TY  - JOUR
T1  - SChool-based health center use and high school dropout rates
AU  - Sharkansky S
Y1  - 2012/07/01
N1  - 10.1001/archpediatrics.2012.550
JO  - Archives of Pediatrics & Adolescent Medicine
SP  - 675
EP  - 677
VL  - 166
IS  - 7
N2  - 
The apparent association between lower dropout rates and SBHC visits might have been exaggerated by their methods, which seem to have introduced time-dependent (or “immortal time”) bias. This bias, apparently common in clinical studies, arises from modeling a time-dependent treatment in a hazards regression as a fixed baseline covariate instead of as a time-varying covariate.2 In this case, Kerns et al ignored the timing of SBHC visits, modeling the treatment as a fixed covariate representing the frequency of the subject's SBHC visits, averaged over his or her entire high school career.

SN  - 1072-4710
M3  - doi: 10.1001/archpediatrics.2012.550
UR  - http://dx.doi.org/10.1001/archpediatrics.2012.550
ER  -