Putting Evidence Into Practice: An Update on the US Preventive Services Task Force Methods for Developing Recommendations for Preventive Services.

PURPOSE: The US Preventive Services Task Force (USPSTF) is an independent body that makes evidence-based recommendations regarding preventive services to improve health for people nationwide. Here, we summarize current USPSTF methods, describe how methods are evolving to address preventive health equity, and define evidence gaps for future research. METHODS: We summarize current USPSTF methods as well as ongoing methods development. RESULTS: The USPSTF prioritizes topics on the basis of disease burden, extent of new evidence, and whether the service can be provided in primary care and going forward will increasingly consider health equity. Analytic frameworks specify the key questions and linkages connecting the preventive service to health outcomes. Contextual questions provide information on natural history, current practice, health outcomes in high-risk groups, and health equity. The USPSTF assigns a level of certainty to the estimate of net benefit of a preventive service (high, moderate, or low). The magnitude of net benefit is also judged (substantial, moderate, small, or zero/negative). The USPSTF uses these assessments to assign a letter grade from A (recommend) to D (recommend against). I statements are issued when evidence is insufficient. CONCLUSIONS: The USPSTF will continue to evolve its methods for simulation modeling and to use evidence to address conditions for which there are limited data for population groups who bear a disproportionate burden of disease. Additional pilot work is underway to better understand the relations of the social constructs of race, ethnicity, and gender with health outcomes to inform the development of a USPSTF health equity framework.

USPSTF Approach to Addressing Sex and Gender When Making Recommendations for Clinical Preventive Services.

Clinical preventive service recommendations from the US Preventive Services Task Force (USPSTF) are based on transparent, systematic, and rigorous methods that consider the certainty of the evidence and magnitude of net benefit. These guidelines aim to address the needs of diverse populations. Biological sex and gender identity are sources of diversity that are not often considered in studies of clinical preventive services that inform the recommendations, resulting in challenges when evaluating the evidence and communicating recommendations for persons in specific gender identification categories (man/woman/gender nonbinary/gender nonconforming/transgender). To advance its methods, the USPSTF reviewed its past recommendations that included the use of sex and gender terms, reviewed the approaches of other guideline-making bodies, and pilot tested strategies to address sex and gender diversity. Based on the findings, the USPSTF intends to use an inclusive approach to identify issues related to sex and gender at the start of the guideline development process; assess the applicability, variability, and quality of evidence as a function of sex and gender; ensure clarity in the use of language regarding sex and gender; and identify evidence gaps related to sex and gender. Evidence reviews will identify the limitations of applying findings to diverse groups from underlying studies that used unclear terminology regarding sex and gender. The USPSTF will use gender-neutral language when appropriate to communicate that recommendations are inclusive of people of any gender and will clearly state when recommendations apply to individuals with specific anatomy associated with biological sex (male/female) or to specific categories of gender identity. The USPSTF recognizes limited evidence to inform the preventive care of populations based on gender identity.

Developing Recommendations for Evidence-Based Clinical Preventive Services for Diverse Populations: Methods of the U.S. Preventive Services Task Force.

The U.S. Preventive Services Task Force (USPSTF) summarizes the principles and considerations that guide development of its recommendations for diverse U.S. populations. It uses these principles through each step in the evidence-based guideline process: developing the research plan, conducting the evidence review, developing the recommendation, and communicating to guideline users. Three recent recommendations provide examples of how the USPSTF has used these principles: the 2015 recommendation on screening for abnormal blood glucose and type 2 diabetes; the 2016 recommendation on screening for breast cancer; and the recommendation on screening for prostate cancer, which is currently in progress. A more comprehensive list of recommendations that includes considerations for specific populations is also provided.

Sexually Transmitted Infections: Recommendations from the U.S. Preventive Services Task Force.

The U.S. Preventive Services Task Force (USPSTF) has issued recommendations on behavioral counseling to prevent sexually transmitted infections (STIs) and recommendations about screening for individual STIs. Clinicians should obtain a sexual history to assess for behaviors that increase a patient's risk. Community and population risk factors should also be considered. The USPSTF recommends intensive behavioral counseling for all sexually active adolescents and for adults whose history indicates an increased risk of STIs. These interventions can reduce STI acquisition and risky sexual behaviors, and increase condom use and other protective behaviors. The USPSTF recommends screening for chlamydia and gonorrhea in all sexually active women 24 years and younger, and in older women at increased risk. It recommends screening for human immunodeficiency virus (HIV) infection in all patients 15 to 65 years of age regardless of risk, as well as in younger and older patients at increased risk of HIV infection. The USPSTF also recommends screening for hepatitis B virus infection and syphilis in persons at increased risk. All pregnant women should be tested for hepatitis B virus infection, HIV infection, and syphilis. Pregnant women 24 years and younger, and older women with risk factors should be tested for gonorrhea and chlamydia. The USPSTF recommends against screening for asymptomatic herpes simplex virus infection. There is inadequate evidence to determine the optimal interval for repeat screening; clinicians should rescreen patients when their sexual history reveals new or persistent risk factors.

