Implementing GRADE: calculating the risk difference from the baseline risk and the relative risk

Surgical interventions for spontaneous supratentorial intracerebral haemorrhage: a systematic review and network meta-analysis

Background

Surgical interventions for spontaneous supratentorial intracerebral haemorrhage (ICH) include conventional craniotomy (CC), decompressive craniectomy (DC), and minimally invasive surgery (MIS), with the latter encompassing endoscopic surgery (ES) and minimally invasive puncture surgery (MIPS). However, the superiority of surgery over conservative medical treatment (CMT) and the comparative benefits of different surgical procedures remain unclear. We aimed to evaluate the efficacy and safety of various surgical interventions for treating ICH.

Methods

In this systematic review and network meta-analysis, we searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials.gov from inception to June 16, 2024. Eligible studies were randomised controlled trials (RCTs) comparing surgery (i.e., CC, ES, MIPS, or DC) with CMT or comparing different types of surgeries in patients with spontaneous supratentorial ICH. Paired reviewers independently screened citations, assessed the risk of bias of included trials, and extracted data. Primary outcomes were good functional outcome and mortality at 6 months. Secondary outcomes were good functional outcome and mortality at different follow-up times, complications (rebleeding, brain infection, pulmonary infection), and hematoma evacuation rate. The frequentist pairwise and network meta-analysis (NMA) were performed. The GRADE approach was used to evaluate the certainty of evidence. This study is registered with PROSPERO, CRD42024518961.

Findings

Of the 8573 total records identified by our searches, 31 studies (6448 patients) were eligible for the systematic review and network analysis. Compared with CMT, moderate certainty evidence showed that surgery improved good functional outcome (risk ratio [RR] 1.31, 95% CI 1.13-1.52; risk difference [RD] 9.1%, 95% CI 3.8 to 15.3; I 2  = 36%) and reduced mortality (RR 0.82, 95% CI 0.71-0.95; RD -5.1%, 95% CI -8.2 to -1.4; I 2  = 14%). Moderate certainty evidence from NMA suggested that compared with CMT, both ES (RR 1.51, 95% CI 1.18-1.93; RD 9.4%, 95% CI 3.3-17.1) and MIPS (RR 1.48, 95% CI 1.24-1.76; RD 15.7%, 95% CI 7.9-24.9) improved good functional outcome at 6 months, and both ES (RR 0.66, 95% CI 0.52-0.85; RD -17.0%, 95% CI -24.0 to -7.5) and CC (RR 0.75, 95% CI 0.60-0.94; RD -6.3%, 95% CI -10.1 to -1.5) reduced mortality at 6 months, whereas MIPS and DC showed a trend, although not statistically significant, towards a reduction in mortality. ES and MIPS also reduced pulmonary infection risk (ES RR 0.39, 95% CI 0.23-0.69; MIPS RR 0.35, 95% CI 0.20-0.60; RD -5.3%, 95% CI -6.6 to -3.3). ES showed higher hematoma evacuation than CC (MD: 7.03, 95% CI: 3.42-10.65; I 2  = 94%). No difference in rebleeding or brain infection was found between CC and MIS.

Interpretation

Current moderate certainty evidence suggested that surgical intervention of spontaneous supratentorial ICH, may be associated with improved functional outcomes and a reduced risk of death at 6 months. The advantages of surgical haematoma removal are particularly pronounced when MIS including ES and MIPS are employed. ES could improve functional outcomes, reduce the risk of mortality and pulmonary infection, and have a high hematoma evacuation rate, suggesting that it might be an optimal surgical treatment.

Funding

National Natural Science Foundation of China, National Science Fund for Distinguished Young Scholars, Fundamental Research Funds for the Central Public Welfare Research Institutes, and 1·3·5 project for disciplines of excellence, West China Hospital, Sichuan University.

Alcohol consumption and frailty risk: a dose-response meta-analysis of cohort studies

BACKGROUND/AIMS

While previous studies suggest that light-to-moderate alcohol consumption may reduce the frailty risk, the dose-response relationship is still under question. To address the knowledge gap, we conducted a systematic review and dose-response meta-analysis of cohort studies to examine the association of alcohol consumption with the risk of both prefrailty and frailty in adults.

METHODS

We searched MEDLINE (Ovid), PubMed and Scopus to identify relevant cohort studies published before 8 May 2024. The dose-response meta-analysis was performed to investigate the associations between alcohol drinking and the risk of developing pre-frailty and frailty. We used random-effects models to calculate pooled relative risks (RR) with 95% CIs.

RESULTS

We included nine cohort studies with 64 769 participants and 15 075 cases, of which eight studies were rated to have a serious risk of bias as assessed by the ROBINS tool. Based on our analysis, each 12 g increase in alcohol intake did not appear to be associated with risks of prefrailty (RR: 1.08, 95% CI 0.89, 1.31; I2 = 91%, n = 3; GRADE = very low) and frailty (RR: 0.94, 95% CI 0.88, 1.00; I2 = 63%, n = 9; GRADE = low). The nonlinear dose-response meta-analysis indicates a slight inverse association with frailty risk up to an alcohol intake of 20 grams per day, beyond which an upward trend is observed.

CONCLUSION

The inverse association found between moderate alcohol consumption and frailty risk appears to be stronger among older adults, which might be due to the lower and less popular alcohol consumption among older people than the general population. However, because this finding is based on low-quality evidence, more research is needed to develop specific dietary recommendations for alcohol consumption, particularly among young people.

Progestogens in women with threatened miscarriage or recurrent miscarriage: A meta-analysis

INTRODUCTION

Clinical practice guidelines provide inconsistent recommendations regarding progestogen supplementation for threatened and recurrent miscarriage. We conducted a systematic review and meta-analysis to assess the effectiveness and safety of progestogens for these patients.

MATERIAL AND METHODS

We searched Medline, Embase, and Cochrane Central Registry of Controlled Trials up to October 6, 2023 for randomized control trials (RCTs) comparing progestogen supplementation to placebo or no treatment for pregnant women with threatened or recurrent miscarriage. We assessed the risk of bias using a modified version of the Cochrane risk-of-bias tool and the certainty of evidence using the GRADE approach.

RESULTS

Of 15 RCTs (6616 pregnancies) reporting on threatened or recurrent miscarriage, 12 (5610 pregnancies) reported on threatened miscarriage with or without a prior history of miscarriage. Results indicated that progesterone probably increases live births (relative risk (RR) 1.04, 95% confidence interval (CI) 0.99-1.10, absolute increase 3.1%, moderate certainty). Of these RCTs, three (1973 pregnancies) reporting on threatened miscarriage with a prior history of miscarriage indicated that progesterone possibly increases live births (RR 1.06, 95% CI: 0.97-1.16, absolute increase 4.4%; low certainty), while four (2540 pregnancies) reporting on threatened miscarriage and no prior miscarriage left the effect very uncertain (RR 1.02, 95% CI: 0.96-1.10, absolute increase 1.7%; very low certainty). Three trials reporting on 1006 patients with a history of two or more prior miscarriages indicated progesterone probably increases live births (RR 1.08, 95% CI: 0.98-1.19, absolute increase 5.7%, moderate certainty). Six RCTs that reported on 2979 patients with at least one prior miscarriage indicated that progesterone probably increases live births (RR 1.07, 95% CI: 1.01-1.13, absolute increase 5.0%; moderate certainty). Progesterone probably has little or no effect on congenital anomalies (RR 1.06, 95% CI: 0.76-1.48, absolute increase 0.1%; moderate certainty), and other serious adverse pregnancy events (RR 1.07, 95% CI: 0.83-1.40, absolute increase 0.2%, moderate certainty).

CONCLUSIONS

In women at increased risk of pregnancy loss, progestogens probably increase live births without increasing adverse maternal and neonatal events. It remains possible that the benefit is restricted to those with prior miscarriages.

Antivirals for post-exposure prophylaxis of influenza: a systematic review and network meta-analysis

BACKGROUND

Antiviral post-exposure prophylaxis with neuraminidase inhibitors can reduce the incidence of influenza and the risk of symptomatic influenza, but the efficacy of the other classes of antiviral remains unclear. To support an update of WHO influenza guidelines, this systematic review and network meta-analysis evaluated antiviral drugs for post-exposure prophylaxis of influenza.

METHODS

We systematically searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Global Health, Epistemonikos, and ClinicalTrials.gov for randomised controlled trials published up to Sept 20, 2023 that evaluated the efficacy and safety of antivirals compared with another antiviral or placebo or standard care for prevention of influenza. Pairs of reviewers independently screened studies, extracted data, and assessed the risk of bias. We performed network meta-analyses with frequentist random effects model and assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. The outcomes of interest were symptomatic or asymptomatic infection, admission to hospital, all-cause mortality, adverse events related to antivirals, and serious adverse events. This study is registered with PROSPERO, CRD42023466450.

