Patient safety culture: partitioning the variance by organization level

Aim: To document 1) that patient safety culture scores vary not only by individual responder, but also, and to a large degree, by ward and department, and 2) that more of the variation is across wards than across departments. Setting: 500-bed Norwegian university hospital September-December 2006. Methods: Data collected from 1400 staff by (the Norwegian version of) the generic version of the Safety Attitudes Questionnaire (SAQ Short Form 2006). Multilevel analysis by MLwiN version 1.10. Results: Considerable parts of the score variations were at ward and department level. More organization level variation was at ward level than at department level. Conclusions: 1) Patient safety culture should be studied as close to the patient as possible. There may be such a thing as “hospital safety culture”, and the variance across hospital departments indicates the existence of department safety cultures. But neglecting the study of patient safety culture at ward level will mask important local variations. 2) Patient safety culture improvement efforts should include interventions at ward level, aimed at low-score wards, not just department or all-hospital interventions. 3) Safety culture research and improvement should not stop at the lowest formal level of the hospital (wards, out-patient clinics, ERs), but proceed to collect and analyze data on the micro-units within them.