Liam Smeeth

London School of Hygiene and Tropical Medicine, Londinium, England, United Kingdom

Are you Liam Smeeth?

Claim your profile

Publications (294)2422.13 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with chronic obstructive pulmonary disease (COPD) have increased mortality following myocardial infarction (MI) compared with patients without COPD. We investigated the extent to which differences in recognition and management after MI could explain the mortality difference. 300 161 patients with a first MI between 2003 and 2013 were identified in the UK Myocardial Ischaemia National Audit Project database. Logistic regression was used to compare mortality in hospital and at 180 days postdischarge between patients with and without COPD. Variables relating to inhospital factors (delay in diagnosis, use of reperfusion and time to reperfusion/use of angiography) and use of secondary prevention were sequentially added to models. Mortality was higher for patients with COPD both inhospital (4.6% vs 3.2%) and at 180 days (12.8% vs 7.7%). After adjusting for inhospital factors, the effect of COPD on inhospital mortality after MI was reduced for both ST-elevation myocardial infarctions (STEMIs) and non-STEMIs (STEMIs OR 1.24 (95% CI 1.10 to 1.41) to 1.13 (95% CI 0.99 to 1.29); non-STEMIs OR 1.34 (95% CI 1.24 to 1.45) to 1.16 (95% CI 1.07 to 1.26)). Adjusting for inhospital factors reduced the effect of COPD on mortality after non-STEMI at 180 days (OR 1.56 (95% CI 1.47 to 1.65) to 1.37 (95% CI 1.31 to 1.44)). Adjusting for use of secondary prevention also reduced the effect of COPD on mortality at 180 days for STEMIs and non-STEMIs (STEMIs OR 1.45 (95% CI 1.31 to 1.61) to 1.25 (95% CI 1.11 to 1.41); non-STEMIs OR 1.37 (95% CI 1.31 to 1.44) to 1.26 (95% CI 1.17 to 1.35). Delayed diagnosis, timing and use of reperfusion of a STEMI, use of angiography after a non-STEMI and use of secondary prevention medicines are all potential explanations for the mortality gap after MI in people with COPD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
    Heart (British Cardiac Society) 03/2015; DOI:10.1136/heartjnl-2014-307251 · 6.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The CRONICAS Centre of Excellence in Chronic Diseases, based at Universidad Peruana Cayetano Heredia, was created in 2009 with support from the U.S. National Heart, Lung, and Blood Institute (NHLBI). The vision of CRONICAS is to build a globally recognized center of excellence conducting quality and innovative research and generating high-impact evidence for health. The center's identity is embedded in its core values: generosity, innovation, integrity, and quality. This review has been structured to describe the development of the CRONICAS Centre, with a focus on highlighting the ongoing translational research projects and capacity-building strategies. The CRONICAS Centre of Excellence is not a risk-averse organization: it benefits from past experiences, including past mistakes, and improves upon them and thus challenges traditional research approaches. This ethos and environment are key to fostering innovation in research. Copyright © 2015 World Heart Federation (Geneva). All rights reserved.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: AbstracObjectives To examine the prevalence of seizures, epilepsy, and seropositivity to cysticercosis in rural villagers (cysticercosis-endemic setting), rural-to-urban migrants into a non-endemic urban shantytown, and urban inhabitants of the same non-endemic shanty town.Methods Three Peruvian populations (n=985) originally recruited into a study about chronic diseases and migration, were studied. These groups included rural inhabitants from an endemic region (n=200), long-term rural-to-urban migrants (n=589), and individuals living in the same urban setting (n=196). Seizure disorders were detected by a survey and a neurologist examined positive respondents. Serum samples from 981/985 individuals were processed for cysticercosis antibodies on immunoblot.ResultsEpilepsy prevalence (per 1,000 people) was 15.3 in the urban group, 35.6 in migrants, and 25 in rural inhabitants. A gradient in cysticercosis antibody seroprevalence was observed: urban 2%, migrant 13.5%, and rural group 18% (p<0.05). A similarly increasing pattern of higher seroprevalence was observed among migrants by age at migration. In rural villagers, there was strong evidence of an association between positive serology and having seizures (p=0.011) but such an association was not observed in long-term migrants or in urban residents. In the entire study population, compared to seronegative participants, those with strong antibody reactions (≥4 antibody bands) were more likely to have epilepsy (p<0.001).Conclusions It is not only international migration that affects cysticercosis endemicity; internal migration can also affect patterns of endemicity within an endemic country. The neurologic consequences of cysticercosis infection likely outlast the antibody response for years after rural-to-urban migration.This article is protected by copyright. All rights reserved.
