Validate BRFSS Weighted Percents


Introduction - By comparing with existing analyses from other sources, we verified Vitalnet (VB-QMS) produces correct BRFSS weighted percents.

Methods - There are many sources that publish weighted BRFSS percents. VB-QMS has been extensively validated and verified against published data. For the purposes of this report, we chose a few 2005 results to show. Each result was produced for the entire US by the CDC WEAT software, and compared with the VB-QMS result. We used the following BRFSS questions:

_BMICAT______25_30_ - Is overweight (BMI 25 to 30)?
DIABETES_ANY__EVER_ - Ever had diabetes (including pregnancy)?
GENHLTH_________FP_ - Has fair or poor general health?
HLTHPLAN_______NOW_ - Has health care coverage or insurance?
LASTDEN________1YR_ - Visited a dentist within past year?
LSTBLDST_______1YR_ - Had a home blood stool test in past year?
PNEUMVAC______EVER_ - Ever had pneumococcal vaccine?
VETERAN_______EVER_ - Was ever active duty in US military?

Results - Each of 8 comparisons exactly matched:

Question Code VB-QMS CDC WEAT
_BMICAT______25_30_36.836.8
DIABETES_ANY__EVER_08.708.7
GENHLTH_________FP_16.716.7
HLTHPLAN_______NOW_84.084.0
LASTDEN________1YR_68.468.4
LSTBLDST_______1YR_44.044.0
PNEUMVAC______EVER_22.922.9
VETERAN_______EVER_10.810.8

Discussion - We validated that VB-QMS BRFSS weighted percents work correctly. We have done hundreds of other comparisons (not shown), and VB-QMS always produces correct weighted percents.

Different methods, such as VB-QMS, SAS, and SUDAAN, can produce correct BRFSS results. You can compare for yourself, in terms of ease-of-use, speed, reliability, output quality, and other criteria, which method is better.

You can easily generate your own VB-QMS results to do additional comparisons with results from other sources. If you have suggestions / comments, or to discuss licensing Vitalnet BRFSS Query & Mapping Software to make much better use of your data, please contact us.