Strengths and limitations of healthcare databases in the evaluation of hypoglycaemia

In this issue of DOM, Zaccardi et al. present an analysis of hypoglycaemia-related hospitalizations in the Hospital Episodes Statistics (HES) administrative database of the English National Health Service. [1] Notable strengths of the work include a large sample size involving more than 100 000 cases of hypoglycaemia, and nationwide capture spanning a duration of ten years. Key conclusions include the possibility of a U-shaped relationship between risk of hypoglycaemia and age, as well as possible associations between social deprivation and ethnicity with greater risk of hypoglycaemia

Methodological review: quality of randomized controlled trials in health literacy

Background: The growing move towards patient-centred care has led to substantial research into improving the health literacy skills of patients and members of the public. Hence, there is a pressing need to assess the methodology used in contemporary randomized controlled trials (RCTs) of interventions directed at health literacy, in particular the quality (risk of bias), and the types of outcomes reported. Methods: We conducted a systematic database search for RCTs involving interventions directed at health literacy in adults, published from 2009 to 2014. The Cochrane Risk of Bias tool was used to assess quality of RCT implementation. We also checked the sample size calculation for primary outcomes. Reported evidence of efficacy (statistical significance) was extracted for intervention outcomes in any of three domains of effect: knowledge, behaviour, health status. Demographics of intervention participants were also extracted, including socioeconomic status. Results: We found areas of methodological strength (good randomization and allocation concealment), but areas of weakness regarding blinding of participants, people delivering the intervention and outcomes assessors. Substantial attrition (losses by monitoring time point) was seen in a third of RCTs, potentially leading to insufficient power to obtain precise estimates of intervention effect on primary outcomes. Most RCTs showed that the health literacy interventions had some beneficial effect on knowledge outcomes, but this was typically for less than 3 months after intervention end. There were far fewer reports of significant improvements in substantive patient-oriented outcomes, such as beneficial effects on behavioural change or health (clinical) status. Most RCTs featured participants from vulnerable populations. Conclusions: Our evaluation shows that health literacy trial design, conduct and reporting could be considerably improved, particularly by reducing attrition and obtaining longer follow-up. More meaningful RCTs would also result if health literacy trials were designed with public and patient involvement to focus on clinically important patient-oriented outcomes, rather than just knowledge, behaviour or skills in isolation

Anticholinergic burden measures and older people's falls risk : a systematic prognostic review.

Funding The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Dunhill Medical Trust (grant number RPGF1806/66). Acknowledgements We thank Ms Kaisa Yrjana and Ms Mitrysha Kishor greatly for their help during the study search and screening phases of this review.Peer reviewedPublisher PD

Effectiveness of 80% vs 30–35% fraction of inspired oxygen in patients undergoing surgery: an updated systematic review and meta-analysis

Background In 2016, the World Health Organization (WHO) strongly recommended the use of a high fraction of inspired oxygen (FiO2) in adult patients undergoing general anaesthesia to reduce the risk of surgical site infection (SSI). Since then, further trials have been published, trials included previously have come under scrutiny, and one article was retracted. We updated the systematic review on which the recommendation was based. Methods We performed a systematic literature search from January 1990 to April 2018 for RCTs comparing the effect of high (80%) vs standard (30–35%) FiO2 on the incidence of SSI. Studies retracted or under investigation were excluded. A random effects model was used for meta-analyses; the sources of heterogeneity were explored using meta-regression. Results Of 21 RCTs included, six were newly identified since the publication of the WHO guideline review; 17 could be included in the final analyses. Overall, no evidence for a reduction of SSI after the use of high FiO2 was found [relative risk (RR): 0.89; 95% confidence interval (CI): 0.73–1.07]. There was evidence that high FiO2 was beneficial in intubated patients [RR: 0.80 (95% CI: 0.64–0.99)], but not in non-intubated patients [RR: 1.20 (95% CI: 0.91–1.58); test of interaction; P=0.048]. Conclusions The WHO updated analyses did not show definite beneficial effect of the use of high perioperative FiO2, overall, but there was evidence of effect of reducing the SSI risk in surgical patients under general anaesthesia with tracheal intubation. However, the evidence for this beneficial effect has become weaker and the strength of the recommendation needs to be reconsidered

