Inpatient Volume and Quality of Mental Health Care Among Patients With Unipolar Depression

OBJECTIVE: The relationship between inpatient volume and the quality of mental health care remains unclear. This study examined the association between inpatient volume in psychiatric hospital wards and quality of mental health care among patients with depression admitted to wards in Denmark.

METHODS: In a nationwide, population-based cohort study, 17,971 patients (N=21,120 admissions) admitted to psychiatric hospital wards between 2011 and 2016 were identified from the Danish Depression Database. Inpatient volume was categorized into quartiles according to the individual ward's average caseload volume per year during the study period: low volume (quartile 1, <102 inpatients per year), medium volume (quartile 2, 102-172 inpatients per year), high volume (quartile 3, 173-227 inpatients per year) and very high volume (quartile 4, >227 inpatients per year). Quality of mental health care was assessed by receipt of process performance measures reflecting national clinical guidelines for care of depression.

RESULTS: Compared with patients admitted to low-volume psychiatric hospital wards, patients admitted to very-high-volume wards were more likely to receive a high overall quality of mental health care (≥80% of the recommended process performance measures) (adjusted relative risk [ARR]=1.78, 95% confidence interval [CI]=1.02-3.09) as well as individual processes of care, including a somatic examination (ARR=1.35, CI=1.03-1.78).

CONCLUSIONS: Admission to very-high-volume psychiatric hospital wards was associated with a greater chance of receiving guideline-recommended process performance measures for care of depression.