The Norwegian EUROPEP questionnaire for patient evaluation of general practice: data quality, reliability and construct validity.

BACKGROUND: The EUROPEP is a widely used international instrument to evaluate general practice care from the perspective of patients, but measurement properties including reliability at the GP level are not sufficiently documented.

OBJECTIVE: The objectives of this study were to assess the psychometric properties of the Norwegian version of the EUROPEP and estimate GP-level reliability for scales and items.

METHODS: Nine hundred patients consulting nine GPs at a medical centre in Norway were invited to complete the Norwegian EUROPEP at home following a recent consultation. We assessed item missing and ceiling effects and used factor analysis to assess the structure of the 23 items of the EUROPEP. Scales were tested for reliability and construct validity, while reliability at the GP level was tested for items and scales.

RESULTS: Five hundred and fifty-seven patients (61.9%) returned the questionnaire. Seven of 23 items had missing responses >10% and 20% had high ceiling effects. Factor analysis identified two groups of questions that formed scales with satisfactory internal consistency reliability and validity. The clinical behaviour scale (12 items) and the organization of care scale (4 items) met the criterion of 0.7 for Cronbach's alpha. The GP-level reliability was >0.7 for both scales, but 9 of 23 items were below the criterion of 0.7.

CONCLUSIONS: The study identified two scales in the Norwegian EUROPEP instrument with satisfactory psychometric properties. However, high proportions of item non-response large ceiling effects and low GP-level reliability for several items indicate the need for further instrument refinement.