Improved methods for preparing, appraising, and abstracting overviews of available evidence about a clinical topic can bring a broader range of high-quality information within the busy practitioner's grasp [1-4]. However, even well-designed overviews often do not synthesize information about benefits, harms, and costs of medical practices in a way that facilitates clinical decision making.

Clinical practice guidelines have been defined as "systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances" [5]. Guidelines that are based on sound scientific evidence, and a trustworthy process for judging the value of alternative practices, could help physicians deal with the information overload they face. Existing practice guidelines, however, vary widely in their quality, and clinicians should carefully consider the validity and applicability of each guideline they read.

We propose a structured format for abstracts of articles describing practice guidelines that is based on emerging principles of guideline development and evaluation [6-13]. The proposal is designed to help readers obtain the key information needed to assess the applicability, importance, and validity of any guideline.

The proposed structure for more informative abstracts of articles describing clinical practice guidelines has been reviewed and pilot-tested by guideline developers, evaluators, and implementors and by groups of practicing clinicians. Early versions of the proposal were sent to consultants at the National Library of Medicine, the Institute of Medicine, the American College of Physicians (ACP), and the Agency for Health Care Policy and Research. Subsequent versions of the proposal were pilot tested on various published guidelines and were assessed by selected health care organizations for applicability to guidelines under development. An improved proposal was sent to 82 persons active in guideline development, evaluation, and implementation. The Internal Medicine Center to Advance Research and Education circulated the proposal to volunteer practitioners, and the authors solicited feedback from physician and health administrator participants at three national workshops about practice guidelines. The proposal that follows represents an integration of the collective wisdom of our external reviewers. (A glossary of terms used in articles on clinical practice guidelines is supplied in the Appendix.)

Proposed Structure and Content for Abstracts of Articles Describing Clinical Practice Guidelines

The proposed structure for abstracts of papers describing clinical practice guidelines is summarized in Table 1. Key elements of the guideline development process are captured with statements about the principal objective and target of the guideline, the main practice options and outcomes that were considered, the nature of the evidence and values that were analyzed, the main benefits and harms expected from guideline implementation, the key recommendations, and a statement of whether the recommendations have been tested and by whom they have been endorsed. If details about guideline development methods or supporting evidence are published separately, then the abstract should indicate the existence of supporting documents and the most relevant parts of those should be summarized in the abstract. To be included in their entirety in the online bibliographic databases of the National Library of Medicine, structured abstracts of clinical practice guidelines should not exceed 4096 characters (approximately 500 words) in length. Individual journals may have different requirements.

Objective

The abstract should state the objective of the guideline by identifying the targeted health problem, the targeted patients and physicians, and the main reason or reasons for developing new recommendations concerning this problem for this population.

For guidelines primarily concerned with the management of health conditions, the stage of illness and intent to prevent, diagnose, treat, or palliate the disorder should be specified. For guidelines primarily concerned with health procedures, an intervention and its role in patient management should be defined. Targeted providers, settings, and patients should be specified so that readers can tell who should do what, where it should be done, and to whom. A statement of objective also may specify why a new guideline is needed and how it should be used. Practice guidelines may be written to clarify or resolve clinical controversies, to communicate important new findings from clinical studies, or to promote more effective, efficient, or consistent physician practices at less cost or risk to patients. Guidelines may be used concurrently to help physicians and patients make choices (for example, clinical algorithms), retrospectively to compare physician choices to pre-established criteria (for example, utilization review), or prospectively to set limits on physician choices (for example, preprocedure approval).

Options

Clinical practice guidelines pertain to clinical decisions. The nature of those decisions should be made explicit by disclosing the main management options considered. The abstract should list principal alternative preventive, diagnostic, or therapeutic strategies available to targeted clinicians and patients.

Outcomes

The abstract also should specify which health outcomes, such as death, morbidity, quality of life, economic costs, or changes in the process of health care were considered.

Evidence

To estimate the probable effect of a health intervention on an outcome, relevant data must be defined, gathered, and appraised. Readers need to know what kind of evidence was considered and what methods were used to select and combine evidence from different sources.

Potential sources of evidence about clinical outcomes include the results of clinical studies (published or unpublished), expert opinion, information contained in public or private health databases, and direct input from patients or providers. Potential sources of evidence about economic outcomes include the results of cost-effectiveness studies, various fee schedules, and information contained in public or private health claims databases. Potential methods of gathering evidence include computerized searches for articles that satisfy predetermined criteria, reviews of bibliographies of relevant articles, and surveys of relevant persons or organizations [1].

