An epistemology of patient safety research: a framework for study design and interpretation. Part 3. End points and measurement
- 1Department of Public Health and Epidemiology, University of Birmingham, Birmingham, UK
- 2University of Michigan Medical School, Ann Arbor, Michigan, USA
- 3National Patient Safety Agency, London, UK
- 4Newcastle upon Tyne Medical School, Newcastle upon Tyne, UK
- 5University of Sheffield, Sheffield, UK
- 6London School of Pharmacy, London, UK
- Dr C Brown, Research Methodology Programme, Department of Public Health and Epidemiology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Accepted 1 January 2008
This article builds on the previous two articles in this series, which focused on an evaluation framework and study designs for patient safety research. The current article focuses on what to measure as evidence of safety and how these measurements can be undertaken. It considers four different end points, highlighting their methodological advantages and disadvantages: patient outcomes, fidelity, intervening variables and clinical error. The choice of end point depends on the nature of the intervention being evaluated and the patient safety problem it has been designed to address. This paper also discusses the different methods of measuring error, reviewing best practice and paying particular attention to case note review. Two key issues with any method of data collection are ensuring construct validity and reliability. Since no end point or method of data collection is infallible, the present authors advocate the use of multiple end points and methods where feasible.
See Editorial, p 154
Competing interests: None.
Authors’ contributions: RL conceived the Network and formulated the first draft of the report and the current paper with assistance from AJ. CB contributed to subsequent drafts of the report and this paper. BDF, TH, RT and JN contributed to the Research Network and provided comments on drafts of the report and papers in their areas of expertise.
This work forms part of the output of a Cross-Council Research Network in Patient Safety Research funded by the Medical Research Council (Reference G0300370). More details of the Research Network can be found at: http://www.pcpoh.bham.ac.uk/publichealth/psrp/MRC.htm