Development of a Health Equity Framework for the US Preventive Services Task Force

Importance

Clinical practice guidelines can play an important role in mitigating health inequities. The US Preventive Services Task Force (USPSTF) has prioritized addressing health equity and racism in its recommendations.

Objective

To develop a framework that would allow the USPSTF to incorporate a health equity lens that spans the entirety of its recommendation-making process.

Evidence Review

Key guidance, policy, and explanatory frameworks related to health equity were identified, and their recommendations and findings were mapped to current USPSTF methods. USPSTF members as well as staff from multiple entities supporting the USPSTF portfolio were consulted. Based on all the gathered information, a draft health equity framework and checklist were developed; they were then circulated to the USPSTF's key partners for input and review.

Findings

An equity framework was developed that could be applied to all phases of the recommendation process: (1) topic nomination, selection, and prioritization; (2) development of the work plan; (3) evidence review; (4) evidence deliberation; (5) development of the recommendation statement; and (6) dissemination of recommendations. For each phase, several considerations and checklist items to address are presented. These items include using health equity as a prioritization criterion and engaging a diverse group of stakeholders at the earliest phases in identifying topics for recommendations; developing necessary equity-relevant questions (eg, beyond effectiveness and harms) to address during the protocol phase; using methods in synthesizing the evidence and contextual issues in the evidence review related to specific populations experiencing a disproportionate burden of disease; and examining the magnitude and certainty of net benefit, implementation considerations, risk assessment, and evidence gaps through an equity lens when developing evidence-based recommendations.

Conclusions and Relevance

Executing this entire framework and checklist as described will be challenging and will take additional time and resources. Nonetheless, whether adopted in its entirety or in parts, this framework offers guidance to the USPSTF, as well as other evidence-based guideline entities, in its mission to develop a more transparent, consistent, and intentional approach to addressing health equity in its recommendations.

Screening for Lipid Disorders in Children and Adolescents: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

Lipid screening in childhood and adolescence can lead to early dyslipidemia diagnosis. The long-term benefits of lipid screening and subsequent treatment in this population are uncertain.

Objective

To review benefits and harms of screening and treatment of pediatric dyslipidemia due to familial hypercholesterolemia (FH) and multifactorial dyslipidemia.

Data Sources

MEDLINE and the Cochrane Central Register of Controlled Trials through May 16, 2022; literature surveillance through March 24, 2023.

Study Selection

English-language randomized clinical trials (RCTs) of lipid screening; recent, large US cohort studies reporting diagnostic yield or screen positivity; and RCTs of lipid-lowering interventions.

Data Extraction and Synthesis

Single extraction, verified by a second reviewer. Quantitative synthesis using random-effects meta-analysis.

Main Outcomes and Measures

Health outcomes, diagnostic yield, intermediate outcomes, behavioral outcomes, and harms.

Results

Forty-three studies were included (n = 491 516). No RCTs directly addressed screening effectiveness and harms. Three US studies (n = 395 465) reported prevalence of phenotypically defined FH of 0.2% to 0.4% (1:250 to 1:500). Five studies (n = 142 257) reported multifactorial dyslipidemia prevalence; the prevalence of elevated total cholesterol level (≥200 mg/dL) was 7.1% to 9.4% and of any lipid abnormality was 19.2%. Ten RCTs in children and adolescents with FH (n = 1230) demonstrated that statins were associated with an 81- to 82-mg/dL greater mean reduction in levels of total cholesterol and LDL-C compared with placebo at up to 2 years. Nonstatin-drug trials showed statistically significant lowering of lipid levels in FH populations, but few studies were available for any single drug. Observational studies suggest that statin treatment for FH starting in childhood or adolescence reduces long-term cardiovascular disease risk. Two multifactorial dyslipidemia behavioral counseling trials (n = 934) demonstrated 3- to 6-mg/dL greater reductions in total cholesterol levels compared with the control group, but findings did not persist at longest follow-up. Harms reported in the short-term drug trials were similar in the intervention and control groups.

Conclusions and Relevance

No direct evidence on the benefits or harms of pediatric lipid screening was identified. While multifactorial dyslipidemia is common, no evidence was found that treatment is effective for this condition. In contrast, FH is relatively rare; evidence shows that statins reduce lipid levels in children with FH, and observational studies suggest that such treatment has long-term benefit for this condition.

Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease and cancer are the 2 leading causes of death in the US, and vitamin and mineral supplementation has been proposed to help prevent these conditions.

