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National Information Center on Health Services Research and Health Care Technology (NICHSR)

Health Services Research Study Design Definitions

Appropriateness category: Defined as content pertaining directly to determining whether individuals who are provided with a health care service had the appropriate clinical indications to receive that service. Methodologic criteria for this category: Explicit criteria for appropriateness of care applied; data source was independent of the study investigators or there was an assessment of the reliability of the application of the criteria and the auditors were blind to practitioner identity and, if more than one institution was involved, institution identity.

Process Assessment category: Defined as content pertaining directly to assessing the process of care for people with a given health problem. These observational studies addressed who did what, to whom, why, where, when and how well. Methodologic criteria for this category: Explicit criteria for process of care applied; the data source is independent of the study investigators, or there was an assessment of the reliability of the application of the criteria and the auditors were blind to practitioner identity and, if more than one institution was involved, institution identity.

Outcomes Assessment category: Defined as content pertaining directly to the appraisal of various clinical decisions/management paths and their effects on patient well-being (outcomes). Studies were observational in nature. Methodologic criteria for this category: At least one of the outcomes is objective or derived from a data source that is independent of the study.

Clinical Practice Guidelines category: Defined as content pertaining directly to the development or application of statements intended to assist practitioner or patient decisions about appropriate health care (for specific clinical circumstances). Methodologic criteria for this category: For development, there was an explicit methods statement describing the process for developing the guidelines including methods of evidence assembly, method of review of studies and at least 1 of: the organizations and individuals involved; methods of formulating guidelines; and methods of reaching agreement or consensus. Evidence had to be cited in support of at least 1 of the recommendations. For application, at least 1 of the exact guidelines had to be provided in a table, figure or the text of the study.

Costs category: Defined as content pertaining directly to the costs or financing of a health care issue. No methodologic criteria applied.

Economics category: Defined as content pertaining directly to a comparison of the cost and effects of at least two different forms of service provision. Methodologic criteria for this category: Question is a comparison of alternatives; alternative services or activities are compared on outcomes produced (effectiveness) and resources consumed (costs); effectiveness and cost estimated are based on individual patient data; results are presented in terms of the incremental or additional costs and outcomes of one intervention over another; sensitivity analysis is performed if there is uncertainty. Evidence of effectiveness must be from a methodologically rigorous study of diagnosis, treatment, quality improvement, or a systematic review article that involved real patients. NOTE: Economics is a subset of the Costs category.