Closing Evidence Gaps in Clinical Prevention (2022) / Chapter Skim
Currently Skimming:
4 Taxonomy and Workflow
4 Taxonomy and Workflow
Pages 65-112
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 65... ...
The need for a taxonomy of research gaps in preventive medicine is best understood in terms of the current situation facing the USPSTF. As described in Chapter 2, the 16-member USPSTF reviews the scientific evidence related to various clinical preventive services and then makes evidence-based conclusions about the benefits of these services.
|
From page 66... ...
institutes and centers to make evidence gaps identified by the USPSTF known across NIH. However, the potential synergy between the USPSTF recommendations and the clinical prevention research community remains unrealized: recommendation updates are published about every 5 years, but a recent paper by Klabunde et al.
|
From page 67... ...
Ultimately, the main contribution of the taxonomy is to provide a structured approach to describing evidence gaps related to preventive services so that recommendations and I statements can be thorough and consistent in how they list and describe those gaps. The taxonomy serves as a road map, providing a systematic, step-by-step approach to the characterization of evidence gaps to supplement or replace the more subjective and less systematic descriptions that are currently found in USPSTF recommendations and I statements.
|
From page 68... ...
Thus the development of a taxonomy is just one step in this larger task. With this framework having been described, the next section goes into detail about using the taxonomy to characterize evidence gaps, while the following section discusses how those evidence gaps might be prioritized and a research agenda created that will fill in those gaps according to the prioritization.
|
From page 69... ...
Additionally, taxonomy documents are living documents, which should be updated regularly to incorporate new concepts and elements as needed. In learning about taxonomies and thinking about which would be most appropriate to apply to evidence gaps in preventive services, the committee decided the traditional hierarchical taxonomy was not an appropriate system to identify and categorize evidence gaps in clinical prevention, which required the allowance of multiple nested terms.
|
From page 70... ...
Adapting the U.S. Preventive Services Task Force Analytic Framework In its search for a suitable taxonomy, the committee examined various potential choices.
|
From page 71... ...
The committee decided that these main components of the analytic framework -- the risk assessment, early detection, intermediate outcomes, effectiveness, harms -- could serve as ideal building blocks of the taxon FIGURE 4-1 Generic analytic framework for screenings.
|
From page 72... ...
However, the committee determined that a taxonomy consisting only of elements from the analytic framework would be incomplete; thus they added other components to fill it out. Evidence gap categories related to the foundational issues facet are often already recognized by the USPSTF.
|
From page 73... ...
The USPSTF does not routinely consider gaps related to D&I, but the committee agreed it was crucial to include as part of a taxonomy of clinical prevention evidence gaps. How a preventive service affects morbidity and mortality is necessary but insufficient for effective clinical prevention practice -- preventive services must also be feasible, scalable, and sustainable for clinicians to implement and for patients to adhere to.
|
From page 74... ...
FIGURE 4-5 The workflow for identifying evidence gaps in clinical prevention with the taxonomy. NOTE: To view the taxonomy as an interactive graphic, see https://www.nap.
|
From page 75... ...
However, the committee recognizes that gaps in D&I evidence are also important to address to improve health outcomes related to clinical preventive services. Thus, although it was not mentioned in the statement of task, the committee chose to make D&I part of its taxonomy.
|
From page 76... ...
Not every I statement will have foundational issues to address, but they will be important in some cases as prerequisites or complements to address analytic framework questions. The third facet of the evidence gaps taxonomy is D&I, which covers an aspect of preventive services that the USPSTF traditionally does not address in recommendation statements.
|
From page 77... ...
on Morbidity and Mortality Harms Screening Harms Treatment Harms Dissemination and Implementation Size Scope of Services, Including Costs Scalability Sustainability Penetration of Program into the Intended Audience Implementation of the Scope of Services Participation in the Program Effectiveness of the Program continued
|
From page 78... ...
The committee developed the following categories for foundational evidence gaps related to clinical preventive services (see Figure 4-6 for the corresponding workflow section)
|
From page 79... ...
Characterize Evidence Gaps Using Relevant Taxonomies Analytic Dissemination and Foundational Framework Implementation Issues Taxonomy Taxonomy Taxonomy Gaps in Foundational Knowledge • Condition Definition and • Development of Standards Nomenclature • Psychometric Properties • Disease Processes • Preventive Service Develop a Research Agenda Set priorities across all evidence gaps using the prioritization criteria. Outline study specifications to address each high-priority gap.
|
From page 80... ...
To be recommended by the USPSTF, a screening test should be consistent and well defined. Foundational evidence gaps regarding preventive services may include what devices or technology may be required to administer it, how frequently it should be administered, or if it has any method issues (e.g., does this test require a special diet?
|
From page 81... ...