FINDINGS

Of 11 845 records identified by our search, 33 trials of six antivirals (zanamivir, oseltamivir, laninamivir, baloxavir, amantadine, and rimantadine) that enrolled 19 096 individuals (mean age 6·75-81·15 years) were included in this systematic review and network meta-analysis. Most of the studies were rated as having a low risk of bias. Zanamivir, oseltamivir, laninamivir, and baloxavir probably achieve important reductions in symptomatic influenza in individuals at high risk of severe disease (zanamivir: risk ratio 0·35, 95% CI 0·25-0·50; oseltamivir: 0·40, 0·26-0·62; laninamivir: 0·43, 0·30-0·63; baloxavir: 0·43, 0·23-0·79; moderate certainty) when given promptly (eg, within 48 h) after exposure to seasonal influenza. These antivirals probably do not achieve important reductions in symptomatic influenza in individuals at low risk of severe disease when given promptly after exposure to seasonal influenza (moderate certainty). Zanamivir, oseltamivir, laninamivir, and baloxavir might achieve important reductions in symptomatic zoonotic influenza in individuals exposed to novel influenza A viruses associated with severe disease in infected humans when given promptly after exposure (low certainty). Oseltamivir, laninamivir, baloxavir, and amantadine probably decrease the risk of all influenza (symptomatic and asymptomatic infection; moderate certainty). Zanamivir, oseltamivir, laninamivir, and baloxavir probably have little or no effect on prevention of asymptomatic influenza virus infection or all-cause mortality (high or moderate certainty). Oseltamivir probably has little or no effect on admission to hospital (moderate certainty). All six antivirals do not significantly increase the incidence of drug-related adverse events or serious adverse events, although the certainty of evidence varies.

INTERPRETATION

Post-exposure prophylaxis with zanamivir, oseltamivir, laninamivir, or baloxavir probably decreases the risk of symptomatic seasonal influenza in individuals at high risk for severe disease after exposure to seasonal influenza viruses. Post-exposure prophylaxis with zanamivir, oseltamivir, laninamivir, or baloxavir might reduce the risk of symptomatic zoonotic influenza after exposure to novel influenza A viruses associated with severe disease in infected humans.

FUNDING

World Health Organization.

Heterogeneity of Benefit from Earlier Time-to-Antibiotics for Sepsis

Rationale: Shorter time-to-antibiotics improves survival from sepsis, particularly among patients in shock. There may be other subgroups for whom faster antibiotics are particularly beneficial.Objectives: Identify patient characteristics associated with greater benefit from shorter time-to-antibiotics.Methods: Observational cohort study of patients hospitalized with community-onset sepsis at 173 hospitals and treated with antimicrobials within 12 hours. We used three approaches to evaluate heterogeneity of benefit from shorter time-to-antibiotics: 1) conditional average treatment effects of shorter (⩽3 h) versus longer (>3-12 h) time-to-antibiotics on 30-day mortality using multivariable Poisson regression; 2) causal forest to identify characteristics associated with greatest benefit from shorter time-to-antibiotics; and 3) logistic regression with time-to-antibiotics modeled as a spline.Measurements and Main Results: Among 273,255 patients with community-onset sepsis, 131,094 (48.0%) received antibiotics within 3 hours. In Poisson models, shorter time-to-antibiotics was associated with greater absolute mortality reduction among patients with metastatic cancer (5.0% [95% confidence interval; CI: 4.3-5.7] vs. 0.4% [95% CI: 0.2-0.6] for patients without cancer, P < 0.001); patients with shock (7.0% [95% CI: 5.8-8.2%] vs. 2.8% [95% CI: 2.7-3.5%] for patients without shock, P = 0.005); and patients with more acute organ dysfunctions (4.8% [95% CI: 3.9-5.6%] for three or more dysfunctions vs. 0.5% [95% CI: 0.3-0.8] for one dysfunction, P < 0.001). In causal forest, metastatic cancer and shock were associated with greatest benefit from shorter time-to-antibiotics. Spline analysis confirmed differential nonlinear associations of time-to-antibiotics with mortality in patients with metastatic cancer and shock.Conclusions: In patients with community-onset sepsis, the mortality benefit of shorter time-to-antibiotics varied by patient characteristics. These findings suggest that shorter time-to-antibiotics for sepsis is particularly important among patients with cancer and/or shock.

Direct Oral Anticoagulants for Stroke Prevention in Patients With Device-Detected Atrial Fibrillation: A Study-Level Meta-Analysis of the NOAH-AFNET 6 and ARTESiA Trials

BACKGROUND

Device-detected atrial fibrillation (also known as subclinical atrial fibrillation or atrial high-rate episodes) is a common finding in patients with an implanted cardiac rhythm device and is associated with an increased risk of ischemic stroke. Whether oral anticoagulation is effective and safe in this patient population is unclear.

METHODS

We performed a systematic review of MEDLINE and Embase for randomized trials comparing oral anticoagulation with antiplatelet or no antithrombotic therapy in adults with device-detected atrial fibrillation recorded by a pacemaker, implantable cardioverter defibrillator, cardiac resynchronization therapy device, or implanted cardiac monitor. We used random-effects models for meta-analysis and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). The review was preregistered (PROSPERO CRD42023463212).

RESULTS

From 785 citations, we identified 2 randomized trials with relevant clinical outcome data: NOAH-AFNET 6 (Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes; 2536 participants) evaluated edoxaban, and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; 4012 participants) evaluated apixaban. Meta-analysis demonstrated that oral anticoagulation with these agents reduced ischemic stroke (relative risk [RR], 0.68 [95% CI, 0.50-0.92]; high-quality evidence). The results from the 2 trials were consistent (I2 statistic for heterogeneity=0%). Oral anticoagulation also reduced a composite of cardiovascular death, all-cause stroke, peripheral arterial embolism, myocardial infarction, or pulmonary embolism (RR, 0.85 [95% CI, 0.73-0.99]; I2=0%; moderate-quality evidence). There was no reduction in cardiovascular death (RR, 0.95 [95% CI, 0.76-1.17]; I2=0%; moderate-quality evidence) or all-cause mortality (RR, 1.08 [95% CI, 0.96-1.21]; I2=0%; moderate-quality evidence). Oral anticoagulation increased major bleeding (RR, 1.62 [95% CI, 1.05-2.50]; I²=61%; high-quality evidence).

CONCLUSIONS

The results of the NOAH-AFNET 6 and ARTESiA trials are consistent with each other. Meta-analysis of these 2 large randomized trials provides high-quality evidence that oral anticoagulation with edoxaban or apixaban reduces the risk of stroke in patients with device-detected atrial fibrillation and increases the risk of major bleeding.

Walking speed and the risk of type 2 diabetes: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between walking speed and the risk of type 2 diabetes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Scopus, CENTRAL and Web of Science to 30 May 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included cohort studies that explored the association between walking speed and the risk of type 2 diabetes in adults. We used random-effects meta-analyses to calculate relative risk (RR) and risk difference (RD). We rated the credibility of subgroup differences and the certainty of evidence using the Instrument to assess the Credibility of Effect Modification ANalyses (ICEMAN) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) tools, respectively.

RESULTS

Ten cohort studies were included. Compared with easy/casual walking (<3.2 km/hour), the RR of type 2 diabetes was 0.85 (95% CI 0.70 to 1.00); RD=0.86 (95% CI 1.72 to 0) fewer cases per 100 patients; n=4, GRADE=low) for average/normal walking (3.2-4.8 km/hour), 0.76 (95% CI 0.65 to 0.87); RD=1.38 (95% CI 2.01 to 0.75) fewer cases per 100 patients; n=10, GRADE=low) for fairly brisk walking (4.8-6.4 km/hour) and 0.61 (95% CI 0.49 to 0.73; RD=2.24 (95% CI 2.93 to 1.55) fewer cases per 100 patients; n=6, GRADE=moderate) for brisk/striding walking (>6.4 km/hour). There was no significant or credible difference across subgroups based on adjustment for the total volume of physical activity and time spent walking per day. Dose-response analysis suggested that the risk of type 2 diabetes decreased significantly at a walking speed of 4 km/h and above.

CONCLUSIONS

Low to moderate certainty evidence, mainly from studies with a high risk of bias, suggests that walking at faster speeds is associated with a graded decrease in the risk of type 2 diabetes.

PROSPERO REGISTRATION NUMBER

CRD42023432795.

Association of Gestational Free and Total Triiodothyronine With Gestational Hypertension, Preeclampsia, Preterm Birth, and Birth Weight: An Individual Participant Data Meta-analysis

CONTEXT

Triiodothyronine (T3) is the bioactive form of thyroid hormone. In contrast to thyroid-stimulating hormone and free thyroxine, we lack knowledge on the association of gestational T3 with adverse obstetric outcomes.

OBJECTIVE

To investigate the associaiton of gestational free or total T3 (FT3 or TT3) with adverse obstetric outcomes.

METHODS

We collected individual participant data from prospective cohort studies on gestational FT3 or TT3, adverse obstetric outcomes (preeclampsia, gestational hypertension, preterm birth and very preterm birth, small for gestational age [SGA], and large for gestational age [LGA]), and potential confounders. We used mixed-effects regression models adjusting for potential confounders.

RESULTS

The final study population comprised 33 118 mother-child pairs of which 27 331 had data on FT3 and 16 164 on TT3. There was a U-shaped association of FT3 with preeclampsia (P = .0069) and a J-shaped association with the risk of gestational hypertension (P = .029). Higher TT3 was associated with a higher risk of gestational hypertension (OR per SD of TT3 1.20, 95% CI 1.08 to 1.33; P = .0007). A lower TT3 but not FT3 was associated with a higher risk of very preterm birth (OR 0.72, 95% CI 0.55 to 0.94; P = .018). TT3 but not FT3 was positively associated with birth weight (mean difference per 1 SD increase in TT3 12.8, 95% CI 6.5 to 19.1 g, P < .0001) but there was no association with SGA or LGA.

