Impact of Imprecise Household Location on Effective Coverage Estimates Generated through Linking Household and Health Provider Data by Geographic Proximity

Background: Combining household and health provider data can be used to estimate coverage of interventions and identify barriers to use. Without data on specific sources of care utilized by individuals, researchers often assign individuals to healthcare providers based on geographic proximity. The Demographic and Health Survey (DHS), a common source of population health data, does not collect data on the location of participant households. They present displaced data on the central point within household clusters. This may introduce error into analyses based on the distance between households and providers. Methods: We assessed the effect of imprecise household location on quality-adjusted effective coverage of child curative services estimated by linking sick children to providers based on geographic proximity. We used data on care-seeking for child illness and health provider quality in Southern Province, Zambia. The dataset included the location of respondent households, a census of providers, and data on the exact outlets utilized by sick children included in the study. We displaced the central point of each household cluster point five times. We calculated quality-adjusted coverage by assigning each sick child to a provider’s care based on three measures of geographic proximity (absolute distance, travel time, and geographic radius) from the household location, cluster point, and displaced cluster locations. We compared the estimates of quality-adjusted coverage to each other and estimates calculated using each sick child’s true source of care. Results: Fewer children were linked to their true source of care using cluster locations than household locations. Estimates of coverage were not statistically different using different measures of geographic proximity or household location. Estimates did not vary significantly from estimates produced using each sick child’s true source of care. Conclusions: Use of original or displaced cluster location did not produce statistically different coverage estimates than using household location. However, it did reduce the proportion of children that linked to their true source of care. The limited effect of household location imprecision on quality-adjusted coverage estimates could be due to a lack of variability in provider quality. These findings may not hold in a setting with more considerable variation in provider quality. This work was supported by the Bill & Melinda Gates Foundation, Grant Number INV-006966