OBJECTIVE

To review the benefits and harms of vitamin and mineral supplementation in healthy adults to prevent cardiovascular disease and cancer to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed (publisher-supplied records only), Cochrane Library, and Embase (January 2013 to February 1, 2022); prior reviews.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of vitamin or mineral use among adults without cardiovascular disease or cancer and with no known vitamin or mineral deficiencies; observational cohort studies examining serious harms.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative pooling methods appropriate for rare events were used for most analyses.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular disease events, cancer incidence, serious harms.

RESULTS

Eighty-four studies (N=739 803) were included. In pooled analyses, multivitamin use was significantly associated with a lower incidence of any cancer (odds ratio [OR], 0.93 [95% CI, 0.87-0.99]; 4 RCTs [n=48 859]; absolute risk difference [ARD] range among adequately powered trials, -0.2% to -1.2%) and lung cancer (OR, 0.75 [95% CI, 0.58-0.95]; 2 RCTs [n=36 052]; ARD, 0.2%). However, the evidence for multivitamins had important limitations. Beta carotene (with or without vitamin A) was significantly associated with an increased risk of lung cancer (OR, 1.20 [95% CI, 1.01-1.42]; 4 RCTs [n=94 830]; ARD range, -0.1% to 0.6%) and cardiovascular mortality (OR, 1.10 [95% CI, 1.02-1.19]; 5 RCTs [n=94 506] ARD range, -0.8% to 0.8%). Vitamin D use was not significantly associated with all-cause mortality (OR, 0.96 [95% CI, 0.91-1.02]; 27 RCTs [n=117 082]), cardiovascular disease (eg, composite cardiovascular disease event outcome: OR, 1.00 [95% CI, 0.95-1.05]; 7 RCTs [n=74 925]), or cancer outcomes (eg, any cancer incidence: OR, 0.98 [95% CI, 0.92-1.03]; 19 RCTs [n=86 899]). Vitamin E was not significantly associated with all-cause mortality (OR, 1.02 [95% CI, 0.97-1.07]; 9 RCTs [n=107 772]), cardiovascular disease events (OR, 0.96 [95% CI, 0.90-1.04]; 4 RCTs [n=62 136]), or cancer incidence (OR, 1.02 [95% CI, 0.98-1.08]; 5 RCTs [n=76 777]). Evidence for benefit of other supplements was equivocal, minimal, or absent. Limited evidence suggested some supplements may be associated with higher risk of serious harms (hip fracture [vitamin A], hemorrhagic stroke [vitamin E], and kidney stones [vitamin C, calcium]).

CONCLUSIONS AND RELEVANCE

Vitamin and mineral supplementation was associated with little or no benefit in preventing cancer, cardiovascular disease, and death, with the exception of a small benefit for cancer incidence with multivitamin use. Beta carotene was associated with an increased risk of lung cancer and other harmful outcomes in persons at high risk of lung cancer.

Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Modeling Study for the US Preventive Services Task Force

IMPORTANCE

The US Preventive Services Task Force (USPSTF) is updating its 2016 recommendation on the use of aspirin for the primary prevention of cardiovascular disease (CVD) and colorectal cancer (CRC).

OBJECTIVE

To provide updated model-based estimates of the net balance in benefits and harms from routine use of low-dose aspirin for primary prevention.

DESIGN, SETTING, AND PARTICIPANTS

Microsimulation modeling was used to estimate long-term benefits and harms for hypothetical US cohorts of men and women aged 40 to 79 years with up to 20% 10-year risk for an atherosclerotic CVD event and without prior history of CVD or elevated bleeding risks.

EXPOSURES

Low-dose (≤100 mg/d) aspirin for lifetime use, unless contraindicated by a bleeding event, and with stopping ages in 5-year intervals from age 65 to 85 years.

MAIN OUTCOMES AND MEASURES

Primary outcomes were lifetime net benefits measured in quality-adjusted life-years (QALYs) and life-years. Benefits included reduced nonfatal myocardial infarction and ischemic stroke. Harms included increased nonfatal major gastrointestinal bleeding and intracranial hemorrhage. Reduced CRC incidence was considered in sensitivity analysis.

RESULTS

Estimated lifetime net QALYs were positive for both men and women at 5% or greater 10-year CVD risk when starting between ages 40 and 59 years and at 10% or greater 10-year CVD risk when starting between ages 60 and 69 years. These estimates ranged from 2.3 (95% CI, -2.7 to 7.4) to 66.2 (95% CI, 58.2 to 74.1) QALYs per 1000 persons. Lifetime net life-years were positive for men at 5% or greater and women at 10% or greater 10-year CVD risk starting aspirin at ages 40 to 49 years and for men at 7.5% or greater and women at 15% or greater 10-year CVD risk at ages 50 to 59 years. These estimates ranged from 0.4 (95% CI, -6.1 to 6.9) to 52.4 (95% CI, 43.9 to 60.9) life-years per 1000 persons. Lifetime net life-years were negative in most cases for persons starting aspirin between ages 60 and 79 years, as were lifetime net QALYs for persons aged 70 to 79 years. Stopping aspirin between ages 65 and 85 years generally showed little advantage compared with lifetime use. Sensitivity analyses showed lifetime net benefits may be higher if aspirin reduced CRC incidence or CVD mortality and lower if aspirin increased fatal major gastrointestinal bleeding or reduced quality of life with routine use.