CONCLUSION

This study provides new insights on the association of gestational FT3 and TT3 with major adverse pregnancy outcomes that form the basis for future studies required to elucidate the effects of thyroid function on pregnancy outcomes. Based on the current study, routine FT3 or TT3 measurements for the assessment of thyroid function during pregnancy do not seem to be of added value in the risk assessment for adverse outcomes.

Ideal cardiovascular health metrics and risk of type 2 diabetes: A systematic review and dose-response meta-analysis of prospective cohort studies

BACKGROUND AND AIMS

Studies suggest a potential link between ideal cardiovascular health (CVH) and the risk of type 2 diabetes (T2D). However, systematic reviews are lacking to pool these data and present a balanced review about this association.

METHODS AND RESULTS

We performed a systematic search of PubMed/Medline, Web of Sciences, and Scopus from inception until November 2022 to search for prospective observational studies assessing the link between ideal CVH metrics, as introduced by the American Heart Association, and the risk of T2D in adults. Nine cohort studies with 78,912 participants and 6242 cases of T2D were included. The pooled relative risk of T2D for the highest versus the lowest category of ideal CVH metrics was 0.36 (95% confidence interval [CI]: 0.25, 0.47; risk difference: 5 fewer per 100 patients, 95% CI: 6 fewer, 4 fewer; Grading of Recommendations Assessment, Development and Evaluation certainty = high). Each unit increase in the components of the ideal CVH metrics was associated with a 20% lower risk of T2D. Dose-response meta-analysis indicated a monotonic inverse association between ideal CVH metrics and the risk of T2D. Results from analysis of individual components showed that having a normal weight, adopting a healthy diet, and having normal blood pressure levels were associated with a reduced risk of T2D.

CONCLUSIONS

Having an ideal CVH profile and a unit increase in any CVH metric are inversely associated with the risk of T2D.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022376934.

Assessing Health and Economic Benefits of Omega-3 Fatty Acid Supplementation on Cardiovascular Disease in the Republic of Korea

BACKGROUND

Cardiovascular disease (CVD) is the primary cause of mortality worldwide and imposes a significant social burden on many countries.

METHODS

This study assessed the health and economic benefits of omega-3 associated with CVD. The meta-analysis estimated the risk ratio (RR) and absolute risk reduction (ARR), and the economic impact was calculated using direct and indirect costs related to CVD treatments in Korean adults.

RESULTS

A total of 33 studies were included in the meta-analysis on CVD outcomes, with 80,426 participants in the intervention group and 80,251 participants in the control group. The meta-analysis determined a significant reduction in omega-3 in CVD (RR = 0.92, 95% CI: 0.86~0.97) and ARR (1.48%). Additionally, the subgroup analysis indicated that higher doses and the long-term consumption of omega-3 could further enhance these effects. After applying ARR from meta-analysis to the target population of about 1,167,370 in 2021, the Republic of Korea, it was estimated that omega-3 consumption could result in an economic benefit of KRW 300 billion by subtracting the purchase expenses of omega-3 supplements from the total social cost savings.

CONCLUSION

Omega-3 supplements can help to reduce the risk of CVD and subsequent economic benefits in the Republic of Korea.

Effect of calorie restriction in comparison to usual diet or usual care on remission of type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Limited evidence is available about the dose-dependent effects of calorie restriction in patients with type 2 diabetes.

OBJECTIVE

To gather available evidence on the effect of calorie restriction on management of type 2 diabetes.

METHODS

We systematically searched PubMed, Scopus, CENTRAL, Web of Science, and gray literature to November 2022 for randomized trials longer than 12 weeks looking at the effect of a pre-specified calorie-restricted diet on remission of type 2 diabetes. We performed random-effects meta-analyses to estimate the absolute effect (risk difference) at 6-month (6±3 months) and 12-month (12±3 months) follow-ups. We performed dose-response meta-analyses to estimate mean difference (MD) for the effects of calorie restriction on cardiometabolic outcomes. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to judge the certainty of evidence.

RESULTS

28 randomized trials with 6281 participants were included. Using a remission definition of glycated hemoglobin (HbA_1c) <6.5% without antidiabetic medication use, calorie-restricted diets increased remission by 38 more per 100 patients (95%CI: 9 more, 67 more; n=5 trials, GRADE=moderate) at 6-month, and by 13 more per 100 patients (95%CI: 10 more, 18 more; n=4, GRADE=moderate) at 12-month in comparison to usual diet or usual care. Using a definition of HbA_1c<6.5% after at least two months cessation of antidiabetic medications, remission increased by 34 more per 100 patients (95%CI: 15 more, 53 more; n=1, GRADE=very low) at 6-month and by 16 more per 100 patients (95%CI: 4 more, 49 more; n=2, GRADE=low) at 12-month. At 6-month, each 500 kcal/day decrease in energy intake resulted in clinically meaningful reductions in body weight (MD: -6.33 kg, 95%CI: -7.76, -4.90; n=22; GRADE=high) and HbA_1c (MD: -0.82%, 95%CI: -1.05, -0.59; n=18, GRADE=high), which attenuated remarkably at 12-month.

CONCLUSIONS

Calorie-restricted diets may be effective interventions for type 2 diabetes remission, especially when coupled with an intensive lifestyle modification program.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42022300875).

SGLT2 inhibitors in type 2 diabetes: a systematic review and meta-analysis of cardiovascular outcome trials balancing their risks and benefits

AIMS/HYPOTHESIS

Cardiovascular outcome trials (CVOTs) have demonstrated the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i). However, serious adverse drug reactions have been reported. The risk/benefit ratio of SGLT2i remains unquantified. We aimed to provide an estimation of their risk/benefit ratio in individuals with type 2 diabetes.

METHODS

We conducted a systematic review (MEDLINE, up to 14 September 2021) and meta-analysis. We included randomised CVOTs assessing SGLT2i in individuals with type 2 diabetes with or without other diseases. We used the Cochrane 'Risk of bias' assessment tool. The primary outcomes were overall mortality, major adverse cardiovascular events (MACE), hospitalisation for heart failure (HHF), end-stage renal disease (ESRD), amputation, diabetic ketoacidosis (DKA) and reported genital infections. For each outcome, we estimated the incidence rate ratio (IRR) with a 95% CI; we then computed the number of events expected spontaneously and with SGLT2i.

RESULTS

A total of 46,969 participants from five double-blind, placebo-controlled international trials (weighted mean follow-up 3.5 years) were included. The prevalence of previous CVD ranged from 40.6% to 99.2%. The definition of reported genital infections ranged from 'genital mycotic infection' to 'genital infections that led to discontinuation of the trial regimen or were considered to be serious adverse events'. The number of included studies for each outcomes was five. The use of SGLT2i decreased the risk of all-cause death (IRR 0.86 [95% CI 0.78, 0.95]), MACE (IRR 0.91 [95% CI 0.86, 0.96]), HHF (IRR 0.69 [95% CI 0.62, 0.76]) and ESRD (IRR 0.67 [95% CI 0.53, 0.84]), and increased the risk of DKA (IRR 2.59 [95% CI 1.57, 4.27]) and genital infection (IRR 3.50 [95% CI 3.09, 3.95]) but not of amputation (IRR 1.23 [95% CI 1.00, 1.51]). For 1000 individuals treated over 3.5 years, SGLT2i are expected, on average, to decrease the number of deaths from 70 to 61, to prevent nine MACE, 11 HHF and two cases of ESRD, while inducing two DKA occurrences and 36 genital infections; 778 individuals are expected to avoid all the following outcomes: MACE, HHF, ESRD, amputation, DKA and genital infection.

CONCLUSIONS/INTERPRETATION

Our study is limited to aggregate data. In a population of individuals with type 2 diabetes and a high CVD risk, the cardiovascular and renal benefits of SGLT2i remain substantial despite the risk of DKA and even the hypothetical risk of amputation.

TRIAL REGISTRATION

OSF Registries: https://doi.org/10.17605/OSF.IO/J3R7Y FUNDING: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Herbal medicine for functional dyspepsia: Network meta-analysis of placebo-controlled randomised trials

ETHNOPHARMACOLOGICAL RELEVANCE

Conventional treatments for functional dyspepsia (FD) are limited. Herbal medicine (HM) use is prevalent despite unclear comparative effectiveness among different formulae.

AIM OF THE STUDY

This network meta-analysis (NMA) aimed to evaluate the comparative effectiveness of HM formulae for FD against placebo.

MATERIALS AND METHODS

Seven international and Chinese databases were searched for randomised controlled trials (RCTs) on HM versus placebo. Risk of bias among RCTs was assessed using Cochrane Risk-of-Bias Tool 2. Data from RCTs were extracted for random-effect pairwise meta-analyses. NMAs were performed to evaluate the comparative effectiveness of HM formulae. GRADE partially contextualised framework was adopted to facilitate NMA result interpretation.

RESULTS

Twelve different HM formulae were identified from fifteen RCTs of mediocre quality. At 8-week follow-up, pairwise meta-analyses indicated that HM was superior to placebo in alleviating global symptoms (pooled risk difference (RD): 0.20; 95% confidence interval (CI): 0.11-0.29), with effect size larger than the minimally clinically important difference of 0.20 RD. Sensitivity analysis showed no significant impact on results attributable to risk of bias. NMAs demonstrated that Xiao Yao Pill and Modified Ban Xia Xie Xin Decoction probably have a large beneficial effect on alleviating global symptoms (RD: 0.37; 95% CI: 0.03-0.99) and postprandial fullness (standardised mean difference: -0.93; 95% credible interval: -1.61 to -0.06), respectively. No serious adverse events were reported.

