Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5·24 million UK adults

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/m(2) 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/m(2) 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.

BMI and risk of dementia in two million people over two decades: a retrospective cohort study

BACKGROUND

Dementia and obesity are increasingly important public health issues. Obesity in middle age has been proposed to lead to dementia in old age. We investigated the association between BMI and risk of dementia.

METHODS

For this retrospective cohort study, we used a cohort of 1,958,191 individuals derived from the United Kingdom Clinical Practice Research Datalink (CPRD) which included people aged 40 years or older in whom BMI was recorded between 1992 and 2007. Follow-up was until the practice's final data collection date, patient death or transfer out of practice, or first record of dementia (whichever occurred first). People with a previous record of dementia were excluded. We used Poisson regression to calculate incidence rates of dementia for each BMI category.

FINDINGS

Our cohort of 1,958,191 people from UK general practices had a median age at baseline of 55 years (IQR 45-66) and a median follow-up of 9·1 years (IQR 6·3-12·6). Dementia occurred in 45,507 people, at a rate of 2·4 cases per 1000 person-years. Compared with people of a healthy weight, underweight people (BMI <20 kg/m(2)) had a 34% higher (95% CI 29-38) risk of dementia. Furthermore, the incidence of dementia continued to fall for every increasing BMI category, with very obese people (BMI >40 kg/m(2)) having a 29% lower (95% CI 22-36) dementia risk than people of a healthy weight. These patterns persisted throughout two decades of follow-up, after adjustment for potential confounders and allowance for the J-shape association of BMI with mortality.

INTERPRETATION

Being underweight in middle age and old age carries an increased risk of dementia over two decades. Our results contradict the hypothesis that obesity in middle age could increase the risk of dementia in old age. The reasons for and public health consequences of these findings need further investigation.

FUNDING

None.

ECSIT is an evolutionarily conserved intermediate in the Toll/IL-1 signal transduction pathway

Activation of NF-kappaB as a consequence of signaling through the Toll and IL-1 receptors is a major element of innate immune responses. We report the identification and characterization of a novel intermediate in these signaling pathways that bridges TRAF6 to MEKK-1. This adapter protein, which we have named ECSIT (evolutionarily conserved signaling intermediate in Toll pathways), is specific for the Toll/IL-1 pathways and is a regulator of MEKK-1 processing. Expression of wild-type ECSIT accelerates processing of MEKK-1, whereas a dominant-negative fragment of ECSIT blocks MEKK-1 processing and activation of NF-kappaB. These results indicate an important role for ECSIT in signaling to NF-kappaB and suggest that processing of MEKK-1 is required for its function in the Toll/IL-1 pathway.

The Prevalence of Huntington's Disease

BACKGROUND

Reviews of the epidemiology of Huntington's disease (HD) suggest that its worldwide prevalence varies widely. This review was undertaken to confirm these observations, to assess the extent to which differences in case-ascertainment and/or diagnosis might be responsible, and to investigate whether the prevalence pattern has changed over the past 50 years.

METHODS

Eighty two relevant studies were identified from Medline and Embase, previous reviews, scrutiny of references from included and excluded studies and enquiry among those interested in the field.

RESULTS

The lowest rates were among the Asians and the highest among the Caucasians. The differences are not fully explained by varying approaches to case-ascertainment or diagnosis. There was evidence of an increasing prevalence of between 15 and 20% per decade in studies from Australia, North America and Western Europe.

CONCLUSIONS

The prevalence of HD varies more than tenfold between different geographical regions. This variation can in part be attributed to differences in case-ascertainment and/or diagnostic criteria, but there is consistent evidence of a lower incidence in Asian populations. There is also evidence that in Australia, North America and in Western Europe (including the United Kingdom), prevalence has increased over the past 50 plus years.

Role of unphosphorylated, newly synthesized I kappa B beta in persistent activation of NF-kappa B

Stimulation with inducers that cause persistent activation of NF-kappa B results in the degradation of the NF-kappa B inhibitors, I kappa B alpha and I kappa B beta. Despite the rapid resynthesis and accumulation of I kappa B alpha, NF-kappa B remains induced under these conditions. We now report that I kappa B beta is also resynthesized in stimulated cells and appears as an unphosphorylated protein. The unphosphorylated I kappa B beta forms a stable complex with NF-kappa B in the cytosol; however, this binding fails to mask the nuclear localization signal and DNA binding domain on NF-kappa B, and the I kappa B beta-NF-kappa B complex enters the nucleus. It appears therefore that during prolonged stimulation, I kappa B beta functions as a chaperone for NF-kappa B by protecting it from I kappa B alpha and allowing it to be transported to the nucleus.