Reconsidering the approach to prevention recommendations for older adults.

The U.S. Preventive Services Task Force (USPSTF) bases its recommendations on an evidence-based model of clinical prevention that focuses on specific diseases, well-defined preventive interventions, and evidence of improved health outcomes. Applying this model to prevention for very old patients has been problematic for several reasons: Many geriatric disorders have multiple risk factors, interventions, and expected outcomes; older adults are not often represented in clinical trials; and important outcomes may not be measured and reported in ways that are conducive to evidence synthesis and interpretation. In 2005, the USPSTF convened a geriatrics workgroup to refine USPSTF methodology and processes to better address the preventive needs of older adults. The USPSTF has begun to apply these new approaches to the review and recommendation on interventions to prevent falls in older adults.

Aspirin for the primary prevention of cardiovascular events: an update of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: Coronary heart disease and cerebrovascular disease are leading causes of death in the United States. In 2002, the U.S. Preventive Services Task Force (USPSTF) strongly recommended that clinicians discuss aspirin with adults who are at increased risk for coronary heart disease. PURPOSE: To determine the benefits and harms of taking aspirin for the primary prevention of myocardial infarctions, strokes, and death. DATA SOURCES: MEDLINE and Cochrane Library (search dates, 1 January 2001 to 28 August 2008), recent systematic reviews, reference lists of retrieved articles, and suggestions from experts. STUDY SELECTION: English-language randomized, controlled trials (RCTs); case-control studies; meta-analyses; and systematic reviews of aspirin versus control for the primary prevention of cardiovascular disease (CVD) were selected to answer the following questions: Does aspirin decrease coronary heart events, strokes, death from coronary heart events or stroke, or all-cause mortality in adults without known CVD? Does aspirin increase gastrointestinal bleeding or hemorrhagic strokes? DATA EXTRACTION: All studies were reviewed, abstracted, and rated for quality by using predefined USPSTF criteria. DATA SYNTHESIS: New evidence from 1 good-quality RCT, 1 good-quality meta-analysis, and 2 fair-quality subanalyses of RCTs demonstrates that aspirin use reduces the number of CVD events in patients without known CVD. Men in these studies experienced fewer myocardial infarctions and women experienced fewer ischemic strokes. Aspirin does not seem to affect CVD mortality or all-cause mortality in either men or women. The use of aspirin for primary prevention increases the risk for major bleeding events, primarily gastrointestinal bleeding events, in both men and women. Men have an increased risk for hemorrhagic strokes with aspirin use. A new RCT and meta-analysis suggest that the risk for hemorrhagic strokes in women is not statistically significantly increased. LIMITATIONS: New evidence on aspirin for the primary prevention of CVD is limited. The dose of aspirin used in the RCTs varied, which prevented the estimation of the most appropriate dose for primary prevention. Several of the RCTs were conducted within populations of health professionals, which potentially limits generalizability. CONCLUSION: Aspirin reduces the risk for myocardial infarction in men and strokes in women. Aspirin use increases the risk for serious bleeding events.

Screening for syphilis infection in pregnant women: evidence for the U.S. Preventive Services Task Force reaffirmation recommendation statement.

