Coronary revascularisation practices have evolved over the last three decades. This study sought to examine the variations in percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) rates, alongside mortality from acute myocardial infarction (AMI) across a group of 16 high-income countries between 2006 and 2020.

Retrospective observational analysis using data from the Organisation for Economic Co-operation and Development (OECD) database between 2006 and 2020. Estimated annual percent change in revascularisation was analysed using Joinpoint regression model, and mortality rates were evaluated using the locally weighted scatterplot smoothing model.

Publicly available data on PCI and CABG procedure rates alongside AMI mortality rate from 2006 to 2020.

16 countries from the OECD database.

Not applicable.

Standardised PCI and CABG procedure rates and AMI age-standardised mortality rate (ASMR) from 2006 to 2020.

Over the 15 year period, 14.0 million PCI and 2.8 million CABG procedures were collectively recorded across 16 countries. PCI rates varied among nations, but from 2006 to 2020 increased in 11 of the 16 nations overall, led by Finland (+36.0%), Ireland (+34.5%) and France (+31.5%). Meanwhile, CABG rates declined in 14 out of the 16 countries, with Luxembourg (–71.3%), the UK (–62.6%) and Finland (–60.6%) experiencing the most substantial decreases. Throughout the study period, the PCI-to-CABG ratio increased, while AMI ASMR decreased consistently across all countries.

Despite evidence supporting CABG over PCI in specific scenarios, CABG rates have declined, and PCI rates have increased. Possible factors for this trend may include patient preference and advancement in interventional techniques. The varied use of PCI among these nations, alongside a sustained decline in AMI mortality rates, may be expected given the importance of optimal medical therapy in the management of ischaemic heart disease. The results further suggest the significance of factors beyond revascularisation in driving improved outcomes.

To evaluate the psychometric properties of the Hospital Survey on Patient Safety Culture (HSoPSC) version 2.0 in Ethiopian public hospitals.

A cross-sectional study.

Five public hospitals in Eastern Ethiopia.

Healthcare professionals (N=582).

An adapted and contextualised version of HSoPSC 2.0 was used to conduct structural validity using exploratory and confirmatory factor analyses (EFA and CFA). Convergent and discriminant validity were evaluated through item loadings and interfactor correlations, respectively. Reliability was measured using McDonald’s omega and Cronbach’s alpha.

CFA indicated a poor model fit for the original 10-factor, 32-item HSoPSC 2.0 across all statistical indices: relative chi-square (²/df=7.71), root mean square error of approximation (RMSEA=0.108), standardised root mean square residual (SRMR=0.088), comparative fit index (CFI=0.814) and Tucker-Lewis’s index (TLI=0.780). Consequently, a comprehensive EFA was conducted, which identified a revised model comprising 5-factor, 21-item. This model accounted for 62.8% of the total variance and demonstrated strong construct validity, with excellent fit indices (²/df=3.67, RMSEA=0.068, SRMR=0.034, CFI=0.969, TLI=0.945). Internal consistency, assessed via McDonald’s omega and Cronbach’s alpha, exceeded the acceptable threshold of 0.70 across all dimensions, except for Response to Error (0.66). The convergent and discriminant validity of the new model was confirmed, ensuring an accurate representation of the underlying constructs.

The original HSoPSC 2.0 with 10-factor, 32-item failed to demonstrate structural validity in the Ethiopian healthcare context. In contrast, a revised 5-factor, 21-item model showed strong validity and acceptable reliability. This adapted version provides a culturally and contextually relevant tool for assessing patient safety culture in Ethiopian healthcare settings.

Artificial intelligence (AI)-based clinical decision support systems (CDSSs) are currently being developed to aid prescribing in primary care. There is a lack of research on how these systems will be perceived and used by healthcare professionals and subsequently on how to optimise the implementation process of AI-based CDSSs (AICDSSs).

To explore healthcare professionals’ perspectives on the use of an AICDSS for prescribing in co-existing multiple long-term conditions (MLTC), and the relevance to shared decision making (SDM).

Qualitative study using template analysis of semistructured interviews, based on a case vignette and a mock-up of an AICDSS.

Healthcare professionals prescribing for patients working in the English National Health Service (NHS) primary care in the West Midlands region.

A purposive sample of general practitioners/resident doctors (10), nurse prescribers (3) and prescribing pharmacists (2) working in the English NHS primary care.

