Vascular disease in women: comparison of diagnoses in hospital episode statistics and general practice records in England

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

Multimorbidity of cardiovascular disease subtypes in a prospective cohort of 1.2 million UK women

OBJECTIVE

Cardiovascular multimorbidity (CVM) is the co-occurrence of multiple cardiovascular disease subtypes (CVDs) in one person. Because common patterns and incidence of CVM are not well-described, particularly in women, we conducted a descriptive study of CVM in the Million Women Study, a large population-based cohort of women.

METHODS

UK women aged 50-64 years were followed up using hospital admissions and mortality records for an average of 19 years. CVM was defined as having ≥2 of 19 selected CVDs. The age-specific cumulative incidence of CVM between age 60 and 80 years was estimated. The numbers and proportions of individual, pairs and other combinations of CVDs that comprised incident CVM were calculated. For each individual CVD subtype, age-standardised proportions of the counts of other co-occurring CVDs were estimated.

RESULTS

The age-specific likelihood of having CVM nearly doubled every 5 years between age 60 and 80 years. Among 1.2 million women without CVD at study baseline, 16% (n=196 651) had incident CVM by the end of follow-up. Around half of all women with CVM had a diagnosis of ischaemic heart disease (n=102 536) or atrial fibrillation (n=96 022), almost a third had heart failure (n=72 186) and a fifth had stroke (n=40 442). The pair of CVDs with the highest age-adjusted incidence was ischaemic heart disease and atrial fibrillation (18.95 per 10 000 person-years). Over 60% of individuals with any given CVD subtype also had other CVDs, after age standardisation.

CONCLUSIONS

CVM is common. The majority of women with any specific CVD subtype eventually develop at least one other. Clinical and public health guidelines for CVD management should acknowledge this high likelihood of CVM.

Analysis of the development of gastric cancer after resecting colorectal lesions using large-scale health insurance claims data

BACKGROUND

Colorectal endoscopic resection (C-ER) is spreading due to the increase of colorectal cancer (CRC) in Japan. Gastric cancer (GC) sometimes occurs after C-ER. We aimed to analyze the status of GC after C-ER using large-scale data.

METHODS

We retrospectively used commercially anonymized health insurance claims data of 5.71 million patients from 2005 to 2018, and extracted 62,392 patients ≥ 50 years old who received C-ER. The incidence and risk factors of GC were analyzed. Additionally, subjects were divided into ≥ 2 cm group and < 2 cm group and risks of GC were analyzed.

RESULTS

The median age (range) was 58 (50-75) years and the overall rate of GC was 0.68% (423/62,392). Multivariate analysis showed that significant risk factors for GC [odds rates (OR), 95% confidence interval (CI)] were colorectal lesion size ≥ 2 cm (1.75, 1.24-2.47, p = 0.002), age ≥ 65 y.o. (1.65, 1.31-2.07, p < 0.001), male (2.35, 1. 76-3.13, p < 0.001), diabetes mellitus (1.40, 1.02-1.92, p = 0.035), liver disease (1.54, 1.06-2.24, p = 0.025), Helicobacter pylori infection (2.10, 1.65-2.67, p < 0.001), chronic atrophic gastritis (1.58, 1.14-2.18, p = 0.006), and CRC (1.72, 1.10-2.68, p = 0.017). The rate of GC in the ≥ 2 cm was significantly higher than that in < 2 cm groups (1.17% and 0.65%, p < 0.001). According to the number of significant risk factors, the rates of GC and the hazard ratios of GC (95%CI) were 0.64% and 3.64 (2.20-6.02) and 1.95% and 11.17 (6.57-19.00) for patient with 1-2 and ≥ 3 risk factors, compared with patients without risk factors.

CONCLUSIONS

Using large-scale data, risk factors for GC, including colorecal lesions ≥ 2 cm after C-ER could be investigated.

Association of PSA variability with prostate cancer development using large-scale medical information data: a retrospective cohort study

BACKGROUND

Prostate cancer is one of the most common cancers among men worldwide and the fourth most common cause of death. The number of prostate cancer cases and deaths is increasing every year because of population aging. This study aimed to clarify the risk of developing prostate cancer due to fluctuations in Prostate Specific Antigen (PSA) levels in patients without a history of prostate cancer using large medical information data.

RESULTS

This retrospective cohort included 1707 male patients aged 60 years or older who had a PSA level measurement date (2-PSA) within 3 months or more and 2 years from the first PSA level measurement date (1-PSA) in the database between 2008 and 2019. We subtracted 1-PSA from 2-PSA and designated patients with a higher 2-PSA than 1-PSA to the "up" group (n = 967) and patients with a lower 2-PSA than 1-PSA to the "down" group (n = 740). By using Cox proportional hazards model, a significant increase in prostate cancer risk was observed in the up group compared with the down group (adjusted hazard ratio [HR] = 1.82, 95% confidence interval [CI] = 1.21-2.72; adjusted for patient background factors). Subgroup analysis showed that patients with PSA levels < 4 ng/mL had a significantly increased risk of developing prostate cancer if the next PSA level increases by approximately 20% (adjusted HR = 2.94, 95% CI = 1.14-7.58), and patients with PSA levels of 4 ng/mL or higher if the next PSA level is decreased by approximately 20% had a significantly reduced risk of developing prostate cancer (adjusted HR = 0.36, 95% CI = 0.18-0.74), compared to that with no change.

CONCLUSIONS

This is the first study to clarify the association between PSA variability and risk of developing prostate cancer in patients without a history of prostate cancer. These results suggest that the suppression of elevated PSA levels may lead to the prevention of prostate cancer and that it would be better to perform a biopsy because the risk of developing prostate cancer may increase in the future if the PSA value increases above a certain level.

Depression, anxiety, psychotropic drugs, and acute myocardial infarction: large prospective study of United Kingdom women

BACKGROUND

Reported associations between depression and myocardial infarction in some studies might be explained by use of psychotropic drugs, residual confounding, and/or reverse causation (whereby heart disease precedes depression). We investigated these hypotheses in a large prospective study of UK women with no previous vascular disease.

METHODS

At baseline in median year 2001 (IQR 2001-2003), Million Women Study participants reported whether or not they were currently being treated for depression or anxiety, their self-rated health, and medication use during the previous 4 weeks. Follow-up was through linkage to national hospital admission and mortality databases. Cox regression yielded adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the first myocardial infarction event in those reporting treatment for depression or anxiety (subdivided by whether or not the treatment was with psychotropic drugs) v. not, and stratified by self-reported health and length of follow-up.

RESULTS

During mean follow-up of 13.9 years of 690 335 women (mean age 59.8 years) with no prior heart disease, stroke, transient ischaemic attack, or cancer, 12 819 had a first hospital admission or death from myocardial infarction. The aHRs for those reporting treatment for depression or anxiety with, and without, regular use of psychotropic drugs were 0.96 (95% CI 0.89-1.03) and 0.99 (0.89-1.11), respectively. No associations were found separately in women who reported being in good/excellent or poor/fair health or by length of follow-up.

CONCLUSION

The null findings in this large prospective study are consistent with depression not being an independent risk factor for myocardial infarction.

Accuracy of efficient data methods to determine the incidence of hospital-acquired thrombosis and major bleeding in medical and surgical inpatients: a multicentre observational cohort study in four UK hospitals

OBJECTIVES

We evaluated the accuracy of using routine health service data to identify hospital-acquired thrombosis (HAT) and major bleeding events (MBE) compared with a reference standard of case note review.

DESIGN

A multicentre observational cohort study.

SETTING

Four acute hospitals in the UK.

PARTICIPANTS

A consecutive unselective cohort of general medical and surgical patients requiring hospitalisation for a period of >24 hours during the calendar year 2021. We excluded paediatric, obstetric and critical care patients due to differential risk profiles.

INTERVENTIONS

We compared preidentified sources of routinely collected information (using hospital coding data and local contractually mandated thrombosis datasets) to data extracted from case notes using a predesigned workflow methodology.

PRIMARY AND SECONDARY OUTCOME MEASURES

We defined HAT as objectively confirmed venous thromboembolism occurring during hospital stay or within 90 days of discharge and MBE as per international consensus.

RESULTS

We were able to source all necessary routinely collected outcome data for 87% of 2008 case episodes reviewed. The sensitivity of hospital coding data (International Classification of Diseases 10th Revision, ICD-10) for the diagnosis of HAT and MBE was 62% (95% CI, 54 to 69) and 38% (95% CI, 27 to 50), respectively. Sensitivity improved to 81% (95% CI, 75 to 87) when using local thrombosis data sets.

CONCLUSIONS

Using routinely collected data appeared to miss a substantial proportion of outcome events, when compared with case note review. Our study suggests that currently available routine data collection methods in the UK are inadequate to support efficient study designs in venous thromboembolism research.

TRIAL REGISTRATION NUMBER

NIHR127454.

ERCP for bile duct stones across a national service, demonstrating a high requirement for repeat procedures

Background and study aims  Bile duct stones (BDS) represent approximately 50 % of the requirement for endoscopic retrograde cholangiopancreatography (ERCP) within most services. Significant variation in outcome rates for BDS clearance at ERCP has been reported, and endoscopy societies have set standards for expected clearance rates. The aim of this study was to analyze procedure outcomes across a national service. Patients and methods  Using verified hospital episode statistics (HES) data for the National Health Service (NHS) in England, we analyzed all patients having first ERCPs for BDS from 2015 to 2017, and followed these patients for at least 2 years. Results  In total 37,468 patients underwent a first ERCP for BDS, with 69.8 % undergoing only one procedure. This figure of less than 70 % of BDS cleared at first ERCP is below the Key Performance Indicators as set by the British Society of Gastroenterology (> 75 %) and the European Society of Gastrointestinal Endoscopy (> 90 %). Of 55,556 ERCPs done for BDS, 52.9 % were repeat procedures, with 11,322 patients needing multiple procedures. For hospitals performing significant numbers of ERCPs (more than 600 for BDS during the study period) patients undergoing repeat ERCPs for BDS ranged from 9 % to 50 %. Conclusions  In this nationwide study, the performance at clearing BDS at first ERCP was suboptimal, with high numbers of repeat procedures required. This may have a negative impact on both patient outcomes and experience, and increase pressure on endoscopy services. Apparent variation of outcome between acute hospital care providers requires further analysis.

