Exercise-based cardiac rehabilitation for adults with heart failure.

BACKGROUND: People with heart failure experience substantial disease burden that includes low exercise tolerance, poor health-related quality of life (HRQoL), increased risk of mortality and hospital admission, and high healthcare costs. The previous 2018 Cochrane review reported that exercise-based cardiac rehabilitation (ExCR) compared to no exercise control shows improvement in HRQoL and hospital admission amongst people with heart failure, as well as possible reduction in mortality over the longer term, and that these reductions appear to be consistent across patient and programme characteristics. Limitations noted by the authors of this previous Cochrane review include the following: (1) most trials were undertaken in patients with heart failure with reduced (< 45%) ejection fraction (HFrEF), and women, older people, and those with heart failure with preserved (≥ 45%) ejection fraction (HFpEF) were under-represented; and (2) most trials were undertaken in a hospital or centre-based setting. OBJECTIVES: To assess the effects of ExCR on mortality, hospital admission, and health-related quality of life of adults with heart failure. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO and Web of Science without language restriction on 13 December 2021. We also checked the bibliographies of included studies, identified relevant systematic reviews, and two clinical trials registers. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared ExCR interventions (either exercise only or exercise as part of a comprehensive cardiac rehabilitation) with a follow-up of six months or longer versus a no-exercise control (e.g. usual medical care). The study population comprised adults (≥ 18 years) with heart failure - either HFrEF or HFpEF. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were all-cause mortality, mortality due to heart failure, all-cause hospital admissions, heart failure-related hospital admissions, and HRQoL. Secondary outcomes were costs and cost-effectiveness. We used GRADE to assess the certainty of the evidence. MAIN RESULTS: We included 60 trials (8728 participants) with a median of six months' follow-up. For this latest update, we identified 16 new trials (2945 new participants), in addition to the previously identified 44 trials (5783 existing participants). Although the existing evidence base predominantly includes patients with HFrEF, with New York Heart Association (NYHA) classes II and III receiving centre-based ExCR programmes, a growing body of trials includes patients with HFpEF with ExCR undertaken in a home-based setting. All included trials employed a usual care comparator with a formal no-exercise intervention as well as a wide range of active comparators, such as education, psychological intervention, or medical management. The overall risk of bias in the included trials was low or unclear, and we mostly downgraded the certainty of evidence of outcomes upon GRADE assessment. There was no evidence of a difference in the short term (up to 12 months' follow-up) in the pooled risk of all-cause mortality when comparing ExCR versus usual care (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.71 to 1.21; absolute effects 5.0% versus 5.8%; 34 trials, 36 comparisons, 3941 participants; low-certainty evidence). Only a few trials reported information on whether participants died due to heart failure. Participation in ExCR versus usual care likely reduced the risk of all-cause hospital admissions (RR 0.69, 95% CI 0.56 to 0.86; absolute effects 15.9% versus 23.8%; 23 trials, 24 comparisons, 2283 participants; moderate-certainty evidence) and heart failure-related hospital admissions (RR 0.82, 95% CI 0.49 to 1.35; absolute effects 5.6% versus 6.4%; 10 trials; 10 comparisons, 911 participants; moderate-certainty evidence) in the short term. Participation in ExCR likely improved short-term HRQoL as measured by the Minnesota Living with Heart Failure (MLWHF) questionnaire (lower scores indicate better HRQoL and a difference of 5 points or more indicates clinical importance; mean difference (MD) -7.39 points, 95% CI -10.30 to -4.77; 21 trials, 22 comparisons, 2699 participants; moderate-certainty evidence). When pooling HRQoL data measured by any questionnaire/scale, we found that ExCR may improve HRQoL in the short term, but the evidence is very uncertain (33 trials, 37 comparisons, 4769 participants; standardised mean difference (SMD) -0.52, 95% CI -0.70 to -0.34; very-low certainty evidence). ExCR effects appeared to be consistent across different models of ExCR delivery: centre- versus home-based, exercise dose, exercise only versus comprehensive programmes, and aerobic training alone versus aerobic plus resistance programmes. AUTHORS' CONCLUSIONS: This updated Cochrane review provides additional randomised evidence (16 trials) to support the conclusions of the previous 2018 version of the review. Compared to no exercise control, whilst there was no evidence of a difference in all-cause mortality in people with heart failure, ExCR participation likely reduces the risk of all-cause hospital admissions and heart failure-related hospital admissions, and may result in important improvements in HRQoL. Importantly, this updated review provides additional evidence supporting the use of alternative modes of ExCR delivery, including home-based and digitally-supported programmes. Future ExCR trials need to focus on the recruitment of traditionally less represented heart failure patient groups including older patients, women, and those with HFpEF.

Meditation for the primary and secondary prevention of cardiovascular disease.