    Tropical Medicine & International Health 01/2015; 20(4). DOI:10.1111/tmi.12456 · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: UK primary care databases are frequently used in observational studies with cancer outcomes. We aimed to systematically review methods used by such studies to identify and validate incident cancers of the breast, colorectum, and prostate. Medline and Embase (1980-2013) were searched for UK primary care database studies with incident breast, colorectal, or prostate cancer outcomes. Data on the methods used for case ascertainment were extracted and summarised. Questionnaires were sent to corresponding authors to obtain details about case ascertainment. Eighty-four studies of breast (n = 51), colorectal (n = 54), and prostate cancer (n = 31) were identified; 30 examined >1 cancer type. Among the 84 studies, 57 defined cancers using only diagnosis codes, while 27 required further evidence such as chemotherapy. Few studies described methods used to create cancer code lists (n = 5); or made lists available directly (n = 5). Twenty-eight code lists were received on request from study authors. All included malignant neoplasm diagnosis codes, but there was considerable variation in the specific codes included which was not explained by coding dictionary changes. Code lists also varied in terms of other types of codes included, such as in-situ, cancer morphology, history of cancer, and secondary/suspected/borderline cancer codes. In UK primary care database studies, methods for identifying breast, colorectal, and prostate cancers were often unclear. Code lists were often unavailable, and where provided, we observed variation in the individual codes and types of codes included. Clearer reporting of methods and publication of code lists would improve transparency and reproducibility of studies. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 01/2015; 24(1). DOI:10.1002/pds.3729 · 3.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Routinely collected health data, collected for administrative and clinical purposes, without specific a priori research questions, are increasingly used for observational, comparative effectiveness, health services research, and clinical trials. The rapid evolution and availability of routinely collected data for research has brought to light specific issues not addressed by existing reporting guidelines. The aim of the present project was to determine the priorities of stakeholders in order to guide the development of the REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement. Methods: Two modified electronic Delphi surveys were sent to stakeholders. The first determined themes deemed important to include in the RECORD statement, and was analyzed using qualitative methods. The second determined quantitative prioritization of the themes based on categorization of manuscript headings. The surveys were followed by a meeting of RECORD working committee, and re-engagement with stakeholders via an online commentary period. Results: The qualitative survey (76 responses of 123 surveys sent) generated 10 overarching themes and 13 themes derived from existing STROBE categories. Highest-rated overall items for inclusion were: Disease/exposure identification algorithms; Characteristics of the population included in databases; and Characteristics of the data. In the quantitative survey (71 responses of 135 sent), the importance assigned to each of the compiled themes varied depending on the manuscript section to which they were assigned. Following the working committee meeting, online ranking by stakeholders provided feedback and resulted in revision of the final checklist. Conclusions: The RECORD statement incorporated the suggestions provided by a large, diverse group of stakeholders to create a reporting checklist specific to observational research using routinely collected health data. Our findings point to unique aspects of studies conducted with routinely collected health data and the perceived need for better reporting of methodological issues.
