RT Journal
A1 van Troostenburg de Bruyn A, Dormandy J
T1 RIsk of thiazolidinedione-associated fracture should be appropriately assessed
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 2010
FD January 25
VO 170
IS 2
SP 209
OP 210
DO 10.1001/archinternmed.2009.487
UL http://dx.doi.org/10.1001/archinternmed.2009.487
AB 
Dormuth et al1 described their study as a prospective cohort study, when in fact it was a retrospective database analysis. It is well recognized that prospective studies offer a higher probability of detecting true associations than retrospective studies because they allow greater control to be exercised over confounding factors and data collection. We do not mean to question the validity of the results of their analysis but to suggest that the data should be interpreted in the context of the retrospective study design used.