A systematic review of COPD patients’ values and preferences: what quantitative information can suggest outcome importance?

Article type
Year
Authors
Zhang Y1, Alonso-Coello P2, Guyatt G1, Schünemann H1
1McMaster University, Canada
2Iberoamerican Cochrane Centre, Institute of Biomedical Research, Spain
Abstract
Background: Consideration of people’s values and preferences is essential in evidence-based decision-making. Systematic reviews of values and preferences are not yet common, and take different approaches.

Objectives: To summarize the quantitative evidence of patient values and preferences on COPD and to discuss the definition, measurement techniques for values and preferences, and their applicability in decision making.

Methods: We operationalized values and preferences as 'the relative importance patients place on the outcomes'. We used a specifically developed search strategy to search electronic databases including PubMed, EMBASE, PsychoInfo, and CINAHL from inception to January 2015. Systematic review authors independently screened title and abstract records, and full text and resolved disagreements through discussion. We summarized the eligible studies into prespecified categories as utility or health state value, direct choice, non-utility measurement of health states, or qualitative studies.

Results: We included 170 quantitative and 153 qualitative studies from the 33,601 records screened. The quantitative studies could be divided into sub-categories: direct measurement of utilities included eight standard gamble studies, five time trade-off studies, 51 visual analogue scale studies and 74 studies on indirect measurements, five willingness-to-pay studies and 12 studies asking patients to trade-off between options or rank them, nine preference trials, and 22 surveys asking what patients would prefer, or how important outcomes are. Other studies reported preference of other aspects, such as place of dying. Depending on whether to inform decision making in a clinical or public health setting, at an individual patient level or population level, the magnitude of relevance for one certain study would change.

Conclusions: We summarized the evidence of patient values and preferences in COPD according to the definition of 'relative importance of outcomes' and developed a classification system for the large number of relevant studies. Our classification system may be helpful to other authors conducting systematic reviews of values and preference.