    PLoS ONE 01/2015; In Press. · 3.53 Impact Factor
  • British Thoracic Society Winter Meeting 2014; 12/2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: AimsDrug treatments for obesity have proven efficacy from randomised trials, but their effectiveness in routine clinical practice is unknown. We assessed the effects on weight and body mass index (BMI) of orlistat and sibutramine when delivered in routine primary care.Methods We used United Kingdom data from the Clinical Practice Research Datalink to estimate the effects of orlistat or sibutramine on weight and BMI over three years following treatment initiation. For comparison, we matched each patient with up to five obese patients receiving neither drug. Mixed effects linear regression with splines was used to model change in weight and BMI. Mean change with 95 % confidence intervals (CI) was estimated.ResultsWe identified 100,701 patients receiving orlistat, 15,355 receiving sibutramine and 508,140 non-intervention patients, with body mass index of 37.2, 36.6 and 33.2 kg/m2 respectively. Patients receiving orlistat lost, on average, 0.94 kg/month (0.93 to 0.95) over the first four months. Weight gain then occurred, although weight remained slightly below baseline at three years. Patients receiving sibutramine lost, 1.28 kg/month (1.26 to 1.30) over the first four months, but by three years had exceeded baseline weight. Non-intervention patients had slight increases in weight throughout the three-year period, with gains ranging between 0.01 and 0.06 kg/month..Conclusions Orlistat and sibutramine had early effects on weight loss, not sustained over three years. As new treatments for obesity are approved, their effectiveness should be measured in routine clinical practice, as effectiveness may be considerably less than seen in randomised trials.
    British Journal of Clinical Pharmacology 12/2014; DOI:10.1111/bcp.12578 · 3.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It is not known how smoking affects the initial presentation of a wide range of chronic and acute cardiovascular diseases (CVDs), nor the extent to which associations are heterogeneous. We estimated the lifetime cumulative incidence of 12 CVD presentations, and examined associations with smoking and smoking cessation. Cohort study of 1.93 million people aged ≥30years, with no history of CVD, in 1997-2010. Individuals were drawn from linked electronic health records in England, covering primary care, hospitalizations, myocardial infarction (MI) registry and cause-specific mortality (the CALIBER programme). During 11.6 million person-years of follow-up, 114 859 people had an initial non-fatal or fatal CVD presentation. By age 90 years, current vs never smokers' lifetime risks varied from 0.4% vs 0.2% for subarachnoid haemorrhage (SAH), to 8.9% vs 2.6% for peripheral arterial disease (PAD). Current smoking showed no association with cardiac arrest or sudden cardiac death [hazard ratio (HR) = 1.04, 95% confidence interval (CI) 0.91-1.19).The strength of association differed markedly according to disease type: stable angina (HR = 1.08, 95% CI 1.01-1.15),transient ischaemic attack (HR = 1.41, 95% CI 1.28-1.55), unstable angina (HR = 1.54, 95% CI 1.38-1.72), intracerebral haemorrhage (HR = 1.61, 95% CI 1.37-1.89), heart failure (HR = 1.62, 95% CI 1.47-1.79), ischaemic stroke (HR = 1.90, 95% CI 1.72-2.10), MI (HR = 2.32, 95% CI 2.20-2.45), SAH (HR = 2.70, 95% CI 2.27-3.21), PAD (HR = 5.16, 95% CI 4.80-5.54) and abdominal aortic aneurysm (AAA) (HR = 5.18, 95% CI 4.61-5.82). Population-attributable fractions were lower for women than men for unheralded coronary death, ischaemic stroke, PAD and AAA. Ten years after quitting smoking, the risks of PAD, AAA (in men) and unheralded coronary death remained increased (HR = 1.36, 1.47 and 2.74, respectively). The heterogeneous associations of smoking with different CVD presentations suggests different underlying mechanisms and have important implications for research, clinical screening and risk prediction. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 11/2014; 44(1). DOI:10.1093/ije/dyu218 · 9.