In that sense, the need for clear standards is similar to the need for standardized nomenclature and disease definitions -- both help provide a solid foundation for everything else. In some cases, what seems to be conflicting evidence regarding a particular preventive service or intervention may actually be an indication of a lack of standards in the performance of the service or in the measurement of the outcome, and it may be necessary to clear up these inconsistencies before a clear conclusion can be drawn about the effectiveness of the service.
|
From page 82... ...
The committee classified these evidence gaps according to the outcomes shown in the USPSTF's analytic frameworks: Risk Assessment and Health Equity Considerations, Early Detection, Intermediate Outcomes, Effectiveness, and Harms. Those five categories form the first level of the committee's analytic framework taxonomy, with various subcategories included within each main category (see Figure 4-7 for the corresponding workflow section)
|
From page 83... ...
Characterize Evidence Gaps Using Relevant Taxonomies Analytic Dissemination and Foundational Framework Implementation Issues Taxonomy Taxonomy Taxonomy Analytic Framework Gaps • Risk Assessment and Health • Effectiveness: Effects of Equity Considerations: Screening, Effects of Treatment Behavioral and or Behavioral Intervention Sociodemographic and • Harms: Screening Harms, Develop a Research Clinical and Biological Agenda Treatment Harms • Early Detection Set Priorities Across All Evidence Gaps • Intermediate Outcomes: Using the Prioritization Criteria Effects of Treatment, Association with Morbidity and Mortality Outline study specifications to address each high-priority gap. FIGURE 4-7 The workflow with analytic framework evidence gaps facet.
|
From page 84... ...
They also grouped most risk factors in two categories, "behavioral and sociodemographic," and "biological and clinical." A list of important respective risk factors can be found in Box 4-1, though the committee recognizes that the list of risk factors is not comprehensive, and AHRQ, NIH, the USPSTF, or other stakeholders may expand the list as needed. Behavioral and sociodemographic risk factors This category is a large and complex set of risk factors that encompasses many of the risk characteristics that, with sufficient research, can guide application of preventive services.
|
From page 85... ...
Due to the proximal pathophysiology between blood pressure and morbidity and mortality outcomes, an evidence base linking regular blood pressure screenings (preventive service) with lower blood pressure (intermediate outcome)
|
From page 86... ...
inhibitor -- leads to lower blood pressure, while the second category would contain questions such as whether lowering an individual's blood pressure as a result of treatment leads to a longer life expectancy or lowers the risk of stroke. Effectiveness The effectiveness category involves questions relating to whether an early preventive service (i.e., screening, behavioral counseling, or medication)
|
From page 87... ...
Dissemination and Implementation Gaps Historically, the USPSTF has not reviewed issues of D&I in its recommendation statements, focusing instead on whether sufficient evidence exists to conclude that a particular preventive service is effective in reducing harms. If this is the sole focus, then the taxonomy would be complete with just the two previous facets -- the foundational taxonomy and the analytic framework taxonomy.
|
From page 88... ...
Together they provide a breakdown of important components of the design, dissemination, and implementation of a program, so that evidence gaps related to D&I can generally be placed into one of the eight slots defined by 4S/PIPE (see Figure 4-8 for the corresponding workflow section)
|
From page 89... ...
Characterize Evidence Gaps Using Relevant Taxonomies Analytic Dissemination and Foundational Framework Implementation Issues Taxonomy Taxonomy Taxonomy Dissemination and Implementation Evidence Gaps • Size • Penetration of Program into • Scope of Services, Including the Intended Audience Costs • Implementation of the Scope • Scalability Develop a Research of Services Agenda • Sustainability • Participation in the Program Set Priorities Across •AllEffectiveness Evidence Gaps of the Program Using the Prioritization Criteria Outline study specifications to address each high-priority gap. FIGURE 4-8 The workflow with dissemination and implementation evidence gaps facet.
|
From page 90... ...
Scalability is dependent upon multiple factors, including, but not limited to, the willingness of members of the target population to participate, the per-unit costs of the intervention in the context of total resource availability, the effective use of all available media to recruit and engage individuals, and the partnership potential with other stakeholders supporting similar goals. In the case of novel interventions, there may be a lack of key insights or critical evidence concerning this scalability, creating an evidence gap regarding the D&I of that preventive service.
|
From page 91... ...
The interpretation of the X rays or CT images used in screening can be complex, for instance, with great variation in the interpretation among practitioners; such variation could blunt the effectiveness of a preventive service that would otherwise be quite valuable. Alternatively, outreach efforts related to mammography screening may use a variety of strategies in order to achieve a certain performance target; not achieving the target may be related to incomplete implementation of the work plans specific to such strategies.
|
From page 92... ...
