BMJ medicine最新文献

{"title":"Epidemiology: a partnership of technical expertise and clinical insight.","authors":"Stephen Burgess, Deborah A Lawlor","doi":"10.1136/bmjmed-2022-000348","DOIUrl":"10.1136/bmjmed-2022-000348","url":null,"abstract":"","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e000348"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12215109/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144556034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection bias and the role of negative control outcomes.","authors":"Isaac Núñez, Anthony A Matthews","doi":"10.1136/bmjmed-2025-001336","DOIUrl":"10.1136/bmjmed-2025-001336","url":null,"abstract":"<p><p>Investigators, patients, or clinicians knowing which treatment is assigned in pragmatic randomised trials and observational analyses can lead to detection bias (ie, systematic differences in determining outcomes between groups). A structural definition of detection bias with directed acyclic graphs is provided, together with several published examples. Why negative control outcomes are best placed to assess detection bias is discussed, and how to correctly select a negative control outcome for this purpose is explained.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001336"},"PeriodicalIF":0.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12172073/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144318860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk factors, impact, and healthcare use related to initial suicide attempts: comprehensive analysis of Swedish population.","authors":"Kejia Hu, Thuy-Dung Nguyen, Karen Borges, Ralf Kuja-Halkola, Agnieszka Butwicka, Isabell Brikell, James J Crowley, Zheng Chang, Brian M D'Onofrio, Henrik Larsson, Paul Lichtenstein, Christian Rück, Cynthia Bulik, Patrick Sullivan, Fang Fang, Yi Lu","doi":"10.1136/bmjmed-2024-001129","DOIUrl":"10.1136/bmjmed-2024-001129","url":null,"abstract":"<p><strong>Abstract: </strong></p><p><strong>Objective: </strong>To provide a comprehensive analysis of initial suicide attempts, covering incidence, risk factors, outcomes, and healthcare use in the month before and the month after the attempts.</p><p><strong>Design: </strong>Comprehensive analysis of the Swedish population that included three designs: a retrospective cohort study to investigate incidence and healthcare use, a nested case-control study to investigate risk factors, and a matched cohort study to examine subsequent suicide attempts and mortality.</p><p><strong>Setting: </strong>Comprehensive Swedish national registers that include patient diagnoses from hospitals and specialist outpatient care, and cause of death information updated to the end of 2019.</p><p><strong>Participants: </strong>3.7 million people born in Sweden in 1963-98 and followed from age 10 to 57 years.</p><p><strong>Main outcome measure: </strong>First lifetime suicide attempt identified in patient and death registers using ICD (international classification of diseases) codes for intentional self-harm, any self-harm with lethal methods or requiring hospital admission, or any self-harm resulting in death.</p><p><strong>Results: </strong>The lifetime risk of an initial suicide attempt in the study population was 4.6%, with greater risk in females and highest risk between ages 18 and 24. One in 10 families in Sweden had at least one family member who attempted suicide. Overdose and poisoning were the most common methods. Previous psychiatric disorders, general medical diseases, and adverse life events were associated with increased risk of initial suicide attempt, while higher socioeconomic status was associated with decreased risk. People with an initial suicide attempt were at substantially increased risk of subsequent attempts (hazard ratio 23.4), death by suicide (16.4), and all cause mortality (7.3). At least 60% of those who made an initial suicide attempt had a healthcare contact in the month before the attempt.</p><p><strong>Conclusions: </strong>This study provides comprehensive data on the incidence, risk factors, outcomes, and healthcare use of initial suicide attempts in the Swedish population, highlighting the need for systematic prevention efforts for people who have attempted suicide for the first time.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001129"},"PeriodicalIF":0.