CONCLUSIONS

Xiao Yao Pill and Modified Ban Xia Xie Xin Decoction may be considered as an alternative among patients unresponsive to conventional treatments. The comparative effectiveness of these two formulae should be evaluated in future trials.

Clinical Outcomes With Medium Cut-Off Versus High-Flux Hemodialysis Membranes: A Systematic Review and Meta-Analysis

BACKGROUND

A novel medium cut-off (MCO) dialyzer (Theranova, Baxter Healthcare, Deerfield, IL, USA) enhances large middle molecule clearance while retaining selectivity for molecules >45 000 Da.

OBJECTIVE

We undertook a systematic review and meta-analysis evaluating clinical outcomes with MCO vs high-flux membranes.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Cochrane Library, and Web of Science through July 2020, and gray literature sources from 2017. We included randomized (RS) and nonrandomized studies (NRS) comparing MCO and high-flux membranes in adults receiving maintenance hemodialysis. Pairs of reviewers performed study selection, data extraction, and risk of bias assessment in duplicate. We conducted random-effects pairwise meta-analyses to pool results across studies and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess evidence certainty.

RESULTS

We identified 22 eligible studies (6 RS, 16 NRS; N = 1811 patients; patient-years = 1546). The MCO dialyzer improved (estimate; 95% confidence interval [CI]; certainty rating) quality of life (mean difference [MD] = 16.7/100 points; 6.9 to 26.4; moderate), Kidney Disease Quality of Life Instrument (KDQOL) subscales-burden (MD = 4.0; 1.1 to 6.9; moderate) and effects (MD = 5.4; 3.2 to 7.6; moderate), pruritus (MD = -4.4; -7.1 to -1.7; moderate), recovery time (MD = -420 minutes; -541 to -299; high), and restless legs syndrome (odds ratio = 0.39; 0.29 to 0.53; moderate). There was little to no difference in all-cause mortality (risk difference = -0.4%; -2.8 to 2.1; moderate) and serious adverse events (rate ratio = 0.63; 0.38 to 1.04; low). MCO dialysis reduced hospitalization (rate ratio = 0.48; 0.27 to 0.84; low), infection (rate ratio = 0.38; 0.17 to 0.85; moderate), hospitalization days (MD = -1.5 days; 95% CI, -2.22 to -0.78; moderate), erythropoiesis resistance index (MD = -2.92 U/kg/week/g/L; 95% CI, -4.25 to -1.6; moderate) and cumulative iron use over 12 weeks (MD = -293 mg; 95% CI, -368 to -218; moderate). We found with low certainty that MCO dialysis had little to no effect on KDQOL symptoms/problem list, pain, and physical health and moderate certainty that MCO dialysis likely has no effect on the KDQOL mental health composite.

CONCLUSIONS

We found with predominantly moderate certainty that the MCO dialyzer improves several patient-important outcomes with no apparent risks or harms. More definitive studies are needed to better quantify the effects of MCO membranes on mortality, hospitalization, and other rare events.

Chinese herbal medicine for functional dyspepsia: a network meta-analysis of prokinetic-controlled randomised trials

BACKGROUND

Prokinetic is the first-line conventional treatment for functional dyspepsia (FD) in Asia despite potential adverse events. Chinese herbal medicine (CHM) may be an effective and safe substitution. This network meta-analysis (NMA) aimed to evaluate the comparative effectiveness of different CHM formulae for FD against prokinetics.

METHODS

Seven international and Chinese databases were searched from their inception to July 2020 for randomised controlled trials (RCTs) on CHM versus prokinetics. Data from each RCT were first pooled using random-effect pairwise meta-analyses and illustrated as risk difference (RD) or standardised mean difference (SMD) with 95% confidence interval (CI). Random-effect NMAs were then performed to evaluate the comparative effectiveness of CHM formulae and displayed as RD with 95% CI or SMD with 95% credible interval (CrI). The GRADE partially contextualised framework was applied for NMA result interpretation.

RESULTS

Twenty-six unique CHM formulae were identified from twenty-eight RCTs of mediocre quality. Pairwise meta-analyses indicated that CHM was superior to prokinetics in alleviating global symptoms at 4-week follow-up (pooled RD: 0.14; 95% CI: 0.10-0.19), even after trim and fill adjustment for publication bias. NMAs demonstrated that Modified Zhi Zhu Decoction may have a moderate beneficial effect on alleviating global symptoms at 4-week follow-up (RD: 0.28; 95% CI: - 0.03 to 0.75). Xiao Pi Kuan Wei Decoction may have a large beneficial effect on alleviating postprandial fullness (SMD: - 2.14; 95% CI: - 2.76 to 0.70), early satiety (SMD: - 3.90; 95% CI: - 0.68 to - 0.42), and epigastric pain (SMD: - 1.23; 95% CI: - 1.66 to - 0.29). No serious adverse events were reported.

CONCLUSION

Modified Zhi Zhu Decoction and Xiao Pi Kuan Wei Decoction may be considered as an alternative for patients unresponsive to prokinetics. Confirmatory head-to-head trials should be conducted to investigate their comparative effectiveness against prokinetics.

Diabetes, hypertension, body mass index, smoking and COVID-19-related mortality: a systematic review and meta-analysis of observational studies

OBJECTIVES

We conducted a systematic literature review and meta-analysis of observational studies to investigate the association between diabetes, hypertension, body mass index (BMI) or smoking with the risk of death in patients with COVID-19 and to estimate the proportion of deaths attributable to these conditions.

METHODS

Relevant observational studies were identified by searches in the PubMed, Cochrane library and Embase databases through 14 November 2020. Random-effects models were used to estimate summary relative risks (SRRs) and 95% CIs. Certainty of evidence was assessed using the Cochrane methods and the Grading of Recommendations, Assessment, Development and Evaluations framework.

RESULTS

A total of 186 studies representing 210 447 deaths among 1 304 587 patients with COVID-19 were included in this analysis. The SRR for death in patients with COVID-19 was 1.54 (95% CI 1.44 to 1.64, I2=92%, n=145, low certainty) for diabetes and 1.42 (95% CI 1.30 to 1.54, I2=90%, n=127, low certainty) for hypertension compared with patients without each of these comorbidities. Regarding obesity, the SSR was 1.45 (95% CI 1.31 to 1.61, I2=91%, n=54, high certainty) for patients with BMI ≥30 kg/m2 compared with those with BMI <30 kg/m2 and 1.12 (95% CI 1.07 to 1.17, I2=68%, n=25) per 5 kg/m2 increase in BMI. There was evidence of a J-shaped non-linear dose-response relationship between BMI and mortality from COVID-19, with the nadir of the curve at a BMI of around 22-24, and a 1.5-2-fold increase in COVID-19 mortality with extreme obesity (BMI of 40-45). The SRR was 1.28 (95% CI 1.17 to 1.40, I2=74%, n=28, low certainty) for ever, 1.29 (95% CI 1.03 to 1.62, I2=84%, n=19) for current and 1.25 (95% CI 1.11 to 1.42, I2=75%, n=14) for former smokers compared with never smokers. The absolute risk of COVID-19 death was increased by 14%, 11%, 12% and 7% for diabetes, hypertension, obesity and smoking, respectively. The proportion of deaths attributable to diabetes, hypertension, obesity and smoking was 8%, 7%, 11% and 2%, respectively.

CONCLUSION

Our findings suggest that diabetes, hypertension, obesity and smoking were associated with higher COVID-19 mortality, contributing to nearly 30% of COVID-19 deaths.

TRIAL REGISTRATION NUMBER

CRD42020218115.

Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis

BACKGROUND

The effects of omega-3 fatty acids (FAs), such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, on cardiovascular outcomes are uncertain. We aimed to determine the effectiveness of omega-3 FAs on fatal and non-fatal cardiovascular outcomes and examine the potential variability in EPA vs. EPA+DHA treatment effects.

METHODS

We searched EMBASE, PubMed, ClinicalTrials.gov, and Cochrane library databases through June 7, 2021. We performed a meta-analysis of 38 randomized controlled trials of omega-3 FAs, stratified by EPA monotherapy and EPA+DHA therapy. We estimated random-effects rate ratios (RRs) with (95% confidence intervals) and rated the certainty of evidence using GRADE. The key outcomes of interest were cardiovascular mortality, non-fatal cardiovascular outcomes, bleeding, and atrial fibrillation (AF). The protocol was registered in PROSPERO (CRD42021227580).

FINDINGS

In 149,051 participants, omega-3 FA was associated with reducing cardiovascular mortality (RR, 0.93 [0.88-0.98]; p = 0.01), non-fatal myocardial infarction (MI) (RR, 0.87 [0.81-0.93]; p = 0.0001), coronary heart disease events (CHD) (RR, 0.91 [0.87-0.96]; p = 0.0002), major adverse cardiovascular events (MACE) (RR, 0.95 [0.92-0.98]; p = 0.002), and revascularization (RR, 0.91 [0.87-0.95]; p = 0.0001). The meta-analysis showed higher RR reductions with EPA monotherapy (0.82 [0.68-0.99]) than with EPA + DHA (0.94 [0.89-0.99]) for cardiovascular mortality, non-fatal MI (EPA: 0.72 [0.62-0.84]; EPA+DHA: 0.92 [0.85-1.00]), CHD events (EPA: 0.73 [0.62-0.85]; EPA+DHA: 0.94 [0.89-0.99]), as well for MACE and revascularization. Omega-3 FA increased incident AF (RR, 1.26 [1.08-1.48]). EPA monotherapy vs. control was associated with a higher risk of total bleeding (RR: 1.49 [1.20-1.84]) and AF (RR, 1.35 [1.10-1.66]).