Thus, evidence gaps are likely for this category for any new type of preventive service. From an equity perspective, participation in preventive interventions may be closely related to the degree of outreach and attention provided to the target audience.
|
From page 93... ...
. However it is done, the committee believes it is important that the USPSTF and other groups invested in improving clinical prevention research identify evidence gaps related to the D&I of the preventive services.
|
From page 94... ...
There can be similar interplay between foundational issues and D&I or between the analytic framework and D&I. Thus, it is important to keep in mind when categorizing the various evidence gaps related to a preventive intervention that various crosscutting issues can arise, and each of these must be dealt with on a case-bycase basis as there is no easy way to account for them in the taxonomy as defined.
|
From page 95... ...
Characterize Evidence Gaps Using Relevant Taxonomies Analytic Dissemination and Foundational Framework Implementation Issues Taxonomy Taxonomy Taxonomy Develop a Research Agenda Set priorities across all evidence gaps using the prioritization criteria. Outline study specifications to address each Criteria for Prioritizing Evidence Gaps high-priority gap.
|
From page 96... ...
After a great deal of discussion, the committee settled on a list of categories that should be taken into consideration when prioritizing research into evidence gaps related to preventive interventions. The list, which is not exhaustive, contains the following areas to consider: Population Impact Population impact assesses the magnitude of net benefit if the I statement under consideration could be transformed into a recommendation.
|
From page 97... ...
But depending on the burden of disease, some evidence gaps may be more pressing and thus more highly prioritized. Adoptability Some preventive services can be adopted more quickly and more widely than others, perhaps because of the nature of the intervention or of the population in which the intervention will take place.
|
From page 98... ...
Study Specification The final step in developing a research agenda, after developing a taxonomy of evidence gaps and prioritizing those gaps is to decide on the details of the studies that will be required to fill in those gaps. This is not a novel process; indeed, it is one familiar to many investigators and funders.
|
From page 99... ...
. The committee added three more considerations important in specifying research aimed at filling in evidence gaps: Aggregability, design considerations, and potential funders and funding mechanisms (see Figure 4-10 for the corresponding workflow section)
|
From page 100... ...
Characterize Evidence Gaps Using Relevant Taxonomies Analytic Dissemination and Foundational Framework Implementation Issues Taxonomy Taxonomy Taxonomy Develop a Research Agenda Set priorities across all evidence gaps using the prioritization criteria. Outline study specifications to address each high-priority gap.
|
From page 101... ...
. Aggregability Aggregability refers to how well a new study will combine with previous studies to get closer to a definitive answer to a question about preventive services.
|
From page 102... ...
By combining these prioritization and specification steps, researchers can develop a systematic approach to addressing relevant evidence gaps in the evidence base for preventive interventions. The goal, of course, is to address those gaps with well-designed, high-quality studies that have the greatest chance of closing the gaps and leading to new recommendations.
|
From page 103... ...
(The letters following each are intended to make it easier to see how the statements from the USPSTF research needs and gaps section map onto statements in the committee's taxonomy.) See Box 4-2 for an example of the original evidence gaps described by the USPSTF in the cognitive impairment screening, and see Tables 4-1 through 4-3 for an example of those gaps mapped to the taxonomy (identified with the same letters as Box 4-2)
|
From page 104... ...
If these are found, further studies would be needed to see if identifying and treating these individuals can positively affect outcomes. Preventive Services Studies are needed on ways to improve the detection of those with early cognitive impairment who will respond to treatment.
|
From page 105... ...
. Harms Harms Associated with It is also important that studies on screening for Screening cognitive impairment report harms and reasons for attrition of trial participants (H)
|
From page 106... ...
. A draft new recommendation statement for late 2021 is available for public comment, and includes the following evidence gaps (letters in parentheses were added by the committee)
|
From page 107... ...
Unlike the paragraphs on evidence gaps, the USPSTF's recommendation statement, which contains much of the same information, this structured taxonomy shows at a glance that there are a couple of foundational issues to address along with a large number of evidence gaps concerning the clinical application of the preventive services (i.e., the analytic framework)
|
From page 108... ...
. Effectiveness Effects of Screening on Randomized trials enrolling asymptomatic persons Reduced Morbidity or that assess health outcomes and harms are needed Mortality to understand the balance of benefits and harms of screening for atrial fibrillation (B)
|
From page 109... ...
Effectiveness of Research is needed to assess if the rate of case finding significantly the Program improved over other preventive services, such as pulse palpitation. REFERENCES AHRQ (Agency for Healthcare Research and Quality)
|
From page 110... ...
U.S. Preventive Services Task Force priorities for prevention research.
|
From page 111... ...
2018. Update on the methods of the US Preventive Services Task Force: Linking intermediate outcomes and health outcomes in prevention.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.