Differences in mortality and complication rates following revision knee arthroplasty performed for urgent versus elective indications

AIMS

To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty.

METHODS

Patients undergoing primary knee arthroplasty were identified in the national Hospital Episode Statistics (HES) between 1 April 1997 to 31 March 2017. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes, including infection (undergoing surgery), pulmonary embolism, myocardial infarction, and stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications (e.g. loosening, instability, wear) were included in the elective indications cohort.

RESULTS

A total of 939,021 primary knee arthroplasty procedures were included (939,021 patients), of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% confidence interval (CI) 0.37 to 0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44 to 0.47). Revision arthroplasty for infection was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75 to 2.35; odds ratio (OR) 3.54; 95% CI 2.81 to 4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94 to 6.82; OR 6.23; 95% CI 4.39 to 8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort.

CONCLUSION

Patients undergoing revision arthroplasty for urgent indications (infection or fracture) are at higher risk of mortality and serious adverse events in comparison to primary knee arthroplasty and revision arthroplasty for elective indications. These findings will be important for patient consent and shared decision-making and should inform service design for this patient cohort. Cite this article: Bone Joint J 2021;103-B(10):1578-1585.

Temporal Trends and Geographical Variation in Dupuytren Disease Surgery in England: A Population-Based Cohort Study

BACKGROUND

Dupuytren disease (DD) is a common fibroproliferative disease of the palmar fascia. The mainstay of DD treatment in England is surgery with either percutaneous needle fasciotomy, limited fasciectomy, or dermofasciectomy. This study aimed to investigate the temporal trends and geographical variation of primary DD surgery in England.

METHODS

A longitudinal population-based cohort study was perfomed using the Hospital Episode Statistics database from April 1, 2007, to March 31, 2017. Directly standarized rates were estimated over time (between financial years 2007-2008 and 2016-2017) and by geographic region (by clinical commissioning groups [CCGs]; financial years 2010-2011, 2013-2014, and 2016-2017). The Office for National Statistics midyear population estimates were used as the reference population.

MAIN FINDINGS

Primary DD surgery was undertaken at a steadily increasing rate from financial year 2007 to 2008, to 2016 to 2017 in England. There was a striking 3.6-fold variation in the rates of primary DD surgery among National Health Service CCGs in England place of residence.

CONCLUSIONS

This significant variation in DD surgical treatment in England suggests a need for the development of standardized surgical practice across all CCGs and National Health Service hospitals, promoting equality of access to cost-effective health care.

Evidence for the validity of a patient-based instrument for assessment of outcome after revision knee arthroplasty

AIMS

To estimate the measurement properties for the Oxford Knee Score (OKS) in patients undergoing revision knee arthroplasty (responsiveness, minimal detectable change (MDC-90), minimal important change (MIC), minimal important difference (MID), internal consistency, construct validity, and interpretability).

METHODS

Secondary data analysis was performed for 10,727 patients undergoing revision knee arthroplasty between 2013 to 2019 using a UK national patient-reported outcome measure (PROM) dataset. Outcome data were collected before revision and at six months postoperatively, using the OKS and EuroQol five-dimension score (EQ-5D). Measurement properties were assessed according to COnsensus-based Standards for the selection of health status Measurement Instruments (COSMIN) guidelines.

RESULTS

A total of 9,219 patients had complete outcome data. Mean preoperative OKS was 16.7 points (SD 8.1), mean postoperative OKS 29.1 (SD 11.4), and mean change in OKS + 12.5 (SD 10.7). Median preoperative EQ-5D index was 0.260 (interquartile range (IQR) 0.055 to 0.691), median postoperative EQ-5D index 0.691 (IQR 0.516 to 0.796), and median change in EQ-5D index + 0.240 (IQR 0.000 to 0.567). Internal consistency was good with Cronbach's α 0.88 (baseline) and 0.94 (post-revision). Construct validity found a high correlation of OKS total score with EQ-5D index (r = 0.76 (baseline), r = 0.83 (post-revision), p < 0.001). The OKS was responsive with standardized effect size (SES) 1.54 (95% confidence interval (CI) 1.51 to 1.57), compared to SES 0.83 (0.81 to 0.86) for the EQ-5D index. The MIC for the OKS was 7.5 points (95% CI 5.5 to 8.5) based on the optimal cut-off with specificity 0.72, sensitivity 0.60, and area under the curve 0.66. The MID for the OKS was 5.2 points. The MDC-90 was 3.9 points. The OKS did not demonstrate significant floor or ceiling effects.

CONCLUSION

This study found that the OKS was a useful and valid instrument for assessment of outcome following revision knee arthroplasty. The OKS was responsive to change and demonstrated good measurement properties. Cite this article: Bone Joint J 2021;103-B(4):627-634.

SGLT-2 inhibitors and the risk of hospitalization for community-acquired pneumonia: A population-based cohort study

PURPOSE

Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) have been associated with an increased risk of genitourinary tract infections. Through similar biological mechanisms, they may also increase the risk of community-acquired pneumonia. Our objective was to compare the rate of hospitalization for community-acquired pneumonia (HCAP) with SGLT-2i compared to dipeptidyl peptidase-4 inhibitors (DPP-4i) among patients with type 2 diabetes.

METHODS

We used the United Kingdom's Clinical Practice Research Datalink Gold, linked to hospitalization data, to construct a cohort of patients with type 2 diabetes. Using a time-dependent Cox proportional hazards model, we estimated the adjusted hazard ratio (HR) for HCAP with current use of SGLT-2i versus DPP-4i.

RESULTS

Among 29 896 patients, 705 HCAPs occurred over a mean follow-up of 1.7 years (SD: 1.2). Incidence rates for SGLT-2i and DPP-4i users were 6.2 (95% confidence interval [CI]: 3.7, 10.2) and 17.8 (95% CI: 15.3, 20.7) per 1000 person-years, respectively. Current use of SGLT-2i was associated with a decreased risk of HCAP compared to current use of DPP-4i (adjusted HR: 0.48, 95% CI: 0.28, 0.82). However, a comparison of SGLT-2i versus glucagon-like peptide-1 receptor agonists (GLP-1 RA) found no difference in risk of HCAP (adjusted HR: 0.94, 95% CI: 0.44, 1.89).

CONCLUSIONS

SGLT-2i are associated with a decreased rate of HCAP compared to DPP-4i, but not when compared to GLP-1 RA, among patients with type 2 diabetes.

Validity of Acute Cardiovascular Outcome Diagnoses Recorded in European Electronic Health Records: A Systematic Review

BACKGROUND

Electronic health records are widely used in cardiovascular disease research. We appraised the validity of stroke, acute coronary syndrome and heart failure diagnoses in studies conducted using European electronic health records.

METHODS

Using a prespecified strategy, we systematically searched seven databases from dates of inception to April 2019. Two reviewers independently completed study selection, followed by partial parallel data extraction and risk of bias assessment. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value estimates were narratively synthesized and heterogeneity between sensitivity and PPV estimates were assessed using I2.

RESULTS

We identified 81 studies, of which 20 validated heart failure diagnoses, 31 validated acute coronary syndrome diagnoses with 29 specifically recording estimates for myocardial infarction, and 41 validated stroke diagnoses. Few studies reported specificity or negative predictive value estimates. Sensitivity was ≤66% in all but one heart failure study, ≥80% for 91% of myocardial infarction studies, and ≥70% for 73% of stroke studies. PPV was ≥80% in 74% of heart failure, 88% of myocardial infarction, and 70% of stroke studies. PPV by stroke subtype was variable, at ≥80% for 80% of ischaemic stroke but only 44% of haemorrhagic stroke. There was considerable heterogeneity (I2 >75%) between sensitivity and PPV estimates for all diagnoses.

CONCLUSION

Overall, European electronic health record stroke, acute coronary syndrome and heart failure diagnoses are accurate for use in research, although validity estimates for heart failure and individual stroke subtypes were lower. Where possible, researchers should validate data before use or carefully interpret the results of previous validation studies for their own study purposes.

Manipulation Under Anesthetic After Primary Knee Arthroplasty Is Associated With a Higher Rate of Subsequent Revision Surgery

AIM

To determine the association between manipulation under anesthetic (MUA) after primary knee arthroplasty and subsequent revision surgery.

METHODS

Patients undergoing primary knee arthroplasty from April 2011 to April 2016 with minimum 1-year follow-up to April 2017 were identified from the national hospital episode statistics for England. The first arthroplasty per patient, per side, was included; cases with a record of subsequent infection or periprosthetic fracture were excluded. Patients undergoing MUA within 1 year to the same knee were identified, defining the populations for the MUA and non-MUA cohorts. Mortality-adjusted Kaplan-Meier survival analysis (revision arthroplasty) was performed to a maximum of 6 years. A Cox proportional hazards model was used to determine the hazard for revision, adjusting for type of primary arthroplasty, gender, age group, year, comorbidity index, obesity, regional deprivation, rurality, and ethnicity.

RESULTS

A total of 309,650 primary arthroplasty cases (309,650 patients) were included. MUA within 1 year was recorded in 6882 patients (2.22%; 95% confidence interval [95% CI], 2.17-2.28) defining the MUA cohort; all others were included in the parallel non-MUA cohort. At 6 years, the mortality-adjusted estimated implant survival rate in the MUA cohort was 91.2% (95% CI, 90.0-92.2) in comparison to 98.1% (95% CI, 98.0-98.2) in the non-MUA cohort. In the fully adjusted model, this corresponded to an adjusted hazard for revision of 5.03 (hazard ratio; 95% CI, 4.55-5.57).

CONCLUSION

Patients who underwent MUA within 1 year of primary arthroplasty were at a 5-fold increased risk of subsequent revision even after excluding cases of infection or fracture. Further investigation of the etiology of stiffness after primary knee arthroplasty and the optimal treatment options to improve outcomes is justified.

