The Consumer Quality Index in an accident and emergency department: internal consistency, validity and discriminative capacity

Background: Patients' experiences are an indicator of health-care performance in the accident and emergency department (A&E). The Consumer Quality Index for the Accident and Emergency department (CQI A&E), a questionnaire to assess the quality of care as experienced by patients, was investigated. The internal consistency, construct validity and discriminative capacity of the questionnaire were examined. Methods: In the Netherlands, twenty-one A&Es participated in a cross-sectional survey, covering 4883 patients. The questionnaire consisted of 78 questions. Principal components analysis determined underlying domains. Internal consistency was determined by Cronbach's alpha coefficients, construct validity by Pearson's correlation coefficients and the discriminative capacity by intraclass correlation coefficients and reliability of A&E-level mean scores (G-coefficient). Results: Seven quality domains emerged from the principal components analysis: information before treatment, timeliness, attitude of health-care professionals, professionalism of received care, information during treatment, environment and facilities, and discharge management. Domains were internally consistent (range: 0.67-0.84). Five domains and the 'global quality rating' had the capacity to discriminate among A&Es (significant intraclass correlation coefficient). Four domains and the 'global quality rating' were close to or above the threshold for reliably demonstrating differences among A&Es. The patients' experiences score on the domain timeliness showed the largest range between the worst- and best-performing A&E. Conclusions: The CQI A&E is a validated survey to measure health-care performance in the A&E from patients' perspective. Five domains regarding quality of care aspects and the 'global quality rating' had the capacity to discriminate among A&Es.