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The contemporary associations of type 2 diabetes with a wide range of incident cardiovascular diseases have not been compared. We aimed to study associations between type 2 diabetes and 12 initial manifestations of cardiovascular disease. We used linked primary care, hospital admission, disease registry, and death certificate records from the CALIBER programme, which links data for people in England recorded in four electronic health data sources. We included people who were (or turned) 30 years or older between Jan 1, 1998, to March 25, 2010, who were free from cardiovascular disease at baseline. The primary endpoint was the first record of one of 12 cardiovascular presentations in any of the data sources. We compared cumulative incidence curves for the initial presentation of cardiovascular disease and used Cox models to estimate cause-specific hazard ratios (HRs). This study is registered at (NCT01804439). Our cohort consisted of 1 921 260 individuals, of whom 1 887 062 (98·2%) did not have diabetes and 34 198 (1·8%) had type 2 diabetes. We observed 113 638 first presentations of cardiovascular disease during a median follow-up of 5·5 years (IQR 2·1-10·1). Of people with type 2 diabetes, 6137 (17·9%) had a first cardiovascular presentation, the most common of which were peripheral arterial disease (reported in 992 [16·2%] of 6137 patients) and heart failure (866 [14·1%] of 6137 patients). Type 2 diabetes was positively associated with peripheral arterial disease (adjusted HR 2·98 [95% CI 2·76-3·22]), ischaemic stroke (1·72 [1·52-1·95]), stable angina (1·62 [1·49-1·77]), heart failure (1·56 [1·45-1·69]), and non-fatal myocardial infarction (1·54 [1·42-1·67]), but was inversely associated with abdominal aortic aneurysm (0·46 [0·35-0·59]) and subarachnoid haemorrhage (0·48 [0·26-0.89]), and not associated with arrhythmia or sudden cardiac death (0·95 [0·76-1·19]). Heart failure and peripheral arterial disease are the most common initial manifestations of cardiovascular disease in type 2 diabetes. The differences between relative risks of different cardiovascular diseases in patients with type 2 diabetes have implications for clinical risk assessment and trial design. Wellcome Trust, National Institute for Health Research, and Medical Research Council. Copyright © 2014 Shah et al. Open Access article distributed under the terms of CC BY. Published by .. All rights reserved.
    11/2014; DOI:10.1016/S2213-8587(14)70219-0
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background The objective of this study was to evaluate the performance of risk scores (Framingham, Assign and QRISK2) in predicting high cardiovascular disease (CVD) risk in individuals rather than populations. Methods and findings This study included 1.8 million persons without CVD and prior statin prescribing using the Clinical Practice Research Datalink. This contains electronic medical records of the general population registered with a UK general practice. Individual CVD risks were estimated using competing risk regression models. Individual differences in the 10-year CVD risks as predicted by risk scores and competing risk models were estimated; the population was divided into 20 subgroups based on predicted risk. CVD outcomes occurred in 69,870 persons. In the subgroup with lowest risks, risk predictions by QRISK2 were similar to individual risks predicted using our competing risk model (99.9% of people had differences of less than 2%); in the subgroup with highest risks, risk predictions varied greatly (only 13.3% of people had differences of less than 2%). Larger deviations between QRISK2 and our individual predicted risks occurred with calendar year, different ethnicities, diabetes mellitus and number of records for medical events in the electronic health records in the year before the index date. A QRISK2 estimate of low 10-year CVD risk (<15%) was confirmed by Framingham, ASSIGN and our individual predicted risks in 89.8% while an estimate of high 10-year CVD risk (≥20%) was confirmed in only 48.6% of people. The majority of cases occurred in people who had predicted 10-year CVD risk of less than 20%. Conclusions Application of existing CVD risk scores may result in considerable misclassification of high risk status. Current practice to use a constant threshold level for intervention for all patients, together with the use of different scoring methods, may inadvertently create an arbitrary classification of high CVD risk.
