Behavioral Risk Factor Surveillance System and American Community Survey Estimates of Vision Difficulty Prevalence

Inconsistent estimates of self-reported vision impairment across survey sources may cause confusion about the true size of the population with vision problems.

To explain why the American Community Survey (ACS) and Behavioral Risk Factor Surveillance System (BRFSS) produce different prevalence estimates for self-reported vision problems in the US, despite using the same question wording.

This was a cross-sectional analysis of the 2021 ACS and BRFSS using subgroup analysis and decomposition. Respondents were from 49 states and the District of Columbia. Included in the analysis were a civilian noninstitutionalized population 18 years and older. Data were analyzed from August 2022 to October 2023.

Aspects of sample design and composition.

Self-reported vision problems.

This study included a weighted sample of 2.8 million individuals (median [IQR] age, 47.7 [32.8-63.1] years; 51% male). The estimate of self-reported vision problems prevalence from the BRFSS (4.89%; 95% CI, 4.73%-5.04%) was 1.7 times as high as the estimate from the ACS (2.95%; 95% CI, 2.92%-2.97%) for similarly defined populations. If the BRFSS sample were weighted to align with the composition of other disability types in the ACS, the prevalence of vision problems would be 3.67% (95% CI, 3.53%-3.80%), closing about 63% of the gap between survey estimates.

Results of this survey study suggest that the focus on health may be associated with the higher prevalence in the BRFSS through differential nonresponse or question priming. Differences in other survey operations including frame construction, proxy reporting, and imputation had little impact.