Accuracy of identifying incident stroke cases from linked health care data in UK Biobank

OBJECTIVE

In UK Biobank (UKB), a large population-based prospective study, cases of many diseases are ascertained through linkage to routinely collected, coded national health datasets. We assessed the accuracy of these for identifying incident strokes.

METHODS

In a regional UKB subpopulation (n = 17,249), we identified all participants with ≥1 code signifying a first stroke after recruitment (incident stroke-coded cases) in linked hospital admission, primary care, or death record data. Stroke physicians reviewed their full electronic patient records (EPRs) and generated reference standard diagnoses. We evaluated the number and proportion of cases that were true-positives (i.e., positive predictive value [PPV]) for all codes combined and by code source and type.

RESULTS

Of 232 incident stroke-coded cases, 97% had EPR information available. Data sources were 30% hospital admission only, 39% primary care only, 28% hospital and primary care, and 3% death records only. While 42% of cases were coded as unspecified stroke type, review of EPRs enabled a pathologic type to be assigned in >99%. PPVs (95% confidence intervals) were 79% (73%-84%) for any stroke (89% for hospital admission codes, 80% for primary care codes) and 83% (74%-90%) for ischemic stroke. PPVs for small numbers of death record and hemorrhagic stroke codes were low but imprecise.

CONCLUSIONS

Stroke and ischemic stroke cases in UKB can be ascertained through linked health datasets with sufficient accuracy for many research studies. Further work is needed to understand the accuracy of death record and hemorrhagic stroke codes and to develop scalable approaches for better identifying stroke types.

Streamlined mail-based methods for large randomised trials: lessons learnt from the ASCEND study

Reliable assessment of the effects of an intervention usually requires large randomised trials but such studies are becoming increasingly complex and costly to run. 'Streamlined' trials are needed in which every aspect of the trial design and conduct is simplified, retaining only those elements needed to answer the research question and ensure the safety of the individual participants. In this review we discuss how the trial 'A Study of Cardiovascular Events iN Diabetes' (ASCEND) was streamlined. The study included a two-by-two factorial design: it assessed the effects of low-dose aspirin and, separately, supplementation with n-3 fatty acids on serious vascular events in 15,480 people with diabetes but no overt cardiovascular disease. Other key streamlined design features, such as mail-based recruitment and follow-up, mainly by post, with no in-person visits and use of a run-in period, are also described. We go on to discuss the success of the study and other studies that have employed a similar mail-based approach, and the type of clinical trials that are suitable for mail-based design. Finally, we consider the limitations of the study, and how these could be circumvented in future studies. ASCEND randomised large numbers of eligible participants, achieved good adherence rates and almost complete follow-up at a fraction of the cost of traditional clinic-based trials. Such studies are necessary if researchers are to address the important clinical questions most relevant to improving health.

Data-driven discovery of changes in clinical code usage over time: a case-study on changes in cardiovascular disease recording in two English electronic health records databases (2001-2015)

OBJECTIVES

To demonstrate how data-driven variability methods can be used to identify changes in disease recording in two English electronic health records databases between 2001 and 2015.

DESIGN

Repeated cross-sectional analysis that applied data-driven temporal variability methods to assess month-by-month changes in routinely collected medical data. A measure of difference between months was calculated based on joint distributions of age, gender, socioeconomic status and recorded cardiovascular diseases. Distances between months were used to identify temporal trends in data recording.

SETTING

400 English primary care practices from the Clinical Practice Research Datalink (CPRD GOLD) and 451 hospital providers from the Hospital Episode Statistics (HES).

MAIN OUTCOMES

The proportion of patients (CPRD GOLD) and hospital admissions (HES) with a recorded cardiovascular disease (CPRD GOLD: coronary heart disease, heart failure, peripheral arterial disease, stroke; HES: International Classification of Disease codes I20-I69/G45).

RESULTS

Both databases showed gradual changes in cardiovascular disease recording between 2001 and 2008. The recorded prevalence of included cardiovascular diseases in CPRD GOLD increased by 47%-62%, which partially reversed after 2008. For hospital records in HES, there was a relative decrease in angina pectoris (-34.4%) and unspecified stroke (-42.3%) over the same time period, with a concomitant increase in chronic coronary heart disease (+14.3%). Multiple abrupt changes in the use of myocardial infarction codes in hospital were found in March/April 2010, 2012 and 2014, possibly linked to updates of clinical coding guidelines.

CONCLUSIONS

Identified temporal variability could be related to potentially non-medical causes such as updated coding guidelines. These artificial changes may introduce temporal correlation among diagnoses inferred from routine data, violating the assumptions of frequently used statistical methods. Temporal variability measures provide an objective and robust technique to identify, and subsequently account for, those changes in electronic health records studies without any prior knowledge of the data collection process.

Paediatric and adolescent anterior cruciate ligament reconstruction surgery

Aims

Anterior cruciate ligament (ACL) surgery in children and the adolescent population has increased steadily over recent years. We used a national database to look at trends in ACL reconstruction and rates of serious complications, growth disturbance, and revision surgery, over 20 years.

Methods

All hospital episodes for patients undergoing ACL reconstruction, under the age of 20 years, between 1 April 1997 and 31 March 2017, were extracted by procedure code from the national Hospital Episode Statistics (HES). Population standardized rates of intervention were determined by age group and year of treatment. Subsequent rates of serious complications including reoperation for infection, growth disturbance (osteotomy, epiphysiodesis), revision reconstruction, and/or contralateral ACL reconstruction rates were determined.

Results

Over the 20 year period, 16,125 ACL reconstructions were included. The mean age of patients was 16.9 years (SD 2.0; 27.1% female, n = 4,374/16,125). The majority of procedures were observed in the 15 to 19 years age group. The rate of ACL reconstruction increased 29-fold from 1997 to 1998, to 2016 to 2017. Within 90 days of ACL reconstruction, the rate of reoperation for infection was 0.31% (95% confidence interval (CI) 0.23 to 0.41, n = 50/16,125) and the rate of pulmonary embolism was 0.037% (95%.CI 0.014 to 0.081, n = 6/16,125). Of those with minimum five-year follow-up following ACL reconstruction (n = 7,585), 1.00% of patients subsequently underwent an osteotomy (95% CI 0.79 to 1.25, n = 76/7,585), 0.09% an epiphysiodesis (95% CI 0.04 to 0.19, n = 7/7,585), 7.46% revision ACL reconstruction (95% CI 6.88 to 8.08, n = 566/7,585), and 6.37% contralateral ACL reconstruction (95% CI 5.83 to 6.94, n = 483/7,585).

Conclusion

Rates of paediatric and adolescent ACL reconstruction have increased 29-fold over the last 20 years. Despite the increasing rate in the younger population, the risk of serious complications, including further surgery for growth disturbance is very low. The results of our study provide a point of reference for shared decision making in the management of ACL injury in the paediatric and adolescent population. Cite this article: Bone Joint J 2020;102-B(2):239–245.

Rates of knee arthroplasty in anterior cruciate ligament reconstructed patients: a longitudinal cohort study of 111,212 procedures over 20 years

Background and purpose - Long-term rates of knee arthroplasty in patients with anterior cruciate ligament (ACL) injury who undergo ligament reconstruction (ACLr) are unclear. We determined this risk of arthroplasty through comparison with the general population.Patients and methods - All patients undergoing an ACLr in England, 1997-2017, were identified from national hospital statistics. Patients subsequently undergoing a knee arthroplasty were identified and survival analysis was performed (survival without undergoing knee arthroplasty). A Cox proportional hazards model was used to identify factors associated with knee arthroplasty. Relative risk of knee arthroplasty (total or partial) in comparison with the general population was determined.Results - 111,212 ACLr patients were eligible for analysis (mean age 29; 77% male). Overall, 0.46% (95% confidence interval [CI] 0.40-0.52) ACLr patients underwent knee arthroplasty within 5 years, 0.97% (CI 0.82-1.2) within 10 years, and 1.8% (CI 1.4-2.3) within 15 years. Knee arthroplasty risk was greater in older age groups and women. In comparison with the general population, the relative risk of undergoing arthroplasty at a younger age (at time of arthroplasty) was elevated: at 30-39 years (risk ratio [RR] 20; CI 11-35), 40-49 years (RR 7.5; CI 5.5-10), and 50-59 years (RR 2.5; CI 1.8-3.5), but not 60-69 years (RR 1.7; CI 0.93-3.2).Interpretation - Patients sustaining an ACL injury who undergo ACLr are at elevated risk of subsequent knee arthroplasty in comparison with the general population. Although the absolute rate of arthroplasty is low, the risk of arthroplasty at a younger age is particularly elevated. When the outcome of shared decision-making is ACLr, this data will help inform patients and clinicians about the long-term risk of requiring knee arthroplasty.

Rates of knee arthroplasty within one-year of undergoing arthroscopic partial meniscectomy in England: temporal trends, regional and age-group variation in conversion rates

OBJECTIVE

The aim of this study was to determine the proportion of patients undergoing arthroscopic partial meniscectomy (APM) then subsequently receiving a knee arthroplasty within one or two years, with focus on patients over the age of 60 years and regional variation.

METHODS

Patients undergoing APM in England over 20-years (01-April-1997 to 31-March 2017) were identified in the national Hospital Episode Statistics (HES). The proportion of patients undergoing arthroplasty in the same knee within one or two years of APM was determined and trends were analysed over time nationally and by NHS Clinical Commissioning Group (CCG) region.

RESULTS

806,195 APM patients were eligible for analysis with at least one-year of follow up and 746,630 with two-years. The odds of arthroplasty conversion within one year increased over the study period (odds ratio [OR] 3.10 within 1-year in 2014 vs 2000; 95% confidence interval [CI] 2.75-3.50). For patients undergoing APM aged 60 years or older in 2015-16, 9.9% (1689/17,043; 95% CI 9.5-10.4) underwent arthroplasty within 1-year and, in 2014-15, 16.6% (3100/18,734; 95% CI 16.0-17.1) underwent arthroplasty within 2-years. There was greater than 10-fold variation by CCG.