The proposed tool generated interest among the participants. Findings included the perception of the tool as user friendly and as a valuable complement to existing clinical guidelines, particularly in a patient population with multiple long-term conditions and polypharmacy, where existing guidelines may be inadequate. Concerns were raised about integration into existing clinical documentation systems, medicolegal aspects, how to interpret findings that were inconsistent with clinical guidelines, and the impact on patient-prescriber relationships. Views differed on whether the tool would aid SDM.

AICDSSs such as the OPTIMAL tool hold potential for optimising pharmaceutical treatment in patients with MLTC. However, specific issues related to the tool need to be addressed and careful implementation into the existing clinical practice is necessary to realise the potential benefits.

People experiencing severe and multiple disadvantage (SMD: homelessness, substance use and criminal offending) have multiple intersecting unmet health and social care needs and high mortality rates, often due to street-drug overdose. Pilot randomised controlled trials (RCTs) suggest an integrated, holistic, collaborative outreach intervention (Pharmacy Homeless Outreach Engagement Non-medical Independent Prescribing Rx (PHOENIx)) involving generalist-trained pharmacists, nurses or General Practitioners accompanied by staff from third sector homeless organisations may improve outcomes, including reducing overdose.

Multicentre, parallel group, prospective RCT with parallel economic and process evaluation. Set in six areas of Scotland, UK, 378 adults with SMD will be recruited and randomised (stratified by setting and previous non-fatal overdoses) to PHOENIx intervention in addition to usual care (UC) or UC. Aiming to meet participants weekly for 9–15 months, PHOENIx teams assess and address health and social care needs while referring onwards as necessary, co-ordinating care with wider health and third sector teams. During a person-centred consultation, in the participants’ choice of venue, and taking account of the participant’s priorities, the NHS clinician may prescribe, de-prescribe and treat, for example, wound care, and refer to other health services as necessary. The third sector worker may help with welfare benefit applications, social prescribing or advocacy, for example, securing stable housing. Pairings of clinicians and third sector workers support the same participants. The primary outcome is time to first fatal/non-fatal street-drug overdose at nine months. Secondary endpoints include health-related quality of life, healthcare use and criminal justice encounters. A health economic evaluation will assess cost per quality adjusted life year of PHOENIx relative to standard care. A parallel qualitative process evaluation will explore the perceptions and experiences of PHOENIx, by participants, stakeholders and PHOENIx staff.

The primary and other time-to-event secondary outcomes will be analysed by Cox proportional hazards regression.

IRAS number 345246, approved 23/10/2024 by North of Scotland Research Ethics Service. Results will be shared with participants, third sector homelessness organisations, health and social care partnerships, then peer-reviewed journals and conferences worldwide, from the first quarter of 2027.

ISRCTN12234059 registered on 20/2/2025 (ISRCTN).

Dysregulated immunity may account for an increased risk of infection and other adverse outcomes among frail hospitalised persons. The primary objective of this study is to examine whether baseline frailty is associated with the risk of developing ventilator-associated pneumonia (VAP) or other intensive care unit (ICU)-acquired infections among invasively ventilated adults. Additional objectives are to examine the relationship between frailty and hospital length of stay, discharge to a long-term care facility and vital status. We hypothesise that persons with frailty compared with others would have an increased risk of VAP and other infections, a longer hospital stay, higher probability of discharge to a long-term care facility and higher mortality.

This is a preplanned secondary analysis of the PROSPECT trial (Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial) which enrolled patients across 44 ICUs in three countries. We will use Cox proportional hazards regression analysis to assess the association of frailty with the clinical outcomes of interest, adjusting for other baseline variables. Baseline demographic and descriptive outcome data will be reported using descriptive statistics. Regression results will be presented as adjusted HRs or ORs with 95% CIs for the associations of each independent variable with the primary, secondary and tertiary outcomes.

Participating hospital research ethics board approved the PROSPECT trial and data collection. The protocol for this study was approved by the Hamilton Integrated Research Ethics Board on 20 August 2015 (Project ID:19128). This study will identify whether frailty is associated with risk of VAP and other healthcare-associated infections in invasively ventilated patients, adjusted for other baseline factors. Results may be useful to patients, their caregivers, clinicians and the design of future research. Findings will be disseminated to investigators at a meeting of the Canadian Critical Care Trials Group. We will present study results at an international conference in the fields of critical care and infectious diseases, to coincide with or precede open-access peer-review publication. To aid knowledge dissemination, we will use a variety of formats. For example, for traditional and social media, we will create two different visual abstracts and infographics of our results suitable to share on clinician-facing and public-facing platforms.