CONCLUSIONS AND RELEVANCE

This microsimulation study suggested that several population groups may benefit from taking aspirin for the primary prevention of CVD, primarily in persons starting at younger ages with higher 10-year CVD risk.

Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Low-dose aspirin is used for primary cardiovascular disease prevention and may have benefits for colorectal cancer prevention.

OBJECTIVE

To review the benefits and harms of aspirin in primary cardiovascular disease prevention and colorectal cancer prevention to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, Embase, and the Cochrane Central Register of Controlled Trials through January 2021; literature surveillance through January 21, 2022.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of low-dose aspirin (≤100 mg/d) compared with placebo or no intervention in primary prevention populations.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative synthesis using Peto fixed-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Cardiovascular disease events and mortality, all-cause mortality, colorectal cancer incidence and mortality, major bleeding, and hemorrhagic stroke.

RESULTS

Eleven RCTs (N = 134 470) and 1 pilot trial (N = 400) of low-dose aspirin for primary cardiovascular disease prevention were included. Low-dose aspirin was associated with a significant decrease in major cardiovascular disease events (odds ratio [OR], 0.90 [95% CI, 0.85-0.95]; 11 RCTs [n = 134 470]; I2 = 0%; range in absolute effects, -2.5% to 0.1%). Results for individual cardiovascular disease outcomes were significant, with similar magnitude of benefit. Aspirin was not significantly associated with reductions in cardiovascular disease mortality or all-cause mortality. There was limited trial evidence on benefits for colorectal cancer, with the findings highly variable by length of follow-up and statistically significant only when considering long-term observational follow-up beyond randomized trial periods. Low-dose aspirin was associated with significant increases in total major bleeding (OR, 1.44 [95% CI, 1.32-1.57]; 10 RCTs [n = 133 194]; I2 = 4.7%; range in absolute effects, 0.1% to 1.0%) and in site-specific bleeding, with similar magnitude.

CONCLUSIONS AND RELEVANCE

Low-dose aspirin was associated with small absolute risk reductions in major cardiovascular disease events and small absolute increases in major bleeding. Colorectal cancer results were less robust and highly variable.

Screening for Hypertension in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Hypertension is a major risk factor for cardiovascular disease and can be modified through lifestyle and pharmacological interventions to reduce cardiovascular events and mortality.

OBJECTIVE

To systematically review the benefits and harms of screening and confirmatory blood pressure measurements in adults, to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, Cochrane Collaboration Central Registry of Controlled Trials, and CINAHL; surveillance through March 26, 2021.

STUDY SELECTION

Randomized clinical trials (RCTs) and nonrandomized controlled intervention studies for effectiveness of screening; accuracy studies for screening and confirmatory measurements (ambulatory blood pressure monitoring as the reference standard); RCTs and nonrandomized controlled intervention studies and observational studies for harms of screening and confirmation.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction; meta-analyses and qualitative syntheses.

MAIN OUTCOMES AND MEASURES

Mortality; cardiovascular events; quality of life; sensitivity, specificity, positive and negative predictive values; harms of screening.

RESULTS

A total of 52 studies (N = 215 534) were identified in this systematic review. One cluster RCT (n = 140 642) of a multicomponent intervention including hypertension screening reported fewer annual cardiovascular-related hospital admissions for cardiovascular disease in the intervention group compared with the control group (difference, 3.02 per 1000 people; rate ratio, 0.91 [95% CI, 0.86-0.97]). Meta-analysis of 15 studies (n = 11 309) of initial office-based blood pressure screening showed a pooled sensitivity of 0.54 (95% CI, 0.37-0.70) and specificity of 0.90 (95% CI, 0.84-0.95), with considerable clinical and statistical heterogeneity. Eighteen studies (n = 57 128) of various confirmatory blood pressure measurement modalities were heterogeneous. Meta-analysis of 8 office-based confirmation studies (n = 53 183) showed a pooled sensitivity of 0.80 (95% CI, 0.68-0.88) and specificity of 0.55 (95% CI, 0.42-0.66). Meta-analysis of 4 home-based confirmation studies (n = 1001) showed a pooled sensitivity of 0.84 (95% CI, 0.76-0.90) and a specificity of 0.60 (95% CI, 0.48-0.71). Thirteen studies (n = 5150) suggested that screening was associated with no decrement in quality of life or psychological distress; evidence on absenteeism was mixed. Ambulatory blood pressure measurement was associated with temporary sleep disturbance and bruising.