BACKGROUND: In 2004, the U.S. Preventive Services Task Force strongly recommended that clinicians screen all pregnant women for syphilis infection. PURPOSE: To update the evidence on screening pregnant women for syphilis infection. DATA SOURCES: MEDLINE searches from 1 January 2003 through 31 July 2008, recent systematic reviews, reference lists of retrieved articles, and expert suggestions. STUDY SELECTION: English-language studies were selected to answer the following 2 questions: Does screening for syphilis in pregnancy reduce the prevalence of congenital syphilis in neonates? Are there harms of screening for syphilis or harms of treatment with penicillin in pregnancy to women or neonates? Randomized, controlled trials; meta-analyses; systematic reviews; cohort studies; and ecologic studies were selected for the potential benefits question. Randomized, controlled trials; meta-analyses; systematic reviews; cohort studies; case-control studies; and large case series were selected for the potential harms question. DATA EXTRACTION: Information on the study design, selection criteria, demographic characteristics, and clinical outcomes was extracted from each study. DATA SYNTHESIS: One study on benefits evaluated the effect before and after the implementation of a universal syphilis screening program for pregnant women and found reductions in rates of congenital syphilis. Two studies on screening accuracy for syphilis reported false-positive rates of less than 1%. One study that used a large insurance claims database reported an incidence of anaphylaxis after oral penicillin of 0.1 per 10,000 dispensings. In a study from Hungary, oral penicillin in pregnancy was not associated with orofacial clefts. LIMITATIONS: This was a targeted literature search and could have missed small studies on the benefits and harms of screening for syphilis in pregnancy. We did not review evidence on interventions to improve rates of prenatal screening. CONCLUSION: New evidence from a study of universal screening supports previous evidence on the effectiveness of screening for syphilis in pregnancy to prevent congenital syphilis. Harms include testing and follow-up for false-positive test results and adverse effects from penicillin treatment.

Screening for skin cancer: an update of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: Skin cancer is the most commonly diagnosed cancer in the United States. The majority of skin cancer is nonmelanoma cancer, either basal cell cancer or squamous cell cancer. The incidence of both melanoma and nonmelanoma skin cancer has been increasing over the past 3 decades. In 2001, the U.S. Preventive Services Task Force (USPSTF) found insufficient evidence to recommend for or against routine screening for skin cancer by using whole-body skin examination for early detection of skin cancer. PURPOSE: To update the evidence of benefits and harms of screening for skin cancer in the general population. DATA SOURCES: MEDLINE and Cochrane Library searches from 1 June 1999 to 9 August 2005 for English-language articles; recent systematic reviews; reference lists of retrieved articles; and expert suggestions. STUDY SELECTION: English-language studies were selected to answer the following key question: Does screening in asymptomatic persons with whole-body examination by a primary care clinician or by self-examination reduce morbidity and mortality from skin cancer? Randomized, controlled trials and case-control studies of screening for skin cancer were selected. One author selected English-language studies to answer the following contextual questions: Can screening with whole-body examination by primary care clinicians or by self-examination accurately detect skin cancer? Does screening with whole-body examination or by self-examination detect melanomas at an earlier stage (thinner lesions)? DATA EXTRACTION: All studies for the key question were reviewed, abstracted, and rated for quality by using predefined USPSTF criteria. DATA SYNTHESIS: No new evidence from controlled studies was found that addressed the benefit of screening for skin cancer with a whole-body examination by a physician. One article of fair quality, which reanalyzed data from a 1996 study identified for the 2001 report for the USPSTF, provides limited but insufficient evidence on the benefit of skin self-examination in the reduction of morbidity and mortality from melanoma. LIMITATIONS: Direct evidence linking skin cancer screening to improved health outcomes is lacking. Information is limited on the accuracy of screening by physicians or patients using real patients and lesions. CONCLUSION: The limited evidence prevents accurate estimation of the benefits of screening for skin cancer in the general primary care population.

Folic acid supplementation for the prevention of neural tube defects: an update of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: Neural tube defects (NTDs) are among the most common birth defects in the United States. In 1996, the U.S. Preventive Services Task Force (USPSTF) recommended that all women planning a pregnancy or capable of conception take a supplement containing folic acid to reduce the risk for NTDs. PURPOSE: To search for new evidence published since 1996 on the benefits and harms of folic acid supplementation for women of childbearing age to prevent neural tube defects in offspring, to inform an updated USPSTF recommendation. DATA SOURCES: MEDLINE and Cochrane Central Register of Controlled Trials searches from January 1995 through December 2008, recent systematic reviews, reference lists of retrieved articles, and expert suggestions. STUDY SELECTION: English-language randomized, controlled trials; cohort studies; case-control studies; systematic reviews; and meta-analyses were selected if they provided information on the benefits and harms of folic acid supplementation in women of childbearing age to reduce NTDs in offspring. DATA EXTRACTION: All studies were reviewed, abstracted, and rated for quality by using predefined USPSTF criteria. DATA SYNTHESIS: Four observational studies reported benefit of reduction of risk for NTDs associated with folic acid-containing supplements. Differences in study type and methods prevent the calculation of a summary of the reduction in risk. The one included study on harms reported that the association of twinning with folic acid intake disappeared after adjustment for in vitro fertilization and underreporting of folic acid intake. LIMITATIONS: The evidence on dose was limited. No evidence was found on the potential harm of masking vitamin B(12) deficiency in women of childbearing age. The search focused on the association of NTDs with supplementation only and therefore does not provide a comprehensive review of the effects of folic acid on all possible outcomes or of the effects of dietary intake of folic acid. CONCLUSION: New observational evidence supports previous evidence from a randomized, controlled trial that folic acid-containing supplements reduce the risk for NTD-affected pregnancies. The association of folic acid use with twin gestation may be confounded by fertility interventions.

