4. Assessment of risk of bias: cohort study.

Franzman 2006
Adequate sampling procedure?	Unclear	Unclear how representative the 8 hospitals were. Unclear if there is bias in who returned questionnaires at 16, 24 and 36 months n = 343.
Ascertainment of exposure?	Yes	Comment: Current parental questionnaires at regular intervals.
Adequate diagnosis of fluorosis?	Yes	Fluorosis Risk Index criteria.
Incomplete outcome data addressed?	Unclear	Insufficient information.
Free of selective reporting?	Yes	Probably.
Blinding of outcome assessors?	Yes