CONCLUSIONS AND RELEVANCE

Screening using office-based blood pressure measurement had major accuracy limitations, including misdiagnosis; however, direct harms of measurement were minimal. Research is needed to determine optimal screening and confirmatory algorithms for clinical practice.

Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease Prevention in Adults With Cardiovascular Risk Factors: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease is the leading cause of death in the US, and poor diet and lack of physical activity are major factors contributing to cardiovascular morbidity and mortality.

OBJECTIVE

To review the benefits and harms of behavioral counseling interventions to improve diet and physical activity in adults with cardiovascular risk factors.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, and the Cochrane Central Register of Controlled Trials through September 2019; literature surveillance through July 24, 2020.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of behavioral counseling interventions to help people with elevated blood pressure or lipid levels improve their diet and increase physical activity.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from studies by one reviewer and checked by a second. Random-effects meta-analysis and qualitative synthesis were used.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, subjective well-being, cardiovascular risk factors, diet and physical activity measures (eg, minutes of physical activity, meeting physical activity recommendations), and harms. Interventions were categorized according to estimated contact time as low (≤30 minutes), medium (31-360 minutes), and high (>360 minutes).

RESULTS

Ninety-four RCTs were included (N = 52 174). Behavioral counseling interventions involved a median of 6 contact hours and 12 sessions over the course of 12 months and varied in format and dietary recommendations; only 5% addressed physical activity alone. Interventions were associated with a lower risk of cardiovascular events (pooled relative risk, 0.80 [95% CI, 0.73-0.87]; 9 RCTs [n = 12 551]; I2 = 0%). Event rates were variable; in the largest trial (Prevención con Dieta Mediterránea [PREDIMED]), 3.6% in the intervention groups experienced a cardiovascular event, compared with 4.4% in the control group. Behavioral counseling interventions were associated with small, statistically significant reductions in continuous measures of blood pressure, low-density lipoprotein cholesterol levels, fasting glucose levels, and adiposity at 12 to 24 months' follow-up. Measurement of diet and physical activity was heterogeneous, and evidence suggested small improvements in diet consistent with the intervention recommendation targets but mixed findings and a more limited evidence base for physical activity. Adverse events were rare, with generally no group differences in serious adverse events, any adverse events, hospitalizations, musculoskeletal injuries, or withdrawals due to adverse events.

CONCLUSIONS AND RELEVANCE

Medium- and high-contact multisession behavioral counseling interventions to improve diet and increase physical activity for people with elevated blood pressure and lipid levels were effective in reducing cardiovascular events, blood pressure, low-density lipoproteins, and adiposity-related outcomes, with little to no risk of serious harm.

Nontraditional Risk Factors in Cardiovascular Disease Risk Assessment: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Incorporating nontraditional risk factors may improve the performance of traditional multivariable risk assessment for cardiovascular disease (CVD).

OBJECTIVE

To systematically review evidence for the US Preventive Services Task Force on the benefits and harms of 3 nontraditional risk factors in cardiovascular risk assessment: the ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP) level, and coronary artery calcium (CAC) score.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for studies published through May 22, 2017. Surveillance continued through February 7, 2018.

STUDY SELECTION

Studies of asymptomatic adults with no known cardiovascular disease.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, risk assessment performance measures (calibration, discrimination, or risk reclassification), and serious adverse events.

RESULTS

Forty-three studies (N = 267 244) were included. No adequately powered trials have evaluated the clinical effect of risk assessment with nontraditional risk factors on patient health outcomes. The addition of the ABI (10 studies), hsCRP level (25 studies), or CAC score (19 studies) can improve both discrimination and reclassification; the magnitude and consistency of improvement varies by nontraditional risk factor. For the ABI, improvements in performance were the greatest for women, in whom traditional risk assessment has poor discrimination (C statistic change of 0.112 and net reclassification index [NRI] of 0.096). Results were inconsistent for hsCRP level, with the largest analysis (n = 166 596) showing a minimal effect on risk prediction (C statistic change of 0.0039, NRI of 0.0152). The largest improvements in discrimination (C statistic change ranging from 0.018 to 0.144) and reclassification (NRI ranging from 0.084 to 0.35) were seen for CAC score, although CAC score may inappropriately reclassify individuals not having cardiovascular events into higher-risk categories, as determined by negative nonevent NRI. Evidence for the harms of nontraditional risk factor assessment was limited to computed tomography imaging for CAC scoring (8 studies) and showed that radiation exposure is low but may result in additional testing.