Effect of statins on a wide range of health outcomes: a cohort study validated by comparison with randomized trials

AIMS

To assess the effect of statins on a range of health outcomes.

METHODS

We undertook a population-based cohort study to assess the effect of statins on a range of health outcomes using a propensity score-based method to control for differences between people prescribed and not prescribed statins. We validated our design by comparing our results for vascular outcomes with the effects established in large randomized trials. The study was based on the United Kingdom Health Improvement Network database that includes the computerized medical records of over four and a half million patients.

RESULTS

People who initiated treatment with a statin (n = 129,288) were compared with a matched sample of 600,241 people who did not initiate treatment, with a median follow-up period of 4.4 years. Statin use was not associated with an effect on a wide range of outcomes, including infections, fractures, venous thromboembolism, gastrointestinal haemorrhage, or on specific eye, neurological or autoimmune diseases. A protective effect against dementia was observed (hazard ratio 0.80, 99% confidence interval 0.68, 0.95). There was no effect on the risk of cancer even after > or =8 years of follow-up. The effect sizes for statins on vascular end-points and mortality were comparable to those observed in large randomized trials, suggesting bias and confounding had been well controlled for.

CONCLUSIONS

We found little evidence to support wide-ranging effects of statins on health outcomes beyond their established beneficial effect on vascular disease.

Propensity score analysis with partially observed covariates: How should multiple imputation be used?

Inverse probability of treatment weighting is a popular propensity score-based approach to estimate marginal treatment effects in observational studies at risk of confounding bias. A major issue when estimating the propensity score is the presence of partially observed covariates. Multiple imputation is a natural approach to handle missing data on covariates: covariates are imputed and a propensity score analysis is performed in each imputed dataset to estimate the treatment effect. The treatment effect estimates from each imputed dataset are then combined to obtain an overall estimate. We call this method MIte. However, an alternative approach has been proposed, in which the propensity scores are combined across the imputed datasets (MIps). Therefore, there are remaining uncertainties about how to implement multiple imputation for propensity score analysis: (a) should we apply Rubin's rules to the inverse probability of treatment weighting treatment effect estimates or to the propensity score estimates themselves? (b) does the outcome have to be included in the imputation model? (c) how should we estimate the variance of the inverse probability of treatment weighting estimator after multiple imputation? We studied the consistency and balancing properties of the MIte and MIps estimators and performed a simulation study to empirically assess their performance for the analysis of a binary outcome. We also compared the performance of these methods to complete case analysis and the missingness pattern approach, which uses a different propensity score model for each pattern of missingness, and a third multiple imputation approach in which the propensity score parameters are combined rather than the propensity scores themselves (MIpar). Under a missing at random mechanism, complete case and missingness pattern analyses were biased in most cases for estimating the marginal treatment effect, whereas multiple imputation approaches were approximately unbiased as long as the outcome was included in the imputation model. Only MIte was unbiased in all the studied scenarios and Rubin's rules provided good variance estimates for MIte. The propensity score estimated in the MIte approach showed good balancing properties. In conclusion, when using multiple imputation in the inverse probability of treatment weighting context, MIte with the outcome included in the imputation model is the preferred approach.

Prevalence of adult Huntington's disease in the UK based on diagnoses recorded in general practice records

BACKGROUND AND PURPOSE

The prevalence of Huntington's disease (HD) in the UK is uncertain. Recently, it has been suggested that the prevalence may be substantially greater than previously reported. This study was undertaken to estimate the overall UK prevalence in adults diagnosed with HD, using data from primary care.

METHODS

The electronic medical records of patients aged 21 years or more, with recorded diagnoses of HD, were retrieved from the UK's General Practice Research Database. Prevalence was estimated from the number of persons with recorded diagnoses of HD, on 1 July each year, between 1990 and 2010. This number was divided by the total number of persons registered with participating general practices on that same date. These data were also used to estimate both age specific prevalence and prevalence in various regions of the UK.

