Item reduction, reliability, and validation of the Patient Engagement In Research Scale (PEIRS)

Authors: Hamilton C, Hoens A, McKinnon A, McQuitty S, English K, and Li L

Presenter: Dr. Clayon Hamilton

Institution: Department of Physical Therapy, University of British Columbia


The PEIRS was developed as a 37-item self-reported experience questionnaire to assess the degree of meaningful engagement in health research project from a patient partner perspective. PEIRS is based on a conceptual framework for meaningful patient engagement in research and empirical research. The items use 5-point Likert response scales and are arranged into seven domains corresponding to themes of the conceptual framework. Refining the PEIRS to include only items statistically necessary for measurement could reduce its administrative burden. Furthermore, confirming the PEIRS internal consistency and construct validity would endorse its total score. We sought to shorten the Patient Engagement In Research Scale (PEIRS) to its most essential items and evaluate its measurement properties for assessing the degree of patients’ and family caregivers’ meaningful engagement as partners in research projects.


We conducted a research ethics board approved cross-sectional web-based survey in Canada and the USA, and also paper-based in Canada. Participants were patients or family caregivers who had engaged in research projects within the last 3 years, were ≥17 years old, and communicated in English. Guided by quality criteria for the measurement properties of health status questionnaires, the target sample size was at least 100 participants for satisfactory evaluation of internal consistency and 50 participants for test-retest reliability over two to seven days. Data analysis was conducted in RStudio and in RUMM2030. Extensive psychometric analyses were conducted, including exploration of each item’s fit with the other items of the PEIRS using polychoric correlation among items and polyserial correlation between each item and PEIRS total scores. Once the PEIRS was refined for adequate internal consistency, its underlying construct was assessed through exploratory factor analysis and Rasch analysis. We evaluated reliability of the validated PEIRS’s scores and the extent to which qualitative meaning can be assigned to PEIRS scores.


119 participants: 99 from Canada, 74 female, 51 aged 17–35 years and 50 aged 36–65 years, 60 had post-secondary education, and 74 were Caucasian/white. The original 37-item PEIRS was shortened to 22 items (PEIRS-22), mainly because of low inter-item correlations. PEIRS-22 had a single dominant construct that accounted for 55% of explained variance. Analysis of PEIRS-22 scores revealed: (1) acceptable floor and ceiling effects (<15%), (2) internal consistency (ordinal alpha=0.96), (3) structural validity by fit to a Rasch measurement model, (4) construct validity by moderate correlations with the Public and Patient Engagement Evaluation Tool, (5) good test-retest reliability (ICC2,1=0.86), and (6) interpretability demonstrated by significant differences among PEIRS-22 scores across three levels of global meaningful engagement in research.


The shortened 22-item PEIRS is valid and reliable for assessing the degree of meaningful patient and family caregiver engagement in research. It enables standardized assessment of engagement in research across various contexts.


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