The effectiveness of systematic quality improvement initiatives in psychiatric care remains unclear.

To elucidate the adherence to recommended evidence-based guidelines in clinical practice.

To examine whether the quality of care among patients hospitalized with schizophrenia has changed following the implementation of a systematic monitoring and auditing program of hospital performance measures.

In a nationwide population-based cohort study, we identified 14,228 patients admitted to Danish psychiatric departments between 2004 and 2011 and registered in The Danish Schizophrenia Registry. The registry systematically monitors and audits the adherence to clinical guideline recommended processes of care at all Danish psychiatric hospital departments treating patients with schizophrenia.

The overall proportion of all relevant recommended processes of care delivered to the patients increased from 64 % to 76 % between 2004 and 2011. The adherence to a number of individual processes of care increased over time, including assessment of psychopathology using a diagnostic interview (Relative risk (RR) 2.01, 95 % CI: 1.50; 2.69), contact with relatives (RR 1.44, 95 % CI: 1.27; 1.62), psychoeducation (RR 1.33, 95 % CI: 1.18; 1.48), psychiatric aftercare (RR 1.06 95 % CI: 1.01; 1.11) and suicide risk assessment (RR 1.31, 95 % CI: 1.20; 1.43). However, improvements were not observed for all assessed processes of care and substantial variation remained between the hospitals.

Quality of care improved substantially from 2004 to 2011 among patients hospitalized with schizophrenia at Danish hospitals. However, continued efforts to reduce performance variation between hospitals are warranted.