RESULTS

A total of 1136 patients diagnosed with HD, aged 21 years or more, were identified from the database. The estimated prevalence (expressed per 100 000 population) rose from 5.4 (95% CI 3.8 to 7.5) in 1990 to 12.3 (95% CI 11.2 to 13.5) in 2010. Although an increased prevalence was observed within every age group, the most dramatic was in older patients. Age specific prevalence was highest in the 51-60 year age range (15.8 95% CI 9.0 to 22.3). The prevalence of adult HD was lowest in the London region (5.4 (95% CI 3.0 to 8.9)) and highest in the North East of England (18.3 (95% CI 8.6 to 34.6)) and Scotland (16.1 (95% CI 10.8 to 22.9)).

CONCLUSIONS

The prevalence of diagnosed HD is clearly substantially higher in the UK than suggested from previous studies. By extrapolation to the UK as a whole, it is estimated that there are more than 5700 people, aged 21 years or more, with HD. There has also been a surprising doubling of the HD population between 1990 and 2010. Many factors may have caused this increase, including more accurate diagnoses, better and more available therapies and an improved life expectancy, even with HD. There also appears to be a greater willingness to register a diagnosis of HD in patients' electronic medical records. Such a high prevalence of HD requires more ingenuity and responsiveness in its care. How to appropriately care for, and respond to, so many individuals and families coping with the exigencies of HD demands our greatest resolve and imagination.

Reporting to Improve Reproducibility and Facilitate Validity Assessment for Healthcare Database Studies V1.0

Purpose

Defining a study population and creating an analytic dataset from longitudinal healthcare databases involves many decisions. Our objective was to catalogue scientific decisions underpinning study execution that should be reported to facilitate replication and enable assessment of validity of studies conducted in large healthcare databases.

Methods

We reviewed key investigator decisions required to operate a sample of macros and software tools designed to create and analyze analytic cohorts from longitudinal streams of healthcare data. A panel of academic, regulatory, and industry experts in healthcare database analytics discussed and added to this list.

Conclusion

Evidence generated from large healthcare encounter and reimbursement databases is increasingly being sought by decision‐makers. Varied terminology is used around the world for the same concepts. Agreeing on terminology and which parameters from a large catalogue are the most essential to report for replicable research would improve transparency and facilitate assessment of validity. At a minimum, reporting for a database study should provide clarity regarding operational definitions for key temporal anchors and their relation to each other when creating the analytic dataset, accompanied by an attrition table and a design diagram.

A substantial improvement in reproducibility, rigor and confidence in real world evidence generated from healthcare databases could be achieved with greater transparency about operational study parameters used to create analytic datasets from longitudinal healthcare databases.

Representativeness and optimal use of body mass index (BMI) in the UK Clinical Practice Research Datalink (CPRD)

OBJECTIVES

To assess the completeness and representativeness of body mass index (BMI) data in the Clinical Practice Research Datalink (CPRD), and determine an optimal strategy for their use.

DESIGN

Descriptive study.

SETTING

Electronic healthcare records from primary care.

PARTICIPANTS

A million patient random sample from the UK CPRD primary care database, aged ≥16 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

BMI completeness in CPRD was evaluated by age, sex and calendar period. CPRD-based summary BMI statistics for each calendar year (2003-2010) were age-standardised and sex-standardised and compared with equivalent statistics from the Health Survey for England (HSE).

RESULTS

BMI completeness increased over calendar time from 37% in 1990-1994 to 77% in 2005-2011, was higher among females and increased with age. When BMI at specific time points was assigned based on the most recent record, calendar-year-specific mean BMI statistics underestimated equivalent HSE statistics by 0.75-1.1 kg/m(2). Restriction to those with a recent (≤3 years) BMI resulted in mean BMI estimates closer to HSE (≤0.28 kg/m(2) underestimation), but excluded up to 47% of patients. An alternative strategy of imputing up-to-date BMI based on modelled changes in BMI over time since the last available record also led to mean BMI estimates that were close to HSE (≤0.37 kg/m(2) underestimation).

CONCLUSIONS

Completeness of BMI in CPRD increased over time and varied by age and sex. At a given point in time, a large proportion of the most recent BMIs are unlikely to reflect current BMI; consequent BMI misclassification might be reduced by employing model-based imputation of current BMI.

