The design of studies testing the effectiveness of risk-guided care has many challenges: a scoping review addressing key considerations

OBJECTIVES

Studies evaluating the effectiveness of care based on patients' risk of adverse outcomes (risk-guided care) use a variety of study designs. In this scoping review, using examples, we review characteristics of relevant studies and present key design features to optimize the trustworthiness of results.

STUDY DESIGN AND SETTING

We searched five online databases for studies evaluating the effect of risk-guided care among adults on clinical outcomes, process, or cost. Pairs of reviewers independently performed screening and data abstraction. We descriptively summarized the study design and characteristics.

RESULTS

Among 14,561 hits, we identified 116 eligible studies. Study designs included randomized controlled trials (RCTs), post hoc analysis of RCTs, and retrospective or prospective cohort studies. Challenges and sources of bias in the design included limited performance of predictive models, contamination, inadequacy to address the credibility of subgroup effects, absence of differences in care across risk strata, reporting only process measures as opposed to clinical outcomes, and failure to report benefits and harms.

CONCLUSION

To assess the benefit of risk-guided care, RCTs provide the most trustworthy evidence. Observational studies offer an alternative but are hampered by confounding and other limitations. Reaching valid conclusions when testing risk-guided care requires addressing the challenges identified in our review.

Perioperative Factors Associated With Postoperative Delirium in Patients Undergoing Noncardiac Surgery: An Individual Patient Data Meta-Analysis

Importance

Postoperative delirium (POD) is a common and serious complication after surgery. Various predisposing factors are associated with POD, but their magnitude and importance using an individual patient data (IPD) meta-analysis have not been assessed.

Objective

To identify perioperative factors associated with POD and assess their relative prognostic value among adults undergoing noncardiac surgery.

Data Sources

MEDLINE, EMBASE, and CINAHL from inception to May 2020.

Study Selection

Studies were included that (1) enrolled adult patients undergoing noncardiac surgery, (2) assessed perioperative risk factors for POD, and (3) measured the incidence of delirium (measured using a validated approach). Data were analyzed in 2020.

Data Extraction and Synthesis

Individual patient data were pooled from 21 studies and 1-stage meta-analysis was performed using multilevel mixed-effects logistic regression after a multivariable imputation via chained equations model to impute missing data.

Main Outcomes and Measures

The end point of interest was POD diagnosed up to 10 days after a procedure. A wide range of perioperative risk factors was considered as potentially associated with POD.

Results

A total of 192 studies met the eligibility criteria, and IPD were acquired from 21 studies that enrolled 8382 patients. Almost 1 in 5 patients developed POD (18%), and an increased risk of POD was associated with American Society of Anesthesiologists (ASA) status 4 (odds ratio [OR], 2.43; 95% CI, 1.42-4.14), older age (OR for 65-85 years, 2.67; 95% CI, 2.16-3.29; OR for >85 years, 6.24; 95% CI, 4.65-8.37), low body mass index (OR for body mass index <18.5, 2.25; 95% CI, 1.64-3.09), history of delirium (OR, 3.9; 95% CI, 2.69-5.66), preoperative cognitive impairment (OR, 3.99; 95% CI, 2.94-5.43), and preoperative C-reactive protein levels (OR for 5-10 mg/dL, 2.35; 95% CI, 1.59-3.50; OR for >10 mg/dL, 3.56; 95% CI, 2.46-5.17). Completing a college degree or higher was associated with a decreased likelihood of developing POD (OR 0.45; 95% CI, 0.28-0.72).

Conclusions and Relevance

In this systematic review and meta-analysis of individual patient data, several important factors associated with POD were found that may help identify patients at high risk and may have utility in clinical practice to inform patients and caregivers about the expected risk of developing delirium after surgery. Future studies should explore strategies to reduce delirium after surgery.

Predicting 1-Year Mortality in Outpatients With Heart Failure With Reduced Left Ventricular Ejection Fraction: Do Empiric Models Outperform Physician Intuitive Estimates? A Multicenter Cohort Study

BACKGROUND

Many studies have demonstrated that physicians often err in estimating patient prognosis. No studies have directly compared physician to model predictive performance in heart failure (HF). We aimed to compare the accuracy of physician versus model predictions of 1-year mortality.

