Interventions Using Informed Decision Making to Increase Cancer Screening

Research Gaps

What are Research Gaps?

Prior to and during the literature review and data analysis, the review team and the Community Preventive Services Task Force attempt to address the key questions of what interventions work, for whom, under what conditions, and at what cost. Lack of sufficient information often leaves one or more of these questions unanswered. The Community Guide refers to these as "research gaps." Research gaps can be pulled together in the form of a basic set of questions to inform a research agenda for those in the field.

Identified Research Gaps

Results from the Community Guide review indicate that there were not enough studies to determine the effectiveness of informed decision making (IDM). Thus, numerous research issues remain.

More work is needed on the effect of these interventions on all of the outcomes in the conceptual framework, especially on recommendation outcomes other than knowledge, beliefs, and perceptions of risk. Few studies reported individuals' participation in decision making, and only one of those reported whether participation was at a desired level. It is not possible to know from the published reports whether questions about this issue were not asked or whether current instruments are not sufficiently sensitive to discriminate different levels of patient interest in participation, causing investigators not to report the data. If the problem is the latter, more sensitive measures of patient desire for participation should be developed.

The medical decision-making field has given considerable attention to assessing patient preferences for health states—that is, the quality of life in a particular health situation. Health economists call these preferences “utilities” and use them, among other purposes, to inform cost-utility analyses. This research needs, however, to be extended to accurate and feasible ways to assess preferences in clinical encounters and to ensure that patient decisions are congruent with individual preferences and values.

Because most of the included studies in this review addressed prostate cancer, additional work on other cancer screenings would be welcome. Additional studies are needed in community contexts outside of clinical settings. Similarly, studies are needed that focus on providers and healthcare systems to promote shared decision making (SDM) instead of, or in addition to, directly targeting individuals. Studies with providers and in healthcare systems should measure provider and system outcomes, but should also measure the client outcomes that are the ultimate goal of these programs and policies.

Social and demographic variables have been shown to affect individuals' desire for involvement in healthcare decisions and may also affect the effectiveness of IDM interventions. To date, IDM seems to be more acceptable to younger and more educated patients. However, this may be a consequence both of how questions are asked and of patients' confidence. More empirical work is needed in diverse populations, such as nonwhite, older, and medically underserved populations. Achieving IDM in such populations is a challenging but desirable goal.

Although the study designs and executions of available studies in this review were generally strong, some measurement issues need additional attention. Sensitive, appropriate measures are still needed of individual involvement in decision making and the match between decisions and preferences or values. In addition, work is needed on how best to elicit patient preferences and respond to them in nonthreatening, time-sensitive, and culturally appropriate ways.

Although much work has already been published in the risk communication literature about how to communicate complex information involving probabilities to individuals, additional work is still needed on appropriate and feasible ways of communicating technical information so that it is helpful and not overwhelming. Additional empirical work on people's information needs and preferences for level of involvement in decision making, how those needs and preferences might evolve over time, and how best to meet those needs and preferences would also be useful. Finally, more work is needed on whether IDM or SDM increases or decreases the use of effective services.

It is known that, at least for some diseases (e.g., breast cancer), individuals overestimate both the disease risks and the benefits of screening. IDM could help patients achieve a more realistic perspective on risks and benefits. In particular, quantitative risk models, which clearly show patients the risks and benefits of screening in terms of their personal characteristics, would allow patients to take personal risk factors into account when making healthcare decisions. Such techniques, which permit individualization of the risks and benefits, might help people to make better-informed decisions.

Evidence Review

Briss PA, Rimer BK, Reilley B, et al. Promoting informed decisions about cancer screening in communities and healthcare systems: a conceptual background and systematic review from the Task Force on Community Preventive Services. Am J Prev Med 2004;26(1):67-80.