Conclusions
There was no statistically significant increased risk of blad- der cancer associated with pioglitazone use. However, a small increased risk, as previously observed, could not be ex- cluded. The increased prostate and pancreatic cancer risks as- sociated with ever use of pioglitazone merit further investi- gation to assess whether the observed associations are causal or due to chance, residual confounding, or reverse causality.