Benzodiazepine use and risk of mortality among patients with schizophrenia: a retrospective longitudinal study.

OBJECTIVE

This study examined the association between benzodiazepine use alone or in combination with antipsychotics and risk of mortality in patients with schizophrenia.

METHODS

A retrospective longitudinal analysis was performed using Medicaid claims data merged with death certificate data for 18,953 patients (aged 18-58 years) with ICD-9-diagnosed schizophrenia followed from July 1, 2006, to December 31, 2013. Cox proportional hazard analyses were used to estimate the risk of all-cause mortality associated with benzodiazepine use; adjustment was made for a wide array of fixed and time-varying confounders, including demographics, psychiatric and medical comorbidities, and other psychotropic medications.

RESULTS

Of the 18,953 patients diagnosed with schizophrenia, 13,741 (72.5%) were not prescribed a benzodiazepine, 3,476 (18.3%) were prescribed benzodiazepines in the absence of antipsychotic medication, and 1,736 (9.2%) were prescribed benzodiazepines in combination with antipsychotics. Controlling for a wide array of demographic and clinical variables, the hazard of mortality was 208% higher for patients prescribed benzodiazepines without an antipsychotic (HR = 3.08; 95% CI, 2.63-3.61; P < .001) and 48% higher for patients prescribed benzodiazepines in combination with antipsychotics (HR = 1.48; 95% CI, 1.15-1.91; P = .002). Benzodiazepine-prescribed patients were at greater risk of death by suicide and accidental poisoning as well as from natural causes.

CONCLUSIONS

Benzodiazepine use is associated with increased mortality risk in patients with schizophrenia after adjusting for a wide range of potential confounders. Given unproven efficacy, physicians should exercise caution in prescribing benzodiazepines to schizophrenic patients.