Nurse Staffing in Psychiatric Inpatient Care: A Multicentre Study Using Routine Patient and Structural Data

Area of Science:

• Psychiatric Nursing
• Healthcare Management
• Clinical Informatics

Background:

• Nurse staffing in psychiatric inpatient care is challenging due to a lack of reliable patient demand measures.
• Existing indicators are not universally applicable across diverse patient groups.
• The Health of the Nation Outcome Scales (HoNOS) is routinely collected in Switzerland and may serve as a patient acuity proxy.

Purpose of the Study:

• To investigate the association between patient acuity, measured by HoNOS scores, and registered nurse (RN) staffing levels in Swiss psychiatric inpatient units.
• To assess the utility of routine clinical data for informing psychiatric nurse workforce planning.

Main Methods:

• A multicentre cross-sectional study (MatchRN Psychiatry) analyzed routine patient data and unit-manager reports from adult, non-forensic psychiatric units in Switzerland.
• Patient mental health status and symptom severity were assessed using HoNOS scores.
• Lasso-selected linear mixed-effects models were used to analyze associations between RN staffing hours, HoNOS scores, and unit characteristics.

Main Results:

• Data from 107 units (25,294 patients) revealed significant associations between higher HoNOS scores and increased RN staffing.
• A 20% increase in HoNOS total score corresponded to an additional 48.5 RN hours per week.
• Unit size also influenced staffing, with smaller units tending to have less and larger units more staffing than predicted.

Conclusions:

• Routinely collected clinical data, specifically HoNOS scores, can be effectively linked to nurse staffing in psychiatric inpatient settings.
• Both patient acuity and unit size are significant factors associated with staffing levels.
• Routine data offers a pragmatic foundation for more transparent and sustainable psychiatric workforce planning.