RT Journal
A1 Etminan M, Brophy JM, Maberley D
T1 REtinal detachment and fluoroquinolones—reply
JF JAMA
JO JAMA
YR 2012
FD July 18
VO 308
IS 3
SP 233
OP 233
DO 10.1001/jama.2012.6634
UL http://dx.doi.org/10.1001/jama.2012.6634
AB 
In Reply: Dr Nowroozzadeh requests information on the study power. For past use, the relatively narrow confidence interval (RR, 1.03; 95% CI, 0.89-1.19) indicates sufficient power; however, the wider confidence interval with recent use (RR, 0.92; 95% CI, 0.45-1.87) reveals less power to reliably estimate an association with retinal detachment. This is not surprising given the short exposure window for recent use (7 days) compared with that for past use (8 to 365 days prior to index date). Nowroozzadeh also suggests examining the effect of cumulative dose. The small number of exposed cases did not allow us to adequately examine the effect of dose. We agree that future studies should examine this question.