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Statistics in Medicine Dec 2015The propensity score is defined as a subject's probability of treatment selection, conditional on observed baseline covariates. Weighting subjects by the inverse... (Review)
Review
Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies.
The propensity score is defined as a subject's probability of treatment selection, conditional on observed baseline covariates. Weighting subjects by the inverse probability of treatment received creates a synthetic sample in which treatment assignment is independent of measured baseline covariates. Inverse probability of treatment weighting (IPTW) using the propensity score allows one to obtain unbiased estimates of average treatment effects. However, these estimates are only valid if there are no residual systematic differences in observed baseline characteristics between treated and control subjects in the sample weighted by the estimated inverse probability of treatment. We report on a systematic literature review, in which we found that the use of IPTW has increased rapidly in recent years, but that in the most recent year, a majority of studies did not formally examine whether weighting balanced measured covariates between treatment groups. We then proceed to describe a suite of quantitative and qualitative methods that allow one to assess whether measured baseline covariates are balanced between treatment groups in the weighted sample. The quantitative methods use the weighted standardized difference to compare means, prevalences, higher-order moments, and interactions. The qualitative methods employ graphical methods to compare the distribution of continuous baseline covariates between treated and control subjects in the weighted sample. Finally, we illustrate the application of these methods in an empirical case study. We propose a formal set of balance diagnostics that contribute towards an evolving concept of 'best practice' when using IPTW to estimate causal treatment effects using observational data.
Topics: Humans; Models, Statistical; Monte Carlo Method; Observational Studies as Topic; Outcome Assessment, Health Care; Propensity Score
PubMed: 26238958
DOI: 10.1002/sim.6607 -
Sports Medicine (Auckland, N.Z.) Feb 2022Body-fluid loss during prolonged continuous exercise can impair cardiovascular function, harming performance. Delta percent plasma volume (dPV) represents the change in... (Meta-Analysis)
Meta-Analysis
The Hydrating Effects of Hypertonic, Isotonic and Hypotonic Sports Drinks and Waters on Central Hydration During Continuous Exercise: A Systematic Meta-Analysis and Perspective.
BACKGROUND
Body-fluid loss during prolonged continuous exercise can impair cardiovascular function, harming performance. Delta percent plasma volume (dPV) represents the change in central and circulatory body-water volume and therefore hydration during exercise; however, the effect of carbohydrate-electrolyte drinks and water on the dPV response is unclear.
OBJECTIVE
To determine by meta-analysis the effects of ingested hypertonic (> 300 mOsmol kg), isotonic (275-300 mOsmol kg) and hypotonic (< 275 mOsmol kg) drinks containing carbohydrate and electrolyte ([Na] < 50 mmol L), and non-carbohydrate drinks/water (< 40 mOsmol kg) on dPV during continuous exercise.
METHODS
A systematic review produced 28 qualifying studies and 68 drink treatment effects. Random-effects meta-analyses with repeated measures provided estimates of effects and probability of superiority (p) during 0-180 min of exercise, adjusted for drink osmolality, ingestion rate, metabolic rate and a weakly informative Bayesian prior.
RESULTS
Mean drink effects on dPV were: hypertonic - 7.4% [90% compatibility limits (CL) - 8.5, - 6.3], isotonic - 8.7% (90% CL - 10.1, - 7.4), hypotonic - 6.3% (90% CL - 7.4, - 5.3) and water - 7.5% (90% CL - 8.5, - 6.4). Posterior contrast estimates relative to the smallest important effect (dPV = 0.75%) were: hypertonic-isotonic 1.2% (90% CL - 0.1, 2.6; p = 0.74), hypotonic-isotonic 2.3% (90% CL 1.1, 3.5; p = 0.984), water-isotonic 1.3% (90% CL 0.0, 2.5; p = 0.76), hypotonic-hypertonic 1.1% (90% CL 0.1, 2.1; p = 0.71), hypertonic-water 0.1% (90% CL - 0.8, 1.0; p = 0.12) and hypotonic-water 1.1% (90% CL 0.1, 2.0; p = 0.72). Thus, hypotonic drinks were very likely superior to isotonic and likely superior to hypertonic and water. Metabolic rate, ingestion rate, carbohydrate characteristics and electrolyte concentration were generally substantial modifiers of dPV.
CONCLUSION
Hypotonic carbohydrate-electrolyte drinks ingested continuously during exercise provide the greatest benefit to hydration.
