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After completing this chapter, the reader will be able to

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  • Describe examples of other study designs besides the basic controlled clinical trial.
  • Discuss the potential utility, limitations, and questions to ask when evaluating other study designs.
  • Describe the characteristics of various observational trial designs.
  • Differentiate between the three types of literature reviews: narrative (nonsystematic) review, systematic review, and meta-analysis.
  • Describe common quality of life (QOL) measures used in health outcomes research and discuss the appropriate use of these measures in the medical literature.
  • Discuss common issues encountered in dietary supplement (botanical and nonbotanical) medical literature.
  • Describe how to efficiently and effectively evaluate the available evidence associated with a clinical question and categorize the quality of that evidence to develop a recommendation/clinical decision.

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  • Image not available. Although the randomized, controlled trial is the most frequently used study design for clinical research, several other designs are used in specific situations, such as investigating rare outcome incidences, studying equivalency/non-inferiority between drugs, or minimizing patient exposure to new drugs with inadequate efficacy.
  • Image not available. Observational study designs offer an alternative to interventional trials. These designs are used in specific situations such as when large populations of patients must be followed over extended periods of time. They can be prospective, retrospective, or a single snapshot (or slice) in time. Interpretation of results from these trials only allows associations to be formed rather than true cause-and-effect relationships.
  • Image not available. Reports describing observations made regarding a patient or patient group exposure to a drug or technology can be valuable to record preliminary findings that will lead to further study. A key characteristic to these reports is the lack of a control or comparison group. These observational or interventional reports are referred to as case studies, case reports, or case series.
  • Image not available. Survey research is commonly used and represents information gathered from an identified group from which conclusions are drawn and applied to a larger population. This gathered information is considered either descriptive (such as opinions and attitudes) or explanatory (such as explaining a cause and effect) in nature. Validity of the results depends on the quality of the study's internal rigor.
  • Image not available. Reviews provide support for clinical decisions when large, well-conducted trials are lacking. Meta-analyses are the only type of review that provides new quantitative data. This new data is derived from combining the results of each study included in the meta-analysis and performing a statistical analysis on that data set. The overall reliability of conclusions stemming from a meta-analysis is ultimately dependent upon the quality of the individual studies and the homogeneity between these studies involved in the analysis.
  • Image not available. Multiple health outcome measurements have been developed to address a patient's quality of life (QOL). Physical and social environment, in addition to the emotional and existential reactions to this environment, all affect QOL. The value assigned to quality and quantity of life affected by many different variables including disease, injury, treatment, or policy is termed health-related quality of life (HR-QOL). This HR-QOL value is used to assist ...

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