METHODS

This multicenter prospective cohort study on 11 HF clinics in 5 provinces in Canada included consecutive consented outpatients with HF with reduced left ventricular ejection fraction (<40%). By collecting clinical data, we calculated predicted 1-year mortality using the Seattle HF Model (SHFM), the Meta-Analysis Global Group in Chronic HF score, and the HF Meta-Score. HF cardiologists and family doctors, blinded to model predictions, estimated patient 1-year mortality. During 1-year follow-up, we recorded the composite end point of mortality, urgent ventricular assist device implant, or heart transplant. We compared physicians and model discrimination (C statistic), calibration (observed versus predicted event rate), and risk reclassification.

RESULTS

The study included 1643 patients with ambulatory HF with a mean age of 65 years, 24% female, and mean left ventricular ejection fraction of 28%. Over 1-year follow-up, 9% had an event. The SHFM had the best discrimination (SHFM C statistic 0.76; HF Meta-Score 0.73; Meta-Analysis Global Group in Chronic Heart Failure 0.70) and calibration. Physicians' discrimination differed little (0.75 for HF cardiologists and 0.73 for family doctors) but both physician groups substantially overestimated risk by >10% in both low- and high-risk patients (poor calibration). In risk reclassification analysis, among patients without events, the SHFM better classified 51% in comparison to HF cardiologists and 43% in comparison to family doctors. In patients with events, the SHFM erroneously assigned lower risk to 44% in comparison to HF cardiologists and 34% in comparison to family doctors.

CONCLUSIONS

Family doctors and HF cardiologists showed adequate risk discrimination, with however substantial overestimation of absolute risk. Predictive models showed higher accuracy. Incorporating models in family and HF cardiology practices may improve patient care and resource use in HF with reduced left ventricular ejection fraction.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04009798.

Extracorporeal Membrane Oxygenation for Graft Dysfunction Early After Heart Transplantation: A Systematic Review and Meta-analysis

INTRODUCTION

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a prevailing option for the management of severe early graft dysfunction. This systematic review and individual patient data (IPD) meta-analysis aims to evaluate (1) mortality, (2) rates of major complications, (3) prognostic factors, and (4) the effect of different VA-ECMO strategies on outcomes in adult heart transplant (HT) recipients supported with VA-ECMO.

METHODS AND RESULTS

We conducted a systematic search and included studies of adults (≥18 years) who received VA-ECMO during their index hospitalization after HT and reported on mortality at any timepoint. We pooled data using random effects models. To identify prognostic factors, we analysed IPD using mixed effects logistic regression. We assessed the certainty in the evidence using the GRADE framework. We included 49 observational studies of 1477 patients who received VA-ECMO after HT, of which 15 studies provided IPD for 448 patients. There were no differences in mortality estimates between IPD and non-IPD studies. The short-term (30-day/in-hospital) mortality estimate was 33% (moderate certainty, 95% confidence interval [CI] 28%-39%) and 1-year mortality estimate 50% (moderate certainty, 95% CI 43%-57%). Recipient age (odds ratio 1.02, 95% CI 1.01-1.04) and prior sternotomy (OR 1.57, 95% CI 0.99-2.49) are associated with increased short-term mortality. There is low certainty evidence that early intraoperative cannulation and peripheral cannulation reduce the risk of short-term death.

CONCLUSIONS

One-third of patients who receive VA-ECMO for early graft dysfunction do not survive 30 days or to hospital discharge, and one-half do not survive to 1 year after HT. Improving outcomes will require ongoing research focused on optimizing VA-ECMO strategies and care in the first year after HT.