CONCLUSIONS

Over the study period, the proportion of patients undergoing arthroplasty within one-year of APM increased. In 2015-16, of patients aged 60 years or older who underwent APM, 10% subsequently underwent knee arthroplasty within one year (17% within two years in 2014-15) and there was a high level of regional variation in this outcome. The development and adoption of national treatment guidance is recommended to improve and standardise treatment selection.

Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study

OBJECTIVE

To examine the associations of vegetarianism with risks of ischaemic heart disease and stroke.

DESIGN

Prospective cohort study.

SETTING

The EPIC-Oxford study, a cohort in the United Kingdom with a large proportion of non-meat eaters, recruited across the country between 1993 and 2001.

PARTICIPANTS

48 188 participants with no history of ischaemic heart disease, stroke, or angina (or cardiovascular disease) were classified into three distinct diet groups: meat eaters (participants who consumed meat, regardless of whether they consumed fish, dairy, or eggs; n=24 428), fish eaters (consumed fish but no meat; n=7506), and vegetarians including vegans (n=16 254), based on dietary information collected at baseline, and subsequently around 2010 (n=28 364).

MAIN OUTCOME MEASURES

Incident cases of ischaemic heart disease and stroke (including ischaemic and haemorrhagic types) identified through record linkage until 2016.

RESULTS

Over 18.1 years of follow-up, 2820 cases of ischaemic heart disease and 1072 cases of total stroke (519 ischaemic stroke and 300 haemorrhagic stroke) were recorded. After adjusting for sociodemographic and lifestyle confounders, fish eaters and vegetarians had 13% (hazard ratio 0.87, 95% confidence interval 0.77 to 0.99) and 22% (0.78, 0.70 to 0.87) lower rates of ischaemic heart disease than meat eaters, respectively (P<0.001 for heterogeneity). This difference was equivalent to 10 fewer cases of ischaemic heart disease (95% confidence interval 6.7 to 13.1 fewer) in vegetarians than in meat eaters per 1000 population over 10 years. The associations for ischaemic heart disease were partly attenuated after adjustment for self reported high blood cholesterol, high blood pressure, diabetes, and body mass index (hazard ratio 0.90, 95% confidence interval 0.81 to 1.00 in vegetarians with all adjustments). By contrast, vegetarians had 20% higher rates of total stroke (hazard ratio 1.20, 95% confidence interval 1.02 to 1.40) than meat eaters, equivalent to three more cases of total stroke (95% confidence interval 0.8 to 5.4 more) per 1000 population over 10 years, mostly due to a higher rate of haemorrhagic stroke. The associations for stroke did not attenuate after further adjustment of disease risk factors.

CONCLUSIONS

In this prospective cohort in the UK, fish eaters and vegetarians had lower rates of ischaemic heart disease than meat eaters, although vegetarians had higher rates of haemorrhagic and total stroke.

Rates of Adverse Outcomes and Revision Surgery After Anterior Cruciate Ligament Reconstruction: A Study of 104,255 Procedures Using the National Hospital Episode Statistics Database for England, UK

BACKGROUND

After an anterior cruciate ligament (ACL) injury, ACL reconstruction is an elective procedure, and therefore, an understanding of the attributable risk from undergoing ACL reconstruction is necessary for patients to make a fully informed treatment decision.

PURPOSE

To determine the absolute risk of adverse outcomes including reoperation after ACL reconstruction with comparison, where possible, to the rate of adverse events reported in the general population.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

National hospital data on all ACL reconstructions performed in England between April 1, 1997, and March 31, 2017, were analyzed. Revision cases, bilateral procedures within 6 months, and cases with concurrent cartilage or multiple ligament surgery were excluded. The primary outcome was the occurrence of at least 1 serious complication (myocardial infarction, stroke, pulmonary embolism, infection requiring surgery, fasciotomy, neurovascular injury, or death) within 90 days. Additionally, 5-year rates of revision ACL reconstruction, contralateral ACL reconstruction, and meniscal surgery were investigated.

RESULTS

There were 133,270 ACL reconstructions performed, of which 104,255 were eligible for analysis. Within 90 days, serious complications occurred in 675 (0.65% [95% CI, 0.60-0.70]), including 494 reoperations for infections (0.47% [95% CI, 0.43-0.52]) and 129 for pulmonary embolism (0.12% [95% CI, 0.10-0.15]). Of 54,275 procedures with at least 5 years' follow-up, 1746 (3.22% [95% CI, 3.07-3.37]) underwent revision ACL reconstruction in the same knee, 1553 underwent contralateral ACL reconstruction (2.86% [95% CI, 2.72-3.01]), and 340 underwent meniscal surgery (0.63% [95% CI, 0.56-0.70]). The overall risk of serious complications fell over time (adjusted odds ratio [OR], 0.96 per year [95% CI, 0.95-0.98]); however, older patients (adjusted OR, 1.11 per 5 years [95% CI, 1.07-1.16]) and patients with a greater modified Charlson Comorbidity Index (adjusted OR, 2.41 per 10 units [95% CI, 1.65-3.51]) were at a higher risk. For every 850 (95% CI, 720-1039) ACL reconstructions, 1 pulmonary embolism could be provoked. For every 213 (95% CI, 195-233), 1 native knee joint infection could be provoked.

CONCLUSION

The overall risk of adverse events after ACL reconstruction is low; however, some rare but serious complications, including infections or pulmonary embolism, may occur. Around 3% of patients undergo further ipsilateral or contralateral ACL reconstruction within 5 years. These data will inform shared decision making between clinicians and patients considering their treatment options.

Long-term rates of knee arthroplasty in a cohort of 834 393 patients with a history of arthroscopic partial meniscectomy

Aims

The aim of this study was to determine the long-term risk of undergoing knee arthroplasty in a cohort of patients with meniscal tears who had undergone arthroscopic partial meniscectomy (APM).

Patients and Methods

A retrospective national cohort of patients with a history of isolated APM was identified over a 20-year period. Patients with prior surgery to the same knee were excluded. The primary outcome was knee arthroplasty. Hazard ratios (HRs) were adjusted by patient age, sex, year of APM, Charlson comorbidity index, regional deprivation, rurality, and ethnicity. Risk of arthroplasty in the index knee was compared with the patient’s contralateral knee (with vs without a history of APM). A total of 834 393 patients were included (mean age 50 years; 37% female).

Results

Of those with at least 15 years of follow-up, 13.49% (16 256/120 493; 95% confidence interval (CI) 13.30 to 13.69) underwent subsequent arthroplasty within this time. In women, 22.07% (95% CI 21.64 to 22.51) underwent arthroplasty within 15 years compared with 9.91% of men (95% CI 9.71 to 10.12), corresponding to a risk ratio (RR) of 2.23 (95% CI 2.16 to 2.29). Relative to the general population, patients with a history of APM were over ten times more likely (RR 10.27; 95% CI 10.07 to 10.47) to undergo arthroplasty rising to almost 40 times more likely (RR 39.62; 95% CI 27.68 to 56.70) at a younger age (30 to 39 years). In patients with a history of APM in only one knee, the risk of arthroplasty in that knee was greatly elevated in comparison with the contralateral knee (no APM; HR 2.99; 95% CI 2.95 to 3.02).

Conclusion

Patients developing a meniscal tear undergoing APM are at greater risk of knee arthroplasty than the general population. This risk is three-times greater in the patient’s affected knee than in the contralateral knee. Women in the cohort were at double the risk of progressing to knee arthroplasty compared with men. These important new reference data will inform shared decision making and enhance approaches to treatment, prevention, and clinical surveillance. Cite this article: Bone Joint J 2019;101-B:1071–1080.

Determinants of the decline in mortality from acute stroke in England: linked national database study of 795 869 adults

OBJECTIVES

To study trends in stroke mortality rates, event rates, and case fatality, and to explain the extent to which the reduction in stroke mortality rates was influenced by changes in stroke event rates or case fatality.

DESIGN

Population based study.

SETTING

Person linked routine hospital and mortality data, England.

PARTICIPANTS

795 869 adults aged 20 and older who were admitted to hospital with acute stroke or died from stroke.

MAIN OUTCOME MEASURES

Stroke mortality rates, stroke event rates (stroke admission or stroke death without admission), and case fatality within 30 days after stroke.

RESULTS

Between 2001 and 2010 stroke mortality rates decreased by 55%, stroke event rates by 20%, and case fatality by 40%. The study population included 358 599 (45%) men and 437 270 (55%) women. Average annual change in mortality rate was -6.0% (95% confidence interval -6.2% to -5.8%) in men and -6.1% (-6.3% to -6.0%) in women, in stroke event rate was -1.3% (-1.4% to -1.2%) in men and -2.1% (-2.2 to -2.0) in women, and in case fatality was -4.7% (-4.9% to -4.5%) in men and -4.4% (-4.5% to -4.2%) in women. Mortality and case fatality but not event rate declined in all age groups: the stroke event rate decreased in older people but increased by 2% each year in adults aged 35 to 54 years. Of the total decline in mortality rates, 71% was attributed to the decline in case fatality (78% in men and 66% in women) and the remainder to the reduction in stroke event rates. The contribution of the two factors varied between age groups. Whereas the reduction in mortality rates in people younger than 55 years was due to the reduction in case fatality, in the oldest age group (≥85 years) reductions in case fatality and event rates contributed nearly equally.

CONCLUSIONS

Declines in case fatality, probably driven by improvements in stroke care, contributed more than declines in event rates to the overall reduction in stroke mortality. Mortality reduction in men and women younger than 55 was solely a result of a decrease in case fatality, whereas stroke event rates increased in the age group 35 to 54 years. The increase in stroke event rates in young adults is a concern. This suggests that stroke prevention needs to be strengthened to reduce the occurrence of stroke in people younger than 55 years.

Serious adverse events and lifetime risk of reoperation after elective shoulder replacement: population based cohort study using hospital episode statistics for England

OBJECTIVES

To provide accurate risk estimates of serious adverse events after elective shoulder replacement surgery for arthritis, including age and sex specific estimates of the lifetime risk of revision surgery.

DESIGN

Population based cohort study.