NCT02462590.

To examine the longitudinal impact of time-varying factors on US youth’s trajectories of initiation and use of e-cigarettes and cigarettes during the transition from adolescence to young adulthood.

Longitudinal.

Nationally representative US survey, the Population Assessment of Tobacco and Health (PATH) Study.

2682 US youth (aged 16–17) at wave (W)1 of the PATH Study across six waves (2013–2020) into young adulthood (aged 22–23).

Unweighted longitudinal latent class analyses identified trajectory classes of e-cigarette and cigarette use, separately. Nationally representative weighted multinomial logistic regression analyses examined time-varying harm perceptions, substance use problems and tobacco product first tried as predictors of these trajectory classes.

Five e-cigarette classes (2013–2020; 41.5% Persistent Never Use, 12.6% W5 Initiation, 19.9% W3 Initiation, 15.2% Prior Initiation, 10.8% High Frequency Past 30-Day (P30D) Use) and five cigarette classes (2013–2019; 58.6% Persistent Never Use, 11.5% W4 Initiation, 10.9% W2 Initiation, 9.6% Prior Initiation, 9.5% High Frequency P30D Use) were identified. Time-varying harm perceptions and substance use problems were associated with trajectories of initiation and use for both products. Cigarettes, cigarillos, other combustibles and any smokeless tobacco as first product tried were associated with e-cigarette initiation and/or progression to high frequency use. E-cigarettes and hookah as first product tried were associated with later cigarette initiation. High Frequency P30D Cigarette Use was less likely if the first product tried was e-cigarettes, cigarillos, hookah or any smokeless tobacco product.

Results reinforce the need for identification and intervention of early substance use among younger adolescents and targeted public health messaging to address changing harm perceptions and prevent initiation among older adolescents.

The Maharashtra Anaemia Study 3 (MAS 3) aims to (1) Investigate the nutritional, environmental, and economic impacts on haemoglobin concentration/anaemia, (2) Identify the underlying micronutrient causes of anaemia and (3) Investigate the association between anaemia and physical and cognitive development of Indian children during their first 18 years of life. This paper introduces the MAS 3 cohort, which consists of data collected from the participants in the prospective Pune Maternal Nutrition Study from the antenatal period to children at 18 years of age (1996–2014) in the Maharashtra state, India.

Recruitment of 2466 married non-pregnant women, and their husbands, took place between June 1994 and April 1996 in six villages, approximately 50 km from Pune city in India. Women were followed up monthly to identify those who became pregnant. A total of 797 pregnant women were followed up for data collection at or near gestational week 18 and 28, with further data collection for women and children occurring within 72 hours of delivery, for both live and stillbirths. Of the 797 women, 710 were included in the MAS 3 cohort, and long-term follow-up of children occurred at 6 years, 12 years and 18 years of age.

In the MAS 3 cohort, most mothers (73%) were aged between 18 and 25 years at the time of their final prepregnancy visit (baseline), and half (55%) belonged to families of middle-upper socioeconomic status (SES). At the children’s baseline (birth) visit, children had a mean birth weight of 2630 g (SD: 376), with one third (31%) of low birth weight. At the 6-year, 12-year and 18-year follow-up visits, data were available for 706 (99%), 689 (97%) and 694 (98%) children.

MAS 3 will be used to address a number of research objectives, including (1) Trends of haemoglobin and anaemia-related micronutrients from age 6 to 18 years, (2) Micronutrient causes of anaemia during childhood, (3) Prevalence and risk factors for maternal anaemia and childhood anaemia, (4) Impact of maternal anaemia on immediate birth outcomes and (5) Intergenerational risk factors associated with anaemia.

Frequent use of emergency departments (EDs) places a considerable burden on healthcare systems. Although frequent attenders are known to have complex physical, mental health and social needs, national-level evidence on their characteristics and patterns of attendance remains limited. This study aimed to provide a comprehensive, population-level description of frequent ED attendance in England, with a focus on age-based subgroups.

Retrospective cohort study.

EDs in England via the Hospital Episode Statistics and the Emergency Care Dataset data linked with primary care prescribing and mortality data, between March 2016 and March 2021.

The dataset received from National Health Service Digital contained approximately 150 million ED attendances by 30 million adult (>18 years) patients over the time period April 2016 to March 2021. A random sample of 5 million people was used for this analysis.