Alterations of pulmonary vascular afterload in exercise-induced pre- and post-capillary pulmonary hypertension

Exercise imposes increased pulmonary vascular afterload based on rises in pulmonary artery (PA) wedge pressure, declines in PA compliance, and resistance-compliance time. In health, afterload stress stabilizes during steady-state exercise. Our objective was to examine alterations of these exercise-associated stresses in states of pre- and post-capillary pulmonary hypertension (PH). PA hemodynamics were evaluated at rest, 2 and 7 min of steady-state exercise at moderate intensity in patients who exhibited Pre-capillary (n = 22) and post-capillary PH (n = 22). Patients with normal exercise hemodynamics (NOR-HD) (n = 32) were also studied. During exercise in all groups, PA wedge pressure increased at 2 min, with no further change at 7 min. In post-capillary PH and NOR-HD, increases in PA diastolic pressure and diastolic pressure gradient remained stable at 2 and 7 min of exercise, while in pre-capillary PH, both continued to increase at 7 min. The behavior of the diastolic pressure gradient was linearly related to the duration of resistance-compliance time at rest (r²  = 0.843) and exercise (r²  = 0.760). Exercise resistance-compliance time was longer in pre-capillary PH associated with larger increases in diastolic pressure gradient. Conversely, resistance-compliance time was shortest in post-capillary PH compared to pre-capillary PH and NOR-HD and associated with limited increases in exercise diastolic pressure gradient. During steady-state, modest-intensity exercise-specific patterns of pulmonary vascular afterload responses were observed in pre- and post-capillary PH relative to NOR-HD. Longer resistance-compliance time related to greater increases in PA diastolic pressure and diastolic pressure gradients in pre-capillary PH, while shorter resistance-compliance time appeared to limit these increases in post-capillary PH.

Increased Mortality in Patients With Acutely Decompensated Heart Failure During the COVID-19 Pandemic in Toronto, Canada

Background

Methods

Results

Conclusions

Comparative efficacy and safety of alternative glucocorticoids regimens in patients with ANCA-associated vasculitis: a systematic review

OBJECTIVE

To compare the efficacy and safety of alternative glucocorticoids (GCs) regimens as induction therapy for patients with antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis.

DESIGN

Systematic review of randomised controlled trials (RCTs).

DATA SOURCES

Medline, Embase, Clinicaltrials.gov and Cochrane Central Register of Controlled Trials up to 10 April 2020.

STUDY SELECTION AND REVIEW METHODS

RCTs comparing two (or more) different dose regimens of GC in ANCA-associated vasculitis during induction of remission, regardless of other therapies. Pairs of reviewers independently screened records, extracted data and assessed risk of bias. Two reviewers rated certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Of 3912 records identified, the full texts of two records met the eligibility criteria. Due to the heterogeneity of population and dose regimen of GCs between the two trials, we descriptively presented the two trials and did not combine the results using meta-analysis. Compared with the standard-dose regimen, the reduced-dose regimen of GC may reduce death risk difference (RD): from -1.7% to -2.1%, low certainty), while not increasing end-stage kidney disease (ESKD) (RD: from -1.5% to 0.4%, moderate certainty). The reduced-dose regimen probably has an important reduction in serious infections at 1 year (RD: from -12.8% to -5.9%, moderate certainty). Reduced-dose regimen of GCs probably has trivial or no effect in disease remission, relapse or health-related quality of life (moderate to high certainty).

CONCLUSIONS

The reduced-dose regimen of GC may reduce death at the follow-up of 6 months to longer than 1 year and serious infections while not increasing ESKD.

PROSPERO REGISTRATION NUMBER

CRD42020179087.

Predictive models for cardiovascular and kidney outcomes in patients with type 2 diabetes: systematic review and meta-analyses

OBJECTIVE

To inform a clinical practice guideline (BMJ Rapid Recommendations) considering sodium glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists for treatment of adults with type 2 diabetes, we summarised the available evidence regarding the performance of validated risk models on cardiovascular and kidney outcomes in these patients.

METHODS

We systematically searched bibliographic databases in January 2020 to identify observational studies evaluating risk models for all-cause and cardiovascular mortality, heart failure (HF) hospitalisations, end-stage kidney disease (ESKD), myocardial infarction (MI) and ischaemic stroke in ambulatory adults with type 2 diabetes. Using a random effects model, we pooled discrimination measures for each model and outcome, separately, and descriptively summarised calibration plots, when available. We used the Prediction Model Risk of Bias Assessment Tool to assess risk of bias of each included study and the Grading of Recommendations, Assessment, Development, and Evaluation approach to evaluate our certainty in the evidence.