The abstract should state whether explicit methods were used to combine results from scientific studies (for example, meta-analysis) or opinions of experts (for example, Delphi technique) [14, 15]. The abstract may also indicate whether specific criteria were used to gauge the quality of information from different sources [16, 17]. Scientific evidence regarding the likelihood of certain outcomes is often missing or conflicting. It is desirable for the strength of evidence supporting a guideline to be gauged in some way [16]. If gaps in the evidence were bridged formally (for example, through use of decision-analysis models) or informally (for example, best guess of clinical experts), then major assumptions or areas of uncertainty should be acknowledged [11].

Because of the extraordinary time required to properly assemble and review evidence and then to achieve consensus about practice recommendations, the abstract of a practice guideline should specify the publication dates of the most recent evidence considered. If a sensitivity analysis was performed, then any major vulnerability of the guideline to weaknesses in the evidence should be acknowledged. These considerations may be summarized by qualifying a guideline as "provisional" by specifying dates for expiration or review, by listing studies in progress that could affect the guideline, or by identifying key research priorities.

Values

The declaration of a recommended practice presumes an implicit or explicit process for judging the relative desirability of the health, economic, and process outcomes associated with alternative practices. These are matters of opinion and value. For example, in developing guidelines for breast cancer screening, it is necessary to weigh the value of preventing a death from breast cancer against the value of avoiding unnecessary harm or anxiety in women who do not have breast cancer. A high value placed on maximizing detection of asymptomatic malignancy may motivate an organization to recommend teaching self-examination of breasts to young women [18]. A relatively greater value placed on avoiding false-positive results may motivate others to not promote such programs [19]. Consequently, the principal sources of such values and the method by which judgments were made should be reported in guideline abstracts.

At a minimum, the abstract should identify the major groups that participated in the process of assigning values to outcomes (for example, generalist or specialist physicians, other health care providers, insurers, representatives of health organizations, and special-interest groups) and whether patient preferences were represented. The abstract may also indicate the method used to synthesize opinions from multiple sources (for example, formal group judgment process) and whether there was significant disagreement among judges [20]. It is desirable to report whether the guideline is intended to optimize health care from the point of view of individual patients, health practitioners, reimbursement agencies, or society as a whole.

Benefits, Harms, and Costs

Abstracts should describe the type and magnitude of the main benefits, harms, and costs that are expected to result to patients from application of the guideline in typical settings. Absolute measures of practice effects are preferred (for example, an absolute reduction of 50% in the mortality rate [from 50/100 to 25/100] is more compelling than a relative reduction of 50% [from 5/10 000 to 2.5/10 000]) [6, 21]. Key benefits should be quantified using measures that reflect possible effects on morbidity as well as mortality (for example, quality-adjusted life-years). The abstract should also identify the main potential undesirable outcomes of guideline use, such as the consequences of mislabeling patients.

If a cost analysis was carried out, the abstract should indicate the expected effect of guideline use on direct and indirect costs. If costs were not considered, this should be stated.

Recommendations

Abstracted recommendations should be brief and specific and should include major advice that applies to the stated goals and the defined problem. If space is insufficient to state all recommendations, abstracts should state the most important recommendations in clear, unambiguous language. The flexibility of the guideline may be indicated by specification of patient or practice characteristics that require individualization or that justify departures from the recommendations. Recommendations may be characterized as "pathway" guidelines if they describe a preferred course of action or as "boundary" guidelines if they mark the limits within which appropriate practices may be found [22]. Alternatively, guidelines may be classified as "standards," "recommendations," or "options," depending on the degree of flexibility of the advice given [23].

Validation

Methods to enhance guideline validity may include subjecting evidence and judgments to external review by concerned groups, explaining conflict or agreement with guidelines for the same health problem from other organizations, and pretesting guideline recommendations in clinical environments. Ideal, but rarely achievable, is validation by a clinical trial comparing health outcomes in persons randomly assigned either to physicians who attempt guideline implementation or to those who pursue their usual practices. The abstract should indicate whether these or other methods were used and whether they identified any problems with the reported guideline.

Sponsors

The abstract should conclude with a brief statement of who developed and funded the guideline. The health organization or organizations that endorse the guideline may be identified.

Application of the Recommended Structure

To exemplify the application of the recommended structure, a conventional summary of an American College of Physicians (ACP) guideline about screening for breast cancer and a prototype structured abstract are shown in Figure 1 [24]. The College's Clinical Efficacy Assessment Project (CEAP) methods [8] and the independently assembled evidence supporting the breast cancer guideline were published separately [25]. Using information from these documents, we prepared a more informative abstract according to the structure proposed in this article. The original summary is 372 words long, whereas the structured abstract is 489 words long.

