Measures used in studies of informed decision making about cancer screening: a systematic review.
Interventions to promote informed decision making (IDM) for cancer screening are increasingly common. The resulting body of literature provides an opportunity for a systematic review of measures in use. We searched standard databases for intervention trials and other studies of screening decisions and decision aids, finding 2,110 unique citations (most with abstracts) that we reduced to 104 full-text articles; 36 studies met inclusion criteria (prostate = 20, colorectal = 9, breast = 6, cervical = 1). Two independent coders abstracted data on study characteristics, constructs, and measures. Our findings revealed that most studies measured screening (or intention) and knowledge; fewer measured recommended IDM-related constructs and none measured all outcomes proposed for evaluating IDM interventions. Validity and reliability of measures received inadequate attention in study reports, and conceptual overlap exists among measures. Few IDM measures have been developed/carefully adapted from treatment measures and tested for cancer screening or in diverse populations. We recommend that new and in-progress studies emphasize outcomes beyond knowledge-participation in decision making according to personal preference, satisfaction with the process, and consistency between decisions and values. Also needed is better use of theory to guide conceptualization and operationalization of measures, greater attention to reliability and validity (particularly in diverse populations), more thorough reporting of sources and operating characteristics of measures, and increased emphasis and resources focused on these issues by funders, researchers, and journal editors.