Long-term use of valproic acid reduced mortality in bipolar disorder patients in a Taiwanese population: An association analysis using the national health insurance research database (NHIRD)

OBJECTIVE Valproic acid (VPA) is used for the treatment of epilepsy and bipolar disorder (BD). The aims of this study was to examine that long-term VPA use affects mortality in BD patients. METHODS Association analysis was conducted using the National Health Insurance Research Database (NHIRD) of Taiwan. The long-term VPA use group was selected as patients treated with VPA for BD who used VPA only. The control group consisted of BD patients who were not treated with VPA or lithium. The lithium use group consisted by BD patients used lithium only was also joined the analysis. The cofactors included age (>65 years), sex and the Charlson Comorbidity Index. RESULTS The hazard ratio (HR) of mortality for the VPA group was 0.83 (95% confidence interval (CI), (0.70-0.99); P = 0.04) and the result of lithium group did not reach statistical significance. Furthermore only the duration> 3 years subgroup had a significantly lower incidence of mortality than the control group, with an HR of 0.54 (95% CI, (0.42-0.70); P