understand the assumptions and strength of underlying data used to generate them.