View larger version (96K): [in this window] [in a new window]   Figure 1. The published and structured abstracts for American College of Physicians practice guidelines about screening for breast cancer. The "Original Summary" is reprinted from reference 24.

The ACP position statement includes a description of a health problem (prevention of breast cancer in asymptomatic women) and of available interventions for managing that problem (physical examination, mammography). Specific recommendations are listed, a supporting rationale is given, and a concluding paragraph describes the safety of the preferred practice.

The structured abstract includes considerably more information about the methods and assumptions underlying this particular guideline. The CEAP mandate and the intended use of its guidelines is made clear in the opening statement of objectives, as is the specific proposal to prevent deaths from breast cancer through early, cost-effective detection of new malignancies. Next, alternative strategies for breast cancer detection are identified together with the criteria by which their effectiveness was assessed. Information about admissible evidence and the decision-analysis model used to synthesize that evidence appears in the structured abstract but not in the conventional abstract. The process by which recommendations were derived from the evidence is reported only in the structured abstract. Benefits, harms, and costs appear in the structured abstract much as they do in the abstract of the background paper [25]. Finally, the extensive review process used by ACP and the relationship of CEAP screening guidelines to the Blue Cross and Blue Shield Medical Necessity Project are made clear in the last two sections of the structured abstract.

Discussion

Top Discussion Author & Article Info References

A recent description of prominent guideline development projects showed major differences in the emphasis placed on formal literature reviews, expert opinion, and assessments of local experience when different groups assemble evidence on which to base guidelines [26]. Major variations were also seen in the techniques organizations used to reach a consensus about preferred practices. These differences, and the viewpoints and values of guideline developers, are key to understanding apparent conflicts among guidelines developed by different organizations on similar topics [27]. Although the ACP position statement on screening for breast cancer provides clinicians with valuable information about the patients, providers, and practices affected by the guideline, it is difficult to appreciate why the ACP guidelines differ from those of other organizations [28]. A structured abstract of the type we propose could help to expose the basis for apparent conflicts among guidelines.

Structured abstracts of original research articles [29] and reviews [3] have been adopted by many medical journals. Guidelines differ from original research articles and reviews in several ways; however, the primary difference is that guidelines make specific, authoritative recommendations about medical practices. Because these declarations involve value judgments about the relative importance of various health and economic consequences of clinical decisions, unique aspects of guideline development may not be represented in existing specifications for structured abstracts.

The primary purpose of structured abstracts for original research articles and overviews has been to enhance readers' ability to quickly appraise the applicability, importance, and validity of journal articles. Structured abstracts may provide other benefits as well. For example, more informative abstracts of original research articles can enhance the ability of clinicians and researchers to efficiently scan articles identified in literature searches. They can promote more accurate and consistent reporting of study methods [4]. Ultimately, they may influence the preparation and evaluation of study proposals submitted to potential sources of funding [30]. Similar benefits could accrue through use of structured abstracts for clinical practice guidelines. Guidelines are disseminated to doctors largely through publication in medical journals. More informative abstracts may help clinicians to gain a better appreciation of the ways in which articles describing practice guidelines differ from other types of medical literature. The National Library of Medicine recently created the unique indexing term "Practice Guideline (PT)" to allow users of its MEDLINE database to identify citations of practice guidelines. As more abstracts of guideline articles become available for online review, a more informative format for these abstracts could help readers quickly obtain critical information about the development and content of specific guidelines. Structured abstracts for guidelines may also encourage the use of sound methods in guideline development and more consistent reporting procedures for practice guidelines. Ultimately, they may facilitate more effective use of guidelines by clinicians.

Appendix: Glossary of Terms Used in Articles about Clinical Practice Guidelines

Definitions listed in the glossary borrow heavily from standard texts in clinical epidemiology and clinical decision analysis [4, 31-35].