BACKGROUND: Interventions incorporating meditation to address stress, anxiety, and depression, and improve self-management, are becoming popular for many health conditions. Stress is a risk factor for cardiovascular disease (CVD) and clusters with other modifiable behavioural risk factors, such as smoking. Meditation may therefore be a useful CVD prevention strategy. OBJECTIVES: To determine the effectiveness of meditation, primarily mindfulness-based interventions (MBIs) and transcendental meditation (TM), for the primary and secondary prevention of CVD. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, three other databases, and two trials registers on 14 November 2021, together with reference checking, citation searching, and contact with study authors to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of 12 weeks or more in adults at high risk of CVD and those with established CVD. We explored four comparisons: MBIs versus active comparators (alternative interventions); MBIs versus non-active comparators (no intervention, wait list, usual care); TM versus active comparators; TM versus non-active comparators. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were CVD clinical events (e.g. cardiovascular mortality), blood pressure, measures of psychological distress and well-being, and adverse events. Secondary outcomes included other CVD risk factors (e.g. blood lipid levels), quality of life, and coping abilities. We used GRADE to assess the certainty of evidence. MAIN RESULTS: We included 81 RCTs (6971 participants), with most studies at unclear risk of bias. MBIs versus active comparators (29 RCTs, 2883 participants) Systolic (SBP) and diastolic (DBP) blood pressure were reported in six trials (388 participants) where heterogeneity was considerable (SBP: MD -6.08 mmHg, 95% CI -12.79 to 0.63, I2 = 88%; DBP: MD -5.18 mmHg, 95% CI -10.65 to 0.29, I2 = 91%; both outcomes based on low-certainty evidence). There was little or no effect of MBIs on anxiety (SMD -0.06 units, 95% CI -0.25 to 0.13; I2 = 0%; 9 trials, 438 participants; moderate-certainty evidence), or depression (SMD 0.08 units, 95% CI -0.08 to 0.24; I2 = 0%; 11 trials, 595 participants; moderate-certainty evidence). Perceived stress was reduced with MBIs (SMD -0.24 units, 95% CI -0.45 to -0.03; I2 = 0%; P = 0.03; 6 trials, 357 participants; moderate-certainty evidence). There was little to no effect on well-being (SMD -0.18 units, 95% CI -0.67 to 0.32; 1 trial, 63 participants; low-certainty evidence). There was little to no effect on smoking cessation (RR 1.45, 95% CI 0.78 to 2.68; I2 = 79%; 6 trials, 1087 participants; low-certainty evidence). None of the trials reported CVD clinical events or adverse events. MBIs versus non-active comparators (38 RCTs, 2905 participants) Clinical events were reported in one trial (110 participants), providing very low-certainty evidence (RR 0.94, 95% CI 0.37 to 2.42). SBP and DBP were reduced in nine trials (379 participants) but heterogeneity was substantial (SBP: MD -6.62 mmHg, 95% CI -13.15 to -0.1, I2 = 87%; DBP: MD -3.35 mmHg, 95% CI -5.86 to -0.85, I2 = 61%; both outcomes based on low-certainty evidence). There was low-certainty evidence of reductions in anxiety (SMD -0.78 units, 95% CI -1.09 to -0.41; I2 = 61%; 9 trials, 533 participants; low-certainty evidence), depression (SMD -0.66 units, 95% CI -0.91 to -0.41; I2 = 67%; 15 trials, 912 participants; low-certainty evidence) and perceived stress (SMD -0.59 units, 95% CI -0.89 to -0.29; I2 = 70%; 11 trials, 708 participants; low-certainty evidence) but heterogeneity was substantial. Well-being increased (SMD 0.5 units, 95% CI 0.09 to 0.91; I2 = 47%; 2 trials, 198 participants; moderate-certainty evidence). There was little to no effect on smoking cessation (RR 1.36, 95% CI 0.86 to 2.13; I2 = 0%; 2 trials, 453 participants; low-certainty evidence). One small study (18 participants) reported two adverse events in the MBI group, which were not regarded as serious by the study investigators (RR 5.0, 95% CI 0.27 to 91.52; low-certainty evidence). No subgroup effects were seen for SBP, DBP, anxiety, depression, or perceived stress by primary and secondary prevention. TM versus active comparators (8 RCTs, 830 participants) Clinical events were reported in one trial (201 participants) based on low-certainty evidence (RR 0.91, 95% CI 0.56 to 1.49). SBP was reduced (MD -2.33 mmHg, 95% CI -3.99 to -0.68; I2 = 2%; 8 trials, 774 participants; moderate-certainty evidence), with an uncertain effect on DBP (MD -1.15 mmHg, 95% CI -2.85 to 0.55; I2 = 53%; low-certainty evidence). There was little or no effect on anxiety (SMD 0.06 units, 95% CI -0.22 to 0.33; I2 = 0%; 3 trials, 200 participants; low-certainty evidence), depression (SMD -0.12 units, 95% CI -0.31 to 0.07; I2 = 0%; 5 trials, 421 participants; moderate-certainty evidence), or perceived stress (SMD 0.04 units, 95% CI -0.49 to 0.57; I2 = 70%; 3 trials, 194 participants; very low-certainty evidence). None of the trials reported adverse events or smoking rates. No subgroup effects were seen for SBP or DBP by primary and secondary prevention. TM versus non-active comparators (2 RCTs, 186 participants) Two trials (139 participants) reported blood pressure, where reductions were seen in SBP (MD -6.34 mmHg, 95% CI -9.86 to -2.81; I2 = 0%; low-certainty evidence) and DBP (MD -5.13 mmHg, 95% CI -9.07 to -1.19; I2 = 18%; very low-certainty evidence). One trial (112 participants) reported anxiety and depression and found reductions in both (anxiety SMD -0.71 units, 95% CI -1.09 to -0.32; depression SMD -0.48 units, 95% CI -0.86 to -0.11; low-certainty evidence). None of the trials reported CVD clinical events, adverse events, or smoking rates. AUTHORS' CONCLUSIONS: Despite the large number of studies included in the review, heterogeneity was substantial for many of the outcomes, which reduced the certainty of our findings. We attempted to address this by presenting four main comparisons of MBIs or TM versus active or inactive comparators, and by subgroup analyses according to primary or secondary prevention, where there were sufficient studies. The majority of studies were small and there was unclear risk of bias for most domains. Overall, we found very little information on the effects of meditation on CVD clinical endpoints, and limited information on blood pressure and psychological outcomes, for people at risk of or with established CVD. This is a very active area of research as shown by the large number of ongoing studies, with some having been completed at the time of writing this review. The status of all ongoing studies will be formally assessed and incorporated in further updates.