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12161434/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144287403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between maternal body mass index and hospital admissions for infection in offspring: longitudinal cohort study.","authors":"Victoria Coathup, Claire Carson, Helen Ashdown, Gillian Santorelli, Maria A Quigley","doi":"10.1136/bmjmed-2024-001050","DOIUrl":"10.1136/bmjmed-2024-001050","url":null,"abstract":"<p><strong>Objective: </strong>To investigate the relation between maternal body mass index and hospital admissions for infections in their offspring, and to identify potentially modifiable mediators.</p><p><strong>Design: </strong>Longitudinal cohort study.</p><p><strong>Setting: </strong>Born in Bradford longitudinal, multi-ethnic birth cohort, Bradford, UK. Secondary analysis linked to routine hospital admission data, January 2007 to 3 October 2022.</p><p><strong>Participants: </strong>9540 singleton births between 2007 and 2011, born to 9037 mothers, followed up from birth to about age 15 years.</p><p><strong>Main outcome measures: </strong>Total number of hospital admissions related to infections, between birth and age 15 years, in age categories <1 year, 1-4 years, and 5-15 years.</p><p><strong>Results: </strong>The main study cohort comprised 9540 children and 9037 mothers. About 56% of mothers were overweight or obese. First trimester maternal body mass index was positively associated with rates of hospital admissions for infection across all ages, but associations were significant (P<0.05) only for children born to women with the highest body mass index (obesity grades 2-3). Compared with women with a healthy body mass index, children born to women with obesity grades 2-3 had an adjusted rate ratio of 1.41 (95% confidence interval 1.13 to 1.77) at <1 year and an adjusted rate ratio of 1.53 (1.19 to 1.98) for hospital admissions for infection by age 5-15 years. Similar trends were seen for respiratory and gastrointestinal infections, and multisystem viral infections. Being born by caesarean section and child obesity at aged 4-5 years accounted for 21% and 26% of the association, respectively.</p><p><strong>Conclusions: </strong>In this study, a modest but consistent association between maternal obesity (grades 2-3) and hospital admissions for infection throughout childhood was found. Healthcare professionals and public health campaigns should continue to support mothers to achieve and maintain a healthy body weight before conception and during the postpartum period.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001050"},"PeriodicalIF":0.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12164307/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144303793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metformin for covid-19: systematic review and meta-analysis of randomised controlled trials.","authors":"Saifur R Chowdhury, Nazmul Islam, Qi Zhou, Md Kamrul Hasan, Mahmudur Rahman Chowdhury, Reed Ac Siemieniuk, Arnav Agarwal, Romina Brignardello-Petersen, Thomas Agoritsas, Per Olav Vandvik, Dena Zeraatkar, Gordon Guyatt","doi":"10.1136/bmjmed-2024-001126","DOIUrl":"10.1136/bmjmed-2024-001126","url":null,"abstract":"<p><strong>Objective: </strong>To summarise the effects of metformin on covid-19 to inform a World Health Organization (WHO) clinical practice guideline.</p><p><strong>Design: </strong>Systematic review and meta-analysis.</p><p><strong>Data sources: </strong>As part of a living systematic review and network meta-analysis of drug treatments for covid-19 (covid-19 LNMA), a search was performed of the WHO covid-19 database, six Chinese databases, and the Epistemonikos Foundation's Living Overview of the Evidence covid-19 Repository (covid-19 L-OVE).</p><p><strong>Eligibility criteria for selecting studies: </strong>Randomised controlled trials that compared metformin with placebo in patients with acute covid-19 infection.</p><p><strong>Data synthesis: </strong>Frequentist pairwise meta-analyses were performed using the restricted maximum likelihood random effects model. The effects of interventions on selected outcomes were summarised using risk ratios, risk difference, and mean difference when appropriate, along with their corresponding 95% confidence intervals (CIs). To estimate absolute effects, the control arm event rate was used as the baseline risk. The risk of bias of the included studies was assessed using a modification of the Cochrane risk of bias 2.0 tool and the certainty of evidence using the GRADE (grading of recommendations assessment, development and evaluation) approach, with the minimally important difference in effect as the threshold.