Evaluating the Quality of Health Care
9. Selecting Measures
Given the numerous considerations summarized above, selecting quality of care measures is a daunting task for someone who is not an expert in this type of assessment. However, by specifying different aspects of the measure requirements, one can narrow down the possibilities considerably.
In our opinion, for the reason summarized above, the assessment of quality should depend much more on process data than on outcome or structure data. Researchers should be aware however, that we recommend the use of measures with a strong evidence base and such evidence is lacking for many process of care that we would like to assess.
The first task is to specify the study design requirements. A major consideration, for example, is the unit of assessment. Although one usually is assessing the care of individuals, it is important to know if one wants to make decisions about the individual, a clinician, organization, or population (e.g. state). The requirements of such measurement tasks are very different. For example, if one is assessing the care of clinicians, there often is a “small numbers problem,” as described above for assessment of the impact of breast cancer screening and diabetes care. That is, a specific clinician may not see enough patients with diabetes during the study period to yield a reliable measure of his or her performance. If one is evaluating the care system, one must determine, for example, whether the focus is hospital care, ambulatory care, or the combined effect of care provides by multiple providers.