The impact of the COVID-19 pandemic and associated disruptions in health-care provision on clinical outcomes in people with diabetes: a systematic review.

The COVID-19 pandemic triggered disruptions to health care and lifestyles that could conceivably impact diabetes management. We set out to identify the impact of disruptions caused by COVID-19 on clinical outcomes in people with diabetes. We performed a systematic review of the available literature in the MEDLINE and OVID databases from Jan 1, 2020, to June 7, 2023, and included 138 studies (n>1 000 000 people). All but five studies were judged to be at some risk of bias. All studies compared prepandemic with pandemic periods. All-cause mortality (six studies) and diabetes-related mortality (13 studies) showed consistent increases, and most studies indicated increases in sight loss (six studies). In adult and mixed samples, data generally suggested no difference in diabetic ketoacidosis frequency or severity, whereas in children and adolescents most studies showed increases with some due to new-onset diabetes (69 studies). Data suggested decreases in hospital admissions in adults but increases in diabetes-related admissions to paediatric intensive care units (35 studies). Data were equivocal on diabetic foot ulcer presentations (nine studies), emergency department admissions (nine studies), and overall amputation rates (20 studies). No studies investigated renal failure. Where reported, the impact was most pronounced for females, younger people, and racial and ethnic minority groups. Further studies are needed to investigate the longer-term impact of the pandemic and the on potential differential impacts, which risk further exacerbating existing inequalities within people with diabetes.

Exercise-based cardiac rehabilitation for adults with heart failure - 2023 Cochrane systematic review and meta-analysis.

AIMS: Despite strong evidence, access to exercise-based cardiac rehabilitation (ExCR) remains low across global healthcare systems. We provide a contemporary update of the Cochrane review randomized trial evidence for ExCR for adults with heart failure (HF) and compare different delivery modes: centre-based, home-based (including digital support), and both (hybrid). METHODS AND RESULTS: Databases, bibliographies of previous systematic reviews and included trials, and trials registers were searched with no language restrictions. Randomized controlled trials, recruiting adults with HF, assigned to either ExCR or a no-exercise control group, with follow-up of ≥6 months were included. Two review authors independently screened titles for inclusion, extracted trial and patient characteristics, outcome data, and assessed risk of bias. Outcomes of mortality, hospitalization, and health-related quality of life (HRQoL) were pooled across trials using meta-analysis at short-term (≤12 months) and long-term follow-up (>12 months) and stratified by delivery mode. Sixty trials (8728 participants) were included. In the short term, compared to control, ExCR did not impact all-cause mortality (relative risk [RR] 0.93; 95% confidence interval [CI] 0.71-1.21), reduced all-cause hospitalization (RR 0.69; 95% CI 0.56-0.86, number needed to treat: 13, 95% CI 9-22), and was associated with a clinically important improvement in HRQoL measured by the Minnesota Living with Heart Failure Questionnaire (MLWHF) overall score (mean difference: -7.39; 95% CI -10.30 to -4.47). Improvements in outcomes with ExCR was seen across centre, home (including digitally supported), and hybrid settings. A similar pattern of results was seen in the long term (mortality: RR 0.87, 95% CI 0.72-1.04; all-cause hospitalization: RR 0.84, 95% CI 0.70-1.01, MLWHF: -9.59, 95% CI -17.48 to -1.50). CONCLUSIONS: To improve global suboptimal levels of uptake for HF patients, global healthcare systems need to routinely recommend ExCR and offer a choice of mode of delivery, dependent on an individual patient's level of risk and complexity.

Exercise-based cardiac rehabilitation for coronary heart disease: a meta-analysis.