</p><p><strong>Results: </strong>Three randomised controlled trials of 1869 patients were included; one study provided long term follow-up on long covid. Metformin might have little or no impact on mortality (risk ratio 0.76, 95% CI 0.30 to 1.90; risk difference 3 fewer per 1000, 95% CI 8 fewer to 11 more; low certainty). The effects of metformin on admission to hospital because of covid-19 remain uncertain (risk ratio 0.74, 95% CI 0.28 to 1.95; risk difference 15 fewer per 1000, 95% CI 42 fewer to 55 more; very low certainty). Metformin results in little or no difference in adverse effects leading to discontinuation (risk difference 0.2 more per 1000, 95% CI 2.7 fewer to 3.1 more; high certainty). Metformin might decrease the development of long covid (risk ratio 0.6, 95% CI 0.4 to 0.9; risk difference 41 fewer per 1000, 95% CI 62 fewer to 10 fewer; low certainty). However, the effect is based on a single trial of 1126 patients, which has a high risk of bias owing to missing data, and nearly half of the participants were unvaccinated.</p><p><strong>Conclusions: </strong>Current evidence based on randomised trials suggests no significant effect of metformin on acute clinical outcomes in patients with non-severe covid-19. Metformin might reduce the incidence of long covid when used to treat patients with non-severe acute covid-19 infection, but this was suggested by low certainty evidence from a single trial.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001126"},"PeriodicalIF":0.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107632/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144163938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ending nuclear weapons, before they end us.","authors":"Chris Zielinski","doi":"10.1136/bmjmed-2025-001654","DOIUrl":"10.1136/bmjmed-2025-001654","url":null,"abstract":"","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001654"},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12086931/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144102596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding research on artificial intelligence in healthcare.","authors":"Chris Paton","doi":"10.1136/bmjmed-2025-001614","DOIUrl":"10.1136/bmjmed-2025-001614","url":null,"abstract":"","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001614"},"PeriodicalIF":0.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12090526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144112872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring complete hydatidiform molar pregnancies after normalisation of human chorionic gonadotrophin: national retrospective population study.","authors":"Brenna E Swift, Leonoor Coopmans, Kam Singh, Christopher Coyle, Edmund H Wilkes, Imran Jabbar, Geoffrey Maher, Xianne Aguiar, Lina Salman, Julia E Palmer, Naveed Sarwar, Reece Caldwell, Eshan Ghorani, Baljeet Kaur, Nienke E van Trommel, Christianne A R Lok, Matthew Winter, Michael J Seckl","doi":"10.1136/bmjmed-2024-001017","DOIUrl":"https://doi.org/10.1136/bmjmed-2024-001017","url":null,"abstract":"<p><strong>Objective: </strong>To provide evidence for a reduced surveillance protocol to detect gestational trophoblastic neoplasia after normalisation of human chorionic gonadotrophin (hCG) levels following uterine evacuation of a complete hydatidiform mole.</p><p><strong>Design: </strong>National retrospective population study.</p><p><strong>Setting: </strong>Two UK Trophoblastic Disease Treatment Centres (Sheffield and London), 1 January 1980 to 30 November 2020.</p><p><strong>Participants: </strong>17 424 patients with hCG normalisation after evacuation of their complete hydatidiform mole were included. Complete hydatidiform moles were verified by centralised pathological review. Patients were excluded if lost to follow-up or required treatment before normalisation of hCG levels.</p><p><strong>Main outcome measures: </strong>Incidence and clinical presentation of gestational trophoblastic neoplasia after normalisation of hCG levels following uterine evacuation of a complete hydatidiform mole.</p><p><strong>Results: </strong>Of 17 424 patients whose hCG normalised after complete hydatidiform mole evacuation, 99.8% (n=17 393 of 17 424) did not subsequently develop gestational trophoblastic neoplasia. The overall risk of gestational trophoblastic neoplasia after previous normalisation of hCG levels was 0.2% (n=31 of 17 424 patients). The risk of developing gestational trophoblastic neoplasia after uterine evacuation was substantially lower if hCG levels returned to normal in <56 days rather than ≥56 days (posterior medians 0.06%, 95% credible interval 0.01% to 0.14% <i>v</i> 0.22%, 0.15% to 0.31%), with a posterior relative risk of 0.25 (0.06 to 0.72). Most patients who developed gestational trophoblastic neoplasia (71.0%, n=22 of 31) had received a diagnosis after the current six month surveillance protocol. The cumulative risk of developing gestational trophoblastic neoplasia in patients whose hCG levels normalised early increased minimally with time. If a patient had normal hCG levels in <56 days, a clinically relevant time point, the risk of developing gestational trophoblastic neoplasia was small (0.04%, about 1 in 2619 patients) at 39 months after normalisation. The equivalent risk for a patient who had normal hCG levels in ≥56 days was 0.16% (about 1 in 642 patients). All 31 women who developed gestational trophoblastic neoplasia achieved sustained remission after subsequent treatment.