Topics: Bayes Theorem; Dehydration; Exercise; Humans; Osmolar Concentration; Sodium; Water-Electrolyte Balance
PubMed: 34716905
DOI: 10.1007/s40279-021-01558-y -
JAMA Network Open Sep 2023Current rehabilitation guidelines for patients with post-COVID-19 condition (PCC) are primarily based on expert opinions and observational data, and there is an urgent... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Current rehabilitation guidelines for patients with post-COVID-19 condition (PCC) are primarily based on expert opinions and observational data, and there is an urgent need for evidence-based rehabilitation interventions to support patients with PCC.
OBJECTIVE
To synthesize the findings of existing studies that report on physical capacity (including functional exercise capacity, muscle function, dyspnea, and respiratory function) and quality of life outcomes following rehabilitation interventions in patients with PCC.
DATA SOURCES
A systematic electronic search was performed from January 2020 until February 2023, in MEDLINE, Scopus, CINAHL, and the Clinical Trials Registry. Key terms that were used to identify potentially relevant studies included long-covid, post-covid, sequelae, exercise therapy, rehabilitation, physical activity, physical therapy, and randomized controlled trial.
STUDY SELECTION
This study included randomized clinical trials that compared respiratory training and exercise-based rehabilitation interventions with either placebo, usual care, waiting list, or control in patients with PCC.
DATA EXTRACTION AND SYNTHESIS
This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A pairwise bayesian random-effects meta-analysis was performed using vague prior distributions. Risk of bias was assessed using the Cochrane risk of bias tool version 2, and the certainty of evidence was evaluated using the GRADE system by 2 independent researchers.
MAIN OUTCOMES AND MEASURES
The primary outcome was functional exercise capacity, measured at the closest postintervention time point by the 6-minute walking test. Secondary outcomes were fatigue, lower limb muscle function, dyspnea, respiratory function, and quality of life. All outcomes were defined a priori. Continuous outcomes were reported as standardized mean differences (SMDs) with 95% credible intervals (CrIs) and binary outcomes were summarized as odds ratios with 95% CrIs. The between-trial heterogeneity was quantified using the between-study variance, τ2, and 95% CrIs.
RESULTS
Of 1834 identified records, 1193 were screened, and 14 trials (1244 patients; 45% female participants; median [IQR] age, 50 [47 to 56] years) were included in the analyses. Rehabilitation interventions were associated with improvements in functional exercise capacity (SMD, -0.56; 95% CrI, -0.87 to -0.22) with moderate certainty in 7 trials (389 participants). These improvements had a 99% posterior probability of superiority when compared with current standard care. The value of τ2 (0.04; 95% CrI, 0.00 to 0.60) indicated low statistical heterogeneity. However, there was significant uncertainty and imprecision regarding the probability of experiencing exercise-induced adverse events (odds ratio, 1.68; 95% CrI, 0.32 to 9.94).
CONCLUSIONS AND RELEVANCE
The findings of this systematic review and meta-analysis suggest that rehabilitation interventions are associated with improvements in functional exercise capacity, dyspnea, and quality of life, with a high probability of improvement compared with the current standard care; the certainty of evidence was moderate for functional exercise capacity and quality of life and low for other outcomes. Given the uncertainty surrounding the safety outcomes, additional trials with enhanced monitoring of adverse events are necessary.
Topics: Humans; Adult; Female; Middle Aged; Male; Quality of Life; Post-Acute COVID-19 Syndrome; Bayes Theorem; COVID-19; Dyspnea; Randomized Controlled Trials as Topic
PubMed: 37725376
DOI: 10.1001/jamanetworkopen.2023.33838 -
BMJ (Clinical Research Ed.) May 2016To provide an overview of prediction models for risk of cardiovascular disease (CVD) in the general population. (Review)
Review
OBJECTIVE
To provide an overview of prediction models for risk of cardiovascular disease (CVD) in the general population.
DESIGN
Systematic review.
DATA SOURCES
Medline and Embase until June 2013.
ELIGIBILITY CRITERIA FOR STUDY SELECTION
Studies describing the development or external validation of a multivariable model for predicting CVD risk in the general population.
RESULTS
9965 references were screened, of which 212 articles were included in the review, describing the development of 363 prediction models and 473 external validations. Most models were developed in Europe (n=167, 46%), predicted risk of fatal or non-fatal coronary heart disease (n=118, 33%) over a 10 year period (n=209, 58%). The most common predictors were smoking (n=325, 90%) and age (n=321, 88%), and most models were sex specific (n=250, 69%). Substantial heterogeneity in predictor and outcome definitions was observed between models, and important clinical and methodological information were often missing. The prediction horizon was not specified for 49 models (13%), and for 92 (25%) crucial information was missing to enable the model to be used for individual risk prediction. Only 132 developed models (36%) were externally validated and only 70 (19%) by independent investigators. Model performance was heterogeneous and measures such as discrimination and calibration were reported for only 65% and 58% of the external validations, respectively.