INTERPRETATION

Omega-3 FAs reduced cardiovascular mortality and improved cardiovascular outcomes. The cardiovascular risk reduction was more prominent with EPA monotherapy than with EPA+DHA.

FUNDING

None.

Effectiveness of training interventions to improve quality of medical certification of cause of death: systematic review and meta-analysis

BACKGROUND

Valid cause of death data are essential for health policy formation. The quality of medical certification of cause of death (MCCOD) by physicians directly affects the utility of cause of death data for public policy and hospital management. Whilst training in correct certification has been provided for physicians and medical students, the impact of training is often unknown. This study was conducted to systematically review and meta-analyse the effectiveness of training interventions to improve the quality of MCCOD.

METHODS

This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO; Registration ID: CRD42020172547) and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. CENTRAL, Ovid MEDLINE and Ovid EMBASE databases were searched using pre-defined search strategies covering the eligibility criteria. Studies were selected using four screening questions using the Distiller-SR software. Risk of bias assessments were conducted with GRADE recommendations and ROBINS-I criteria for randomised and non-randomised interventions, respectively. Study selection, data extraction and bias assessments were performed independently by two reviewers with a third reviewer to resolve conflicts. Clinical, methodological and statistical heterogeneity assessments were conducted. Meta-analyses were performed with Review Manager 5.4 software using the 'generic inverse variance method' with risk difference as the pooled estimate. A 'summary of findings' table was prepared using the 'GRADEproGDT' online tool. Sensitivity analyses and narrative synthesis of the findings were also performed.

RESULTS

After de-duplication, 616 articles were identified and 21 subsequently selected for synthesis of findings; four underwent meta-analysis. The meta-analyses indicated that selected training interventions significantly reduced error rates among participants, with pooled risk differences of 15-33%. Robustness was identified with the sensitivity analyses. The findings of the narrative synthesis were similarly suggestive of favourable outcomes for both physicians and medical trainees.

CONCLUSIONS

Training physicians in correct certification improves the accuracy and policy utility of cause of death data. Investment in MCCOD training activities should be considered as a key component of strategies to improve vital registration systems given the potential of such training to substantially improve the quality of cause of death data.

PCSK9 monoclonal antibodies for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Despite the availability of effective drug therapies that reduce low-density lipoprotein (LDL)-cholesterol (LDL-C), cardiovascular disease (CVD) remains an important cause of mortality and morbidity. Therefore, additional LDL-C reduction may be warranted, especially for people who are unresponsive to, or unable to take, existing LDL-C-reducing therapies. By inhibiting the proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme, monoclonal antibodies (PCSK9 inhibitors) reduce LDL-C and CVD risk.

OBJECTIVES

Primary To quantify the effects of PCSK9 inhibitors on CVD, all-cause mortality, myocardial infarction, and stroke, compared to placebo or active treatment(s) for primary and secondary prevention. Secondary To quantify the safety of PCSK9 inhibitors, with specific focus on the incidence of influenza, hypertension, type 2 diabetes, and cancer, compared to placebo or active treatment(s) for primary and secondary prevention.

SEARCH METHODS

We identified studies by systematically searching CENTRAL, MEDLINE, Embase, and Web of Science in December 2019. We also searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in August 2020 and screened the reference lists of included studies. This is an update of the review first published in 2017.

SELECTION CRITERIA

All parallel-group and factorial randomised controlled trials (RCTs) with a follow-up of at least 24 weeks were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and extracted data. Where data were available, we calculated pooled effect estimates. We used GRADE to assess certainty of evidence and in 'Summary of findings' tables.

MAIN RESULTS

We included 24 studies with data on 60,997 participants. Eighteen trials randomised participants to alirocumab and six to evolocumab. All participants received background lipid-lowering treatment or lifestyle counselling. Six alirocumab studies used  an active treatment comparison group (the remaining used placebo), compared to three evolocumab active comparison trials. Alirocumab compared with placebo decreased the risk of CVD events, with an absolute risk difference (RD) of -2% (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.80 to 0.94; 10 studies, 23,868 participants; high-certainty evidence), decreased the risk of mortality (RD -1%; OR 0.83, 95% CI 0.72 to 0.96; 12 studies, 24,797 participants; high-certainty evidence), and MI (RD -2%; OR 0.86, 95% CI 0.79 to 0.94; 9 studies, 23,352 participants; high-certainty evidence) and for any stroke (RD 0%; OR 0.73, 95% CI 0.58 to 0.91; 8 studies, 22,835 participants; high-certainty evidence). Compared to active treatment the alirocumab effects, for CVD, the RD was 1% (OR 1.37, 95% CI 0.65 to 2.87; 3 studies, 1379 participants; low-certainty evidence); for mortality, RD was -1% (OR 0.51, 95% CI 0.18 to 1.40; 5 studies, 1333 participants; low-certainty evidence); for MI, RD was 1% (OR 1.45, 95% CI 0.64 to 3.28, 5 studies, 1734 participants; low-certainty evidence); and for any stroke, RD was less than 1% (OR 0.85, 95% CI 0.13 to 5.61; 5 studies, 1734 participants; low-certainty evidence). Compared to placebo the evolocumab, for CVD, the RD was -2% (OR 0.84, 95% CI 0.78 to 0.91; 3 studies, 29,432 participants; high-certainty evidence); for mortality, RD was less than 1% (OR 1.04, 95% CI 0.91 to 1.19; 3 studies, 29,432 participants; high-certainty evidence); for MI, RD was -1% (OR 0.72, 95% CI 0.64 to 0.82; 3 studies, 29,432 participants; high-certainty evidence); and for any stroke RD was less than -1% (OR 0.79, 95% CI 0.65 to 0.94; 2 studies, 28,531 participants; high-certainty evidence).  Compared to active treatment, the evolocumab effects, for any CVD event RD was less than -1% (OR 0.66, 95% CI 0.14 to 3.04; 1 study, 218 participants; very low-certainty evidence); for all-cause mortality, the RD was less than 1% (OR 0.43, 95% CI 0.14 to 1.30; 3 studies, 5223 participants; very low-certainty evidence); and for MI, RD was less than 1% (OR 0.66, 95% CI 0.23 to 1.85; 3 studies, 5003 participants; very low-certainty evidence). There were insufficient data on any stroke.  AUTHORS' CONCLUSIONS: The evidence for the clinical endpoint effects of  evolocumab and alirocumab were graded as high. There is a strong evidence base to prescribe PCSK9 monoclonal antibodies to people who might not be eligible for other lipid-lowering drugs, or to people who cannot meet their lipid goals on more traditional therapies, which was the main patient population of the available trials.  The evidence base of PCSK9 inhibitors compared with active treatment is much weaker (low very- to low-certainty evidence) and it is unclear whether evolocumab or alirocumab might be effectively used as replacement therapies. Related, most of the available studies preferentially enrolled people with either established CVD or at a high risk already, and evidence in low- to medium-risk settings is minimal. Finally, there is very limited evidence on any potential safety issues of both evolocumab and alirocumab. While the current evidence synthesis does not reveal any adverse signals, neither does it provide evidence against such signals. This suggests careful consideration of alternative lipid lowering treatments before prescribing PCSK9 inhibitors.

Step by step: Association of device-measured daily steps with all-cause mortality-A prospective cohort Study

Introduction

Walking is free, does not require special training, and can be done almost everywhere. Therefore, walking is a feasible behavior on which to tailor public health messages. This study assesses the prospective association and dose‐response relationship between daily steps and all‐cause mortality.

Materials and Methods

Daily steps were measured by waist‐mounted accelerometers in 2183 individuals (53% women) for seven consecutive days at baseline (2008‐09). Participants were followed for a median period of 9.1 years and associations between steps and all‐cause mortality determined by registry linkage were assessed using Cox proportional hazard regression with adjustment for relevant covariates.

Results

Mean age was 57.0 (SD 10.9) years at baseline. Median (IQR) daily steps across ascending quartiles were 4651 (3495‐5325), 6862 (6388‐7350), 8670 (8215‐9186), and 11 467 (10 556‐13 110), respectively. During follow‐up, 119 individuals died (68% men). Higher number of daily steps was associated with a lower risk of all‐cause mortality with hazard ratios of 1.00 (referent), 0.52 (0.29‐0.93), 0.50 (0.27‐0.94), and 0.43 (0.21‐0.88) across ascending quartiles of daily steps in the multivariable‐adjusted model with follow‐up commencing 2 years after baseline. Risk differences per 1000 individuals for ascending quartiles were 6.8 (2.9‐9.3), 7.1 (0.8‐11.1), and 8.0 (1.7‐12.1), respectively.

Conclusions

Daily steps were associated with lower mortality risk in a non‐linear dose‐response pattern. The risk is almost halved when comparing the least active referent against the second quartile equivalent to a difference of about 2200 daily steps. Encouraging those least active to increase their daily steps may have substantial public health implications.

Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis

BACKGROUND

Adequate transplacental passage of maternal thyroid hormone is important for normal fetal growth and development. Maternal overt hypothyroidism and hyperthyroidism are associated with low birthweight, but important knowledge gaps remain regarding the effect of subclinical thyroid function test abnormalities on birthweight-both in general and during the late second and third trimester of pregnancy. The aim of this study was to examine associations of maternal thyroid function with birthweight.