AIMS: Coronary heart disease is the most common reason for referral to exercise-based cardiac rehabilitation (CR) globally. However, the generalizability of previous meta-analyses of randomized controlled trials (RCTs) is questioned. Therefore, a contemporary updated meta-analysis was undertaken. METHODS AND RESULTS: Database and trial registry searches were conducted to September 2020, seeking RCTs of exercise-based interventions with ≥6-month follow-up, compared with no-exercise control for adults with myocardial infarction, angina pectoris, or following coronary artery bypass graft, or percutaneous coronary intervention. The outcomes of mortality, recurrent clinical events, and health-related quality of life (HRQoL) were pooled using random-effects meta-analysis, and cost-effectiveness data were narratively synthesized. Meta-regression was used to examine effect modification. Study quality was assessed using the Cochrane risk of bias tool. A total of 85 RCTs involving 23 430 participants with a median 12-month follow-up were included. Overall, exercise-based CR was associated with significant risk reductions in cardiovascular mortality [risk ratio (RR): 0.74, 95% confidence interval (CI): 0.64-0.86, number needed to treat (NNT): 37], hospitalizations (RR: 0.77, 95% CI: 0.67-0.89, NNT: 37), and myocardial infarction (RR: 0.82, 95% CI: 0.70-0.96, NNT: 100). There was some evidence of significantly improved HRQoL with CR participation, and CR is cost-effective. There was no significant impact on overall mortality (RR: 0.96, 95% CI: 0.89-1.04), coronary artery bypass graft (RR: 0.96, 95% CI: 0.80-1.15), or percutaneous coronary intervention (RR: 0.84, 95% CI: 0.69-1.02). No significant difference in effects was found across different patient groups, CR delivery models, doses, follow-up, or risk of bias. CONCLUSION: This review confirms that participation in exercise-based CR by patients with coronary heart disease receiving contemporary medical management reduces cardiovascular mortality, recurrent cardiac events, and hospitalizations and provides additional evidence supporting the improvement in HRQoL and the cost-effectiveness of CR.

Evaluating interventions to improve ethical decision making in clinical practice: a review of the literature and reflections on the challenges posed.

Since the 1980s, there has been an increasing acknowledgement of the importance of recognising the ethical dimension of clinical decision-making. Medical professional regulatory authorities in some countries now include ethical knowledge and practice in their required competencies for undergraduate and post graduate medical training. Educational interventions and clinical ethics support services have been developed to support and improve ethical decision making in clinical practice, but research evaluating the effectiveness of these interventions has been limited. We undertook a systematic review of the published literature on measures or models of evaluation used to assess the impact of interventions to improve ethical decision making in clinical care. We identified a range of measures to evaluate educational interventions, and one tool used to evaluate a clinical ethics support intervention. Most measures did not evaluate the key impact of interest, that is the quality of ethical decision making in real-world clinical practice. We describe the results of our review and reflect on the challenges of assessing ethical decision making in clinical practice that face both developers of educational and support interventions and the regulatory organisations that set and assess competency standards.

The effectiveness of group-based gardening interventions for improving wellbeing and reducing symptoms of mental ill-health in adults: a systematic review and meta-analysis.

BACKGROUND: There is increasing interest in the association between nature, health and wellbeing. Gardening is a popular way in which interaction with nature occurs and numerous gardening projects aim to facilitate wellbeing among participants. More research is needed to determine their effectiveness. AIM: To systematically evaluate the effectiveness of group-based gardening interventions for increasing wellbeing and reducing symptoms of mental ill-health in adults. METHODS: A systematic review of Randomised Controlled Trials was conducted following the protocol submitted to PROSPERO (CRD42020162187). Studies reporting quantitative validated health and wellbeing outcomes of the community residing, adult populations (18+) were eligible for inclusion. RESULTS: 24 studies met inclusion criteria: 20 completed and four ongoing trials. Meta-analyses suggest these interventions may increase wellbeing and may reduce symptoms of depression, however, there was uncertainty in the pooled effects due to heterogeneity and unclear risk of bias for many studies. There were mixed results for other outcomes. RESEARCH LIMITATIONS/IMPLICATIONS: Heterogeneity and small sample sizes limited the results. Poor reporting precluded meta-analysis for some studies. Initial findings for wellbeing and depression are promising and should be corroborated in further studies. The research area is active, and the results of the ongoing trials identified will add to the evidence base.

The impact of the COVID-19 pandemic on glycaemic control in people with diabetes: A systematic review and meta-analysis.

AIM: To identify, appraise and synthesize the available evidence on the impact of the coronavirus disease 2019 (COVID-19) pandemic and lockdown (LD) on glycaemic control in people with diabetes. MATERIALS AND METHODS: We searched multiple databases up to 2 February 2021 for studies reporting HbA1c, time in range (TIR), average or fasting glucose, severe hypoglycaemia and diabetic ketoacidosis. Data were pooled using random effects meta-analysis and are presented as mean difference (MD) with 95% confidence intervals (CI). This review was preregistered on PROSPERO (CRD42020179319). RESULTS: We include 59 studies; 44 (n = 15 464) were included in quantitative syntheses and 15 were narratively synthesized. Pooled data were grouped by diabetes type. Results from 28 studies (n = 5048 type 1 diabetes [T1D] and combined diabetes participants) showed that TIR increased during LD compared with before LD (MD 2.74%, 95% CI 1.80% to 3.69%). Data from 10 studies (n = 1294 T1D participants) showed that TIR increased after LD compared with before LD (MD 5.14%, 95% CI 3.12% to 7.16%). Pooled results from 12 studies (n = 4810 T1D and type 2 diabetes participants) resulted in average glucose decreasing after LD compared with before LD (MD -6.86 mg/dl, 95% CI -8.54 to -5.18). Results for other outcomes, including HbA1c, were not statistically significantly different. CONCLUSIONS: The COVID-19 pandemic was associated with small improvements across multiple outcomes of glycaemic control, although there was insufficient evidence to suggest that this led to changes in HbA1c. Most evidence came from people with access to diabetes technologies in high-income countries; more research is needed in less advantaged populations.