CONCLUSIONS
There is an excess of models predicting incident CVD in the general population. The usefulness of most of the models remains unclear owing to methodological shortcomings, incomplete presentation, and lack of external validation and model impact studies. Rather than developing yet another similar CVD risk prediction model, in this era of large datasets, future research should focus on externally validating and comparing head-to-head promising CVD risk models that already exist, on tailoring or even combining these models to local settings, and investigating whether these models can be extended by addition of new predictors.
Topics: Cardiovascular Diseases; Female; Humans; Male; Models, Theoretical; Predictive Value of Tests; Risk Assessment; Risk Factors
PubMed: 27184143
DOI: 10.1136/bmj.i2416 -
Medicina Intensiva 2017Pressure ulcers represent a significant problem for patients, professionals and health systems. Their reported incidence and prevalence are significant worldwide. Their... (Review)
Review
INTRODUCTION
Pressure ulcers represent a significant problem for patients, professionals and health systems. Their reported incidence and prevalence are significant worldwide. Their character iatrogenic states that its appearance is preventable and its incidence is an indicator of scientific and technical quality both in primary care and specialized care. The aim of this review was to identify risk factors associated with the occurrence of pressure ulcers in critically ill patients.
METHODOLOGY
The PRISMA Declaration recommendations have been followed and adapted to studies identifying risk factors. A qualitative systematic review of primary studies has been performed and a search was conducted of the PubMed, The Cochrane Library, Scopus and Web of Science databases. Methodological limitations in observational studies have been considered.
RESULTS
From 200 references, 17 fulfilled the eligibility criteria. These studies included 19,363 patients admitted to intensive care units. Six studies were classified as high quality and 11 were classified as moderate quality. Risk factors that emerged as predictive of pressure ulcers development more frequently included age, length of ICU stay, diabetes, time of MAP <60-70mmHg, mechanical ventilation, length of mechanical ventilation, intermittent haemodialysis or continuous veno-venous haemofiltration therapy, vasopressor support, sedation and turning.
CONCLUSIONS
There is no single factors which can explain the occurrence of pressure ulcers. Rather, it is an interplay of factors that increase the probability of its development.
Topics: Critical Illness; Humans; Intensive Care Units; Pressure Ulcer; Risk Factors
PubMed: 27780589
DOI: 10.1016/j.medin.2016.09.003 -
Journal of Periodontology May 2018A wide selection of Interdental Oral Hygiene (IOH) aids is available to consumers. Recommendations for selection are, however, limited by the lack of direct comparisons... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A wide selection of Interdental Oral Hygiene (IOH) aids is available to consumers. Recommendations for selection are, however, limited by the lack of direct comparisons in available studies. We aimed to assess the comparative efficacy of IOH aids using Bayesian Network Meta-Analysis (BNMA).
METHODS
Two independent reviewers performed a systematic literature review of randomized clinical trials assessing IOH aids, based on a focused question. Gingival inflammation (Gingival Index (GI), Bleeding-on-probing (BOP)) was the primary outcome and plaque and probing depth were secondary outcomes A random-effects arm-based BNMA model was run for each outcome; posterior medians and 95% credible-intervals (CIs) summarized marginal distributions of parameters.
RESULTS
A two-phase selection process identified 22 trials assessing 10 IOH aids as brushing adjuncts. Interdental brushes (IB) yielded the largest reduction in GI (0.23 [95% CI: 0.09, 0.37]) as toothbrushing adjuncts, followed by water-jet (WJ) (0.19 [95% CI: 0.14, 0.24]). Rankings based on posterior probabilities revealed that IB and WJ had the highest probability of being "best" (64.7% and 27.4%, respectively) for GI reduction, whereas the probability for toothpick and floss being the "best" IOH aids was near zero. Notably, except for toothpicks, all IOH aids were better at reducing GI as compared with control.
CONCLUSIONS
BNMA enabled us to quantitatively evaluate IOH aids and provide a global ranking of their efficacy. Interdental brushes and water-jets ranked high for reducing gingival bleeding, whereas toothpicks and floss ranked last. The patient-perceived benefit of IOH aids is not clear because gingival inflammation measures are physical indicators of periodontal health.
Topics: Bayes Theorem; Dental Devices, Home Care; Dental Plaque Index; Gingivitis; Humans; Inflammation; Oral Hygiene; Toothbrushing
PubMed: 29520910
DOI: 10.1002/JPER.17-0368 -
JAMA Oct 2023The effect of continuous positive airway pressure (CPAP) on secondary cardiovascular disease prevention is highly debated. (Meta-Analysis)
Meta-Analysis
IMPORTANCE
The effect of continuous positive airway pressure (CPAP) on secondary cardiovascular disease prevention is highly debated.