CONCLUSIONS AND RELEVANCE

There are insufficient adequately powered clinical trials evaluating the incremental effect of the ABI, hsCRP level, or CAC score in risk assessment and initiation of preventive therapy. Furthermore, the clinical meaning of improvements in measures of calibration, discrimination, and reclassification risk prediction studies is uncertain.

Screening for Peripheral Artery Disease Using the Ankle-Brachial Index: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Peripheral artery disease (PAD) is associated with a high risk for cardiovascular events and poor ambulatory function, even in the absence of symptoms. Screening for PAD with the ankle-brachial index (ABI) may identify patients in need of treatment to improve health outcomes.

OBJECTIVE

To systematically review evidence for the US Preventive Services Task Force on PAD screening with the ABI, the diagnostic accuracy of the test, and the benefits and harms of treatment of screen-detected PAD.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant English-language studies published between January 2012 and May 2, 2017. Surveillance continued through February 7, 2018.

STUDY SELECTION

Studies of unselected or generally asymptomatic adults with no known cardiovascular disease.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Cardiovascular morbidity; PAD morbidity; mortality; health-related quality of life; diagnostic accuracy; and serious adverse events.

RESULTS

Five studies (N = 5864 participants) were included that examined the indirect evidence for the benefits and harms of screening and treatment of screen-detected PAD. No population-based screening trials evaluated the direct benefits or harms of PAD screening with the ABI alone. A single diagnostic accuracy study of the ABI compared with magnetic resonance angiography gold-standard imaging (n = 306) found low sensitivity (7%-34%) and high specificity (96%-100%) in a screening population. Two adequately powered trials (n = 4626) in asymptomatic populations with and without diabetes with a variably defined low ABI (≤0.95 or ≤0.99) showed no statistically significant effect of aspirin (100 mg daily) for composite CVD outcomes (adjusted hazard ratio [HR], 1.00 [95% CI, 0.81-1.23] and HR, 0.98 [95% CI, 0.76-1.26]). One trial (n = 3350) demonstrated no statistically significant increase in major bleeding events with the use of aspirin (adjusted HR, 1.71 [95% CI, 0.99- 2.97]) and no statistically significant increase in major gastrointestinal bleeding (relative risk, 1.13 [95% CI, 0.44-2.91]). Two exercise trials (n = 932) in screen-relevant populations reported no differences in quality of life, Walking Impairment Questionnaire walking distance, or symptoms at 12 and 52 weeks; no harms were reported.

CONCLUSIONS AND RELEVANCE

There was no direct evidence and limited indirect evidence on the benefits of PAD screening with the ABI in unselected or asymptomatic populations. Available studies suggest low sensitivity and lack of beneficial effect on health outcomes, but these studies have important limitations.

Framework for Using Risk Stratification to Improve Clinical Preventive Service Guidelines

People should only receive a preventive service if the potential benefits of the service outweigh the potential harms. Both benefits and risks may vary for different populations. Thus, it is clinically important to understand when and how guidelines for preventive services should be stratified according to the underlying risk of the population. For example, preventive services may be risk stratified with specific clinical recommendations based on age, sex, race/ethnicity, family history, genotype, behavior risks, or comorbidities. This paper articulates the conceptual approach and practical tools that were developed for consideration by the U.S. Preventive Services Task Force to determine if and how risk stratification should be incorporated into clinical guidelines. This approach is described in an algorithm with six sequential questions: (1) Are there clinically relevant subpopulations? (2) Are there credible subgroup analyses for these subpopulations? (3) Do subgroup analyses show clinically important differences? (4) Do these differences result in variation of net benefit, or does the evidence only exist in persons with a narrow spectrum of risk? (5) Can the subpopulations be easily identified? and (6) Does a well-validated multivariate risk tool improve identification of clinically relevant subpopulations compared with a simpler approach? This framework allows for a systematic approach to determine if and how to incorporate evidence for specific populations, a consistent application of critical thinking about this evidence, and transparent communication about the derivation of risk-stratified recommendations or evidence gaps.

Screening for Obesity and Intervention for Weight Management in Children and Adolescents: Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Obesity is common in children and adolescents in the United States, is associated with negative health effects, and increases the likelihood of obesity in adulthood.