Safety of 80% vs 30–35% fraction of inspired oxygen in patients undergoing surgery: a systematic review and meta-analysis

Background: Evidence-based guidelines from the World Health Organization (WHO) have recommended a high (80%) fraction of inspired oxygen (FiO2) to reduce surgical site infection in adult surgical patients undergoing general anaesthesia with tracheal intubation. However, there is ongoing debate over the safety of high FiO2. We performed a systematic review to define the relative risk of clinically relevant adverse events (AE) associated with high FiO2. Methods: We reviewed potentially relevant articles from the WHO review supporting the recommendation, including an updated (July 2018) search of EMBASE and PubMed for randomised and non-randomised controlled studies reporting AE in surgical patients receiving 80% FiO2 compared with 30–35% FiO2. We assessed study quality and performed meta-analyses of risk ratios (RR) comparing 80% FiO2 against 30–35% for major complications, mortality, and intensive care admission. Results: We included 17 moderate–good quality trials and two non-randomised studies with serious-critical risk of bias. No evidence of harm with high FiO2 was found for major AE in the meta-analysis of randomised trials: atelectasis RR 0.91 [95% confidence interval (CI) 0.59–1.42); cardiovascular events RR 0.90 (95% CI 0.32–2.54); intensive care admission RR 0.93 (95% CI 0.7–1.12); and death during the trial RR 0.49 (95% CI 0.17–1.37). One non-randomised study reported that high FiO2 was associated with major respiratory AE [RR 1.99 (95% CI 1.72–2.31)]. Conclusions: No definite signal of harm with 80% FiO2 in adult surgical patients undergoing general anaesthesia was demonstrated and there is little evidence on safety-related issues to discourage its use in this population

Anticholinergic burden (prognostic factor) for prediction of dementia or cognitive decline in older adults with no known cognitive syndrome (Review)

Funding Information: National Institute on Aging, NIH Grants, and the Branta Foundation Funding Information: We followed best practice in design, conduct, and reporting of our prognosis review as detailed in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2019). The review was supported by the Cochrane Prognostic Methods Group, partners within the Cochrane Mental Health and Neuroscience Network, and the UK National Institute for Health Research Complex Reviews Support Unit (NIHR CRSU). Funding Information: American Philosophical Society, the National Institute on Aging grants, and by the Illinois Department of Public Health to DAB Funding Information: This protocol was supported by the National Institute for Health Research (NIHR), via Cochrane Infrastructure funding to the Cochrane Dementia and Cognitive Improvement group. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Systematic Reviews Programme, NIHR, National Health Service or the Department of Health Publisher Copyright: Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.Peer reviewedPublisher PD

Prognostic Tools for Early Mortality in Hemorrhagic Stroke: Systematic Review and Meta-Analysis

Background and Purpose: Several risk scores have been developed to predict mortality in intracerebral hemorrhage (ICH). We aimed to systematically determine the performance of published prognostic tools. Methods: We searched MEDLINE and EMBASE for prognostic models (published between 2004 and April 2014) used in predicting early mortality (<6 months) after ICH. We evaluated the discrimination performance of the tools through a random-effects meta-analysis of the area under the receiver operating characteristic curve (AUC) or c-statistic. We evaluated the following components of the study validity: study design, collection of prognostic variables, treatment pathways, and missing data. Results: We identified 11 articles (involving 41,555 patients) reporting on the accuracy of 12 different tools for predicting mortality in ICH. Most studies were either retrospective or post-hoc analyses of prospectively collected data; all but one produced validation data. The Hemphill-ICH score had the largest number of validation cohorts (9 studies involving 3,819 patients) within our systematic review and showed good performance in 4 countries, with a pooled AUC of 0.80 [95% confidence interval (CI)=0.77-0.85]. We identified several modified versions of the Hemphill-ICH score, with the ICH-Grading Scale (GS) score appearing to be the most promising variant, with a pooled AUC across four studies of 0.87 (95% CI=0.84-0.90). Subgroup testing found statistically significant differences between the AUCs obtained in studies involving Hemphill-ICH and ICH-GS scores (p=0.01). Conclusions: Our meta-analysis evaluated the performance of 12 ICH prognostic tools and found greater supporting evidence for 2 models (Hemphill-ICH and ICH-GS), with generally good performance overall