SETTING

Hospital episode statistics for NHS England, including civil registration mortality data.

PARTICIPANTS

58 054 elective shoulder replacements in 51 895 adults (aged ≥50 years) between April 1998 and April 2017.

MAIN OUTCOME MEASURES

The lifetime risk of revision surgery, calculated using an actuarial life table approach and the cumulative probability method. Rates of serious adverse events at 30 and 90 days post-surgery: pulmonary embolism, myocardial infarction, lower respiratory tract infection, acute kidney injury, urinary tract infection, cerebrovascular events, and all cause death. Secondary outcome measures were the number of surgeries performed each year and Kaplan-Meier estimates of revision risk at 3, 5, 10, and 15 years.

RESULTS

The number of shoulder replacements performed each year increased 5.6-fold between 1998 and 2017. Lifetime risks of revision surgery ranged from 1 in 37 (2.7%, 95% confidence interval 2.6% to 2.8%) in women aged 85 years and older to 1 in 4 (23.6%, 23.2% to 24.0%) in men aged 55-59 years. The risks of revision were highest during the first five years after surgery. The risk of any serious adverse event at 30 days post-surgery was 1 in 28 (3.5%, 3.4% to 3.7%), and at 90 days post-surgery was 1 in 22 (4.6%, 4.4% to 4.8%). At 30 days, the relative risk of pulmonary embolism compared with baseline population risk was 61 (95% confidence interval 50 to 73) for women aged 50-64. Serious adverse events were associated with increasing age, comorbidity, and male sex. 1 in 5 (21.2%, 17.9% to 25.1%) men aged 85 years and older experienced at least one serious adverse event within 90 days.

CONCLUSIONS

Younger patients, particularly men, need to be aware of a higher likelihood of early failure of shoulder replacement and the need for further and more complex revision replacement surgery. All patients should be counselled about the risks of serious adverse events. These risks are higher than previously considered, and for some could outweigh any potential benefits. Our findings caution against unchecked expansion of shoulder replacement surgery in both younger and older patients. The more accurate age and sex specific estimates of risk from this study are long overdue and should improve shared decision making between patients and clinicians.

STUDY REGISTRATION

ClinicalTrials.gov NCT03573765.

Anterior cruciate ligament (ACL) reconstruction and meniscal repair rates have both increased in the past 20 years in England: hospital statistics from 1997 to 2017

Objectives

We investigated the temporal trend and the geographical variation in the rate of an anterior cruciate ligament (ACL) reconstruction and meniscal repair (MR) performed in England during a 20-year window.

Methods

All hospital episodes for patients undergoing ACL reconstruction or MR between 1 April 1997 and 31 March 2017 were extracted by procedure code from the national hospital episode statistics. Age-standardised and sex-standardised rates of surgery were calculated using Office for National Statistics population data as the denominator and analysed over time both nationally and regionally by National Health Service clinical commissioning group (CCG).

Results

Between 1997–1998 and 2016–2017, there were 133 270 cases of ACL reconstruction (124 489 patients) and 42 651 cases of MR (41 120 patients) (isolated or simultaneous). Nationally, the rate of ACL reconstruction increased 12-fold from 2.0/100K population (95% CI 1.9 to 2.1) in 1997–1998 to 24.2/100K (95% CI 23.8 to 24.6) in 2016–2017. The rate of MR increased more than twofold from 3.0/100K (95% CI 2.8 to 3.1) in 1997–1998 to 7.3/100K (95% CI 7.1 to 7.5) in 2016–2017. Of these cases, the rate of simultaneous ACL reconstruction and MR was 2.6/100K (95% CI 2.5 to 2.8) in 2016/2017. In 2016–2017, for patients aged 20–29, the sex-standardised rate of ACL reconstruction was 76.9/100K (95% CI 74.9 to 78.9) and for MR was 19.8/100K (95% CI 18.8 to 20.9). Practice varied by region—in 2016–2017, 14.5% (30/207) of the CCGs performed more than twice the national average rate of ACL reconstruction and 15.0% (31/207) performed more than twice the national average rate of MR.

Conclusions

The rate of ACL reconstruction (12-fold) and MR (2.4-fold) has increased in England over the last two decades. There is variation in these rates across geographical regions and further work is required to deliver standardised treatment guidance for appropriate use.

Adverse outcomes after arthroscopic partial meniscectomy: a study of 700 000 procedures in the national Hospital Episode Statistics database for England

BACKGROUND

Arthroscopic partial meniscectomy is one of the most common orthopaedic procedures worldwide. Clinical trial evidence published in the past 6 years, however, has raised questions about the effectiveness of the procedure in some patient groups. In view of concerns about potential overuse, we aimed to establish the true risk of serious complications after arthroscopic partial meniscectomy.

METHODS

We analysed national Hospital Episode Statistics data for all arthroscopic partial meniscectomies done in England between April 1, 1997, and March 31, 2017. Simultaneous or staged (within 6 months) bilateral cases were excluded. We identified complications occurring in the 90 days after the index procedure. The primary outcome was the occurrence of at least one serious complication within 90 days, which was defined as either myocardial infarction, stroke, pulmonary embolism, infection requiring surgery, fasciotomy, neurovascular injury, or death. Logistic regression modelling was used to identify factors associated with complications and, when possible, risk was compared with general population data.

FINDINGS

During the study period 1 088 782 arthroscopic partial meniscectomies were done, 699 965 of which were eligible for analysis. Within 90 days, serious complications occurred in 2218 (0·317% [95% CI 0·304-0·330]) cases, including 546 pulmonary embolisms (0·078% [95% CI 0·072-0·085]) and 944 infections necessitating further surgery (0·135% [95% CI 0·126-0·144]). Increasing age (adjusted odds ratio [OR] 1·247 per decade [95% CI 1·208-1·288) and modified Charlson comorbidity index (adjusted OR 1·860 per 10 units [95% CI 1·708-2·042]) were associated with an increased risk of serious complications. Female sex was associated with a reduced risk of serious complications (adjusted OR 0·640 [95% CI 0·580-0·705). The risk of mortality fell over time (adjusted OR 0·965 per year [95% CI 0·937-0·994]). Mortality, myocardial infarction, and stroke occurred less frequently in the study cohort than in the general population. The risks of infection and pulmonary embolism did not change during the study, and were significantly higher in the study cohort than in the general population. For every 1390 (95% CI 1272-1532) fewer knee arthroscopies done, one pulmonary embolism could be prevented. For every 749 (95% CI 704-801) fewer procedures done, one native knee joint infection could be prevented.

INTERPRETATION

Overall, the risk associated with undergoing arthroscopic partial meniscectomy was low. However, some rare but serious complications (including pulmonary embolism and infection) are associated with the procedure, and the risks have not fallen with time. In view of uncertainty about the effectiveness of arthroscopic partial meniscectomy, an appreciation of relative risks is crucial for patients and clinicians. Our data provide a basis for decision making and consent.

FUNDING

UK National Institute for Health Research.

Differences in risk factors for 3 types of stroke: UK prospective study and meta-analyses

OBJECTIVE

To compare associations of behavioral and related factors for incident subarachnoid hemorrhage and intracerebral hemorrhage and ischemic stroke.

METHODS

A total of 712,433 Million Women Study participants without prior stroke, heart disease, or cancer reported behavioral and related factors at baseline (1999-2007) and were followed up by record linkage to national hospital admission and death databases. Cox regression yielded adjusted relative risks (RRs) by type of stroke. Heterogeneity was assessed with χ2 tests. When appropriate, meta-analyses were done of published prospective studies.

RESULTS

After 12.9 (SD 2.6) years of follow-up, 8,128 women had an incident ischemic stroke, 2,032 had intracerebral hemorrhage, and 1,536 had subarachnoid hemorrhage. In women with diabetes mellitus, the risk of ischemic stroke was substantially increased (RR 2.01, 95% confidence interval [CI] 1.84-2.20), risk of intracerebral hemorrhage was increased slightly (RR 1.31, 95% CI 1.04-1.65), but risk of subarachnoid hemorrhage was reduced (RR 0.43, 95% CI 0.26-0.69) (heterogeneity by stroke type, p < 0.0001). Stroke incidence was greater in women who rated their health as poor/fair compared to those who rated their health as excellent/good (RR 1.36, 95% CI 1.30-1.42). Among 565,850 women who rated their heath as excellent/good, current smokers were at an increased risk of all 3 stroke types, (although greater for subarachnoid hemorrhage [≥15 cigarettes/d vs never smoker, RR 4.75, 95% CI 4.12-5.47] than for intracerebral hemorrhage [RR 2.30, 95% CI 1.94-2.72] or ischemic stroke [RR 2.50, 95% CI 2.29-2.72]; heterogeneity p < 0.0001). Obesity was associated with an increased risk of ischemic stroke and a decreased risk of hemorrhagic stroke (heterogeneity p < 0.0001). Meta-analyses confirmed the associations and the heterogeneity across the 3 types of stroke.

CONCLUSION

Classic risk factors for stroke have considerably different effects on the 3 main pathologic types of stroke.

Identification of myocardial infarction type from electronic hospital data in England and Australia: a comparative data linkage study

OBJECTIVE

To determine the utility of International Classification of Diseases (ICD) codes in investigating trends in ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) using person-linked electronic hospitalisation data in England and Western Australia (WA).

METHODS

All hospital admissions with myocardial infarction (MI) as the principal diagnosis were identified from 2000 to 2013 from both jurisdictions. Fourth-digit ICD-10 codes were used to delineate all MI types-STEMI, NSTEMI, unspecified and subsequent MI. The annual frequency of each MI type was calculated as a proportion of all MI admissions. For all MI and each MI type, age-standardised rates were calculated and age-adjusted Poisson regression models used to estimate annual percentage changes in rates.

RESULTS

In 2000, STEMI accounted for 49% of all MI admissions in England and 59% in WA, decreasing to 35% and 25% respectively by 2013. Less than 10% of admissions were recorded as NSTEMI in England throughout the study period, whereas by 2013, 70% of admissions were NSTEMI in WA. Unspecified MI comprised 60% of all MI admissions in England by 2013, compared with <1% in WA. Trends in age-standardised rates differed for all MI (England, -2.7%/year; WA, +1.7%/year), underpinned by differing age-adjusted trends in NSTEMI (England, -6.1%/year; WA, +10.2%/year).