OBJECTIVE

To systematically review the benefits and harms of screening and treatment for obesity and overweight in children and adolescents to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, Cochrane Collaboration Registry of Controlled Trials, and the Education Resources Information Center through January 22, 2016; references of relevant publications; government websites. Surveillance continued through December 5, 2016.

STUDY SELECTION

English-language trials of benefits or harms of screening or treatment (behavior-based, orlistat, metformin) for overweight or obesity in children aged 2 through 18 years, conducted in or recruited from health care settings.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently reviewed abstracts and full-text articles, then extracted data from fair- and good-quality trials. Random-effects meta-analysis was used to estimate the benefits of lifestyle-based programs and metformin.

MAIN OUTCOMES AND MEASURES

Weight or excess weight (eg, body mass index [BMI]; BMI z score, measuring the number of standard deviations from the median BMI for age and sex), cardiometabolic outcomes, quality of life, other health outcomes, harms.

RESULTS

There was no direct evidence on the benefits or harms of screening children and adolescents for excess weight. Among 42 trials of lifestyle-based interventions to reduce excess weight (N = 6956), those with an estimated 26 hours or more of contact consistently demonstrated mean reductions in excess weight compared with usual care or other control groups after 6 to 12 months, with no evidence of causing harm. Generally, intervention groups showed absolute reductions in BMI z score of 0.20 or more and maintained their baseline weight within a mean of approximately 5 lb, while control groups showed small increases or no change in BMI z score, typically gaining a mean of 5 to 17 lb. Only 3 of 26 interventions with fewer contact hours showed a benefit in weight reduction. Use of metformin (8 studies, n = 616) and orlistat (3 studies, n = 779) were associated with greater BMI reductions compared with placebo: -0.86 (95% CI, -1.44 to -0.29; 6 studies; I2 = 0%) for metformin and -0.50 to -0.94 for orlistat. Groups receiving lifestyle-based interventions offering 52 or more hours of contact showed greater improvements in blood pressure than control groups: -6.4 mm Hg (95% CI, -8.6 to -4.2; 6 studies; I2 = 51%) for systolic blood pressure and -4.0 mm Hg (95% CI, -5.6 to -2.5; 6 studies; I2 = 17%) for diastolic blood pressure. There were mixed findings for insulin or glucose measures and no benefit for lipids. Medications showed small or no benefit for cardiometabolic outcomes, including fasting glucose level. Nonserious harms were common with medication use, although discontinuation due to adverse effects was usually less than 5%.

CONCLUSIONS AND RELEVANCE

Lifestyle-based weight loss interventions with 26 or more hours of intervention contact are likely to help reduce excess weight in children and adolescents. The clinical significance of the small benefit of medication use is unclear.

An approach to addressing subpopulation considerations in systematic reviews: the experience of reviewers supporting the U.S. Preventive Services Task Force

BACKGROUND

Guideline developers and other users of systematic reviews need information about whether a medical or preventive intervention is likely to benefit or harm some patients more (or less) than the average in order to make clinical practice recommendations tailored to these populations. However, guidance is lacking on how to include patient subpopulation considerations into the systematic reviews upon which guidelines are often based. In this article, we describe methods developed to consistently consider the evidence for relevant subpopulations in systematic reviews conducted to support primary care clinical preventive service recommendations made by the U.S. Preventive Services Task Force (USPSTF).

PROPOSED APPROACH

Our approach is grounded in our experience conducting systematic reviews for the USPSTF and informed by a review of existing guidance on subgroup analysis and subpopulation issues. We developed and refined our approach based on feedback from the Subpopulation Workgroup of the USPSTF and pilot testing on reviews being conducted for the USPSTF. This paper provides processes and tools for incorporating evidence-based identification of important sources of potential heterogeneity of intervention effects into all phases of systematic reviews. Key components of our proposed approach include targeted literature searches and key informant interviews to identify the most important subpopulations a priori during topic scoping, a framework for assessing the credibility of subgroup analyses reported in studies, and structured investigation of sources of heterogeneity of intervention effects.

CONCLUSIONS

Further testing and evaluation are necessary to refine this proposed approach and demonstrate its utility to the producers and users of systematic reviews beyond the context of the USPSTF. Gaps in the evidence on important subpopulations identified by routinely applying this process in systematic reviews will also inform future research needs.

Bleeding Risks With Aspirin Use for Primary Prevention in Adults: A Systematic Review for the U.S. Preventive Services Task Force

BACKGROUND

The balance between potential aspirin-related risks and benefits is critical in primary prevention.

PURPOSE

To evaluate the risk for serious bleeding with regular aspirin use in cardiovascular disease (CVD) primary prevention.

