Explanations and examples of the main risks of bias within the health service accreditation literature
| Main risks of bias | Explanations of main risks of bias | Exemplifying references |
|---|---|---|
| Non-randomised comparison | Direct causal relationships between accreditation programmes and measures of health service quality and safety cannot be easily inferred using descriptive study designs (eg, cross-sectional, matched cohort and case control studies) | 41–43 |
| Detection bias | A variety of indicators are often used within studies to evaluate the impact of accreditation on health service processes of care, patient outcomes and other aspects of quality, such as financial sustainability. The validity and reliability of employed measures is infrequently justified and often debatable | 28 44–46 |
| Performance bias | Proposed accreditation effects may be due to other factors, such as leadership or quality management activities concurrently undertaken by health services. Evaluation studies seldom account for factors that may potentially confound the relationship between accreditation programmes and outcomes measured | 6 24 27 38 |
| Limited reporting and use of rigorous qualitative methodologies | Insufficient reporting of employed data collection and analysis methodologies impacts the credibility of qualitative studies. There is also limited use of rigorous methodologies, such as triangulation, to enhance the credibility and complexity of findings | 47–50 |