Evidence for the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure.

BACKGROUND: High blood pressure is common, and screening is a well-established evidence-based standard of current medical practice. PURPOSE: To perform a literature search for new, substantial evidence on screening for high blood pressure that would inform the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure. DATA SOURCES: The PubMed and Cochrane databases were searched. The searches were limited to English-language articles on studies of adult humans (age >18 years) that were published between 1 October 2001 and 31 March 2006 in core clinical journals. STUDY SELECTION: For the literature on benefits, meta-analyses; systematic reviews; and randomized, controlled trials were included. For harms, meta-analyses; systematic reviews; randomized, controlled trials; cohort studies; case-control studies; and case series of large, multisite databases were included. Two reviewers independently reviewed titles, abstracts, and full articles for inclusion. DATA EXTRACTION: No new evidence was found on benefits or harms of screening. Two reviewers extracted data from studies on the harms of early treatment, including adverse effects of drug therapy and adverse quality-of-life outcomes. DATA SYNTHESIS: No new evidence was found for the benefits of screening for high blood pressure. New evidence on the harms of treatment of early hypertension shows that pharmacologic therapy is associated with common side effects; serious adverse events are uncommon. LIMITATIONS: The nonsystematic search may have missed some smaller studies on the benefits and harms of screening and treatment for high blood pressure. CONCLUSION: No new evidence was found on the benefits of screening. Pharmacotherapy for early hypertension is associated with common side effects.

Screening for carotid artery stenosis: an update of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: Cerebrovascular disease is the third leading cause of death in the United States. The proportion of all strokes attributable to previously asymptomatic carotid artery stenosis (CAS) is low. In 1996, the U.S. Preventive Services Task Force concluded that evidence was insufficient to recommend for or against screening of asymptomatic persons for CAS by using physical examination or carotid ultrasonography. PURPOSE: To examine the evidence of benefits and harms of screening asymptomatic patients with duplex ultrasonography and treatment with carotid endarterectomy for CAS. DATA SOURCES: MEDLINE and Cochrane Library (search dates January 1994 to April 2007), recent systematic reviews, reference lists of retrieved articles, and suggestions from experts. STUDY SELECTION: English-language randomized, controlled trials (RCTs) of screening for CAS; RCTs of carotid endarterectomy versus medical treatment; systematic reviews of screening tests; and observational studies of harms from carotid endarterectomy were selected to answer the following questions: Is there direct evidence that screening with ultrasonography for asymptomatic CAS reduces strokes? What is the accuracy of ultrasonography to detect CAS? Does intervention with carotid endarterectomy reduce morbidity or mortality? Does screening or carotid endarterectomy result in harm? DATA EXTRACTION: All studies were reviewed, abstracted, and rated for quality by using predefined Task Force criteria. DATA SYNTHESIS: No RCTs of screening for CAS have been done. According to systematic reviews, the sensitivity of ultrasonography is approximately 94% and the specificity is approximately 92%. Treatment of CAS in selected patients by selected surgeons could lead to an approximately 5-percentage point absolute reduction in strokes over 5 years. Thirty-day stroke and death rates from carotid endarterectomy vary from 2.7% to 4.7% in RCTs; higher rates have been reported in observational studies (up to 6.7%). LIMITATIONS: Evidence is inadequate to stratify people into categories of risk for clinically important CAS. The RCTs of carotid endarterectomy versus medical treatment were conducted in selected populations with selected surgeons. CONCLUSION: The actual stroke reduction from screening asymptomatic patients and treatment with carotid endarterectomy is unknown; the benefit is limited by a low overall prevalence of treatable disease in the general asymptomatic population and harms from treatment.

How to read the new recommendation statement: methods update from the U.S. Preventive Services Task Force.