Effects of fluid and drinking on pneumonia mortality in older adults: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Advice to drink plenty of fluid is common in respiratory infections. We assessed whether low fluid intake (dehydration) altered outcomes in adults with pneumonia. METHODS: We systematically reviewed trials increasing fluid intake and well-adjusted, well-powered observational studies assessing associations between markers of low-intake dehydration (fluid intake, serum osmolality, urea or blood urea nitrogen, urinary output, signs of dehydration) and mortality in adult pneumonia patients (with any type of pneumonia, including community acquired, health-care acquired, aspiration, COVID-19 and mixed types). Medline, Embase, CENTRAL, references of reviews and included studies were searched to 30/10/2020. Studies were assessed for inclusion, risk of bias and data extracted independently in duplicate. We employed random-effects meta-analysis, sensitivity analyses, subgrouping and GRADE assessment. Prospero registration: CRD42020182599. RESULTS: We identified one trial, 20 well-adjusted cohort studies and one case-control study. None suggested that more fluid (hydration) was associated with harm. Ten of 13 well-powered observational studies found statistically significant positive associations in adjusted analyses between dehydration and medium-term mortality. The other three studies found no significant effect. Meta-analysis suggested doubled odds of medium-term mortality in dehydrated (compared to hydrated) pneumonia patients (GRADE moderate-quality evidence, OR 2.3, 95% CI 1.8 to 2.8, 8619 deaths in 128,319 participants). Heterogeneity was explained by a dose effect (greater dehydration increased risk of mortality further), and the effect was consistent across types of pneumonia (including community-acquired, hospital-acquired, aspiration, nursing and health-care associated, and mixed pneumonia), age and setting (community or hospital). The single trial found that educating pneumonia patients to drink ≥1.5 L fluid/d alongside lifestyle advice increased fluid intake and reduced subsequent healthcare use. No studies in COVID-19 pneumonia met the inclusion criteria, but 70% of those hospitalised with COVID-19 have pneumonia. Smaller COVID-19 studies suggested that hydration is as important in COVID-19 pneumonia mortality as in other pneumonias. CONCLUSIONS: We found consistent moderate-quality evidence mainly from observational studies that improving hydration reduces the risk of medium-term mortality in all types of pneumonia. It is remarkable that while many studies included dehydration as a potential confounder, and major pneumonia risk scores include measures of hydration, optimal fluid volume and the effect of supporting hydration have not been assessed in randomised controlled trials of people with pneumonia. Such trials, are needed as potential benefits may be large, rapid and implemented at low cost. Supporting hydration and reversing dehydration has the potential to have rapid positive impacts on pneumonia outcomes, and perhaps also COVID-19 pneumonia outcomes, in older adults.

Risks of infection, hospital and ICU admission, and death from COVID-19 in people with asthma: systematic review and meta-analyses.

OBJECTIVES: To determine if and to what degree asthma may predispose to worse COVID-19 outcomes in order to inform treatment and prevention decisions, including shielding and vaccine prioritisation. DESIGN: Systematic review and meta-analysis. SETTING: Electronic databases were searched (October 2020) for clinical studies reporting at least one of the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, intensive care unit (ICU) admission or mortality with COVID-19. PARTICIPANTS: Adults and children who tested positive for or were suspected to have COVID-19. MAIN OUTCOME MEASURES: Main outcome measures were the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, ICU admission or mortality with COVID-19. We pooled odds ratios (ORs) and presented these with 95% confidence intervals (CI). Certainty was assessed using GRADE (Grading of Recommendations, Assessment, Development and Evaluations). RESULTS: 30 (n=112 420) studies were included (12 judged high quality, 15 medium, 3 low). Few provided indication of asthma severity. Point estimates indicated reduced risks in people with asthma for all outcomes, but in all cases the evidence was judged to be of very low certainty and 95% CIs all included no difference and the possibility of increased risk (death: OR 0.90, 95% CI 0.72 to 1.13, I2=58%; hospitalisation: OR 0.95, 95% CI 0.71 to 1.26; ICU admission: OR 0.96, 95% CI 0.75 to 1.24). Findings on hospitalisation are also limited by substantial unexplained statistical heterogeneity. Within people with asthma, allergic asthma was associated with less COVID-19 risk and concurrent chronic obstructive pulmonary disease was associated with increased risk. In some studies, corticosteroids were associated with increased risk, but this may reflect increased risk in people with more severe asthma. CONCLUSIONS: Though absence of evidence of a clear association between asthma and worse outcomes from COVID-19 should not be interpreted as evidence of absence, the data reviewed indicate that risks from COVID-19 in people with asthma, as a whole, may be less than originally anticipated.

Exercise-based cardiac rehabilitation for coronary heart disease.