    PLoS ONE 10/2014; 9(10):e106455. DOI:10.1371/journal.pone.0106455 · 3.53 Impact Factor
  • Laurie Tomlinson, Liam Smeeth
    JAMA Internal Medicine 10/2014; 174(10):1706. DOI:10.1001/jamainternmed.2014.1585 · 13.25 Impact Factor
  • ERS International Congress 2014; 09/2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: AimsThis was a cohort study to evaluate if individuals exposed to angiotensin receptor blockers have a reduced risk of dementia compared with those exposed to angiotensin-converting enzyme inhibitors.Methods The study included new users of angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (from 1995 to 2010) from UK primary care practices contributing to the Clinical Research Practice Datalink. The association between exposure to angiotensin receptor blockers and the risk of incident dementia was analysed using a Cox model adjusting for age, sex, body mass index, diabetes, hypertension, heart failure, statin use, socioeconomic status, alcohol, smoking, number of consultations and calendar year.ResultsA total of 426,089 persons were included in the primary analysis, with 45,541 persons exposed to angiotensin receptor blockers and the remainder to angiotensin-converting enzyme inhibitors. The total number of new diagnoses of dementia was 6,517. There was weak evidence of a decreased risk of dementia with exposure to angiotensin receptor blockers, with follow-up beginning at 1 year after start of treatment (adjusted hazard ratio 0.92, 95% CI 0.85-1.00). An analysis restricted to the first 12 months after the index date showed a larger effect on dementia risk (adjusted hazard ratio 0.60, 95% CI 0.50-0.72).ConclusionsA small reduction in dementia risk was seen with angiotensin receptor blockers compared with angiotensin-converting enzyme inhibitors. However the strongest association was seen in early follow-up suggesting the inverse association is unlikely to be causal, but reflects other important but unmeasured differences between angiotensin receptor blocker and angiotensin-converting enzyme inhibitor users.
    British Journal of Clinical Pharmacology 09/2014; 79(2). DOI:10.1111/bcp.12511 · 3.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background High body-mass index (BMI) predisposes to several site-specific cancers, but a large-scale systematic and detailed characterisation of patterns of risk across all common cancers adjusted for potential confounders has not previously been undertaken. We aimed to investigate the links between BMI and the most common site-specific cancers. Methods With primary care data from individuals in the Clinical Practice Research Datalink with BMI data, we fitted Cox models to investigate associations between BMI and 22 of the most common cancers, adjusting for potential confounders. We fitted linear then non-linear (spline) models; investigated effect modification by sex, menopausal status, smoking, and age; and calculated population effects. Findings 5·24 million individuals were included; 166 955 developed cancers of interest. BMI was associated with 17 of 22 cancers, but effects varied substantially by site. Each 5 kg/m2 increase in BMI was roughly linearly associated with cancers of the uterus (hazard ratio [HR] 1·62, 99% CI 1·56–1·69; p<0·0001), gallbladder (1·31, 1·12–1·52; p<0·0001), kidney (1·25, 1·17–1·33; p<0·0001), cervix (1·10, 1·03–1·17; p=0·00035), thyroid (1·09, 1·00–1·19; p=0·0088), and leukaemia (1·09, 1·05–1·13; p≤0·0001). BMI was positively associated with liver (1·19, 1·12–1·27), colon (1·10, 1·07–1·13), ovarian (1·09, 1.04–1.14), and postmenopausal breast cancers (1·05, 1·03–1·07) overall (all p<0·0001), but these effects varied by underlying BMI or individual-level characteristics. We estimated inverse associations with prostate and premenopausal breast cancer risk, both overall (prostate 0·98, 0·95–1·00; premenopausal breast cancer 0·89, 0·86–0·92) and in never-smokers (prostate 0·96, 0·93–0·99; premenopausal breast cancer 0·89, 0·85–0·94). By contrast, for lung and oral cavity cancer, we observed no association in never smokers (lung 0·99, 0·93–1·05; oral cavity 1·07, 0·91–1·26): inverse associations overall were driven by current smokers and ex-smokers, probably because of residual confounding by smoking amount. Assuming causality, 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers could be attributable to excess weight. We estimated that a 1 kg/m2 population-wide increase in BMI would result in 3790 additional annual UK patients developing one of the ten cancers positively associated with BMI. Interpretation BMI is associated with cancer risk, with substantial population-level effects. The heterogeneity in the effects suggests that different mechanisms are associated with different cancer sites and different patient subgroups. Funding National Institute for Health Research, Wellcome Trust, and Medical Research Council.