Glitazone Treatment and Incidence of Parkinson's Disease among People with Diabetes: A Retrospective Cohort Study

BACKGROUND

Recent in vitro and animal experiments suggest that peroxisome proliferation-activated receptor gamma (PPARɣ) agonist medications, such as antidiabetic glitazone (GTZ) drugs, are neuroprotective in models of Parkinson's disease (PD). These findings have not been tested in humans. We hypothesized that individuals prescribed GTZ drugs would have a lower incidence of PD compared to individuals prescribed other treatments for diabetes.

METHODS AND FINDINGS

Using primary care data from the United Kingdom Clinical Practice Research Datalink (CPRD), we conducted a retrospective cohort study in which individuals with diabetes who were newly prescribed GTZ (GTZ-exposed group) were matched by age, sex, practice, and diabetes treatment stage with up to five individuals prescribed other diabetes treatments (other antidiabetic drug-exposed group). Patients were followed up from 1999 until the first recording of a PD diagnosis, end of observation in the database, or end of the study (1 August 2013). An incidence rate ratio (IRR) was calculated using conditional Poisson regression, adjusted for possible confounders. 44,597 GTZ exposed individuals were matched to 120,373 other antidiabetic users. 175 GTZ-exposed individuals were diagnosed with PD compared to 517 individuals in the other antidiabetic drug-exposed group. The incidence rate (IR) of PD in the GTZ-exposed group was 6.4 per 10,000 patient years compared with 8.8 per 10,000 patient years in those prescribed other antidiabetic treatments (IRR 0.72, 95% confidence interval [CI] 0.60-0.87). Adjustments for potential confounding variables, including smoking, other medications, head injury, and disease severity, had no material impact (fully adjusted IRR 0.75, 0.59-0.94). The risk was reduced in those with current GTZ prescriptions (current GTZ-exposed IRR 0.59, 0.46-0.77) but not reduced among those with past prescriptions (past GTZ-exposed IRR 0.85, 0.65-1.10). Our study only included patients with diabetes who did not have a PD diagnosis when they were first prescribed GTZ, and thus, it cannot establish whether GTZ use prevents or slows the progression of PD.

CONCLUSIONS

In patients with diabetes, a current prescription for GTZ is associated with a reduction in incidence of PD. This suggests PPAR gamma pathways may be a fruitful drug target in PD.

A role for glycoprotein Ib in Streptococcus sanguis-induced platelet aggregation

Numerous studies have implicated bacteria in cardiovascular disease, but there is a paucity of information on the mechanism involved. In this study we show how the common oral bacterium Streptococcus sanguis can directly interact with platelets, resulting in activation and aggregate formation. Platelet aggregation was dependent on glycoprotein IIb/IIIa (GPIIb/IIIa) and thromboxane. Platelets could also directly bind to S sanguis, but this interaction was not inhibited by GPIIb/IIIa antagonists. Antibodies to GPIb could inhibit both platelet aggregation and platelet adhesion to bacteria. This suggested a direct interaction between GPIb and S sanguis; however, this interaction did not require von Willebrand factor, the normal ligand for GPIb. By use of a range of monoclonal antibodies to GPIb and the enzyme mocharagin, which cleaves GPIb at amino acid 282, the interaction was localized to a region within the N-terminal 1-225 portion of GPIbalpha. Furthermore S sanguis failed to induce aggregation of platelets from a patient with Bernard-Soulier disease, the organism bound to Chinese hamster ovary cells transfected with the GPIbalpha gene but did not bind to mock-transfected cells and biotin-labeled S sanguis cells bound to purified GPIb in ligand blots. It is suggested that the interaction between S sanguis and GPIb is important in the pathogenesis of infective endocarditis and may also play a contributory role in some cases of myocardial infarction.

Hydrological investigations of forest disturbance and land cover impacts in South-East Asia: a review

Investigations of land management impacts on hydrology are well developed in South-East Asia, having been greatly extended by national organizations in the last two decades. Regional collaborative efforts, such as the ASEAN-US watershed programme, have helped develop skills and long-running monitoring programmes. Work in different countries is significant for particular aspects: the powerful effects of both cyclones and landsliding in Taiwan, the significance of lahars in Java, of small-scale agriculture in Thailand and plantation establishment in Malaysia. Different aid programmes have contributed specialist knowledge such as British work on reservoir sedimentation, Dutch, Swedish and British work on softwood plantations and US work in hill-tribe agriculture. Much has been achieved through individual university research projects, including PhD and MSc theses. The net result is that for most countries there is now good information on changes in the rainfall-run-off relationship due to forest disturbance or conversion, some information on the impacts on sediment delivery and erosion of hillslopes, but relatively little about the dynamics and magnitude of nutrient losses. Improvements have been made in the ability to model the consequences of forest conversion and of selective logging and exciting prospects exist for the development of better predictions of transfer of water from the hillslopes to the stream channels using techniques such as multilevel modelling. Understanding of the processes involved has advanced through the detailed monitoring made possible at permanent field stations such as that at Danum Valley, Sabah.