METHODS

In this systematic review and individual-participant data meta-analysis, we searched MEDLINE (Ovid), Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar from inception to Oct 15, 2019, for prospective cohort studies with data on maternal thyroid function during pregnancy and birthweight, and we issued open invitations to identify study authors to join the Consortium on Thyroid and Pregnancy. We excluded participants with multiple pregnancies, in-vitro fertilisation, pre-existing thyroid disease or thyroid medication usage, miscarriages, and stillbirths. The main outcomes assessed were small for gestational age (SGA) neonates, large for gestational age neonates, and newborn birthweight. We analysed individual-participant data using mixed-effects regression models adjusting for maternal age, BMI, ethnicity, smoking, parity, gestational age at blood sampling, fetal sex, and gestational age at birth. The study protocol was pre-registered at the International Prospective Register of Systematic Reviews, CRD42016043496.

FINDINGS

We identified 2526 published reports, from which 36 cohorts met the inclusion criteria. The study authors for 15 of these cohorts agreed to participate, and five more unpublished datasets were added, giving a study population of 48 145 mother-child pairs after exclusions, of whom 1275 (3·1%) had subclinical hypothyroidism (increased thyroid stimulating hormone [TSH] with normal free thyroxine [FT4]) and 929 (2·2%) had isolated hypothyroxinaemia (decreased FT4 with normal TSH). Maternal subclinical hypothyroidism was associated with a higher risk of SGA than was euthyroidism (11·8% vs 10·0%; adjusted risk difference 2·43%, 95% CI 0·43 to 4·81; odds ratio [OR] 1·24, 1·04 to 1·48; p=0·015) and lower mean birthweight (mean difference -38 g, -61 to -15; p=0·0015), with a higher effect estimate for measurement in the third trimester than in the first or second. Isolated hypothyroxinaemia was associated with a lower risk of SGA than was euthyroidism (7·3% vs 10·0%, adjusted risk difference -2·91, -4·49 to -0·88; OR 0·70, 0·55 to 0·91; p=0·0073) and higher mean birthweight (mean difference 45 g, 18 to 73; p=0·0012). Each 1 SD increase in maternal TSH concentration was associated with a 6 g lower birthweight (-10 to -2; p=0·0030), with higher effect estimates in women who were thyroid peroxidase antibody positive than for women who were negative (pinteraction=0·10). Each 1 SD increase in FT4 concentration was associated with a 21 g lower birthweight (-25 to -17; p<0·0001), with a higher effect estimate for measurement in the third trimester than the first or second.

INTERPRETATION

Maternal subclinical hypothyroidism in pregnancy is associated with a higher risk of SGA and lower birthweight, whereas isolated hypothyroxinaemia is associated with lower risk of SGA and higher birthweight. There was an inverse, dose-response association of maternal TSH and FT4 (even within the normal range) with birthweight. These results advance our understanding of the complex relationships between maternal thyroid function and fetal outcomes, and they should prompt careful consideration of potential risks and benefits of levothyroxine therapy during pregnancy.

FUNDING

Netherlands Organization for Scientific Research (grant 401.16.020).

Prophylactic human papillomavirus vaccination to prevent recurrence of cervical intraepithelial neoplasia: a meta-analysis

Objective

The aim of this systematic review and meta-analysis was to review evidence supporting the use of prophylactic human papillomavirus (HPV) vaccines to influence the risk of recurrence of cervical intraepithelial neoplasia after surgical treatment.

Methods

A systematic literature search was performed for publications reporting risk of recurrence of cervical intraepithelial neoplasia after surgical treatment in patients receiving HPV vaccination (either in the prophylactic or adjuvant setting). Comprehensive searches of six electronic databases (MEDLINE, Embase, Web of Science, PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and references of identified studies) from their inceptions were performed (English language only), and hand search reference lists were performed. Two independent reviewers applied inclusion and exclusion criteria to select manuscripts, with differences discussed and agreed by consensus. The literature search was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results were reported as mean differences or pooled odds ratios (OR) with 95% confidence intervals (95% CI).

Results

A total of 5744 citations were reviewed; 5 studies comprising 2912 patients were selected for the analysis. There were 1338 patients in the vaccinated group and 1574 in the placebo or unvaccinated group. The incidence of histologically confirmed cervical intraepithelial neoplasia 2+ was reduced in the vaccinated compared to the unvaccinated group (OR 0.34, 95% CI 0.21–0.54, p=< 0.00001). The number needed to treat to prevent one recurrence was 27. Both pre-treatment vaccination (OR 0.40, 95% CI 0.21–0.78, p=0.007, number needed to treat – 37) and adjuvant vaccination (OR 0.28, 95% CI 0.14–0.56, p=0.0003, number needed to treat – 30) reduced recurrence rates.

Conclusion

Prophylactic or adjuvant HPV vaccination reduces the risk of recurrent cervical intraepithelial neoplasia 2+. These data support further investigation of its role as an adjuvant to surgical treatment.

GRADE guidelines 27: how to calculate absolute effects for time-to-event outcomes in summary of findings tables and Evidence Profiles

OBJECTIVES

To provide GRADE guidance on how to prepare Summary of Findings tables and Evidence Profiles for time-to-event outcomes with a focus on the calculation of the corresponding absolute effect estimates.

STUDY DESIGN AND SETTING

This guidance was justified by a research project identifying frequent errors and limitations in the presentation of time-to-event outcomes in the Summary of Findings tables. We developed this guidance through an iterative process that included membership consultation, feedback, presentation, and discussion at meetings of the GRADE Working Group.

RESULTS

Review authors need to carefully consider the definition of the outcome of interest; although often the event is used as label for the outcome of interest (e.g., death or mortality), the event-free survival (e.g., overall survival) is reported throughout individual studies. Review authors should calculate the absolute effect correctly, either for the event or absence of the event. We also provide examples on how to calculate the absolute effects for events and the absence of events for various baseline or control group risks and time points.

CONCLUSIONS

This article aids in the development of Summary of Findings tables and Evidence Profiles, including time-to-event outcomes, and addresses the most common scenarios when calculating absolute effects in order to provide an accurate interpretation.

Association of high amounts of physical activity with mortality risk: a systematic review and meta-analysis

OBJECTIVES

To systematically review and analyse studies of high amounts of physical activity and mortality risk in the general population.

ELIGIBILITY CRITERIA

Inclusion criteria related to follow-up (minimum 2 years), outcome (mortality from all causes, cancer, cardiovascular disease (CVD) or coronary heart disease), exposure (eg, a category of >1000 metabolic equivalent of task (MET) min/week), study design (prospective cohort, nested case control or case-cohort) and reports of cases and person years of exposure categories.

INFORMATION SOURCES

Systematic searches were conducted in Embase and Pubmed from database inception to 2 March 2019.

RISK OF BIAS

The quality of the studies was assessed with the Newcastle-Ottawa scale.

INCLUDED STUDIES

From 31 368 studies identified, 48 were included. Two authors independently extracted outcome estimates and assessed study quality.

SYNTHESIS OF RESULTS

We estimated hazard ratios (HRs) using random effect restricted cubic spline dose-response meta-analyses. Compared with the recommended level of physical activity (750 MET min/week), mortality risk was lower at physical activity levels exceeding the recommendations, at least until 5000 MET min/week for all cause mortality (HR=0.86, 95% CI 0.78 to 0.94) and for CVD mortality (HR=0.73, 95% CI 0.56 to 0.95).

STRENGTHS AND LIMITATIONS OF EVIDENCE

The strengths of this study include the detailed dose-response analyses, inclusion of 48 studies and examination of sources of heterogeneity. The limitations include the observational nature of the included studies and the inaccurate estimations of amount of physical activity.

INTERPRETATION

Compared with the recommended level, mortality risk was lower at physical activity levels well above the recommended target range. Further, there was no threshold beyond which lifespan was compromised.

REGISTRATION

PROSPERO CRD42017055727.

Cardiorespiratory fitness, muscular strength and risk of type 2 diabetes: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The study aimed to quantitatively summarise the dose-response relationships between cardiorespiratory fitness and muscular strength on the one hand and risk of type 2 diabetes on the other and estimate the hypothetical benefits associated with population-wide changes in the distribution of fitness.

METHODS

We performed a systematic review with meta-analysis. The PubMed and EMBASE electronic databases were searched from inception dates to 12 December 2018 for cohort studies examining the association of cardiorespiratory fitness or muscular strength with risk of incident type 2 diabetes in adults. The quality of included studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Twenty-two studies of cardiorespiratory fitness and 13 studies of muscular strength were included in the systematic review with both exposures having ten estimates available for the primary adiposity- or body size-controlled meta-analysis. In random-effects meta-analysis including 40,286 incident cases of type 2 diabetes in 1,601,490 participants, each 1 metabolic equivalent (MET) higher cardiorespiratory fitness was associated with an 8% (95% CI 6%, 10%) lower RR of type 2 diabetes. The association was linear throughout the examined spectrum of cardiorespiratory fitness. In 39,233 cases and 1,713,468 participants each 1 SD higher muscular strength was associated with a 13% (95% CI 6%, 19%) lower RR of type 2 diabetes. We estimated that 4% to 21% of new annual cases of type 2 diabetes among 45-64-year-olds could be prevented by feasible and plausible population cardiorespiratory fitness changes.

CONCLUSIONS/INTERPRETATION

Relatively small increments in cardiorespiratory fitness and muscle strength were associated with clinically meaningful reductions in type 2 diabetes risk with indication of a linear dose-response relationship for cardiorespiratory fitness.

