[Validation of a questionnaire to evaluate patient safety in clinical laboratories].

OBJECTIVES The aim of this study was to prepare, pilot and validate a questionnaire to evaluate patient safety in the specific context of clinical laboratories. METHODS A specific questionnaire on patient safety in the laboratory, with 62 items grouped into six areas, was developed, taking into consideration the diverse human and laboratory contextual factors which may contribute to producing errors. A pilot study of 30 interviews was carried out, including validity and reliability analyses using principal components factor analysis and Cronbach's alpha. Subsequently, 240 questionnaires were sent to 21 hospitals, followed by a test-retest of 41 questionnaires with the definitive version. RESULTS The sample analyzed was composed of 225 questionnaires (an overall response rate of 80%). Of the 62 items initially assessed, 17 were eliminated due to non-compliance with the criteria established before the principal components factor analysis was performed. For the 45 remaining items, 12 components were identified, with an cumulative variance of 69.5%. In seven of the 10 components with two or more items, Cronbach's alpha was higher than 0.7. The questionnaire items assessed in the test-retest were found to be stable. CONCLUSIONS We present the first questionnaire with sufficiently proven validity and reliability for evaluating patient safety in the specific context of clinical laboratories. This questionnaire provides a useful instrument to perform a subsequent macrostudy of hospital clinical laboratories in Spain. The questionnaire can also be used to monitor and promote commitment to patient safety within the search for continuous quality improvement.