BACKGROUND: Coronary heart disease (CHD) is the most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people living with CHD may need support to manage their symptoms and prognosis. Exercise-based cardiac rehabilitation (CR) aims to improve the health and outcomes of people with CHD. This is an update of a Cochrane Review previously published in 2016. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of exercise-based CR (exercise training alone or in combination with psychosocial or educational interventions) compared with 'no exercise' control, on mortality, morbidity and health-related quality of life (HRQoL) in people with CHD. SEARCH METHODS: We updated searches from the previous Cochrane Review, by searching CENTRAL, MEDLINE, Embase, and two other databases in September 2020. We also searched two clinical trials registers in June 2021. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of exercise-based interventions with at least six months' follow-up, compared with 'no exercise' control. The study population comprised adult men and women who have had a myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), or have angina pectoris, or coronary artery disease. DATA COLLECTION AND ANALYSIS: We screened all identified references, extracted data and assessed risk of bias according to Cochrane methods. We stratified meta-analysis by duration of follow-up: short-term (6 to 12 months); medium-term (> 12 to 36 months); and long-term ( > 3 years), and used meta-regression to explore potential treatment effect modifiers. We used GRADE for primary outcomes at 6 to 12 months (the most common follow-up time point).  MAIN RESULTS: This review included 85 trials which randomised 23,430 people with CHD. This latest update identified 22 new trials (7795 participants). The population included predominantly post-MI and post-revascularisation patients, with a mean age ranging from 47 to 77 years. In the last decade, the median percentage of women with CHD has increased from 11% to 17%, but females still account for a similarly small percentage of participants recruited overall ( < 15%). Twenty-one of the included trials were performed in low- and middle-income countries (LMICs). Overall trial reporting was poor, although there was evidence of an improvement in quality over the last decade. The median longest follow-up time was 12 months (range 6 months to 19 years). At short-term follow-up (6 to 12 months), exercise-based CR likely results in a slight reduction in all-cause mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.73 to 1.04; 25 trials; moderate certainty evidence), a large reduction in MI (RR 0.72, 95% CI 0.55 to 0.93; 22 trials; number needed to treat for an additional beneficial outcome (NNTB) 75, 95% CI 47 to 298; high certainty evidence), and a large reduction in all-cause hospitalisation (RR 0.58, 95% CI 0.43 to 0.77; 14 trials;  NNTB 12, 95% CI 9 to 21; moderate certainty evidence). Exercise-based CR likely results in little to no difference in risk of cardiovascular mortality (RR 0.88, 95% CI 0.68 to 1.14; 15 trials; moderate certainty evidence), CABG (RR 0.99, 95% CI 0.78 to 1.27; 20 trials; high certainty evidence), and PCI (RR 0.86, 95% CI 0.63 to 1.19; 13 trials; moderate certainty evidence) up to 12 months' follow-up. We are uncertain about the effects of exercise-based CR on cardiovascular hospitalisation, with a wide confidence interval including considerable benefit as well as harm (RR 0.80, 95% CI 0.41 to 1.59; low certainty evidence). There was evidence of substantial heterogeneity across trials for cardiovascular hospitalisations (I2 = 53%), and of small study bias for all-cause hospitalisation, but not for all other outcomes. At medium-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.90, 95% CI 0.80 to 1.02; 15 trials), MI (RR 1.07, 95% CI 0.91 to 1.27; 12 trials), PCI (RR 0.96, 95% CI 0.69 to 1.35; 6 trials), CABG (RR 0.97, 95% CI 0.77 to 1.23; 9 trials), and all-cause hospitalisation (RR 0.92, 95% CI 0.82 to 1.03; 9 trials), a large reduction in cardiovascular mortality was found (RR 0.77, 95% CI 0.63 to 0.93; 5 trials). Evidence is uncertain for difference in risk of cardiovascular hospitalisation (RR 0.92, 95% CI 0.76 to 1.12; 3 trials). At long-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.91, 95% CI 0.75 to 1.10), exercise-based CR may result in a large reduction in cardiovascular mortality (RR 0.58, 95% CI 0.43 to 0.78; 8 trials) and MI (RR 0.67, 95% CI 0.50 to 0.90; 10 trials). Evidence is uncertain for CABG (RR 0.66, 95% CI 0.34 to 1.27; 4 trials), and PCI (RR 0.76, 95% CI 0.48 to 1.20; 3 trials). Meta-regression showed benefits in outcomes were independent of CHD case mix, type of CR, exercise dose, follow-up length, publication year, CR setting, study location, sample size or risk of bias. There was evidence that exercise-based CR may slightly increase HRQoL across several subscales (SF-36 mental component, physical functioning, physical performance, general health, vitality, social functioning and mental health scores) up to 12 months' follow-up; however, these may not be clinically important differences. The eight trial-based economic evaluation studies showed exercise-based CR to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years (QALYs). AUTHORS' CONCLUSIONS: This updated Cochrane Review supports the conclusions of the previous version, that exercise-based CR provides important benefits to people with CHD, including reduced risk of MI, a likely small reduction in all-cause mortality, and a large reduction in all-cause hospitalisation, along with associated healthcare costs, and improved HRQoL up to 12 months' follow-up. Over longer-term follow-up, benefits may include reductions in cardiovascular mortality and MI. In the last decade, trials were more likely to include females, and be undertaken in LMICs, increasing the generalisability of findings. Well-designed, adequately-reported RCTs of CR in people with CHD more representative of usual clinical practice are still needed. Trials should explicitly report clinical outcomes, including mortality and hospital admissions, and include validated HRQoL outcome measures, especially over longer-term follow-up, and assess costs and cost-effectiveness.