CONCLUSION

Differences between the proportion and trends for MI types in English and WA data were observed. These were consistent with the coding standards in each country. This has important implications for using electronic hospital data for monitoring MI and identifying MI types for outcome studies.

Antidepressants, Depression, and Venous Thromboembolism Risk: Large Prospective Study of UK Women

BACKGROUND

Some investigators have reported an excess risk of venous thromboembolism (VTE) associated with depression and with use of antidepressant drugs. We explored these associations in a large prospective study of UK women.

METHODS AND RESULTS

The Million Women Study recruited 1.3 million women through the National Health Service Breast Screening Programme in England and Scotland. Three years after recruitment, women were sent a second questionnaire that enquired about depression and regular use of medications in the previous 4 weeks. The present analysis included those who responded and did not have prior VTE, cancer, or recent surgery. Follow-up for VTE was through linkage to routinely collected National Health Service statistics. Cox regression analyses yielded adjusted hazard ratios and 95% CIs. A total of 734 092 women (mean age 59.9 years) were included in the analysis; 6.9% reported use of antidepressants, 2.7% reported use of other psychotropic drugs, and 1.8% reported being treated for depression or anxiety but not use of psychotropic drugs. During follow-up for an average of 7.3 years, 3922 women were hospitalized for and/or died from VTE. Women who reported antidepressant use had a significantly higher risk of VTE than women who reported neither depression nor use of psychotropic drugs (hazard ratio, 1.39; 95% CI, 1.23-1.56). VTE risk was not significantly increased in women who reported being treated for depression or anxiety but no use of antidepressants or other psychotropic drugs (hazard ratio, 1.19; 95% CI, 0.95-1.49).

CONCLUSIONS

Use of antidepressants is common in UK women and is associated with an increased risk of VTE.

Hypertension in pregnancy and risk of coronary heart disease and stroke: A prospective study in a large UK cohort

BACKGROUND

Many studies investigating long-term vascular disease risk associated with hypertensive pregnancies examined risks in relatively young women among whom vascular disease is uncommon. We examined the prospective relation between a history of hypertension during pregnancy and coronary heart disease (CHD) and stroke in middle-aged UK women.

METHODS

In 1996-2001, 1.1 million parous women (mean age=56years) without vascular disease at baseline reported their history of hypertension during pregnancy and other factors. They were followed for incident CHD and stroke (hospitalisation or death). Adjusted relative risks (RRs) were calculated using Cox regression.

RESULTS

Twenty-six percent (290,008/1.1 million) reported having had a hypertensive pregnancy; 27% (79,163/290,008) of women with hypertensive pregnancy, but only 10% (82,145/815,560) of those without hypertensive pregnancy, reported being treated for hypertension at baseline. Mean follow-up was 11.6years (mean ages at diagnosis/N of events: CHD=65years/N=68,161, ischaemic stroke=67years/N=8365, haemorrhagic stroke=64years/N=5702). Overall, the RRs (95% confidence interval [CI]) of incident disease in women with hypertensive pregnancy versus those without such history were: CHD=1.29 (1.27-1.31), ischaemic stroke=1.29 (1.23-1.35), and haemorrhagic stroke=1.14 (1.07-1.21). However, among women with hypertensive pregnancy who were not taking hypertension treatment at baseline, their RRs (95% CI) were only modestly increased: CHD=1.17 (1.14-1.19), ischaemic stroke=1.18 (1.11-1.25), and haemorrhagic stroke=1.09 (1.02-1.18).

CONCLUSION

Hypertension during pregnancy was associated with increased CHD and stroke incidence in middle age, largely because such women also had hypertension in their 50s and 60s, which has a substantially greater effect on vascular disease risk than hypertension during pregnancy without hypertension later in life.

Comparison of dementia recorded in routinely collected hospital admission data in England with dementia recorded in primary care

BACKGROUND

Electronic linkage of UK cohorts to routinely collected National Health Service (NHS) records provides virtually complete follow-up for cause-specific hospital admissions and deaths. The reliability of dementia diagnoses recorded in NHS hospital data is not well documented.

METHODS

For a sample of Million Women Study participants in England we compared dementia recorded in routinely collected NHS hospital data (Hospital Episode Statistics: HES) with dementia recorded in two separate sources of primary care information: a primary care database [Clinical Practice Research Datalink (CPRD), n = 340] and a survey of study participants' General Practitioners (GPs, n = 244).

RESULTS

Dementia recorded in HES fully agreed both with CPRD and with GP survey data for 85% of women; it did not agree for 1 and 4%, respectively. Agreement was uncertain for the remaining 14 and 11%, respectively; and among those classified as having uncertain agreement in CPRD, non-specific terms compatible with dementia, such as 'memory loss', were recorded in the CPRD database for 79% of the women. Agreement was significantly better (p < 0.05 for all comparisons) for women with HES diagnoses for Alzheimer's disease (95 and 94% agreement with any dementia for CPRD and GP survey, respectively) and for vascular dementia (88 and 88%, respectively) than for women with a record only of dementia not otherwise specified (70 and 72%, respectively). Dementia in the same woman was first mentioned an average 1.6 (SD 2.6) years earlier in primary care (CPRD) than in hospital (HES) data. Age-specific rates for dementia based on the hospital admission data were lower than the rates based on the primary care data, but were similar if the delay in recording in HES was taken into account.

CONCLUSIONS

Dementia recorded in routinely collected NHS hospital admission data for women in England agrees well with primary care records of dementia assessed separately from two different sources, and is sufficiently reliable for epidemiological research.

The role of health-related behavioural factors in accounting for inequalities in coronary heart disease risk by education and area deprivation: prospective study of 1.2 million UK women

BACKGROUND

Some recent research has suggested that health-related behaviours, such as smoking, might explain much of the socio-economic inequalities in coronary heart disease (CHD) risk. In a large prospective study of UK women, we investigated the associations between education and area deprivation and CHD risk and assessed the contributions of smoking, alcohol consumption, physical activity and body mass index (BMI) to these inequalities.

METHODS

After excluding women with heart disease, stroke or cancer at recruitment, 1,202,983 women aged 56 years (SD 5 years) on average, were followed for first coronary event (hospital admission or death) and for CHD mortality. Relative risks of CHD were estimated by Cox regression, and the extent to which any association could be accounted for by smoking, alcohol, physical inactivity, and BMI was assessed by calculating the percentage reduction in the relevant likelihood-ratio (LR) statistic after adjustment for these factors, separately and together.

RESULTS

A total of 71,897 women had a first CHD event (hospital admission or death) and 6032 died from CHD during 12 years follow-up. In analyses adjusted by age, birth cohort and region of residence only, lower levels of education and greater deprivation were associated with higher risks of CHD (P heterogeneity < 0.0001 for each); associations for education were found within every level of deprivation and for deprivation were found within every level of education. Smoking, alcohol consumption, physical inactivity and BMI accounted for most of the associations (adjustment for all four factors together reduced the LR statistics for education and for deprivation by 76 % and 71 %, respectively, for first CHD event; and by 87 % and 79 %, respectively, for CHD mortality). Of these four factors, adjustment for smoking resulted in the largest reduction in the LR statistic. Given the large reduction in the predictive values of education and deprivation after adjustment for only four health-related behavioural factors recorded just at recruitment, residual confounding might plausibly account for the remaining associations.

CONCLUSIONS

Most of the association between CHD risk and education and area deprivation in UK women is accounted for by health-related behaviours, particularly by smoking and to a lesser extent by alcohol consumption, physical inactivity and BMI.

Adiposity and ischemic and hemorrhagic stroke: Prospective study in women and meta-analysis

OBJECTIVE

To compare associations of body mass index (BMI) with ischemic stroke and hemorrhagic stroke risk, and to review the worldwide evidence.

METHODS

We recruited 1.3 million previously stroke-free UK women between 1996 and 2001 (mean age 57 years [SD 5]) and followed them by record linkage for hospital admissions and deaths. We used Cox regression to estimate adjusted relative risks for ischemic and hemorrhagic (intracerebral or subarachnoid hemorrhage) stroke in relation to BMI. We conducted a meta-analysis of published findings from prospective studies on these associations.

RESULTS

During an average follow-up of 11.7 years, there were 20,549 first strokes, of which 9,993 were specified as ischemic and 5,852 as hemorrhagic. Increased BMI was associated with an increased risk of ischemic stroke (relative risk 1.21 per 5 kg/m2 BMI, 95% confidence interval 1.18-1.23, p < 0.0001) but a decreased risk of hemorrhagic stroke (relative risk 0.89 per 5 kg/m2 BMI, 0.86-0.92, p < 0.0001). The BMI-associated trends for ischemic and hemorrhagic stroke were significantly different (heterogeneity: p < 0.0001) but were not significantly different for intracerebral hemorrhage (n = 2,790) and subarachnoid hemorrhage (n = 3,062) (heterogeneity: p = 0.5). Published data from prospective studies showed consistently greater BMI-associated relative risks for ischemic than hemorrhagic stroke with most evidence (prior to this study) coming from Asian populations.

CONCLUSIONS

In UK women, higher BMI is associated with increased risk of ischemic stroke but decreased risk of hemorrhagic stroke. The totality of the available published evidence suggests that BMI-associated risks are greater for ischemic than for hemorrhagic stroke.

Social participation and coronary heart disease risk in a large prospective study of UK women

BACKGROUND

Participation in social activities is thought to prevent heart disease, but evidence is inconclusive.

DESIGN

We assessed whether participating in social activities reduces the risk of coronary heart disease (CHD) in a large prospective study of 735,159 middle-aged UK women.

METHODS

Women reported their participation in eight social activities (religious group, voluntary work, adult education, art/craft/music, dancing, sports club, yoga, bingo) and were followed for first CHD event (hospital admission or death) over the next 8.6 years. Cox regression models were used to estimate relative risks for CHD incidence by participation in each and in any of the social activities.

