Gender differences in use of prescription narcotic medications among living kidney donors.

Prescription narcotic use among living kidney donors is not well described. Using a unique database that integrates national registry identifiers for living kidney donors (1987-2007) in the United States with billing claims from a private health insurer (2000-2007), we identified pharmacy fills for prescription narcotic medications in periods 1-4 and >4 yr post-donation and estimated relative likelihoods of post-donation narcotic use by Cox regression. We also compared narcotic fill rates and medication possession ratios (MPRs, defined as (days of medication supplied)/(days observed)), between donors and age- and sex-matched non-donors. Overall, rates of narcotic medication fills were 32.3 and 32.4 per 100 person-years in periods 1-4 and >4 yr post-donation. After age and race adjustment, women were approximately twice as likely as men to fill a narcotic prescription in years 1-4 (adjusted hazard ratio, aHR, 2.28; 95% confidence interval, CI, 1.86-2.79) and >4 yr (aHR 1.70; 95% CI 1.50-1.93). MPRs in donors were low (<2.5% days exposed), and lower than among age- and sex-matched non-donors. Prescription narcotic medication use is more common among women than men in the intermediate term after live kidney donation. Overall, total narcotic exposure is low, and lower than among non-donors from the general population.