Since 2001, the U.S. Preventive Services Task Force (USPSTF) has worked to refine its methods of evidence review and assessment and to create more usable documents in response to clinicians' needs. These changes have resulted in a revised grading system, as well as a new format and new language for the recommendation statement. This paper focuses on the changes to and the new look of the USPSTF recommendation statement. The new recommendation statement comprises 9 sections. Important changes include standardization of the format of the summary statement to specify what service is being recommended in what population; standardization of the headings in the rationale section; a change in the wording of the grade C recommendation and the I statement; and a new section, called "Other Considerations," in which salient issues related to cost-effectiveness, mandates, and other implementation issues are described.

Update on the Methods of the U.S. Preventive Services Task Force: Methods for Understanding Certainty and Net Benefit When Making Recommendations.

Since the 1980s, the U.S. Preventive Services Task Force (USPSTF) has developed and used rigorous methods to make evidence-based recommendations about preventive services to promote health and well-being for all Americans. Recommendations are based on the evidence of magnitude of net benefit (benefits minus harms). Expert opinion is not substituted when evidence is lacking. Evidence gaps are common. Few preventive services are supported by high-quality studies that directly and comprehensively determine the overall magnitude of benefits and harms in the same study. When assessing the body of evidence, studies may not have been conducted in primary care settings, studies may not have sufficiently included populations of interest, and long-term outcomes may not have been directly assessed. When direct evidence is not available, the USPSTF uses the methodologies of applicability to determine whether evidence can be generalized to an asymptomatic primary care population; coherence to link bodies of evidence and create an indirect evidence pathway; extrapolation to make inferences across the indirect evidence pathway, extend evidence to populations not specifically studied, consider service delivery intervals, and infer long-term outcomes; and conceptual bounding to set theoretical lower or upper limits for plausible benefits or harms. The USPSTF extends the evidence only so far as to maintain at least moderate certainty that its findings are preserved. This manuscript details with examples of how the USPSTF uses these methods to make recommendations that truly reflect the evidence.

Update on the Methods of the U.S. Preventive Services Task Force: Linking Intermediate Outcomes and Health Outcomes in Prevention.

The U.S. Preventive Services Task Force (USPSTF) is an independent body of experts who make evidence-based recommendations about clinical preventive services using a transparent and objective process. Developing recommendations on a clinical preventive service requires evidence of its effect on health outcomes. Health outcomes are symptoms, functional levels, and conditions that affect a patient's quantity or quality of life and are measured by assessments of physical or psychologic well-being. Intermediate outcomes are pathologic, physiologic, psychologic, social, or behavioral measures related to a preventive service. Given the frequent lack of evidence on health outcomes, the USPSTF uses evidence on intermediate outcomes when appropriate. The ultimate goal is to determine precisely a consistent relationship between the direction and magnitude of change in an intermediate outcome with a predictable resultant direction and magnitude of change in the health outcomes. The USPSTF reviewed its historical use of intermediate outcomes, reviewed methods of other evidence-based guideline-making bodies, consulted with other experts, and reviewed scientific literature. Most important were the established criteria for causation, tenets of evidence-based medicine, and consistency with its current standards. Studies that follow participants over time following early treatment, stratify patients according to treatment response, and adjust for important confounders can provide useful information about the association between intermediate and health outcomes. However, such studies remain susceptible to residual confounding. The USPSTF will exercise great caution when making a recommendation that depends on the evidence linking intermediate and health outcomes because of inherent evidence limitations.

Challenges in Developing U.S. Preventive Services Task Force Child Health Recommendations.

The U.S. Preventive Services Task Force (USPSTF) uses an objective evidence-based approach to develop recommendations. As part of this process, the USPSTF also identifies important research gaps in scientific evidence. In March 2016, the USPSTF convened an expert panel to discuss its portfolio of child and adolescent recommendations and identify unique methodologic issues when evaluating evidence regarding children and adolescents. The panel identified key domains of challenges, including measuring patient-centered health outcomes; identifying intermediate outcomes predictive of important health outcomes; evaluating the long time horizon needed to assess the balance of benefits and harms; understanding trajectories of growth and development that result in unique windows of time when expected benefits or harms of a preventive service can vary; and considering the perspectives of other individuals who might be affected by the delivery of a preventive service to a child or adolescent. Although the expert panel expressed an interest in being able to make more recommendations for or against preventive services for children and adolescents, it also reinforced the importance of ensuring recommendations were based on sound and sufficient evidence to ensure greatest benefit and minimize unnecessary harms. Accordingly, the need to highlight areas with insufficient evidence is as important as making recommendations. Having identified these key challenges, the USPSTF and other organizations issuing guidelines have an opportunity to advance their methods of evidence synthesis and identified evidence gaps represent important opportunities for researchers and policy makers.