REGISTRATION

PROSPERO (CRD42017064526).

The number needed to treat in pairwise and network meta-analysis and its graphical representation

OBJECTIVE

The objective of this study was to present ways to graphically represent a number needed to treat (NNT) in (network) meta-analysis (NMA).

STUDY DESIGN AND SETTING

A barrier to using NNT in NMA when an odds ratio (OR) or risk ratio (RR) is used is the determination of a single control event rate (CER). We discuss approaches to calculate a CER, and illustrate six graphical methods for NNT from NMA. We illustrate the graphical approaches using an NMA of cognitive enhancers for Alzheimer's dementia.

RESULTS

The NNT calculation using a relative effect measure, such as OR and RR, requires a CER value, but different CERs, including mean CER across studies, pooled CER in meta-analysis, and expert opinion-based CER may result in different NNTs. An NNT from NMA can be presented in a bar plot, Cates plot, or forest plot for a single outcome, and a bubble plot, scatterplot, or rank-heat plot for ≥2 outcomes. Each plot is associated with different properties and can serve different needs.

CONCLUSION

Caution is needed in NNT interpretation, as considerations such as selection of effect size and CER, and CER assumption across multiple comparisons, may impact NNT and decision-making. The proposed graphs are helpful to interpret NNTs calculated from (network) meta-analyses.

Comparative effectiveness and safety of statins as a class and of specific statins for primary prevention of cardiovascular disease: A systematic review, meta-analysis, and network meta-analysis of randomized trials with 94,283 participants

The current guidelines of statins for primary cardiovascular disease (CVD) prevention were based on results from systematic reviews and meta-analyses that suffer from limitations.

METHODS

We searched in PubMed for existing systematic reviews and individual open-label or double-blinded randomized controlled trials that compared a statin with a placebo or another, which were published in English until January 01, 2018. We performed a random-effect pairwise meta-analysis of all statins as a class and network meta-analysis for the specific statins on different benefit and harm outcomes.

RESULTS

In the pairwise meta-analyses, statins as a class showed statistically significant risk reductions on non-fatal MI (risk ratio [RR] 0.62, 95% CI 0.53-0.72), CVD mortality (RR 0.80, 0.71-0.91), all-cause mortality (RR 0.89, 0.85-0.93), non-fatal stroke (RR 0.83, 0.75-0.92), unstable angina (RR 0.75, 0.63-0.91), and composite major cardiovascular events (RR 0.74, 0.67-0.81). Statins increased statistically significantly relative and absolute risks of myopathy (RR 1.08, 1.01-1.15; Risk difference [RD] 13, 2-24 per 10,000 person-years); renal dysfunction (RR 1.12, 1.00-1.26; RD 16, 0-36 per 10,000 person-years); and hepatic dysfunction (RR 1.16, 1.02-1.31; RD 8, 1-16 per 10,000 person-years). The drug-level network meta-analyses showed that atorvastatin and rosuvastatin were most effective in reducing CVD events while atorvastatin appeared to have the best safety profile.

CONCLUSIONS

All statins showed statistically significant risk reduction of CVD and all-cause mortality in primary prevention populations while increasing the risk for some harm risks. However, the benefit-harm profile differed by statin type. A quantitative assessment of the benefit-harm balance is thus needed since meta-analyses alone are insufficient to inform whether statins provide net benefit.

Medications that reduce emergency hospital admissions: an overview of systematic reviews and prioritisation of treatments

BACKGROUND

Rates of emergency hospitalisations are increasing in many countries, leading to disruption in the quality of care and increases in cost. Therefore, identifying strategies to reduce emergency admission rates is a key priority. There have been large-scale evidence reviews to address this issue; however, there have been no reviews of medication therapies, which have the potential to reduce the use of emergency health-care services. The objectives of this study were to review systematically the evidence to identify medications that affect emergency hospital admissions and prioritise therapies for quality measurement and improvement.

METHODS

This was a systematic review of systematic reviews. We searched MEDLINE, PubMed, the Cochrane Database of Systematic Reviews & Database of Abstracts of Reviews of Effects, Google Scholar and the websites of ten major funding agencies and health charities, using broad search criteria. We included systematic reviews of randomised controlled trials that examined the effect of any medication on emergency hospital admissions among adults. We assessed the quality of reviews using AMSTAR. To prioritise therapies, we assessed the quality of trial evidence underpinning meta-analysed effect estimates and cross-referenced the evidence with clinical guidelines.

RESULTS

We identified 140 systematic reviews, which included 1968 unique randomised controlled trials and 925,364 patients. Reviews contained 100 medications tested in 47 populations. We identified high-to moderate-quality evidence for 28 medications that reduced admissions. Of these medications, 11 were supported by clinical guidelines in the United States, the United Kingdom and Europe. These 11 therapies were for patients with heart failure (angiotensin-converting-enzyme inhibitors, angiotensin II receptor blockers, aldosterone receptor antagonists and digoxin), stable coronary artery disease (intensive statin therapy), asthma exacerbations (early inhaled corticosteroids in the emergency department and anticholinergics), chronic obstructive pulmonary disease (long-acting muscarinic antagonists and long-acting beta-2 adrenoceptor agonists) and schizophrenia (second-generation antipsychotics and depot/maintenance antipsychotics).

CONCLUSIONS

We identified 11 medications supported by strong evidence and clinical guidelines that could be considered in quality monitoring and improvement strategies to help reduce emergency hospital admission rates. The findings are relevant to health systems with a large burden of chronic disease and those managing increasing pressures on acute health-care services.

Laparoscopic Lavage in the Management of Perforated Diverticulitis: a Contemporary Meta-analysis

IMPORTANCE

Perforated diverticulitis carries the risk of significant comorbidity and mortality. Although colon resection provides adequate source control, the procedure itself carries morbidity, as well as later stoma reversal procedures. The effectiveness of laparoscopic lavage to treat perforated diverticulitis remains unclear.

OBJECTIVE

We aimed to conduct a meta-analysis to evaluate current studies comparing laparoscopic lavage with colon resection in cases of perforated diverticulitis for the effectiveness in source control, without the need for subsequent interventions, stoma formation, and death.

DATA SOURCES

Electronic database searches were conducted using EMBASE, Pubmed, CINAHL, Cochrane databases, and clinicaltrials.gov following PRISMA guidelines.

STUDY SELECTION

Randomized controlled trials (RCTs) were included that compared laparoscopic lavage against colon resection for perforated diverticulitis.

DATA EXTRACTION AND SYNTHESIS

Risk of bias in RCT's was assessed the Cochrane Assessment of Bias risk tool and Jadad scale. A meta-analysis was performed using random-effects risk ratios (RR) and 95% confidence intervals (CI).

MAIN OUTCOME

Outcome measures included the total rate of reoperation, rate of reoperation for infection, need for subsequent percutaneous drainage, stoma formation, and mortality rate within 90 days.

RESULTS

Three eligible randomized controlled studies were identified, with a combined total of 372 patients. Laparoscopic lavage carried an increased rate of total reoperations (RR 2.07; CI 1.12-3.84; p = 0.021) and an increased rate of reoperation for infection (RR 5.56; CI 1.97-15.69; p = 0.001) compared with colon resection. In addition, laparoscopic lavage increased the rate of subsequent percutaneous drainage (RR 6.54; CI 1.77-24.16; p = 0.005) compared with colon resection, but a lesser risk of stoma formation within 90 days (RR 0.18; CI 0.12-0.27; p < 0.001). No difference in mortality rate was observed between treatments (RR 1.03; CI 0.45-2.34; p = 0.950).

CONCLUSION

Despite decreased rates of stoma formation and equivalent mortality rates as compared with colon resection, laparoscopic lavage for Hinchey III diverticulitis fails to completely control the source of infection. Our data show that laparoscopic lavage is associated with increased rates of total reoperations, increased rates of reoperation for infections, and need for subsequent percutaneous drainage.

PCSK9 monoclonal antibodies for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Despite the availability of effective drug therapies that reduce low-density lipoprotein (LDL)-cholesterol (LDL-C), cardiovascular disease (CVD) remains an important cause of mortality and morbidity. Therefore, additional LDL-C reduction may be warranted, especially for patients who are unresponsive to, or unable to take, existing LDL-C-reducing therapies. By inhibiting the proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme, monoclonal antibodies (PCSK9 inhibitors) may further reduce LDL-C, potentially reducing CVD risk as well.

OBJECTIVES

Primary To quantify short-term (24 weeks), medium-term (one year), and long-term (five years) effects of PCSK9 inhibitors on lipid parameters and on the incidence of CVD. Secondary To quantify the safety of PCSK9 inhibitors, with specific focus on the incidence of type 2 diabetes, cognitive function, and cancer. Additionally, to determine if specific patient subgroups were more or less likely to benefit from the use of PCSK9 inhibitors.

SEARCH METHODS

We identified studies by systematically searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and Web of Science. We also searched Clinicaltrials.gov and the International Clinical Trials Registry Platform and screened the reference lists of included studies. We identified the studies included in this review through electronic literature searches conducted up to May 2016, and added three large trials published in March 2017.

SELECTION CRITERIA

All parallel-group and factorial randomised controlled trials (RCTs) with a follow-up time of at least 24 weeks were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and extracted data. When data were available, we calculated pooled effect estimates.

