Frequency and correlates of antipsychotic polypharmacy among patients with schizophrenia in Denmark: A nation-wide pharmacoepidemiological study.

Abstract Although evidence for efficacy of antipsychotic polypharmacy (APP) is sparse, APP is common in schizophrenia. The national Danish health registers were accessed to examine in schizophrenia patients: (1) cross-sectional prevalences of APP (1996–2012); (2) geographic variations in APP (2012); and (3) correlates of APP (2012). APP increased from 17.2% in 1996 to 30.8% in 2006 ( p p α =0.653, 95% confidence interval (CI):0.327–0.979, p p p