OBJECTIVE
To assess the effect of CPAP treatment for obstructive sleep apnea (OSA) on the risk of adverse cardiovascular events in randomized clinical trials.
DATA SOURCES
PubMed (MEDLINE), EMBASE, Current Controlled Trials: metaRegister of Controlled Trials, ISRCTN Registry, European Union clinical trials database, CENTRAL (Cochrane Central Register of Controlled Trials), and ClinicalTrials.gov databases were systematically searched through June 22, 2023.
STUDY SELECTION
For qualitative and individual participant data (IPD) meta-analysis, randomized clinical trials addressing the therapeutic effect of CPAP on cardiovascular outcomes and mortality in adults with cardiovascular disease and OSA were included.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently screened records, evaluated potentially eligible primary studies in full text, extracted data, and cross-checked errors. IPD were requested from authors of the selected studies (SAVE [NCT00738179], ISAACC [NCT01335087], and RICCADSA [NCT00519597]).
MAIN OUTCOMES AND MEASURES
One-stage and 2-stage IPD meta-analyses were completed to estimate the effect of CPAP treatment on risk of recurrent major adverse cardiac and cerebrovascular events (MACCEs) using mixed-effect Cox regression models. Additionally, an on-treatment analysis with marginal structural Cox models using inverse probability of treatment weighting was fitted to assess the effect of good adherence to CPAP (≥4 hours per day).
RESULTS
A total of 4186 individual participants were evaluated (82.1% men; mean [SD] body mass index, 28.9 [4.5]; mean [SD] age, 61.2 [8.7] years; mean [SD] apnea-hypopnea index, 31.2 [17] events per hour; 71% with hypertension; 50.1% receiving CPAP [mean {SD} adherence, 3.1 {2.4} hours per day]; 49.9% not receiving CPAP [usual care], mean [SD] follow-up, 3.25 [1.8] years). The main outcome was defined as the first MACCE, which was similar for the CPAP and no CPAP groups (hazard ratio, 1.01 [95% CI, 0.87-1.17]). However, an on-treatment analysis by marginal structural model revealed a reduced risk of MACCEs associated with good adherence to CPAP (hazard ratio, 0.69 [95% CI, 0.52-0.92]).
CONCLUSIONS AND RELEVANCE
Adherence to CPAP was associated with a reduced MACCE recurrence risk, suggesting that treatment adherence is a key factor in secondary cardiovascular prevention in patients with OSA.
Topics: Female; Humans; Male; Middle Aged; Cardiovascular Diseases; Continuous Positive Airway Pressure; Hypertension; Proportional Hazards Models; Sleep Apnea, Obstructive; Risk; Aged; Secondary Prevention; Patient Compliance
PubMed: 37787793
DOI: 10.1001/jama.2023.17465 -
JMIR MHealth and UHealth Dec 2022Coronary artery disease is the main cause of death and loss of disability-adjusted life years worldwide. Information and communication technology has become an important... (Meta-Analysis)
Meta-Analysis Review
Effectiveness of mHealth Interventions in the Control of Lifestyle and Cardiovascular Risk Factors in Patients After a Coronary Event: Systematic Review and Meta-analysis.
BACKGROUND
Coronary artery disease is the main cause of death and loss of disability-adjusted life years worldwide. Information and communication technology has become an important part of health care systems, including the innovative cardiac rehabilitation services through mobile phone and mobile health (mHealth) interventions.
OBJECTIVE
In this study, we aimed to determine the effectiveness of different kinds of mHealth programs in changing lifestyle behavior, promoting adherence to treatment, and controlling modifiable cardiovascular risk factors and psychosocial outcomes in patients who have experienced a coronary event.
METHODS
A systematic review of the literature was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A thorough search of the following biomedical databases was conducted: PubMed, Embase, Web of Science, SciELO, CINAHL, Scopus, The Clinical Trial, and Cochrane. Articles that were randomized clinical trials that involved an intervention consisting of an mHealth program using a mobile app in patients after a coronary event were included. The articles analyzed some of the following variables as outcome variables: changes in lifestyle behavior, cardiovascular risk factors, and anthropometric and psychosocial variables. A meta-analysis of the variables studied was performed with the Cochrane tool. The risk of bias was assessed using the Cochrane Collaboration tool; the quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation tool; and heterogeneity was measured using the I test.