RESULTS

Of 22 589 publications identified, 15 observational studies reporting on seven risk models proved eligible. Among the seven models with >1 validation cohort, the Risk Equations for Complications of Type 2 Diabetes (RECODe) had the best calibration in primary studies and the highest pooled discrimination measures for the following outcomes: all-cause mortality (C-statistics 0.75, 95% CI 0.70 to 0.80; high certainty), cardiovascular mortality (0.79, 95% CI 0.75 to 0.84; low certainty), ESKD (0.73, 95% CI 0.52 to 0.94; low certainty), MI (0.72, 95% CI 0.69 to 0.74; moderate certainty) and stroke (0.71, 95% CI 0.68 to 0.74; moderate certainty). This model does not, however, predict risk of HF hospitalisations.

CONCLUSION

Of available risk models, RECODe proved to have satisfactory calibration in primary validation studies and acceptable discrimination superior to other models, though with high risk of bias in most primary studies.

TRIAL REGISTRATION NUMBER

CRD42020168351.

Incidence and impact of primary graft dysfunction in adult heart transplant recipients: A systematic review and meta-analysis

PURPOSE

Primary graft dysfunction (PGD) is a leading cause of early mortality after heart transplant (HTx). To identify PGD incidence and impact on mortality, and to elucidate risk factors for PGD, we systematically reviewed studies using the ISHLT 2014 Consensus Report definition and reporting the incidence of PGD in adult HTx recipients.

METHODS

We conducted a systematic search in January 2020 including studies reporting the incidence of PGD in adult HTx recipients. We used a random effects model to pool the incidence of PGD among HTx recipients and, for each PGD severity, the mortality rate among those who developed PGD. For prognostic factors evaluated in ≥2 studies, we used random effects meta-analyses to pool the adjusted odds ratios for development of PGD. The GRADE framework informed our certainty in the evidence.

RESULTS

Of 148 publications identified, 36 observational studies proved eligible. With moderate certainty, we observed pooled incidences of 3.5%, 6.6%, 7.7%, and 1.6% and 1-year mortality rates of 15%, 21%, 41%, and 35% for mild, moderate, severe and isolated right ventricular-PGD, respectively. Donor factors (female sex, and undersized), recipient factors (creatinine, and pre-HTx use of amiodarone, and temporary or durable mechanical support), and prolonged ischemic time proved associated with PGD post-HTx.

CONCLUSION

Our review suggests that the incidence of PGD may be low but its risk of mortality high, increasing with PGD severity. Prognostic factors, including undersized donor, recipient use of amiodarone pre-HTx and recipient creatinine may guide future studies in exploring donor and/or recipient selection and risk mitigation strategies.

Preoperative prognostic factors associated with postoperative delirium in older people undergoing surgery: protocol for a systematic review and individual patient data meta-analysis

BACKGROUND

Early identification of patients at risk for postoperative delirium is essential because adequate well-timed interventions could reduce the occurrence of delirium and the related detrimental outcomes.

METHODS

We will conduct a systematic review and individual patient data (IPD) meta-analysis of prognostic studies evaluating the predictive value of risk factors associated with an increased risk of postoperative delirium in elderly patients undergoing elective surgery. We will identify eligible studies through systematic search of MEDLINE, EMBASE, and CINAHL from their inception to May 2020. Eligible studies will enroll older adults (≥ 50 years) undergoing elective surgery and assess pre-operative prognostic risk factors for delirium and incidence of delirium measured by a trained individual using a validated delirium assessment tool. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible studies. We will contact chief investigators of eligible studies requesting to share the IPD to a secured repository. We will use one-stage approach for IPD meta-analysis and will assess certainty of evidence using the GRADE approach.

DISCUSSION

Since we are using existing anonymized data, ethical approval is not required for this study. Our results can be used to guide clinical decisions about the most efficient way to prevent postoperative delirium in elderly patients.

SYSTEMATIC REVIEW REGISTRATION

CRD42020171366 .

Resting Heart Rate as an Important Predictor of Mortality and Morbidity in Ambulatory Patients With Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Resting heart rate is a risk factor of adverse heart failure outcomes; however, studies have shown controversial results. This meta-analysis evaluates the association of resting heart rate with mortality and hospitalization and identifies factors influencing its effect.