A sustained reduction in IkappaB-beta may contribute to persistent NF-kappaB activation in human endothelial cells

The responses of vascular endothelial cells (EC) to tumor necrosis factor-alpha (TNF), interleukin-1alpha (IL-1), and phorbol myristate acetate (PMA) were compared with respect to the kinetics of (i) NF-kappaB activation, (ii) IkappaB-alpha and IkappaB-beta degradation, and (iii) NF-kappaB-dependent cell surface molecule expression. TNF rapidly (</=20 min) and persistently (>20 h) activates NF-kappaB; IL-1 rapidly activates NF-kappaB, but activity declines by 3 h and further by 20 h; PMA slowly and transiently activates NF-kappaB. Untreated EC contain the inhibitory proteins IkappaB-alpha and IkappaB-beta. The onset of NF-kappaB activation correlates with degradation of IkappaB-alpha, but IkappaB-alpha reappears by 4 h without resequestration of NF-kappaB. TNF causes a rapid but partial (50%) reduction in IkappaB-beta, which does not recover by 22 h; IL-1 and PMA cause slower and less sustained reductions in IkappaB-beta. All three agonists induce de novo expression of E-selectin (CD62E) and vascular cell adhesion molecule-1 (CD106) and increase expression of intercellular adhesion molecule-1 (CD54) at 4 h. TNF induces sustained increases in vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 and increases human leukocyte antigen class I molecules at 24 h. We conclude that TNF causes persistent activation of NF-kappaB in human EC and that this may result from sustained reductions in IkappaB-beta levels.

The role of extreme events in the impacts of selective tropical forestry on erosion during harvesting and recovery phases at Danum Valley, Sabah

Ten years' hydrological investigations at Danum have provided strong evidence of the effects of extremes of drought, as in the April 1992 El Niño southern oscillation event, and flood, as in January 1996. The 1.5 km2 undisturbed forest control catchment experienced a complete drying out of the stream for the whole 1.5 km of defined channel above the gauging station in 1992, but concentrated surface flow along every declivity from within a few metres of the catchment divide after the exceptional rains of 19 January 1996. Under these natural conditions, erosion is episodic. Sediment is discharged in pulses caused by storm events, collapse of debris dams and occasional landslips. Disturbance by logging accentuates this irregular regime. In the first few months following disturbance, a wave of sediment is moved by each storm, but over subsequent years, rare events scour sediment from bare areas, gullies and channel deposits. The spatial distribution of sediment sources changes with time after logging, as bare areas on slopes are revegetated and small gullies are filled with debris. Extreme storm events, as in January 1996, cause logging roads to collapse, with landslides leading to surges of sediment into channels, reactivating the pulsed sediment delivery by every storm that happened immediately after logging. These effects are not dampened out with increasing catchment scale. Even the 721 km2 Sungai Segama has a sediment yield regime dominated by extreme events, the sediment yield in that single day on 19 January 1996 exceeding the annual sediment load in several previous years. In a large disturbed catchment, such road failures and logging-activity-induced mass movements increase the mud and silt in floodwaters affecting settlements downstream. Management systems require long-term sediment reduction strategies. This implies careful road design and good water movement regulation and erosion control throughout the logging process.

Methylphenidate and the risk of trauma

BACKGROUND AND OBJECTIVE

Children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are prone to sustaining trauma that requires emergency department (ED) admission. Methylphenidate (MPH) can reduce ADHD symptoms and may thus theoretically reduce the risk of trauma-related ED admission, but previous studies do not make this association clear. This study examines this association.

METHODS

A total of 17 381 patients aged 6 to 19 years who received MPH prescriptions were identified by using the Clinical Data Analysis & Reporting System (2001-2013). Using a self-controlled case series study design, the relative incidence of trauma-related ED admissions was compared with periods of patient exposure and nonexposure to MPH.

