Abstract
The sensitivity analyses suggested in the Letter to the Editor by de Vries et al. was performed, but no material change in relative risk for bladder cancer was found. This is not surprising given the limited contribution of the studies excluded in the sensitivity analyses.
Regarding thiazolodinediones and cancer, we ran the sensitivity analyses suggested by Dr. de Vries et al. despite that data from the three studies [1–3] were not totally overlapping.
The pooled relative risk (RR) for bladder cancer for any thiazolidinedione (TZD) use changed from 1.13 (95% confidence interval [CI]: 1.05–1.23) to 1.12 (95% CI: 1.03–1.22) after the study by Azoulay et al. [1] was excluded and to 1.13 (95% CI: 1.04–1.23) after excluding the study by Wei et al. [2]. With reference to pioglitazone, the pooled RR changed from 1.20 (95% CI: 1.07–1.34) to 1.18 (95% CI: 1.05–1.32) after excluding the study by Azoulay et al. [1] and to 1.20 (95% CI: 1.04–1.39) after excluding the study by Wei et al. [2]. With reference to all cancers, the RR remained 0.96 (95% CI: 0.91–1.01) after of any of the three studies was excluded [1–3].
The limited change in the RR for bladder cancer is not surprising, because the two studies together [1, 2] accounted for about 10% of the weight of the studies of bladder cancer included in the meta-analysis [4], and the three studies [1–3] accounted for about 3.5% of all cancer sites.
Disclosures
The authors indicated no financial relationships.
References
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