RESULTS

After adjustment for age and region only, every activity except bingo was associated with a reduced risk of CHD (n = 30,756 cases in total). However, after additional adjustment for 11 factors (deprivation, education, smoking, physical activity, body mass index, alcohol, marital status, self-rated health, happiness, hypertension, diabetes), every relative risk estimate moved close to 1.0. For example, for participation in any of the activities compared with none, the relative risk adjusted for age and region only was 0.83 (99% confidence interval 0.81-0.86), but changed to 1.06 (99% confidence interval 1.02-1.09) after additional adjustment. Adjustment for education, self-rated health, smoking and physical activity attenuated the associations most strongly. Residual confounding and other unmeasured factors may well account for any small remaining associations.

CONCLUSIONS

Associations between participation in various social activities and CHD risk appear to be largely or wholly due to confounding by personal characteristics of the participants.

Diagnostic outcomes following childhood non-specific abdominal pain: a record-linkage study

AIMS

Non-specific abdominal pain (NSAP) is the most common diagnosis on discharge following admission for abdominal pain in childhood. Our aim was to determine the risk of subsequent hospital diagnosis of organic and functional gastroenterological conditions following a diagnosis of NSAP, and to assess the persistence of this risk.

METHODS

An NSAP cohort of 268,623 children aged 0-16 years was constructed from linked English Hospital Episode Statistics from 1999 to 2011. The control cohort (1,684,923 children, 0-16 years old) comprised children hospitalised with unrelated conditions. Clinically relevant outcomes were selected and standardised rate ratios were calculated.

RESULTS

From the NSAP cohort, 15,515 (5.8%) were later hospitalised with bowel pathology and 13,301 (5%) with a specific functional disorder. Notably, there was a 4.84 (95% CI 4.45 to 5.27) times greater risk of Crohn's disease following NSAP and a 4.23 (4.13 to 4.33) greater risk of acute appendicitis than in the control cohort. The risk of irritable bowel syndrome (IBS) was 7.22 (6.65 to 7.85) times greater following NSAP. The risks of inflammatory bowel disease (IBD), IBS and functional disorder (unspecified) were significantly increased in all age groups except <2-year-olds. The risk of underlying bowel pathology remained raised up to 10 years after first diagnosis with NSAP.

CONCLUSIONS

Only a small proportion of those with NSAP go on to be hospitalised with underlying bowel pathology. However, their risk is increased even at 10 years after the first hospital admission with NSAP. Diagnostic strategies need to be assessed and refined and active surveillance employed for children with NSAP.

Rates of self-harm presenting to general hospitals: a comparison of data from the Multicentre Study of Self-Harm in England and Hospital Episode Statistics

OBJECTIVE

Rates of hospital presentation for self-harm in England were compared using different national and local data sources.

DESIGN

The study was descriptive and compared bespoke data collection methods for recording self-harm presentations to hospital with routinely collected hospital data.

SETTING

Local area data on self-harm from the 3 centres of the Multicentre Study of Self-harm in England (Oxford, Manchester and Derby) were used along with national and local routinely collected data on self-harm admissions and emergency department attendances from Hospital Episode Statistics (HES).

PRIMARY OUTCOME

Rate ratios were calculated to compare rates of self-harm generated using different data sources nationally and locally (between 2010 and 2012) and rates of hospital presentations for self-harm were plotted over time (between 2003 and 2012), based on different data sources.

RESULTS

The total number of self-harm episodes between 2010 and 2012 was 13,547 based on Multicentre Study data, 9600 based on HES emergency department data and 8096 based on HES admission data. Nationally, routine HES data underestimated overall rates of self-harm by approximately 60% compared with rates based on Multicentre Study data (rate ratio for HES emergency department data, 0.41 (95% CI 0.35 to 0.49); rate ratio for HES admission data, 0.42 (95% CI 0.36 to 0.49)). Direct local area comparisons confirmed an overall underascertainment in the HES data, although the difference varied between centres. There was a general increase in self-harm over time according to HES data which contrasted with a fall and then a rise in the Multicentre Study data.

CONCLUSIONS

There was a consistent underestimation of presentations for self-harm recorded by HES emergency department data, and fluctuations in year-on-year figures. HES admission data appeared more reliable but missed non-admitted episodes. Routinely collected data may miss important trends in self-harm and cannot be used in isolation as the basis for a robust national indicator of self-harm.

The use of national administrative data to describe the spatial distribution of in-hospital mortality following stroke in France, 2008-2011

Background

In the context of implementing the National Stroke Plan in France, a spatial approach was used to measure inequalities in this disease. Using the national PMSI-MCO databases, we analyzed the in-hospital prevalence of stroke and established a map of in-hospital mortality rates with regard to the socio-demographic structure of the country.

Methods

The principal characteristics of patients identified according to ICD10 codes relative to stroke (in accordance with earlier validation work) were studied. A map of standardized mortality rates at the level of PMSI geographic codes was established. An exploratory analysis (principal component analysis followed by ascending hierarchical classification) using INSEE socio-economic data and mortality rates was also carried out to identify different area profiles.

Results

Between 2008 and 2011, the number of stroke patients increased by 3.85 %, notably for ischemic stroke in the 36–55 years age group (60 % of men). Over the same period, in-hospital mortality fell, and the map of standardized rates illustrated the diagonal of high mortality extending from the north-east to the south-west of the country. The most severely affected areas were also those with the least favorable socio-professional indicators.

Conclusions

The PMSI-MCO database is a major source of data on the health status of the population. It can be used for the area-by-area observation of the performance of certain healthcare indicators, such as in-hospital mortality, or to follow the implementation of the National Stroke Plan. Our study showed the interplay between social and demographic factors and stroke-related in-hospital mortality. The map derived from the results of the exploratory analysis illustrated a variety of areas where social difficulties, aging and high mortality seemed to meet. The study raises questions about access to neuro-vascular care in isolated areas and in those in demographic decline. Telemedicine appears to be the solution favored by decision makers. The aging of the population managed for stroke must not mask the growing incidence in younger people, which raises questions about the development of classical (smoking, hypertension) or new (drug abuse) risk factors.

Accuracy of Electronic Health Record Data for Identifying Stroke Cases in Large-Scale Epidemiological Studies: A Systematic Review from the UK Biobank Stroke Outcomes Group

Objective

Long-term follow-up of population-based prospective studies is often achieved through linkages to coded regional or national health care data. Our knowledge of the accuracy of such data is incomplete. To inform methods for identifying stroke cases in UK Biobank (a prospective study of 503,000 UK adults recruited in middle-age), we systematically evaluated the accuracy of these data for stroke and its main pathological types (ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage), determining the optimum codes for case identification.

Methods

We sought studies published from 1990-November 2013, which compared coded data from death certificates, hospital admissions or primary care with a reference standard for stroke or its pathological types. We extracted information on a range of study characteristics and assessed study quality with the Quality Assessment of Diagnostic Studies tool (QUADAS-2). To assess accuracy, we extracted data on positive predictive values (PPV) and—where available—on sensitivity, specificity, and negative predictive values (NPV).

Results

37 of 39 eligible studies assessed accuracy of International Classification of Diseases (ICD)-coded hospital or death certificate data. They varied widely in their settings, methods, reporting, quality, and in the choice and accuracy of codes. Although PPVs for stroke and its pathological types ranged from 6–97%, appropriately selected, stroke-specific codes (rather than broad cerebrovascular codes) consistently produced PPVs >70%, and in several studies >90%. The few studies with data on sensitivity, specificity and NPV showed higher sensitivity of hospital versus death certificate data for stroke, with specificity and NPV consistently >96%. Few studies assessed either primary care data or combinations of data sources.

Conclusions

Particular stroke-specific codes can yield high PPVs (>90%) for stroke/stroke types. Inclusion of primary care data and combining data sources should improve accuracy in large epidemiological studies, but there is limited published information about these strategies.

Frequent physical activity may not reduce vascular disease risk as much as moderate activity: large prospective study of women in the United Kingdom

BACKGROUND

Although physical activity has generally been associated with reduced risk of vascular disease, there is limited evidence about the effects of the frequency and duration of various activities on the incidence of particular types of vascular disease.

METHODS AND RESULTS

In 1998, on average, 1.1 million women without prior vascular disease reported their frequency of physical activity and many other personal characteristics. Three years later, they were asked about hours spent walking, cycling, gardening, and housework each week. Women were followed by record linkage to National Health Service cause-specific hospital admissions and death records. Cox regression was used to calculate adjusted relative risks for first vascular events in relation to physical activity. During an average of 9 years follow-up, 49,113 women had a first coronary heart disease event, 17,822 had a first cerebrovascular event, and 14,550 had a first venous thromboembolic event. In comparison with inactive women, those reporting moderate activity had significantly lower risks of all 3 conditions (P<0.001 for each). However, women reporting strenuous physical activity daily had higher risks of coronary heart disease (P=0.002), cerebrovascular disease (P<0.001), and venous thromboembolic events (P<0.001) than those reporting doing such activity 2 to 3 times per week. Risks did not differ between hemorrhagic and ischemic stroke, or between venous thromboembolic events with or without pulmonary embolism.

CONCLUSIONS

Moderate physical activity is associated with a lower risk of coronary heart disease, venous thromboembolic event, and cerebrovascular disease than inactivity. However, among active women, there is little to suggest progressive reductions in risk of vascular diseases with increasing frequency of activity.

Age at menarche and risks of coronary heart and other vascular diseases in a large UK cohort

BACKGROUND

Early menarche has been associated with increased risk of coronary heart disease (CHD), but most studies were relatively small and could not assess risk across a wide range of menarcheal ages; few have examined associations with other vascular diseases. We examined CHD, cerebrovascular disease, and hypertensive disease risks by age at menarche in a large prospective study of UK women.