</p><p><strong>Conclusions: </strong>The findings of the study indicate that surveillance protocols could safely change to one confirmatory normal hCG value for patients whose hCG levels return to normal in <56 days of evacuation of a complete hydatidiform mole. Patients whose hCG levels return to normal in ≥56 days should be counselled on the remaining risk of gestational trophoblastic neoplasia over time to help decide the length of subsequent follow-up.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001017"},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12041671/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prognostic value of cervical length for spontaneous preterm birth in asymptomatic women with twin pregnancy: meta-analysis of individual participant data.","authors":"Kelly Margaret Hughes, Mason Aberoumand, Anna Lene Seidler, Phoebe Swan, Mona Aboulghar, Maria de Lourdes Brizot, Clifton Brock, Marta Benito Vielba, Nathan Fox, Cynthia Gyamfi-Bannerman, Lindsay Kindinger, Giorgio Pagani, Alfredo Perales Marin, Viola Seravalli, Mariarosaria Di Tommaso, Omer Weitzner, Katharina Worda, Lukas Staub, Shaun Brennecke, Shakila Thangaratinam, Ben W Mol, Rui Wang","doi":"10.1136/bmjmed-2024-000877","DOIUrl":"https://doi.org/10.1136/bmjmed-2024-000877","url":null,"abstract":"<p><strong>Objective: </strong>To quantify the prognostic value of mid-trimester cervical length for spontaneous preterm birth in asymptomatic women with twin pregnancy and to assess whether other factors may modify any association.</p><p><strong>Designs: </strong>A two stage meta-analysis of individual participant data in a Cox proportional hazard model was performed using cervical length as a continuous variable.</p><p><strong>Data sources: </strong>Medline, Embase, Cochrane, and LILACS, among others, were searched to identify eligible studies; the search was from 1 January 2000 to 30 September 2020. Risk of bias was assessed with the QUIPS tool. Studies were from eight countries between 2001 and 2018.</p><p><strong>Eligibility criteria: </strong>Individual participant data were sought for eligible studies that reported mid-trimester (defined between 16 and 26 weeks) transvaginal sonographic cervical length and also gestational age at birth in asymptomatic women with twin pregnancy. The primary outcome was spontaneous preterm birth before 37 weeks.</p><p><strong>Results: </strong>Among 29 eligible studies, authors of 17 studies provided individual participant data for 6437 women with a twin pregnancy (69.1% of individual participant data). Mean cervical length measurement was 39 mm (SD=9, range 1-74 mm). 2889 women (44.9%) delivered before 37 weeks' gestation, and 934 (14.9%) delivered before 34 weeks. Each 1 mm increase in cervical length was associated with a 4.0% reduction in the rate of spontaneous preterm birth before 37 weeks (hazard ratio 0.96 (95% confidence interval 0.95 to 0.97)), and a 6.8% reduction in the rate of spontaneous preterm birth before 34 weeks' gestation (0.93 (0.92 to 0.95)). The prognostic value remained stable in models adjusting for different sets of variables.</p><p><strong>Conclusion: </strong>The prognostic value of cervical length for spontaneous preterm birth in twin pregnancy is on a continuous scale. No specific cervical length has been identified that can reliably predict or exclude all spontaneous preterm births.</p><p><strong>Study registration: </strong>CRD42020146987.</p>","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e000877"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12056617/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overactive bladder drugs and the risk of dementia.","authors":"Carolyn Michelle Tan, David Juurlink","doi":"10.1136/bmjmed-2025-001520","DOIUrl":"10.1136/bmjmed-2025-001520","url":null,"abstract":"","PeriodicalId":72433,"journal":{"name":"BMJ medicine","volume":"4 1","pages":"e001520"},"PeriodicalIF":0.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12164308/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144303797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}