Measuring Patient Safety in Primary Care: The Development and Validation of the “Patient Reported Experiences and Outcomes of Safety in Primary Care” (PREOS-PC)

PURPOSE We set out to develop and validate a patient-reported instrument for
measuring experiences and outcomes related to patient safety in primary care.

METHOD The instrument was developed in a multistage process supported by an
international expert panel and informed by a systematic review of instruments,
a meta-synthesis of qualitative studies, 4 patient focus groups, 18 cognitive
interviews, and a pilot study. The trial version of Patient Reported Experiences
and Outcomes of Safety in Primary Care (PREOS-PC) covered 5 domains and 11
scales: practice activation (1 scale); patient activation (1 scale); experiences of
patient safety events (1 scale); harm (6 scales); and general perceptions of patient safety (2 scales). The questionnaire was posted to 6,736 patients in 45 practices across England. We used “gold standard” psychometric methods to evaluate its acceptability, reliability, structural and construct validity, and ability to discriminate among practices.

RESULTS 1,244 completed questionnaires (18.5%) were returned. Median item-specific response rate was 91.3% (interquartile range 28.0%). No major ceiling or
floor effects were observed. All 6 multi-item scales showed high internal consistency (Cronbach’s α 0.75-0.96). Factor analysis, correlation between scales, and known group analyses generally supported structural and construct validity. The scales demonstrated a heterogeneous ability to discriminate between practices. The final version of PREOS-PC consisted of 5 domains, 8 scales, and 58 items.

CONCLUSIONS PREOS-PC is a new multi-dimensional patient safety instrument
for primary care developed with experts and patients. Initial testing shows its
potential for use in primary care, and future developments will further address
its use in actual clinical practice.