RESULTS

Among 17 381 patients prescribed MPH, 4934 had at least 1 trauma-related ED admission. The rate of trauma-related ED admission was lower during exposed periods compared with nonexposed periods (incidence rate ratio [IRR]: 0.91 [95% confidence interval (CI): 0.86-0.97]). The findings were similar only when the incident trauma episode was assessed (IRR: 0.89 [95% CI: 0.82-0.96]). A similar protective association was found in both genders. In validation analysis using nontrauma-related ED admissions as a negative control outcome, no statistically significant association was found (IRR: 0.99 [95% CI: 0.95-1.02]). All sensitivity analyses demonstrated consistent results.

CONCLUSIONS

This study supports the hypothesis that MPH is associated with a reduced risk of trauma-related ED admission in children and adolescents. A similar protective association was found in both male and female patients. This protective association should be considered in clinical practice.

Changing use of antidiabetic drugs in the UK: trends in prescribing 2000-2017

OBJECTIVES

Guidelines for the use of drugs for type 2 diabetes mellitus (T2DM) have changed since 2000, and new classes of drug have been introduced. Our aim was to describe how drug choice at initiation and first stage of intensification have changed over this period, and to what extent prescribing was in accord with clinical guidelines, including adherence to recommendations regarding kidney function.

DESIGN

Repeated cross-sectional study.

SETTING

UK electronic primary care health records from the Clinical Practice Research Datalink.

PARTICIPANTS

Adults initiating treatment with a drug for T2DM between January 2000 and July 2017.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were the proportion of each class of T2DM drug prescribed for initiation and first-stage intensification in each year. We also examined drug prescribing by kidney function and country within the UK.

RESULTS

Of 280 241 people initiating treatment with T2DM drugs from 2000 to 2017, 73% (204 238/280 241) initiated metformin, 15% (42 288/280 241) a sulfonylurea, 5% (12 956/280 241) with metformin and sulfonylurea dual therapy and 7% (20 759/280 241) started other options. Clinicians have increasingly prescribed metformin at initiation: by 2017 this was 89% (2475/2778) of drug initiations. Among people with an estimated glomerular filtration rate of ≤30 mL/min/1.73 m2, the most common drug at initiation was a sulfonylurea, 58% (659/1135). In 2000, sulfonylureas were the predominant drug at the first stage of drug intensification (87%, 534/615) but by 2017 this fell to 30% (355/1183) as the use of newer drug classes increased. In 2017, new prescriptions for dipeptidyl peptidase-4 inhibitors (DPP4i) and sodium/glucose cotransporter-2 inhibitors (SGLT2i) accounted for 42% (502/1183) and 22% (256/1183) of intensification drugs, respectively. Uptake of new classes differs by country with DPP4is and SGLT2is prescribed more in Northern Ireland and Wales than England or Scotland.

CONCLUSIONS

Our findings show markedly changing prescribing patterns for T2DM between 2000 and 2017, largely consistent with clinical guidelines.

Angiotensin receptor blockers and risk of cancer: cohort study among people receiving antihypertensive drugs in UK General Practice Research Database

OBJECTIVES

To investigate whether there is an association between use of angiotensin receptor blockers and risk of cancer.

DESIGN

Cohort study of risk of cancer in people treated with angiotensin receptor blockers compared with angiotensin converting enzyme (ACE) inhibitors. Effects were explored with time updated covariates in Cox models adjusted for age, sex, body mass index (BMI), diabetes and metformin/insulin use, hypertension, heart failure, statin use, socioeconomic status, alcohol, smoking, and calendar year. Absolute changes in risk were predicted from a Poisson model incorporating the strongest determinants of risk from the main analysis.

SETTING

UK primary care practices contributing to the General Practice Research Database.

PARTICIPANTS

377,649 new users of angiotensin receptor blockers or ACE inhibitors with at least one year of initial treatment.

MAIN OUTCOME MEASURES

Adjusted hazard ratios for all cancer and major site specific cancers (breast, lung, colon, prostate) by exposure to angiotensin receptor blockers and by cumulative duration of use.

