Validation of a shortened version of the Patient Measure of Patient Safety (PMOS-10)

The Patient Measure of Safety (PMOS) questionnaire is a 44 item questionnaire which asks patients about factors that can contribute to patient safety incidents in hospital inpatient wards. It was developed by researchers at the Bradford Institute for Health Research as a data collection tool within the Patient Reporting and Action for a Safe Environment (PRASE) intervention.

PRASE is an intervention in which data is systematically collected from hospital patients and fed back to ward staff in a structured feedback report. This provides information for ward staff to use to create action plans, implement and monitor changes in line with the issues raised by patients.

To reduce the burden on patients, the PMOS questionnaire has been reduced in length from a 44 to a 30 item measure. The 30 item measure has been used within another project and worked well. However, hospital teams and managers requested a shorter version of the PMOS to be used for routine monitoring.

Prior to this study, the 10 items from the 30 item questionnaire which seemed to measure patient safety most accurately were identified using statistical modelling. The aim of this study was to test the PMOS-10 questionnaire with a sample of 200 patients to understand:

1. How willing patients were to complete it.

2. Whether the items within the questionnaire were highly correlated, indicating that they are measuring the same thing (patient safety), referred to as reliability.

3. Whether the measure was correlated with other measures of safety, such as the Friends & Family Test (FFT), referred to as validity.

Answering these questions would tell us whether the PMOS-10 is a useful measure.

There were difficulties in recruiting patients on certain wards due to the patients’ medical conditions and the throughput of patients on those wards. After discussion within the research team it was decided to not continue to recruit on those wards. 165 patients were recruited and the team determined that there was sufficient data for the study. Patients were very willing to complete the questionnaire, with 92% of patient approached agreeing to take part.

It was demonstrated that the PMOS-10 is a reliable and valid brief standalone measure for on-going monitoring of ward safety performance from the patient perspective.