METHODS AND RESULTS

We systematically searched electronic databases in February 2019 for studies published in 2005 or before that evaluated the resting heart rate as a primary predictor or covariate of multivariable models of mortality and/or hospitalization in adult ambulatory patients with heart failure. Random effects inverse variance meta-analyses were performed to calculate pooled hazard ratios. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to assess evidence quality. Sixty-two studies on 163,445 patients proved eligible. Median population heart rate was 74 bpm (interquartile range 72-76 bpm). A 10-bpm increase was significantly associated with increased risk of all-cause mortality (hazard ratio 1.10, 95% confidence interval 1.08-1.13, high quality). Overall, subgroup analyses related to patient characteristics showed no changes to the effect estimate; however, there was a strongly positive interaction with age showing increasing risk of all-cause mortality per 10 bpm increase in heart rate.

CONCLUSIONS

High-quality evidence demonstrates increasing resting heart rate is a significant predictor of all-cause mortality in ambulatory patients with heart failure on optimal medical therapy, with consistent effect across most patient factors and an increased risk trending with older age.

Reduced Rate of Hospital Presentations for Heart Failure During the COVID-19 Pandemic in Toronto, Canada

Coronavirus disease 2019 (COVID-19) has resulted in public health measures and health care reconfigurations likely to have impact on chronic disease care. We aimed to assess the volume and characteristics of patients presenting to hospitals with acute decompensated heart failure (ADHF) during the 2020 COVID-19 pandemic compared with a time-matched 2019 cohort. Patients presenting to hospitals with ADHF from March 1, to April 19, 2020 and 2019 in an urban hospital were examined. Multivariable logistic-regression models were used to evaluate the difference in probability of ADHF-related hospitalization between the 2 years. During the COVID-19 pandemic, a total of 1106 emergency department (ED) visits for dyspnea or peripheral edema were recorded, compared with 800 ED visits in 2019. A decrease in ADHF-related ED visits of 43.5% (14.8%-79.4%, P = 0.002) and ADHF-related admissions of 39.3% (8.6%-78.5%, P = 0.009) was observed compared with 2019. Patients with ADHF presenting to hospitals (n = 128) were similar in age, sex, and comorbidities compared with the 2019 cohort (n = 186); however, a higher proportion had recent diagnoses of heart failure. Upon ED presentation, the relative probability of hospitalization or admission to intensive care was not statistically different. There was a trend toward higher in-hospital mortality in 2020. The decline in ADHF-related hospitalizations raises the timely question of how patients with heart failure are managing beyond the acute-care setting and reinforces the need for public education on the availability and safety of emergency services throughout the COVID-19 pandemic.

Comparing DXA and Air Displacement Plethysmography to Assess Body Composition of Male Collegiate Hockey Players

Delisle-Houde, P, Reid, RER, Insogna, JA, Prokop, NW, Buchan, TA, Fontaine, SL, and Andersen, RE. Comparing DXA and air-displacement-plethysmography to assess body composition of male collegiate hockey players. J Strength Cond Res 33(2): 474-478, 2019-Accurate assessment of body composition is an important consideration for athletes because it is a health/performance variable. However, little is known about the variability in values obtained across different assessment methods for specific athlete populations. The purpose of this study was to compare 2 common laboratory methods that assess body composition: air displacement plethysmography (BOD POD) and dual energy x-ray absorptiometry (DXA). Twenty-nine male collegiate hockey players, (Age = 24.07 ± 1.49, BMI = 26.5 ± 2.74) participated in this study. All participants underwent back-to-back BOD POD and DXA evaluations. Paired t-tests and Bland-Altman analyses were performed to compare differences in fat mass, fat percentage, and fat-free mass between methods. Average fat percentage reported by the DXA and BOD POD was 15.34 ± 3.53 and 11.66 ± 4.82 respectively, resulting in a bias score of 3.78 ± 2.33 kg (t(28) = 8.71, p ≤ 0.001). Average fat mass reported by the DXA and BOD POD was 13.42 ± 3.59 and 10.15 ± 4.54 kg respectively, resulting in a bias score of 3.27 ± 1.92 kg (t(28) = 9.18, p ≤ 0.001). Average fat-free mass reported by the DXA and BOD POD was 73.31 ± 5.30 and 76.25 ± 5.74 kg respectively, resulting in a bias score of -2.93 ± 2.06 kg (t(28) = -7.66, p ≤ 0.001). Our findings can help make more insightful comparisons between studies that use different body composition methodologies among athletic populations.

