Improvement in quality of hospital care during accreditation: A nationwide stepped-wedge study.

Objective: To assess changes over time in quality of hospital care in relation to the first accreditation cycle in Denmark.

Design, Setting And Participants: We performed a multi-level, longitudinal, stepped-wedge, nationwide study of process performance measures to evaluate the impact of a mandatory accreditation programme in all Danish public hospitals. Patient-level data (n = 1 624 518 processes of care) on stroke, heart failure, ulcer, diabetes, breast cancer and lung cancer care were obtained from national clinical quality registries.

Intervention: The Danish Healthcare Quality Programme was introduced in 2009, aiming to create a framework for continuous quality improvement.

Main Outcome: Changes in week-by-week trends of hospital care during the study period of 269 weeks prior to, during and post-accreditation.

Results: The quality of hospital care improved over time throughout the study period. The overall positive change in trend odds ratio (OR) = 1.002 per week; 95% confidence interval (CI: 0.997-1.006) observed when comparing the period during accreditation with the period prior to accreditation was not significant. However, when restricting the analyses to processes of care where the performance did not meet target values for satisfactory quality prior to accreditation, we found a significant positive change in trend (OR = 1.006 per week; 95% CI: 1.001-1.011). When comparing the post-accreditation period with the period during accreditation, we found a significantly reduced trend (OR = 0.994 per week; 95% CI: 0.988-0.999), indicating the improvement in quality of care continued but at a lower rate than during accreditation.

Conclusion: These findings support the hypothesis that hospital accreditation leads to improvements in patient care.