Bias in product availability estimates from contraceptive outlet surveys: Evidence from the Consumer's Market for Family Planning (CM4FP) study.

Area-based sampling approaches designed to capture pharmacies, drug shops, and other non-facility service delivery outlets are critical for accurately measuring the contraceptive service environment in contexts of increasing de-medicalization of contraceptive commodities and services. Evidence from other disciplines has demonstrated area-based estimates may be biased if there is spatial heterogeneity in product distribution, but this bias has not yet been assessed in the context of contraceptive supply estimates. The Consumer's Marker for Family Planning (CM4FP) study conducted censuses and product audits of contraceptive outlets across 12 study sites and 2-3 rounds of quarterly data collection in Kenya, Nigeria, and Uganda. We assessed bias in estimates of contraceptive product availability by comparing estimates from simulations of area-based sampling approaches with census counts among all audited facilities for each study site and round of data collection. We found evidence of bias in estimates of contraceptive availability generated from simulated area-based sampling. Within specific study sites and rounds, we observed biased sampling estimates for several but not all contraceptive method types, with bias more likely to occur in sites with heterogeneity in both spatial distribution of outlets and product availability within outlets. In simulations varying size of enumeration areas (EA) and number of outlets sampled per EA, we demonstrated that the likelihood of substantial bias decreases as EA size decreases and as the number of outlets sampled per EA increases. Straightforward approaches such as increasing sample size per EA or applying statistical weights may be used to reduce area-based sampling bias, indicating a pragmatic way forward to improve estimates where design-based sampling is infeasible. Such approaches should be considered in development of improved methods for area-based estimates of contraceptive supply-side environments.

Linking family planning market census data with consumer experiences in three countries: the Consumer's Market for Family Planning study protocol and data.

Background: The Consumer's Market for Family Planning (CM4FP) project was designed to address limitations of existing family planning (FP) data sources that prevent a full understanding of the total FP market. CM4FP data provide a picture of the complete supply environment and how consumers experience it. Study objectives were to 1) test a ring-fenced census approach consisting of an outlet census in a defined geographical area and a household survey in a smaller inner ring, to comprehensively map the total FP market in a local geography; 2) explore FP supply market dynamism through longitudinal data collection from contraceptive outlets; and 3) test a methodology for directly linking household and outlet data to measure the relationship between contraceptive demand and supply. Methods: Data were collected from study sites in Nigeria, Kenya, and Uganda from 2019 to 2020. Longitudinal outlet census data and repeated cross-sectional household survey data from women ages 18-49 were collected at three quarterly time points. Outlets were located in an outer ring geography to encompass locations likely visited by women sampled from a smaller inner ring. Data from women who received a contraceptive method in the past 12 months were linked to data for the outlet from which they received the method. Results: Datasets include product audits for 22,380 individual FP products, collected from a total of 1,836 outlets across 12 study sites. The datasets also contain data from 11,536 female respondents, of whom 1,975 were successfully matched to the outlet where they most recently obtained their method. Conclusions: CM4FP data are available at www.cm4fp.org. This unique dataset enables in-depth exploration of the family planning supply market in addition to interactions between the market and consumer perspectives and behaviors within each study site. The data can also be used to explore novel methodologies to inform future study designs.