The primary outcome was the number of attendances in each financial year by frequent attenders compared with the remaining patients, split by age bands. Patients were classified as frequent attenders if they had ≥5 or ≥10 ED attendances within a rolling 12-month period. Secondary outcomes included demographic, diagnostic and prescribing characteristics, as well as the number of different ED sites visited.

A Gaussian mixture model was used to identify age-based subgroups. Descriptive statistics were used to summarise key features; 95% CIs were reported where applicable. Among 3.91 million unique adult ED attenders, there were 8.7 million attendances. Of these, 222 160 individuals (5.7%) had ≥5 attendances in a year, accounting for 12.6% of total attendances. A trimodal age distribution was identified, with three distinct peaks corresponding to ages 18–34, 35–64 and 65+. Frequent attenders were more likely to live in deprived areas and have a history of psychotropic or analgesic prescribing. Mental health diagnoses and polypharmacy were particularly common in the younger and middle-aged groups. Multisite attendance was uncommon, with over 80% of frequent attenders using only one ED site annually.

This national analysis reveals a trimodal age pattern among frequent ED attenders, with differing clinical and socio-demographic profiles across age groups. These findings highlight the need for age-tailored approaches to managing high-intensity ED use and inform targeted service development.

First post-contrAst SubtracTed (FAST) MRI, an abbreviated breast MRI scan, has high sensitivity for sub-centimetre aggressive breast cancer and short acquisition and interpretation times. These attributes promise effective supplemental screening. Until now, FAST MRI research has focused on women above population-risk of breast cancer (high mammographic density or personal history). DYAMOND aims to define the population within the population-risk NHS Breast Screening Programme (NHSBSP) likely to benefit from FAST MRI. The study population is the 40% of screening clients aged 50–52 who have average mammographic density (BI-RADS (Breast Imaging Reporting and Data System) B) on their first screening mammogram. DYAMOND will answer whether sufficient numbers of breast cancers, missed by mammography, can be detected by FAST MRI to justify the inclusion of this group in a future randomised controlled trial.

Prospective, multicentre, diagnostic yield, single-arm study with an embedded qualitative sub-study: all recruited participants undergo a FAST MRI. An internal pilot will assess the willingness of sites and screening clients to participate in the study. Screening clients aged 50–52, with a clear first NHSBSP mammogram and BI-RADS B mammographic density (by automated measurement) will be invited to participate (recruitment target: 1000). The primary outcome is the number of additional cancers detected by FAST MRI (missed by screening mammography). A Fleming’s two-stage design will be used as this allows for early stopping after stage 1, to save participants, funding costs and time continuing to the end of the study if the question can be answered earlier.

The NHSBSP Research and Innovation Development Advisory Committee and the Yorkshire and Humber–Sheffield Research Ethics Committee (23/YH/0268, study ID (IRAS): 330059) approved this research protocol. Participation involves a two-stage informed consent process, enabling screening for eligibility through automated mammographic density measurement. Patients with breast cancer helped shape the study design and co-produced participant-facing documents. They will disseminate the results to the public in a clear and meaningful way. Results will be published with open access in international peer-reviewed scientific journals.

ISRCTN74193022

The COVID-19 pandemic led to major disruptions in society across many spheres, including healthcare, the economy and social behaviours. While early predictions warned of an increased risk of suicide during and after the COVID-19 pandemic, rates of suicide deaths remained stable or decreased over that period for most countries. In contrast, the prevalence of suicidal ideation doubled and suicide attempts slightly increased during the COVID-19 pandemic in the adult general population worldwide, accompanied by a higher prevalence of major depressive disorder and anxiety disorders. While these data can tell us what happened, they cannot tell us why. Qualitative suicide research seeks to understand experiences of individuals with suicide-related thoughts and behaviours, provides an in-depth exploration of their lives and interactions with others and centres their views and unique context. There is little qualitative research focusing on suicidality during the pandemic. This study will use a qualitative approach to explore the extent and impact of the COVID-19 pandemic on Canadians who experienced suicidality and review their experiences of accessing mental healthcare to identify key components in supporting safety and recovery.

This study will involve approximately 100 semistructured interviews with participants across four Canadian provinces and will explore experiences with suicide-related thoughts and behaviours during the COVID-19 pandemic. Transcripts will be analysed through qualitative analysis informed by constructivist grounded theory.

The study was approved by the Research Ethics Board of the Centre for Addiction and Mental Health, Toronto Academic Health Sciences Network (for JZ: CAMH REB No 104-2022). In addition to traditional peer-reviewed presentations and publications, a report will make study findings accessible to policy makers, media and the public.

