State-based estimates of mammography screening rates based on information from two health surveys.
OBJECTIVE
We compared national and state-based estimates for the prevalence of mammography screening from the National Health Interview Survey (NHIS), the Behavioral Risk Factor Surveillance System (BRFSS), and a model-based approach that combines information from the two surveys.


METHODS
At the state and national levels, we compared the three estimates of prevalence for two time periods (1997-1999 and 2000-2003) and the estimated difference between the periods. We included state-level covariates in the model-based approach through principal components.


RESULTS
The national mammography screening prevalence estimate based on the BRFSS was substantially larger than the NHIS estimate for both time periods. This difference may have been due to nonresponse and noncoverage biases, response mode (telephone vs. in-person) differences, or other factors. However, the estimated change between the two periods was similar for the two surveys. Consistent with the model assumptions, the model-based estimates were more similar to the NHIS estimates than to the BRFSS prevalence estimates. The state-level covariates (through the principal components) were shown to be related to the mammography prevalence with the expected positive relationship for socioeconomic status and urbanicity. In addition, several principal components were significantly related to the difference between NHIS and BRFSS telephone prevalence estimates.


CONCLUSIONS
Model-based estimates, based on information from the two surveys, are useful tools in representing combined information about mammography prevalence estimates from the two surveys. The model-based approach adjusts for the possible nonresponse and noncoverage biases of the telephone survey while using the large BRFSS state sample size to increase precision.
Davis
William W
WW
Statistical Research & Applications Branch, National Cancer Institute, Bethesda, MD, USA. bill.davis@ssa.gov
Parsons
Van L
VL
Xie
Dawei
D
Schenker
Nathaniel
N
Town
Machell
M
Raghunathan
Trivellore E
TE
Feuer
Eric J
EJ
D000328:Adult; D001499:Bayes Theorem; D040343:Behavioral Risk Factor Surveillance System; D005260:Female; D006306:Health Surveys; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D015233:Models, Statistical; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D014481:United States