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:
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_ | 36.8 | 36.8 |
| DIABETES_ANY__EVER_ | 08.7 | 08.7 |
| GENHLTH_________FP_ | 16.7 | 16.7 |
| HLTHPLAN_______NOW_ | 84.0 | 84.0 |
| LASTDEN________1YR_ | 68.4 | 68.4 |
| LSTBLDST_______1YR_ | 44.0 | 44.0 |
| PNEUMVAC______EVER_ | 22.9 | 22.9 |
| VETERAN_______EVER_ | 10.8 | 10.8 |
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.