Sugar-sweetened beverages (SSBs) are sugary drinks such as sodas, fruit drinks and sweetened teas and are the leading source of added sugars in the American diet. SSBs are also linked to chronic diseases like type 2 diabetes, cardiovascular disease and certain cancers. Despite their well-known health risks, SSB consumption remains high in the United States of America (USA), with 63% of adults consuming them daily, often exceeding the recommended limit of 50 g of added sugar per day. Though efforts to reduce SSB intake through educational programmes, policy initiatives and taxes exist, further research is needed to assess the effectiveness of interventions to reduce SSB consumption in the USA. Understanding the role of behavioural interventions in lowering SSB consumption among adults is critical to address public health strategies.

The proposed scoping review will be conducted in accordance with the Joanna Briggs Institute methodological framework for scoping reviews. An advanced search will be conducted in three electronic databases: PubMed, PsycINFO and Scopus. The reference lists of included studies will also be reviewed to identify additional relevant literature. All identified citations will be compiled in EndNote, and duplicate citations will be eliminated. Identification of studies will occur through the three-step search process: (1) initial screening of studies according to inclusion criteria, (2) eligibility determined through full-text assessment and (3) inclusion of qualified studies meeting the criteria. To be included, studies must report on an existing behavioural intervention to reduce SSB consumption. All studies will undergo screening by two independent reviewers. Any disagreements that arise will be resolved through discussion or with an additional reviewer. A data extraction tool has been developed to extract relevant data from all eligible studies. The extracted data will be presented in a diagrammatic form, alongside a narrative summary, in line with Preferred Reporting Items for Systematic Reviews and Meta-Analysis: extension for Scoping Reviews reporting guidelines.

Ethics approval was not sought as all data will be collected from published literature. We will present our findings at relevant conferences and submit manuscripts for publication in peer-reviewed journals.

This study validates the previously tested Screening for Poverty And Related social determinants to improve Knowledge of and access to resources (‘SPARK Tool’) against comparison questions from well-established national surveys (Post Survey Questionnaire (PSQ)) to inform the development of a standardised tool to collect patients’ demographic and social needs data in healthcare.

Cross-sectional study.

Pan-Canadian study of participants from four Canadian provinces (SK, MB, ON and NL).

192 participants were interviewed concurrently, completing both the SPARK tool and PSQ survey.

Survey topics included demographics: language, immigration, race, disability, sex, gender identity, sexual orientation; and social needs: education, income, medication access, transportation, housing, social support and employment status. Concurrent validity was performed to assess agreement and correlation between SPARK and comparison questions at an individual level as well as within domain clusters. We report on Cohen’s kappa measure of inter-rater reliability, Pearson correlation coefficient and Cramer’s V to assess overall capture of needs in the SPARK and PSQ as well as within each domain. Agreement between the surveys was described using correct (true positive and true negative) and incorrect (false positive and false negative) classification.

There was a moderate correlation between SPARK and PSQ (0.44, p60), SPARK correctly classified 90.5% (n=176/191).

SPARK provides a brief 15 min screening tool for primary care clinics to capture social and access needs. SPARK was able to correctly classify most participants within each domain. Related ongoing research is needed to further validate SPARK in a large representative sample and explore primary care implementation strategies to support integration.

Progressive supranuclear palsy (PSP) is a devastating neurodegenerative disease characterised by cognitive, behavioural and motor problems. Motor symptoms are highly disabling, while cognitive and behavioural changes have a major impact on carer burden, quality of life and prognosis. Apathy and impulsivity are very common, often coexistent in PSP, and negatively predict survival. In preclinical models and other diseases, apathy and impulsivity are associated with noradrenergic deficits, which can be severe in PSP.

Noradrenaline for Progressive Supranuclear Palsy Syndromes trial is a randomised, double-blind, placebo-controlled, crossover design, Phase IIb clinical trial to evaluate the efficacy and safety of oral atomoxetine for the treatment of cognitive and behavioural changes in PSP. Participants receive atomoxetine 40 mg (10 mg/mL oral solution) once daily or a matched placebo solution, in random order, each for 8 weeks. An ‘informant’, who knows the patient with PSP well, is co-recruited to complete some of the trial outcome measures. Participants remain in the trial for 22 weeks after randomisation. The primary objectives are to assess (1) safety and tolerability and (2) efficacy versus placebo on challenging behaviours as reported in a subscale of the Cambridge Behavioural Inventory. Secondary and exploratory measures relate to cognition, the PSP Rating Scale, mood and potential baseline predictors of individual response to atomoxetine computed from imaging, genetic and cognitive measures at baseline.