Risks of and From SARS-CoV-2 Infection and COVID-19 in People With Diabetes: A Systematic Review of Reviews.

BACKGROUND: This review was commissioned by the World Health Organization and presents a summary of the latest research evidence on the impact of coronavirus disease 2019 (COVID-19) on people with diabetes (PWD). PURPOSE: To review the evidence regarding the extent to which PWD are at increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and/or of suffering its complications, including associated mortality. DATA SOURCES: We searched the Cochrane COVID-19 Study Register, Embase, MEDLINE, and LitCOVID on 3 December 2020. STUDY SELECTION: Systematic reviews synthesizing data on PWD exposed to SARS-CoV-2 infection, reporting data on confirmed SARS-CoV-2 infection, admission to hospital and/or to intensive care unit (ICU) with COVID-19, and death with COVID-19 were used. DATA EXTRACTION: One reviewer appraised and extracted data; data were checked by a second. DATA SYNTHESIS: Data from 112 systematic reviews were narratively synthesized and displayed using effect direction plots. Reviews provided consistent evidence that diabetes is a risk factor for severe disease and death from COVID-19. Fewer data were available on ICU admission, but where available, these data also signaled increased risk. Within PWD, higher blood glucose levels both prior to and during COVID-19 illness were associated with worse COVID-19 outcomes. Type 1 diabetes was associated with worse outcomes than type 2 diabetes. There were no appropriate data for discerning whether diabetes was a risk factor for acquiring SARS-CoV-2 infection. LIMITATIONS: Due to the nature of the review questions, the majority of data contributing to included reviews come from retrospective observational studies. Reviews varied in the extent to which they assessed risk of bias. CONCLUSIONS: There are no data on whether diabetes predisposes to infection with SARS-CoV-2. Data consistently show that diabetes increases risk of severe COVID-19. As both diabetes and worse COVID-19 outcomes are associated with socioeconomic disadvantage, their intersection warrants particular attention.

Vegan dietary pattern for the primary and secondary prevention of cardiovascular diseases.

BACKGROUND: Diet plays a major role in the aetiology of cardiovascular disease (CVD) and as a modifiable risk factor is the focus of many prevention strategies. Recently vegan diets have gained popularity and there is a need to synthesise existing clinical trial evidence for their potential in CVD prevention. OBJECTIVES: To determine the effectiveness of following a vegan dietary pattern for the primary and secondary prevention of CVD. SEARCH METHODS: We searched the following electronic databases on 4 February 2020: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Web of Science Core Collection. We also searched ClinicalTrials.gov in January 2021. We applied no language restrictions. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). A vegan dietary pattern excludes meat, fish, eggs, dairy and honey; the intervention could be dietary advice, provision of relevant foods, or both. The comparison group received either no intervention, minimal intervention, or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of 12 weeks or more, defined as the intervention period plus post-intervention follow-up. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, extracted data and assessed risks of bias. We used GRADE to assess the certainty of the evidence. We conducted three main comparisons: 1. Vegan dietary intervention versus no intervention or minimal intervention for primary prevention; 2. Vegan dietary intervention versus another dietary intervention for primary prevention; 3. Vegan dietary intervention versus another dietary intervention for secondary prevention. MAIN RESULTS: Thirteen RCTs (38 papers, 7 trial registrations) and eight ongoing trials met our inclusion criteria. Most trials contributed to primary prevention: comparisons 1 (four trials, 466 participants randomised) and comparison 2 (eight trials, 409 participants randomised). We included only one secondary prevention trial for comparison 3 (63 participants randomised). None of the trials reported on clinical endpoints. Other primary outcomes included lipid levels and blood pressure. For comparison 1 there was moderate-certainty evidence from four trials with 449 participants that a vegan diet probably led to a small reduction in total cholesterol (mean difference (MD) -0.24 mmol/L, 95% confidence interval (CI) -0.36 to -0.12) and low-density lipoprotein (LDL) cholesterol (MD -0.22 mmol/L, 95% CI -0.32 to -0.11), a very small decrease in high-density lipoprotein (HDL) levels (MD -0.08 mmol/L, 95% CI -0.11 to -0.04) and a very small increase in triglyceride levels (MD 0.11 mmol/L, 95% CI 0.01 to 0.21). The very small changes in HDL and triglyceride levels are in the opposite direction to that expected. There was a lack of evidence for an effect with the vegan dietary intervention on systolic blood pressure (MD 0.94 mmHg, 95% CI -1.18 to 3.06; 3 trials, 374 participants) and diastolic blood pressure (MD -0.27 mmHg, 95% CI -1.67 to 1.12; 3 trials, 372 participants) (low-certainty evidence). For comparison 2 there was a lack of evidence for an effect of the vegan dietary intervention on total cholesterol levels (MD -0.04 mmol/L, 95% CI -0.28 to 0.20; 4 trials, 163 participants; low-certainty evidence). There was probably little or no effect of the vegan dietary intervention on LDL (MD -0.05 mmol/L, 95% CI -0.21 to 0.11; 4 trials, 244 participants) or HDL cholesterol levels (MD -0.01 mmol/L, 95% CI -0.08 to 0.05; 5 trials, 256 participants) or triglycerides (MD 0.21 mmol/L, 95% CI -0.07 to 0.49; 5 trials, 256 participants) compared to other dietary interventions (moderate-certainty evidence). We are very uncertain about any effect of the vegan dietary intervention on systolic blood pressure (MD 0.02 mmHg, 95% CI -3.59 to 3.62)  or diastolic blood pressure (MD 0.63 mmHg, 95% CI -1.54 to 2.80; 5 trials, 247 participants (very low-certainty evidence)). Only one trial (63 participants) contributed to comparison 3, where there was a lack of evidence for an effect of the vegan dietary intervention on lipid levels or blood pressure compared to other dietary interventions (low- or very low-certainty evidence). Four trials reported on adverse events, which were absent or minor. AUTHORS' CONCLUSIONS: Studies were generally small with few participants contributing to each comparison group. None of the included studies report on CVD clinical events. There is currently insufficient information to draw conclusions about the effects of vegan dietary interventions on CVD risk factors. The eight ongoing studies identified will add to the evidence base, with all eight reporting on primary prevention. There is a paucity of evidence for secondary prevention.

