The Nurse Perceived Adequacy of Staffing Scale for general hospital wards: A development and psychometric validation study

Carmen van der Mark; Justin Bitter; Paul H J Hendriks; Hester Vermeulen; Catharina J van Oostveen

doi:10.1016/j.ijnsa.2023.100138

The Nurse Perceived Adequacy of Staffing Scale for general hospital wards: A development and psychometric validation study

Int J Nurs Stud Adv. 2023 Jun 16:5:100138. doi: 10.1016/j.ijnsa.2023.100138. eCollection 2023 Dec.

Authors

Carmen van der Mark^{1

2}, Justin Bitter³, Paul H J Hendriks⁴, Hester Vermeulen^{2

5}, Catharina J van Oostveen^{6

7}

Affiliations

¹ Rijnstate Hospital, Department of Capacity Management, P.O. Box 9555, 6815 AD, Arnhem, the Netherlands.
² Radboud Institute for Health Sciences, Scientific Center for Quality of Healthcare (IQ healthcare), Radboudumc, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands.
³ Department of Medical Support, VieCuri Medical Center, P.O. Box 1926, 5912 BL, Venlo, the Netherlands.
⁴ Institute for Management Research, Radboud University, P.O. Box 9102, 6500 HC, Nijmegen, the Netherlands.
⁵ Faculty of Health and Social Studies, HAN University of Applied Sciences, P.O. Box 6960, 6503 GL, Nijmegen, the Netherlands.
⁶ Erasmus School of Health Policy & Management, Erasmus University Rotterdam, P.O. Box 1738, Campus Woudestein, 3000 DR, Rotterdam, the Netherlands.
⁷ Spaarne Gasthuis Academy, Spaarne Gasthuis Hospital, P.O. Box 417, 2000 AK, Haarlem, Hoofddorp and Haarlem, the Netherlands.

Abstract

Background: Adequate staffing is crucial for high quality patient care and nurses' wellbeing. Nurses' professional assessment on adequacy of staffing is the gold standard in measuring staffing adequacy. However, available measurement instruments lack reliability and validity.

Objectives: To develop and psychometrically test an instrument to measure nurses' perceived adequacy of staffing (PAS) of general hospital wards.

Design: A multicenter cross-sectional psychometric instrument development and validation study using item response theory.

Settings: Ten general nursing wards in three teaching hospitals in the Netherlands.

Participants: A sample of 881 participants, including third and fourth year nursing students and nurse/care assistants.

Methods: The 13-item self-reported questionnaire was developed based on a previous Delphi study and two focus groups. We interviewed five nurses to evaluate the content validity of the instrument. The field test for psychometric evaluation was conducted on ten general wards of three teaching hospitals in the Netherlands. Structural validity of the item bank was examined by fitting a graded response model (GRM) and inspecting GRM fit. Measurement invariance was assessed by evaluating differential item functioning (DIF) of education level and work experience. We examined convergent validity by testing the hypothesis that there was at least a moderate correlation between the PAS instrument and a single item measuring adequacy of staffing. Internal consistency and reliability across the scale were also examined.

Results: A total of 881 measurements were included in the analysis. The data fitted the GRM adequately and item fit statistics were good. DIF was detected for work experience for the protocols item, but the impact on total scores was negligible. The hypothesis was confirmed and the item bank reliably measured two standard deviations around the mean.

Conclusions: The Nurse Perceived Adequacy of Staffing Scale (NPASS) for nurses of general hospital wards in the Netherlands has sufficient reliability and validity and is ready for use in nurse staffing research and practice.

Keywords: Instruments; Nurse staffing; Perceptions; Personnel staffing and scheduling; Psychometric properties; Staffing adequacy; Workforce planning.