The trial was approved by the South Central-Oxford B Research Ethics Committee (REC) and the Medicines and Healthcare products Regulatory Agency (REC reference: 20/SC/0416). Dissemination will include publication in peer-reviewed journals, presentations at academic and public conferences and engagement with patients, the public, policymakers and practitioners.

ISRCTN99462035; DOI: https://doi.org/10.1186/ISRCTN99462035; EudraCT (European Union Drug Regulating Authorities Clinical Trials Database)/CTIS (Clinical Trial Information System) number: 2019-004472-19; IRAS (Integrated Research Application System) number: 272063; Secondary identifying numbers: CPMS (Central Portfolio Management System) 44441.

Prescribing antibiotics may reinforce patients’ beliefs that antibiotics are needed and increase future consultations for similar symptoms. This review determines the effect of antibiotic prescribing for respiratory infections in primary care on future reattendance.

A systematic review and meta-analysis of randomised controlled trials (RCTs) and cohort studies and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Participants were adults or children presenting with respiratory infection in primary care.

MEDLINE (Ovid), PubMed, Embase, the Cochrane Central Register of Controlled Trials, clinical trial registries and grey literature sources were searched from inception until 6 February 2024.

Eligible studies included open-label RCTs or cohort studies of antibiotics compared with no antibiotics in adults or children with respiratory infections. The outcome of interest was reattendance at least 28 days after the initial consultation.

Two reviewers independently screened, selected, assessed the quality and extracted data. Separate meta-analyses were presented for RCT and cohort studies and a combined meta-analysis of all studies.

We identified 2128 records and reviewed 48 full texts, of which five met the inclusion criteria. These reported three RCTs (1207 randomised to antibiotics, 672 controls) and three cohort studies (209 138 exposed to antibiotics, 46 469 controls). In the meta-analysis of RCTs, relative risk (RR) of reattendance with antibiotics was 1.10 (95% CI: 0.99 to 1.23), and in cohort studies, RR was 1.21 (95% CI: 0.94 to 1.49). An important limitation is that most studies were in UK primary care.

Evidence suggests prescribing antibiotics for acute respiratory tract infections in primary care probably modestly increases future reattendance for similar conditions. Reducing antibiotic prescribing may help decrease demand for primary care.

CRD42023470731.

Exacerbations of chronic obstructive pulmonary disease (COPD) can lead to reduced lung function and worse clinical outcomes. Previous studies have reported associations between severe exacerbations and increased risk of hospitalisation and/or mortality. This meta-analysis examined the impact of moderate exacerbations on the risk of future exacerbations and all-cause mortality.

This meta-analysis included seven observational studies from the EXACOS (EXAcerbations of COPD and their OutcomeS)/AVOIDEX (Impact of AVOIDing EXacerbations of COPD) programme studies.

This meta-analysis used data from regional claims databases or electronic healthcare records from seven countries.

The individual studies included patients with a diagnosis of COPD and ≥12 months of data availability before (regarded as baseline) and after the index (ie, the date of the first COPD diagnosis), with postindex data considered the follow-up period.

The number of COPD exacerbations experienced during the baseline period (ie, the exposure variable) was used to categorise patients into the following groups: no exacerbations, one moderate exacerbation only or two or more moderate/severe exacerbations. Outcomes assessed included risk of COPD exacerbations and all-cause mortality during follow-up as a function of baseline exacerbations. For meta-analyses, all rate ratios (RRs) were log-transformed, and associations were pooled across studies using random-effects meta-analysis models.

Among 2 733 162 patients with COPD, one moderate exacerbation was significantly associated with a twofold increased risk of future exacerbations compared with having no exacerbations during baseline, with pooled RRs (95% CIs) of 2.47 (1.47 to 4.14) at 1 year, 2.49 (1.38 to 4.49) at 2 years and 2.38 (1.30 to 4.34) at 3 years postindex. The pooled RR (95% CI) for all-cause mortality was 1.30 (1.05 to 1.62), indicating a 30% increase in risk following one moderate exacerbation versus no exacerbations.

Preventing moderate exacerbations in patients with COPD should be a priority that may improve patient trajectories and outcomes.