Second-generation antipsychotic medications and risk of chronic kidney disease in schizophrenia: population-based nested case–control study

ObjectivesThe study aims to compare the risk of chronic kidney diseases (CKDs) between patients with schizophrenia using first and second-generation antipsychotics.SettingDatasets of 2000–2013 National Health Insurance in Taiwan were used.ParticipantsThe National Health Insurance reimbursement claims data have been transferred to and managed by the National Health Research Institute in Taiwan since 1996. We used the Psychiatric Inpatient Medical Claims database, a subset of the National Health Insurance Research Database, comprising a cohort of patients hospitalised for psychiatric disorders between 2000 and 2013 (n=2 67 807). The database included patients with at least one psychiatric inpatient record and one discharge diagnosis of mental disorders coded by the International Classification of Diseases, Ninth Revision (ICD-9) codes 290–319. The age of patients at first admission was restricted to 18–65 years.Primary outcomeCKD (ICD-9 code 582, 583, 585, 586, 588) requiring hospitalisation or three outpatient visits. The diagnosis of CKD follows the criteria of ‘Kidney Disease: Improving Global Outcomes’ in Taiwan. CKD is defined as a kidney damage as albumin-to-creatinine ratio >30 mg/g in two of three spot urine specimens or glomerular filtration rate