RESULTS
A total of 23 articles were included in the review, and 20 (87%) were included in the meta-analysis, with a total sample size of 4535 patients. Exercise capacity measured using the 6-minute walk test (mean difference=21.64, 95% CI 12.72-30.55; P<.001), physical activity (standardized mean difference [SMD]=0.42, 95% CI 0.04-0.81; P=.03), and adherence to treatment (risk difference=0.19, 95% CI 0.11-0.28; P<.001) were significantly superior in the mHealth group. Furthermore, both the physical and mental dimensions of quality of life were better in the mHealth group (SMD=0.26, 95% CI 0.09-0.44; P=.004 and SMD=0.27, 95% CI 0.06-0.47; P=.01, respectively). In addition, hospital readmissions for all causes and cardiovascular causes were statistically higher in the control group than in the mHealth group (SMD=-0.03, 95% CI -0.05 to -0.00; P=.04 vs SMD=-0.04, 95% CI -0.07 to -0.00; P=.05).
CONCLUSIONS
mHealth technology has a positive effect on patients who have experienced a coronary event in terms of their exercise capacity, physical activity, adherence to medication, and physical and mental quality of life, as well as readmissions for all causes and cardiovascular causes.
TRIAL REGISTRATION
PROSPERO (International Prospective Register of Systematic Reviews) CRD42022299931; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=299931.
Topics: Humans; Quality of Life; Cardiovascular Diseases; Risk Factors; Heart Disease Risk Factors; Life Style; Telemedicine; Randomized Controlled Trials as Topic
PubMed: 36459396
DOI: 10.2196/39593 -
JAMA Oncology Dec 2020Measurable residual disease (MRD) refers to neoplastic cells that cannot be detected by standard cytomorphologic analysis. In patients with acute myeloid leukemia (AML),... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Measurable residual disease (MRD) refers to neoplastic cells that cannot be detected by standard cytomorphologic analysis. In patients with acute myeloid leukemia (AML), determining the association of MRD with survival may improve prognostication and inform selection of efficient clinical trial end points.
OBJECTIVE
To examine the association between MRD status and disease-free survival (DFS) and overall survival (OS) in patients with AML using scientific literature.
DATA SOURCES
Clinical studies on AML published between January 1, 2000, and October 1, 2018, were identified via searches of PubMed, Embase, and MEDLINE.
STUDY SELECTION
Literature search and study screening were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Studies that assessed DFS or OS by MRD status in patients with AML were included. Reviews, non-English-language articles, and studies reporting only outcomes after hematopoietic cell transplantation or those with insufficient description of MRD information were excluded.
DATA EXTRACTION AND SYNTHESIS
Study sample size, median patient age, median follow-up time, MRD detection method, MRD assessment time points, AML subtype, specimen source, and survival outcomes were extracted. Meta-analyses were performed separately for DFS and OS using bayesian hierarchical modeling.
MAIN OUTCOMES AND MEASURES
Meta-analyses of survival probabilities and hazard ratios (HRs) were conducted for OS and DFS according to MRD status.
RESULTS
Eighty-one publications reporting on 11 151 patients were included. The average HR for achieving MRD negativity was 0.36 (95% bayesian credible interval [CrI], 0.33-0.39) for OS and 0.37 (95% CrI, 0.34-0.40) for DFS. The estimated 5-year DFS was 64% for patients without MRD and 25% for those with MRD, and the estimated OS was 68% for patients without MRD and 34% for those with MRD. The association of MRD negativity with DFS and OS was significant for all subgroups, with the exception of MRD assessed by cytogenetics or fluorescent in situ hybridization.
CONCLUSIONS AND RELEVANCE
The findings of this meta-analysis suggest that achievement of MRD negativity is associated with superior DFS and OS in patients with AML. The value of MRD negativity appears to be consistent across age groups, AML subtypes, time of MRD assessment, specimen source, and MRD detection methods. These results support MRD status as an end point that may allow for accelerated evaluation of novel therapies in AML.
Topics: Bayes Theorem; Hematopoietic Stem Cell Transplantation; Humans; In Situ Hybridization, Fluorescence; Leukemia, Myeloid, Acute; Neoplasm, Residual; Prognosis
PubMed: 33030517
DOI: 10.1001/jamaoncol.2020.4600 -
Journal of the American Heart... Jun 2015Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.
METHODS AND RESULTS
Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment-insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.
CONCLUSIONS
This meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.
Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Biomarkers; Cardiovascular Diseases; Exercise; Female; Health Status; Humans; Male; Middle Aged; Physical Fitness; Prognosis; Protective Factors; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Risk Reduction Behavior; Sex Factors; Young Adult
PubMed: 26116691
DOI: 10.1161/JAHA.115.002014