MAIN RESULTS

We included 20 studies with data on 67,237 participants (median age 61 years; range 52 to 64 years). Twelve trials randomised participants to alirocumab, three trials to bococizumab, one to RG7652, and four to evolocumab. Owing to the small number of trials using agents other than alirocumab, we did not differentiate between types of PCSK9 inhibitors used. We compared PCSK9 inhibitors with placebo (thirteen RCTs), ezetimibe (two RCTs) or ezetimibe and statins (five RCTs).Compared with placebo, PCSK9 inhibitors decreased LDL-C by 53.86% (95% confidence interval (CI) 58.64 to 49.08; eight studies; 4782 participants; GRADE: moderate) at 24 weeks; compared with ezetimibe, PCSK9 inhibitors decreased LDL-C by 30.20% (95% CI 34.18 to 26.23; two studies; 823 participants; GRADE: moderate), and compared with ezetimibe and statins, PCSK9 inhibitors decreased LDL-C by 39.20% (95% CI 56.15 to 22.26; five studies; 5376 participants; GRADE: moderate).Compared with placebo, PCSK9 inhibitors decreased the risk of CVD events, with a risk difference (RD) of 0.91% (odds ratio (OR) of 0.86, 95% CI 0.80 to 0.92; eight studies; 59,294 participants; GRADE: moderate). Compared with ezetimibe and statins, PCSK9 inhibitors appeared to have a stronger protective effect on CVD risk, although with considerable uncertainty (RD 1.06%, OR 0.45, 95% CI 0.27 to 0.75; three studies; 4770 participants; GRADE: very low). No data were available for the ezetimibe only comparison. Compared with placebo, PCSK9 probably had little or no effect on mortality (RD 0.03%, OR 1.02, 95% CI 0.91 to 1.14; 12 studies; 60,684 participants; GRADE: moderate). Compared with placebo, PCSK9 inhibitors increased the risk of any adverse events (RD 1.54%, OR 1.08, 95% CI 1.04 to 1.12; 13 studies; 54,204 participants; GRADE: low). Similar effects were observed for the comparison of ezetimibe and statins: RD 3.70%, OR 1.18, 95% CI 1.05 to 1.34; four studies; 5376 participants; GRADE: low. Clinical event data were unavailable for the ezetimibe only comparison.

AUTHORS' CONCLUSIONS

Over short-term to medium-term follow-up, PCSK9 inhibitors reduced LDL-C. Studies with medium-term follow-up time (longest median follow-up recorded was 26 months) reported that PCSK9 inhibitors (compared with placebo) decreased CVD risk but may have increased the risk of any adverse events (driven by SPIRE-1 and -2 trials). Available evidence suggests that PCSK9 inhibitor use probably leads to little or no difference in mortality. Evidence on relative efficacy and safety when PCSK9 inhibitors were compared with active treatments was of low to very low quality (GRADE); follow-up times were short and events were few. Large trials with longer follow-up are needed to evaluate PCSK9 inhibitors versus active treatments as well as placebo. Owing to the predominant inclusion of high-risk patients in these studies, applicability of results to primary prevention is limited. Finally, estimated risk differences indicate that PCSK9 inhibitors only modestly change absolute risks (often to less than 1%).

Better guidelines for better care: accounting for multimorbidity in clinical guidelines – structured examination of exemplar guidelines and health economic modelling

Background

Multimorbidity is common but most clinical guidelines focus on single diseases.

Aim

To test the feasibility of new approaches to developing single-disease guidelines to better account for multimorbidity.

Design

Literature-based and economic modelling project focused on areas where multimorbidity makes guideline application problematic.

Methods

(1) Examination of accounting for multimorbidity in three exemplar National Institute for Health and Care Excellence guidelines (type 2 diabetes, depression, heart failure); (2) examination of the applicability of evidence in multimorbidity for the exemplar conditions; (3) exploration of methods for comparing absolute benefit of treatment; (4) incorporation of treatment pay-off time and competing risk of death in an exemplar economic model for long-term preventative treatments with slowly accruing benefit; and (5) development of a discrete event simulation model-based cost-effectiveness analysis for people with both depression and coronary heart disease.

Results

(1) Comorbidity was rarely accounted for in the clinical research questions that framed the development of the exemplar guidelines, and was rarely accounted for in treatment recommendations. Drug–disease interactions were common only for comorbid chronic kidney disease, but potentially serious drug–drug interactions between recommended drugs were common and rarely accounted for in guidelines. (2) For all three conditions, the trials underpinning treatment recommendations largely excluded older, more comorbid and more coprescribed patients. The implications of low applicability varied by condition, with type 2 diabetes having large differences in comorbidity, whereas potentially serious drug–drug interactions were more important for depression. (3) Comparing absolute benefit of treatments for different conditions was shown to be technically feasible, but only if guideline developers are willing to make a number of significant assumptions. (4) The lifetime absolute benefit of statins for primary prevention is highly sensitive to the presence of both the direct treatment disutility of taking a daily tablet and competing risk of death. (5) It was feasible to use a discrete event simulation-based model to represent the relevant care pathways to estimate the relative cost-effectiveness of pharmacological treatments of major depressive disorder in primary care for patients who are also likely to go on and receive treatment for coronary heart disease but the analysis was reliant on eliciting some parameter values from experts, which increases the inherent uncertainty in the results. The key limitation was that real-life use in guideline development was not examined.

Conclusions

Guideline developers could feasibly (1) use epidemiological data characterising the guideline population to inform consideration of applicability and interactions; (2) systematically compare the absolute benefit of long-term preventative treatments to inform decision-making in people with multimorbidity and high treatment burden; and (3) modify the output from economic models used in guideline development to examine time to benefit in terms of the pay-off time and varying competing risk of death from other conditions.

Future work

Further research is needed to optimise presentation of comparative absolute benefit information to clinicians and patients, to evaluate the use of epidemiological and time-to-benefit data in guideline development, to better quantify direct treatment disutility and to better quantify benefit and harm in people with multimorbidity.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Belotecan/cisplatin versus etoposide/cisplatin in previously untreated patients with extensive-stage small cell lung carcinoma: a multi-center randomized phase III trial

Background

No novel chemotherapeutic combinations have demonstrated superior efficacy to etoposide/cisplatin (EP), a standard treatment regimen for extensive-stage small cell lung carcinoma (ES-SCLC) over the past decade. We aimed to compare the efficacy and safety of belotecan/cisplatin (BP) and EP regimens in chemotherapy- and radiotherapy-naïve patients with previously untreated ES-SCLC.

Methods

We conducted a multi-center, randomized, open-label, parallel-group, phase III clinical study. A total of 157 patients were recruited at 14 centers with 147 patients meeting the inclusion/exclusion criteria and randomized to either BP (n = 71) or EP (n = 76) treatment arms. A non-inferior response rate (RR) in the BP arm, analyzed by intent-to-treat analysis according to Response Evaluation Criteria in Solid Tumors version 1.0 criteria, was used as the primary endpoint. The secondary endpoints were progression-free survival (PFS) and overall survival (OS).

Results

In the BP arm, one patient had a complete response, 41 had a partial response (PR), and 17 had stable disease (SD). In the EP arm, 35 patients had PR and 28 had SD. The RR in the BP arm was non-inferior to the EP regimen in patients with ES-SCLC (BP: 59.2 %, EP: 46.1 %, difference: 13.1 %, 90 % two-sided confidence interval: -0.3–26.5, meeting the predefined non-inferiority criterion of -15.0 %). No significant differences in OS or PFS were observed between the treatment arms. Hematologic toxicities, including grade 3/4 anemia and thrombocytopenia, were significantly more prevalent in the BP arm than the EP arm.

Conclusions

The RR to the BP regimen was non-inferior to the EP regimen in chemotherapy- and radiotherapy-naïve patients with previously untreated ES-SCLC. Hematologic toxicities were significantly more prevalent in the BP group, indicating that BP should be used with care, particularly in patients with a poor performance status. Further studies assessing PFS and OS are required to validate the superiority of the BP regimen.

Trial registration

ClinicalTrials.gov identifier NCT00826644. Date of Registration: January 21, 2009.

Protocol for an overview of systematic reviews of interventions to reduce unscheduled hospital admissions among adults

INTRODUCTION

Unscheduled hospital admissions are an increasing burden on health systems worldwide. To date, initiatives to reduce admissions have had limited success as it is unclear which strategies effectively reduce admissions and are supported by a strong evidence-base. Therefore, we will conduct an overview to find, assess and summarise all published peer-reviewed systematic reviews of randomised controlled trials that examine the effect of an intervention on unplanned admissions among adults.

METHODS AND ANALYSIS

This is a protocol for a systematic overview of reviews. We will search four databases: Ovid MEDLINE, PubMed, Cochrane Database of Systematic Reviews and the Cochrane Database of Abstracts of Reviews of Effects. We will consider systematic reviews and meta-analyses of randomised controlled trials in adults (≥ 16 years old) evaluating the effect of any intervention on unscheduled hospital admissions including those to treat, monitor, diagnose or prevent a health problem. We will only include reviews that identified unscheduled hospitalisations as a prespecified outcome. Two authors will independently screen articles for inclusion using a priori criteria. We will assess the quality of included reviews and extract ratings of the quality of evidence from within each review. We will create a hierarchical list of interventions based on estimates of absolute admission reductions and the quality of the evidence. Presentation of results will align with guidelines in the Cochrane Handbook of Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement.

ETHICS AND DISSEMINATION

Ethics approval is not required. We will submit the results of this study for peer-review publication. The results will inform future research and could be used by healthcare managers, administrators and policymakers to guide resource allocation decisions and inform local implementation and optimisation of interventions to reduce unscheduled hospital admissions.