Absolute risk: difference in the risk for disease or death among an exposed population and the risk among the unexposed

Algorithm: an explicit description of an ordered sequence of steps to be taken in patient care under specified circumstances

Cost-benefit analysis: a form of economic assessment in which the costs of medical care are compared with the economic benefits of the care, with both costs and benefits expressed in units of currency; the benefits typically include reductions in future health care costs and increased earnings because of the improved health of those receiving the care

Cost-effectiveness analysis: an economic evaluation in which alternative programs, services, or interventions are compared in terms of the cost per unit of clinical effect: for example, cost per life saved, cost per millimeter of mercury of blood pressure lowering

Cost-utility analysis: a type of cost-effectiveness analysis in which outcomes are measured in terms of their social value; cost is expressed per some incremental quality-of-life measure (for example, cost per quality-adjusted life-year, cost per healthy days of life gained)

Decision analysis: a systematic approach to decision making under conditions of uncertainty that involves identifying all available choices and estimating the probabilities of potential outcomes for each in a series of decisions that have to be made regarding patient care; the analysis requires estimates of how persons value different health outcomes

Effectiveness: a measure of the benefit resulting from an intervention for a given health problem under average conditions of use; this form of evaluation considers both the efficacy of an intervention and its acceptance by those to whom it is offered, providing an answer to the following question: Does the practice do more good than harm to people to whom it is offered?

Efficacy: a measure of the benefit resulting from an intervention for a given health problem under ideal conditions of use; it answers the question: Does the practice do more good than harm to people who fully comply with the recommendations?

Efficiency: a measure of the increment in health benefit for a fixed amount of health resources; it answers the question: Is this practice worth doing compared with other things that could be done with the same resources?

Health costs: these concern the use of health care resources (direct and indirect costs) and the inability to use the same resources for other worthwhile purposes (opportunity costs)

Health outcome: all possible changes in health status that may occur for a defined population or may be associated with exposure to an intervention, including changes in the length and quality of life as a result of detecting or treating disease when it is present, the false security associated with failing to detect disease when it is present, and the mislabeling associated with detecting disease when it is really absent

Health process: changes in the conduct of health care; for example, an intervention may change the nature of the doctor-patient relationship or the manner in which health actions are documented

Health state: refers to the health condition of an individual or a group over a specified interval of time (commonly assessed at a particular point in time)

Marginal utility: the change in a person's utility (preference or relative value) for an outcome as the outcome increases in magnitude

Meta-analysis: an overview that incorporates a specific quantitative strategy for combining the results of several studies into a single summary estimate

Overview: a type of review in which primary research relevant to a question is examined and summarized, and an effort is made to identify all available literature (published or unpublished) that pertains to that question

Patient preferences: refer to the degrees of subjective satisfaction, distress, or desirability that patients or potential patients associate with a particular health state

Performance criteria: concern how interventions are done, without regard to whether they should be performed; an example would be the acceptable range of results reported for reference cholesterol samples sent to clinical laboratories

Practice guidelines: systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances; a set of statements, directions, or principles presenting current or future clinical rules or policy concerning the proper indications for doing a procedure or treatment or the proper management for specific clinical problems; guidelines may be developed by government agencies, institutions, organizations such as professional societies or governing boards, or by the convening of expert panels (synonyms include practice parameters and practice policies)

Quality assurance: any procedure, method, or philosophy for collecting, processing, or analyzing data that are aimed at maintaining or improving the appropriateness and reliability of health care services

Quality of care: a level of performance or accomplishment that characterizes the health care provided

Quality-adjusted life-year: a unit of measure for survival that accounts for the effects of morbidity on quality of life; for example, if a patient lives for 10 years and his or her quality of life is decreased by 50% because of chronic lung disease, his survival would be equivalent to 5 quality-adjusted life years

Relative risk: ratio of the risk for disease or death among an exposed population to the risk among the unexposed

Review: a general term for all attempts to obtain and synthesize the results and conclusions of two or more publications on a given topic

Risk aversion: to avoid taking a chance on winning or losing a future outcome, a patient will accept a present outcome that is valued less than the uncertain future outcome

Sensitivity analysis: any test of the stability of the conclusions of a health care evaluation over a range of probability estimates, value judgments, and assumptions about the structure of the decisions to be made; this involves the repeated evaluation of a decision model in which one or more of the parameters of interest are varied

Standards: authoritative statements of minimal levels of acceptable performance or results, excellent levels of performance or results, or the range of acceptable performance or results

Threshold analysis: at what value of the questioned probabilities the decision maker would consider the currently favored strategy no better than its next best alternative

Utility: refers to patient preferences that are measured with techniques consistent with modern utility theory; it is based on specific axioms that describe how a rational decision maker ought to make a decision when the outcomes of that decision are uncertain; commonly used measures of utility include the standard gamble or time-tradeoff techniques

Validity: the extent to which a variable or intervention measures what it is supposed to measure or accomplishes what it is supposed to accomplish

Values: basis for personal preferences concerning different outcomes