Mediterranean-Style Diet for the Primary and Secondary Prevention of Cardiovascular Disease: A Cochrane Review.

Background: Diet plays a major role in cardiovascular disease (CVD) risk. Objectives: To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD. Methods: We searched for randomised controlled trials (RCTs) of Mediterranean-style diets in healthy adults and those at increased risk of CVD (primary prevention) and with established CVD (secondary prevention). Results: Thirty RCTs were included, 22 in primary prevention and eight in secondary prevention. Clinical endpoints were reported in two trials where there was moderate quality evidence for a reduction in strokes for primary prevention, and low quality evidence for a reduction in total and CVD mortality in secondary prevention. We found moderate quality evidence of improvement in CVD risk factors for primary prevention and low quality evidence of little or no effect in secondary prevention. Conclusions: There is still some uncertainty regarding the effects of a Mediterranean-style diet in CVD prevention.

The experiences of health care professionals, patients, and families of the process of referral and admission to intensive care: A systematic literature review.

Treatment in an intensive care unit can be life-saving but it can be distressing and not every patient can benefit. Decisions to admit a patient to an intensive care unit are complex. We wished to explore how the decision to refer or admit is experienced by those involved, and undertook a systematic review of the literature to answer the research question: What are the experiences of health care professionals, patients, and families, of the process of referral and admission to an intensive care unit? Twelve relevant studies were identified, and a thematic analysis was conducted. Most studies involved health care professionals, with only two considering patients' or families' experiences. Four themes were identified which influenced experiences of intensive care unit referral and review: the professional environment; communication; the allocation of limited resources; and acknowledging uncertainty. Patients' and families' experiences have been under-researched in this area.

Exercise-Based Rehabilitation for Heart Failure: Cochrane Systematic Review, Meta-Analysis, and Trial Sequential Analysis.

OBJECTIVES: This study performed a contemporary systematic review and meta-analysis of exercise-based cardiac rehabilitation (ExCR) for heart failure (HF). BACKGROUND: There is an increasing call for trials of models of ExCR for patients with HF that provide alternatives to conventional center-based provision and recruitment of patients that reflect a broader HF population. METHODS: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, and PsycINFO databases were searched between January 2013 and January 2018. Randomized trials comparing patients undergoing ExCR to control patients not undergoing exercise were included. Study outcomes were pooled using meta-analysis. Metaregression examined potential effect modification according to ExCR program characteristics, and risk of bias, trial sequential analysis (TSA), and Grading of Recommendations Assessment Development and Evaluation (GRADE) were applied. RESULTS: Across 44 trials (n = 5,783; median follow-up of 6 months), compared with control subjects, ExCR did not reduce the risk of all-cause mortality (relative risk [RR]: 0.89; 95% confidence interval [CI]: 0.66 to 1.21; TSA-adjusted CI: 0.26 to 3.10) but did reduce all-cause hospitalization (RR: 0.70; 95% CI: 0.60 to 0.83; TSA-adjusted CI: 0.54 to 0.92) and HF-specific hospitalization (RR: 0.59; 95% CI: 0.42 to 0.84; TSA-adjusted CI: 0.14 for 2.46), and patients reported improved Minnesota Living with Heart Failure questionnaire overall scores (mean difference: -7.1; 95% CI: -10.5 to -3.7; TSA-adjusted CI: -13.2 to -1.0). No evidence of differential effects across different models of delivery, including center- versus home-based programs, were found. CONCLUSIONS: This review supports the beneficial effects of ExCR on patient outcomes. These benefits appear to be consistent across ExCR program characteristics. GRADE and TSA assessments indicated that further high-quality randomized trials are needed.

Correction: Interventions for treating children and adolescents with overweight and obesity: an overview of Cochrane reviews.

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