DATA SOURCES

PubMed, MEDLINE, Cochrane Central Register of Controlled Trials (2010 through 6 January 2015), and relevant references from other reviews.

STUDY SELECTION

Randomized, controlled trials; cohort studies; and meta-analyses comparing aspirin with placebo or no treatment to prevent CVD or cancer in adults.

DATA EXTRACTION

One investigator abstracted data, another checked for accuracy, and 2 assessed study quality.

DATA SYNTHESIS

In CVD primary prevention studies, very-low-dose aspirin use (≤100 mg daily or every other day) increased major gastrointestinal (GI) bleeding risk by 58% (odds ratio [OR], 1.58 [95% CI, 1.29 to 1.95]) and hemorrhagic stroke risk by 27% (OR, 1.27 [CI, 0.96 to 1.68]). Projected excess bleeding events with aspirin depend on baseline assumptions. Estimated excess major bleeding events were 1.39 (CI, 0.70 to 2.28) for GI bleeding and 0.32 (CI, -0.05 to 0.82) for hemorrhagic stroke per 1000 person-years of aspirin exposure using baseline bleeding rates from a community-based observational sample. Such events could be greater among older persons, men, and those with CVD risk factors that also increase bleeding risk.

LIMITATIONS

Power to detect effects on hemorrhagic stroke was limited. Harms other than serious bleeding were not examined.

CONCLUSION

Consideration of the safety of primary prevention with aspirin requires an individualized assessment of aspirin's effects on bleeding risks and expected benefits because absolute bleeding risk may vary considerably by patient.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Aspirin for the Primary Prevention of Cardiovascular Events: A Systematic Evidence Review for the U.S. Preventive Services Task Force

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in the United States.

PURPOSE

To update a systematic review about the benefits of aspirin for the primary prevention of cardiovascular events in adults aged 40 years or older and to evaluate effect modification in subpopulations.

DATA SOURCES

MEDLINE, PubMed, Cochrane Central Register of Controlled Trials (January 2008 to January 2015), and Cochrane Database of Systematic Reviews.

STUDY SELECTION

Two investigators independently reviewed 3396 abstracts and 65 articles according to prespecified criteria. All included trials evaluated aspirin for the primary prevention of cardiovascular events.

DATA EXTRACTION

Two investigators assessed study quality; data were abstracted by 1 reviewer and checked by a second.

DATA SYNTHESIS

Two good-quality and 9 fair-quality randomized, controlled trials were identified. In analyses of all doses, aspirin reduced the risk for nonfatal myocardial infarction (MI) (relative risk [RR], 0.78 [95% CI, 0.71 to 0.87]) but not nonfatal stroke; aspirin showed little or no benefit for all-cause or cardiovascular mortality. Benefits began within the first 5 years. Older adults achieved greater relative MI reduction, but no other effect modifications were found in analyzed subpopulations. In trials with aspirin doses of 100 mg or less per day, the reduction in nonfatal MI benefit persisted (absolute risk reduction, 0.15 to 1.43 events per 1000 person-years) and a 14% reduction in nonfatal stroke benefit was noted, but no benefit was found for all-cause mortality (RR, 0.95 [CI, 0.89 to 1.01]) or cardiovascular mortality (RR, 0.97 [CI, 0.85 to 1.10]).

LIMITATION

Evidence for aspirin in primary prevention is heterogeneous and limited by rare events and few credible subgroup analyses.

CONCLUSION

The beneficial effect of aspirin for the primary prevention of CVD is modest and occurs at doses of 100 mg or less per day. Older adults seem to achieve a greater relative MI benefit.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Diagnostic and predictive accuracy of blood pressure screening methods with consideration of rescreening intervals: a systematic review for the U.S. Preventive Services Task Force

BACKGROUND

Elevated blood pressure (BP) is the largest contributing risk factor to all-cause and cardiovascular mortality.

PURPOSE

To update a systematic review on the benefits and harms of screening for high BP in adults and to summarize evidence on rescreening intervals and diagnostic and predictive accuracy of different BP methods for cardiovascular events.

DATA SOURCES

Selected databases searched through 24 February 2014.

STUDY SELECTION

Fair- and good-quality trials and diagnostic accuracy and cohort studies conducted in adults and published in English.

DATA EXTRACTION

One investigator abstracted data, and a second checked for accuracy. Study quality was dual-reviewed.

