Development of EMPRO: a tool for the standardized assessment of patient-reported outcome measures.

OBJECTIVE This study was aimed to develop a tool for the standardized assessment of patient-reported outcomes (PROs) to assist the choice of instruments. METHODS An expert panel adapted the eight attributes proposed by the Medical Outcomes Trust as evaluation review criteria, created items to evaluate them, and included a response scale for each item. A pilot test was designed to test the new tool's feasibility and to obtain preliminary information concerning its psychometric properties. The Spanish versions of five measures were selected for assessment: the SF-36 Health Survey, the Nottingham Health Profile, the COOP-WONCA charts, the EuroQol-5D, and the Quality of Life Questionnaire EORTC-QLQ-C30. We assessed the new tool's reliability (Cronbach's alpha and intraclass correlation coefficient [ICC]) and construct validity. RESULTS The new EMPRO (Evaluating the Measurement of Patient-Reported Outcomes) tool has 39 items covering eight key attributes: conceptual and measurement model, reliability, validity, responsiveness, interpretability, burden, alternative modes of administration, and cross-cultural and linguistic adaptations. Internal consistency was high (alpha = 0.95) as was interrater concordance (ICC: 0.87-0.94). Positive associations consistent with a priori hypotheses were observed between EMPRO attribute scores and the number of articles identified for the measures, the years elapsed since the publication of the first article, and the number of citations. CONCLUSION A new tool for the standardized assessment of PRO measures is available. It has shown good preliminary reliability and validity and should be a useful aid to investigators who need to choose between alternative measures. Further assessment of the tool is necessary.