Problems with study on secondhand smoke and children’s tooth enamelBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h6759 (Published 14 December 2015) Cite this as: BMJ 2015;351:h6759
- Hayato Yamana, research fellow1,
- Sachiko Ono, research student1,
- Hideo Yasunaga, professor1
- 1Department of Clinical Epidemiology and Health Economics, School of Public Health, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
Using data from municipal health check-ups in Japan, Tanaka and colleagues found an association between secondhand smoke and dental caries in children.1 However, several factors should be considered.
The authors used numerous variables to calculate the propensity score—the probability of an infant being exposed to secondhand smoke at 4 months. However, this model was inadequate for distinguishing the exposed from the unexposed. The discriminatory ability of the logistic regression model …