Pulmonary hemodynamic and right ventricular responses to brief and prolonged exercise in middle-aged endurance athletes

Right ventricular (RV) function is closely coupled to pulmonary arterial (PA) hemodynamics and is believed to decline with prolonged exercise. A linear pressure-flow relationship is thought to exist between PA pressures and increasing exercise intensity in athletes, yet a paucity of directly measured pulmonary hemodynamic data exists supporting this contention. We sought to describe the PA pressure, PA wedge pressure (PAWP), and RV functional responses to brief and prolonged exercise in endurance-trained athletes. Twenty-one healthy athletes (54 ± 5 yr) underwent right heart catheterization to assess pulmonary hemodynamics during graded, submaximal exercise. Measurements were made at rest and during three stages of steady-state, semiupright cycle ergometry at heart rates of 100 beats/min (EX1), 130 beats/min (EX2), and 150 beats/min (EX3). Five athletes completed an additional 34 min at 130 beats/min for a total exercise time of 60 min [prolonged exercise (PLG)]. PA pressures and PAWP increased significantly at EX1 without a further rise at EX2, EX3, or PLG. PAWP adjusted for absolute work rate demonstrated a significant decline as exercise intensity increased from EX1 to EX2. The resistance compliance time constant decreased at EX1 without further changes at EX2, EX3, and prolonged exercise. RV function did not decline during PLG. After an initial rise in PA pressure and PAWP during early, nonsteady-state exercise, values remained constant despite increases in exercise intensity and duration. These data indicate that in healthy, middle-aged endurance-trained athletes, the PA and pulmonary venous/left atrial compartments rapidly accommodate high conduit flows produced during intensive and prolonged exercise while maintaining RV function.

NEW & NOTEWORTHY The right ventricular (RV)-pulmonary arterial (PA) circulatory unit has not been well studied during prolonged exercise, and this study provides an ecological approach that reflects a typical bout of endurance training integrating a transition from rest to exercise with successive increases in intensity, progressing to steady-state, sustained exercise. We demonstrated a remarkably constant response of the PA and PA wedge pressure during incremental, steady-state exercise and that no changes occur in pulmonary pressures throughout prolonged exercise, concomitant to a preservation of RV performance.

Flow-related right ventricular to pulmonary arterial pressure gradients during exercise

Aims

The assumption of equivalence between right ventricular (RV) and pulmonary arterial systolic pressure is fundamental to several assessments of RV or pulmonary vascular haemodynamic function. Our aims were to (i) determine whether systolic pressure gradients develop across the RV outflow tract in healthy adults during exercise, (ii) examine the potential correlates of such gradients, and (iii) consider the effect of such gradients on calculated indices of RV function.

Methods and results

Healthy untrained and endurance-trained adult volunteers were studied using right-heart catheterization at rest and during submaximal cycle ergometry. RV and pulmonary artery (PA) pressures were simultaneously transduced, and the cardiac output was determined by thermodilution. Systolic pressures, peak and mean gradients, and indices of chamber, vascular, and valve function were analysed offline. Summary data are reported as mean ± standard deviation or median (interquartile range). No significant RV outflow tract gradients were observed at rest [mean gradient = 4 (3–5) mmHg], and the calculated effective orifice area was 3.6 ± 1.0 cm2. The increase in right ventricular systolic pressure during exercise was greater than the PA systolic pressure. Accordingly, mean gradients were developed during light exercise [8 (7–9) mmHg] and increased during moderate exercise [12 (9–14) mmHg, P < 0.001]. The magnitude of the mean gradient was linearly related to the cardiac output (r2 = 0.70, P < 0.001).

Conclusions

In healthy adults without pulmonic stenosis, systolic pressure gradients develop during exercise, and the magnitude is related to the blood flow rate.