METHODS AND RESULTS

In 1.2 million women (mean±SD age, 56±5 years) without previous heart disease, stroke, or cancer, menarcheal age was reported to be 13 years by 25%, ≤10 years by 4%, and ≥17 years by 1%. After 11.6 years of follow-up, 73 378 women had first hospitalization for or death from CHD, 25 426 from cerebrovascular disease, and 249 426 from hypertensive disease. Using Cox regression, we calculated relative risks for each vascular outcome by single year of menarcheal age. The relationship was U-shaped for CHD. Compared with women with menarche at 13 years, the adjusted relative risk for CHD for menarche at ≤10 years of age was 1.27 (95% confidence interval, 1.22-1.31; P<0.0001) and for menarche at ≥17 years of age was 1.23 (95% confidence interval, 1.16-1.30; P<0.0001). U-shaped relationships were also seen for cerebrovascular and hypertensive disease, although the magnitudes of these risks for early and late menarche were smaller than those for CHD.

CONCLUSIONS

In this cohort, the relation of age at menarche to vascular disease risk was U shaped, with both early and late menarche being associated with increased risk. Associations were weaker for cerebrovascular and hypertensive disease than for CHD.

Marital status and ischemic heart disease incidence and mortality in women: a large prospective study

BACKGROUND

Being married has been associated with a lower mortality from ischemic heart disease (IHD) in men, but there is less evidence of an association for women, and it is unclear whether the associations with being married are similar for incident and for fatal IHD. We examined the relation between marital status and IHD incidence and mortality in the Million Women Study.

METHODS

A total of 734,626 women (mean age 60 years) without previous heart disease, stroke or cancer, were followed prospectively for hospital admissions and deaths. Adjusted relative risks (RRs) for IHD were calculated using Cox regression in women who were married or living with a partner versus women who were not. The role of 14 socio-economic, lifestyle and other potential confounding factors was investigated.

RESULTS

81% of women reported being married or living with a partner and they were less likely to live in deprived areas, to smoke or be physically inactive, but had a higher alcohol intake than women who were not married or living with a partner. During 8.8 years of follow-up, 30,747 women had a first IHD event (hospital admission or death) and 2,148 died from IHD. Women who were married or living with a partner had a similar risk of a first IHD event as women who were not (RR = 0.99, 95% confidence interval (CI) 0.96 to 1.02), but a significantly lower risk of IHD mortality (RR = 0.72, 95% CI 0.66 to 0.80, P <0.0001). This lower risk of IHD death was evident both in women with and without a prior IHD hospital admission (respectively: RR = 0.72, 95% CI 0.60 to 0.85, P <0.0001, n = 683; and 0.70, 95% CI 0.62 to 0.78, P <0.0001, n = 1,465). These findings did not vary appreciably between women of different socio-economic groups or by lifestyle and other factors.

CONCLUSIONS

After adjustment for socioeconomic, lifestyle and other factors, women who were married or living with a partner had a similar risk of developing IHD but a substantially lower IHD mortality compared to women who were not married or living with a partner.

Gout as a risk factor for myocardial infarction and stroke in England: evidence from record linkage studies

OBJECTIVE

Some studies suggest that gout is a risk factor for cardiovascular disease. There is more evidence about the association between gout and acute myocardial infarction (MI) than about gout and stroke, and only limited information about risks by age group and sex. We aimed to study MI and stroke following gout, including types of stroke, by age group and comparing men and women.

METHODS

We analysed an all-England national linked dataset of hospital admissions and death records from 1999 to 2011, and a similar dataset in the Oxford Record Linkage Study spanning 1963-98. The occurrence of MI and stroke was estimated in cohorts of patients admitted to hospital with gout, compared with MI and stroke in control cohorts, and the comparisons were expressed as rate ratios (RRs).

RESULTS

The risk of MI and stroke was elevated, and similar, in both datasets. In the all-England dataset, which included 202 033 hospital patients with gout, the RR for MI following gout was 1.82 (95% CI 1.78, 1.85), for all stroke 1.71 (1.68, 1.75), ischaemic stroke 1.68 (1.64, 1.73), haemorrhagic stroke 1.69 (1.61, 1.77) and stroke of unspecified type 2.00 (1.95, 2.06). Associations were stronger in younger than older age groups, and in the younger were stronger in women than men.

CONCLUSION

Gout was associated with increased risk of stroke as well as MI. These findings should be considered by clinicians and may have implications for preventive management of circulatory disease risks in people with gout.

The incidence of first venous thromboembolism in and around pregnancy using linked primary and secondary care data: a population based cohort study from England and comparative meta-analysis

Background

Recent linkage between primary and secondary care data has provided valuable information for studying heath outcomes that may initially present in different health care settings. The aim of this study was therefore, twofold: to use linked primary and secondary care data to determine an optimum definition for estimating the incidence of first VTE in and around pregnancy; and secondly to conduct a systematic literature review of studies on perinatal VTE incidence with the purpose of comparing our estimates.

Methods

We used primary care data from the Clinical Practice Research Datalink (CPRD), which incorporates linkages to secondary care contained within Hospital Episode Statistics (HES) between 1997 and 2010 to estimate the incidence rate of VTE in the antepartum and postpartum period. We systematically searched the literature on the incidence of VTE during antepartum and postpartum periods and performed a meta-analysis to provide comparison.

Findings

Using combined CPRD and HES data and a restrictive VTE definition, the absolute rate during the antepartum period and first six weeks postpartum (early postpartum) were 99 (95%CI 85–116) and 468 (95%CI 391–561) per 100,000 person-years respectively. These were comparable to the pooled estimates from our meta-analysis (using studies after 2005) during the antepartum period (118/100,000 person-years) and early postpartum (424/100,000 person-years). When we used only secondary care data to identify VTE events, incidence was lower during the early postpartum period (308/100,000 person-years), whereas relying only on primary care data lead to lower incidence during the time around delivery, but higher rates during the postpartum period (558/100,000 person-years).

Conclusion

Using combined CPRD and HES data gives estimates of the risk of VTE in and around pregnancy that are comparable to the existing literature. It also provides more accurate estimation of the date of VTE diagnosis which will allow risk stratification during specific pregnancy and postpartum periods.

Completeness and diagnostic validity of recording acute myocardial infarction events in primary care, hospital care, disease registry, and national mortality records: cohort study

OBJECTIVE

To determine the completeness and diagnostic validity of myocardial infarction recording across four national health record sources in primary care, hospital care, a disease registry, and mortality register.

DESIGN

Cohort study.

PARTICIPANTS

21 482 patients with acute myocardial infarction in England between January 2003 and March 2009, identified in four prospectively collected, linked electronic health record sources: Clinical Practice Research Datalink (primary care data), Hospital Episode Statistics (hospital admissions), the disease registry MINAP (Myocardial Ischaemia National Audit Project), and the Office for National Statistics mortality register (cause specific mortality data).

SETTING

One country (England) with one health system (the National Health Service).

MAIN OUTCOME MEASURES

Recording of acute myocardial infarction, incidence, all cause mortality within one year of acute myocardial infarction, and diagnostic validity of acute myocardial infarction compared with electrocardiographic and troponin findings in the disease registry (gold standard).

RESULTS

Risk factors and non-cardiovascular coexisting conditions were similar across patients identified in primary care, hospital admission, and registry sources. Immediate all cause mortality was highest among patients with acute myocardial infarction recorded in primary care, which (unlike hospital admission and disease registry sources) included patients who did not reach hospital, but at one year mortality rates in cohorts from each source were similar. 5561 (31.0%) patients with non-fatal acute myocardial infarction were recorded in all three sources and 11 482 (63.9%) in at least two sources. The crude incidence of acute myocardial infarction was underestimated by 25-50% using one source compared with using all three sources. Compared with acute myocardial infarction defined in the disease registry, the positive predictive value of acute myocardial infarction recorded in primary care was 92.2% (95% confidence interval 91.6% to 92.8%) and in hospital admissions was 91.5% (90.8% to 92.1%).

CONCLUSION

Each data source missed a substantial proportion (25-50%) of myocardial infarction events. Failure to use linked electronic health records from primary care, hospital care, disease registry, and death certificates may lead to biased estimates of the incidence and outcome of myocardial infarction.

TRIAL REGISTRATION

NCT01569139 clinicaltrials.gov.

Body mass index and incident coronary heart disease in women: a population-based prospective study

BACKGROUND

A high body mass index (BMI) is associated with an increased risk of mortality from coronary heart disease (CHD); however, a low BMI may also be associated with an increased mortality risk. There is limited information on the relation of incident CHD risk across a wide range of BMI, particularly in women. We examined the relation between BMI and incident CHD overall and across different risk factors of the disease in the Million Women Study.

METHODS

1.2 million women (mean age=56 years) participants without heart disease, stroke, or cancer (except non-melanoma skin cancer) at baseline (1996 to 2001) were followed prospectively for 9 years on average. Adjusted relative risks and 20-year cumulative incidence from age 55 to 74 years were calculated for CHD using Cox regression.

RESULTS

After excluding the first 4 years of follow-up, we found that 32,465 women had a first coronary event (hospitalization or death) during follow-up. The adjusted relative risk for incident CHD per 5 kg/m2 increase in BMI was 1.23 (95% confidence interval (CI) 1.22 to 1.25). The cumulative incidence of CHD from age 55 to 74 years increased progressively with BMI, from 1 in 11 (95% CI 1 in 10 to 12) for BMI of 20 kg/m2, to 1 in 6(95% CI 1 in 5 to 7) for BMI of 34 kg/m2. A 10 kg/m2 increase in BMI conferred a similar risk to a 5-year increment in chronological age. The 20 year cumulative incidence increased with BMI in smokers and non-smokers, alcohol drinkers and non-drinkers, physically active and inactive, and in the upper and lower socioeconomic classes. In contrast to incident disease, the relation between BMI and CHD mortality (n=2,431) was J-shaped. For the less than 20 kg/m2 and ≥35 kg/m2 BMI categories, the respective relative risks were 1.27 (95% CI 1.06 to 1.53) and 2.84 (95% CI 2.51 to 3.21) for CHD deaths, and 0.89 (95% CI 0.83 to 0.94) and 1.85 (95% CI 1.78 to 1.92) for incident CHD.

CONCLUSIONS

CHD incidence in women increases progressively with BMI, an association consistently seen in different subgroups. The shape of the relation with BMI differs for incident and fatal disease.