    The Lancet 08/2014; 384(9945). DOI:10.1016/S0140-6736(14)60892-8 · 39.21 Impact Factor
  • Ben Goldacre, Liam Smeeth
    BMJ Clinical Research 07/2014; 349:g4745. DOI:10.1136/bmj.g4745 · 14.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Ischaemia in different arterial territories before acute myocardial infarction (AMI) may influence post-AMI outcomes. No studies have evaluated prospectively collected information on ischaemia and its effect on short- and long-term coronary mortality. The objective of this study was to compare patients with and without prospectively measured ischaemic presentations before AMI in terms of infarct characteristics and coronary mortality. Methods and results As part of the CALIBER programme, we linked data from primary care, hospital admissions, the national acute coronary syndrome registry and cause-specific mortality to identify patients with first AMI (n = 16,439). We analysed time from AMI to coronary mortality (n = 5283 deaths) using Cox regression (median 2.6 years follow-up), comparing patients with and without recent ischaemic presentations. Patients with ischaemic presentations in the 90 days before AMI experienced lower coronary mortality in the first 7 days after AMI compared with those with no prior ischaemic presentations, after adjusting for age, sex, smoking, diabetes, blood pressure and cardiovascular medications [HR: 0.64 (95% CI: 0.57-0.73) P < 0.001], but subsequent mortality was higher [HR: 1.42 (1.13-1.77) P = 0.001]. Patients with ischaemic presentations closer in time to AMI had the lowest seven day mortality (P-trend = 0.001). Conclusion In the first large prospective study of ischaemic presentations prior to AMI, we have shown that those occurring closest to AMI are associated with lower short-term coronary mortality following AMI, which could represent a natural ischaemic preconditioning effect, observed in a clinical setting. identifier NCT01604486.
    European Heart Journal 07/2014; 35(35). DOI:10.1093/eurheartj/ehu286 · 14.72 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective To inform potential pathophysiological mechanisms of air pollution effects on cardiovascular disease (CVD), we investigated short-term associations between ambient air pollution and a range of cardiovascular events from three national databases in England and Wales. Methods Using a time-stratified case-crossover design, over 400 000 myocardial infarction (MI) events from the Myocardial Ischaemia National Audit Project (MINAP) database, over 2 million CVD emergency hospital admissions and over 600 000 CVD deaths were linked with daily mean concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), particulate matter less than 10 m in aerodynamic diameter (PM10), particulate matter less than 2.5 m in aerodynamic diameter (PM2.5) and sulfur dioxide (SO2), and daily maximum of 8-hourly running mean of O-3 measured at the nearest air pollution monitoring site to the place of residence. Pollutant effects were modelled using lags up to 4 days and adjusted for ambient temperature and day of week. Results For mortality, no CVD outcome analysed was clearly associated with any pollutant, except for PM2.5 with arrhythmias, atrial fibrillation and pulmonary embolism. With hospital admissions, only NO2 was associated with a raised risk: CVD 1.7% (95% CI 0.9 to 2.6), non-MI CVD 2.0% (1.1 to 2.9), arrhythmias 2.9% (0.6 to 5.2), atrial fibrillation 2.8% (0.3 to 5.4) and heart failure 4.4% (2.0 to 6.8) for a 10th-90th centile increase. With MINAP, only NO2 was associated with an increased risk of MI, which was specific to non-ST-elevation myocardial infarction (non-STEMIs): 3.6% (95% CI 0.4 to 6.9). Conclusions This study found no clear evidence for pollution effects on STEMIs and stroke, which ultimately represent thrombogenic processes, though it did for pulmonary embolism. The strongest associations with air pollution were observed with selected non-MI outcomes.