DATA SYNTHESIS

Ambulatory BP monitoring (ABPM) predicted long-term cardiovascular outcomes independently of office BP (hazard ratio range, 1.28 to 1.40, in 11 studies). Across 27 studies, 35% to 95% of persons with an elevated BP at screening remained hypertensive after nonoffice confirmatory testing. Cardiovascular outcomes in persons who were normotensive after confirmatory testing (isolated clinic hypertension) were similar to outcomes in those who were normotensive at screening. In 40 studies, hypertension incidence after rescreening varied considerably at each yearly interval up to 6 years. Intrastudy comparisons showed at least 2-fold higher incidence in older adults, those with high-normal BP, overweight and obese persons, and African Americans.

LIMITATION

Few diagnostic accuracy studies of office BP methods and protocols in untreated adults.

CONCLUSION

Evidence supports ABPM as the reference standard for confirming elevated office BP screening results to avoid misdiagnosis and overtreatment of persons with isolated clinic hypertension. Persons with BP in the high-normal range, older persons, those with an above-normal body mass index, and African Americans are at higher risk for hypertension on rescreening within 6 years than are persons without these risk factors.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Behavioral counseling to promote a healthy lifestyle in persons with cardiovascular risk factors: a systematic review for the U.S. Preventive Services Task Force

BACKGROUND

Most Americans do not meet diet and physical activity recommendations despite known health benefits.

PURPOSE

To systematically review the benefits and harms of lifestyle counseling interventions in persons with cardiovascular risk factors for the U.S. Preventive Services Task Force.

DATA SOURCES

MEDLINE, PsycINFO, the Database of Abstracts of Reviews of Effects, and the Cochrane Central Register of Controlled Trials (January 2001 to October 2013); experts; and existing systematic reviews.

STUDY SELECTION

Two investigators independently reviewed 7218 abstracts and 553 articles against a set of inclusion and quality criteria.

DATA EXTRACTION

Data from 74 trials were abstracted by one reviewer and checked by a second.

DATA SYNTHESIS

At 12 to 24 months, intensive lifestyle counseling in persons selected for risk factors reduced total cholesterol levels by an average of 0.12 mmol/L (95% CI, 0.16 to 0.07 mmol/L) (4.48 mg/dL [CI, 6.36 to 2.59 mg/dL]), low-density lipoprotein cholesterol levels by 0.09 mmol/L (CI, 0.14 to 0.04 mmol/L) (3.43 mg/dL [CI, 5.37 to 1.49 mg/dL]), systolic blood pressure by 2.03 mm Hg (CI, 2.91 to 1.15 mm Hg), diastolic blood pressure by 1.38 mm Hg (CI, 1.92 to 0.83 mm Hg), fasting glucose levels by 0.12 mmol/L (CI, 0.18 to 0.05 mmol/L) (2.08 mg/dL [CI, 3.29 to 0.88 mg/dL]), diabetes incidence by a relative risk of 0.58 (CI, 0.37 to 0.89), and weight outcomes by a standardized mean difference of 0.25 (CI, 0.35 to 0.16). Behavioral changes in dietary intake and physical activity were generally concordant with changes in physiologic outcomes.

LIMITATION

Sparse reporting of patient health outcomes, longer-term follow-up of outcomes, and harms.

CONCLUSION

Intensive diet and physical activity behavioral counseling in persons with risk factors for cardiovascular disease resulted in consistent improvements across various important intermediate health outcomes up to 2 years.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Natural uranium and thorium distributions in podzolized soils and native blueberry

Plant uptake of radionuclides is one of many vectors for introduction of contaminants into the human food chain. Thus, it is critical to understand soil-plant relationships that control nuclide bioavailability. Our objectives in this study were to (i) determine the extent of U and Th uptake and cycling by blueberry (Vaccinium pallidum Aiton) in native habitat and (ii) identify the soil properties and processes that contribute most to U and Th bioavailability in this system. We collected composite samples of plant leaves and stems, and samples from surface (AE) horizons and from the upper part of the Bs horizon at two sites. Concentration ratios (CRs) for U and Th were calculated for all plant tissues, using both the AE and Bs horizons as the base. Soil concentrations of U ranged from 16 to 25 microg g(-1), with a mean of 21.1 microg g(-1). Soil concentrations of Th ranged from 14 to 97 microg g(-1), with a mean of 41.8 microg g(-1). Mean U concentrations were 8.65 x 10(-3) microg g(-1) in leaf tissue, and 7.95 x 10(-3) microg g(-1) in stem tissue. Mean Th concentrations were 1.59 x 10(-1) microg g(-1) in leaf tissue, and 9.10 x 10(-2) microg g(-1) in stem tissue. Blueberry plants are cycling both U and Th in this system, with Th cycling occurring to a greater extent than U. In addition, Th was translocated preferentially to plant leaves while U concentrations showed little preferential translocation. Uranium uptake, however, seemed more sensitive than Th uptake to soil properties.