    Heart (British Cardiac Society) 07/2014; 100(14):1093-1098. DOI:10.1136/heartjnl-2013-304963 · 6.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BackgroundThere is strong evidence of reductions in major vascular events from statins across all cardiovascular risk categories. However, trials of statin therapy have provided conflicting results regarding statin use and type 2 diabetes (T2DM). We aimed to assess the effect of statins on T2DM development.MethodWe carried out a population-based cohort study using the Clinical Practice Research Datalink (CPRD), a database of computerized clinical records. Every patient aged 30–85 years old starting a statin between 1989 and 2009 was matched with up to five non-statin users. The observation period in CPRD ended in 31 December 2011. Cox proportional hazard regression was used to compare rates of T2DM between statin users and non-users, using propensity score method to adjust for systematic differences between groups.ResultsThe study basis comprised 2,016,094 individuals, including 430,890 people who received a statin, matched to 1,585,204 people not prescribed a statin. Mean follow-up time was 5.43 years for statin users and 3.89 years for nonusers. During follow-up 130,395 individuals developed T2DM. Statin use was associated with an increased risk of T2DM (HR 1.57; 95% CI 1.54-1.59), which increases with longer duration of use. The increased risk was smaller among people with hypertension or cardiovascular disease and was only apparent after 5 or more years treatment with statins in these groups. Conversely, age-specific risk ratios decreased in older people.ConclusionsStatin use is associated with an increased risk of T2DM. Our results suggest that the relative risk is higher among people without diagnosed hypertension or cardiovascular disease. These findings should be considered in the context of the observational nature of the data which is prone to bias and unmeasured confounding.
    BMC Cardiovascular Disorders 07/2014; 14(1):85. DOI:10.1186/1471-2261-14-85 · 1.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Antipsychotics increase the risk of stroke. Their effect on myocardial infarction remains uncertain because people prescribed and not prescribed antipsychotic drugs differ in their underlying vascular risk making between-person comparisons difficult to interpret. The aim of our study was to investigate this association using the self-controlled case series design that eliminates between-person confounding effects.
    European Heart Journal 07/2014; DOI:10.1093/eurheartj/ehu263 · 14.72 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pragmatic trials compare the effects of different decisions in usual clinical practice.
    Health technology assessment (Winchester, England) 07/2014; 18(43):1-146. DOI:10.3310/hta18430 · 5.12 Impact Factor

Publication Stats

8k Citations
2,422.13 Total Impact Points


  • 2000–2015
    • London School of Hygiene and Tropical Medicine
      • • Department of Non-communicable Disease Epidemiology
      • • Faculty of Epidemiology and Population Health
      Londinium, England, United Kingdom
    • Moorfields Eye Hospital NHS Foundation Trust
      Londinium, England, United Kingdom
  • 1998–2014
    • University College London
      • • Department of Epidemiology and Public Health
      • • Division of Medicine
      • • Centre for Clinical Pharmacology and Theraputics
      • • Department of Primary Care and Population Health (PCPH)
      Londinium, England, United Kingdom
  • 2013
    • Vanderbilt University
      • Vanderbilt Institute for Global Health
      Нашвилл, Michigan, United States
  • 2011–2012
    • Universidad Peruana Cayetano Heredia
      • Centro de Excelencia en Enfermedades Crónicas
      Λίμα, Lima, Peru
  • 2009
    • University of Michigan
      • Division of Rheumatology
      Ann Arbor, MI, United States
  • 2008
    • University of London
      Londinium, England, United Kingdom
  • 2007–2008
    • University of Nottingham
      • Division of Respiratory Medicine
      Nottigham, England, United Kingdom
  • 2000–2005
    • University of Bristol
      Bristol, England, United Kingdom
  • 2004
    • St. George's School
      • Department of Community Health Sciences
      Middletown, Rhode Island, United States
  • 1998–2004
    • University of Oxford
      Oxford, England, United Kingdom
  • 2002
    • McGill University
      • Department of Psychiatry
      Montréal, Quebec, Canada
  • 2001
    • ICL
      Londinium, England, United Kingdom