RESULTS

Follow-up ended a median of 4.6 years after the start of treatment; 20,203 cancers were observed. There was no evidence of any increase in overall risk of cancer among those ever exposed to angiotensin receptor blockers (adjusted hazard ratio 1.03, 95% confidence interval 0.99 to 1.06, P = 0.10). For specific cancers, there was some evidence of an increased risk of breast and prostate cancer (1.11, 1.01 to 1.21, P = 0.02; and 1.10, 1.00 to 1.20, P = 0.04; respectively), which in absolute terms corresponded to an estimated 0.5 and 1.1 extra cases, respectively, per 1000 person years of follow-up among those with the highest baseline risk. Longer duration of treatment did not seem to be associated with higher risk (P>0.15 in each case). There was a decreased risk of lung cancer (0.84, 0.75 to 0.94), but no effect on colon cancer (1.02, 0.91 to 1.16).

CONCLUSIONS

Use of angiotensin receptor blockers was not associated with an increased risk of cancer overall. Observed increased risks for breast and prostate cancer were small in absolute terms, and the lack of association with duration of treatment meant that non-causal explanations could not be excluded.

Population trends in the 10-year incidence and prevalence of diabetic retinopathy in the UK: a cohort study in the Clinical Practice Research Datalink 2004-2014

OBJECTIVES

To describe trends in the incidence and prevalence of diabetic retinopathy (DR) in the UK by diabetes type, age, sex, ethnicity, deprivation, region and calendar year.

DESIGN

Cohort study using the Clinical Practice Research Datalink (CPRD).

SETTING

UK primary care.

PARTICIPANTS

7.7 million patients ≥12 contributing to the CPRD from 2004 to 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-standardised prevalence and incidence of diabetes, DR and severe DR (requiring photocoagulation) by calendar year and population subgroup. Relative risk of developing DR and severe DR by population subgroup.

RESULTS

The prevalence of DR was 48.4% in the population type 1 diabetes mellitus (T1DM) (14 846/30 657) and 28.3% (95 807/338 390) in the population with type 2 diabetes mellitus (T2DM). Prevalence of DR remained stable in people with T2DM and decreased in people with T1DM. Screening for DR increased over time for patients with T2DM and remained static for patients with T1DM Incidence of DR increased in parallel with the incidence of T2DM in both diabetic populations. Among patients with T2DM, relative risk of DR varied significantly by region, was increased for older age groups and in men compared with women, with risk of severe DR increased in South Asian groups and more deprived groups. Relative risk of DR for patients with T1DM varied by age and region, but not by gender, ethnic group or deprivation.

CONCLUSIONS

This is the largest study to date examining the burden of DR in the UK. Regional disparities in incidence may relate to differences in screening delivery and disease ascertainment. Evidence that deprivation and ethnicity are associated with a higher risk of severe DR highlights a significant potential health inequality. Findings from this study will have implications for professionals working in the diabetes and sight loss sectors, particularly to inform approaches for diagnosis of retinopathy and campaigning to better tackle the disease for at risk groups.

Reporting to Improve Reproducibility and Facilitate Validity Assessment for Healthcare Database Studies V1.0

PURPOSE

Defining a study population and creating an analytic dataset from longitudinal healthcare databases involves many decisions. Our objective was to catalogue scientific decisions underpinning study execution that should be reported to facilitate replication and enable assessment of validity of studies conducted in large healthcare databases.

METHODS

We reviewed key investigator decisions required to operate a sample of macros and software tools designed to create and analyze analytic cohorts from longitudinal streams of healthcare data. A panel of academic, regulatory, and industry experts in healthcare database analytics discussed and added to this list.

CONCLUSION

Evidence generated from large healthcare encounter and reimbursement databases is increasingly being sought by decision-makers. Varied terminology is used around the world for the same concepts. Agreeing on terminology and which parameters from a large catalogue are the most essential to report for replicable research would improve transparency and facilitate assessment of validity. At a minimum, reporting for a database study should provide clarity regarding operational definitions for key temporal anchors and their relation to each other when creating the analytic dataset, accompanied by an attrition table and a design diagram. A substantial improvement in reproducibility, rigor and confidence in real world evidence generated from healthcare databases could be achieved with greater transparency about operational study parameters used to create analytic datasets from longitudinal healthcare databases.

Effect of statin treatment on short term mortality after pneumonia episode: cohort study

OBJECTIVE

To determine whether statins protect against all cause mortality after a diagnosis of pneumonia.

DESIGN

Cohort study using propensity score based method to control for differences between people prescribed and not prescribed statins.

SETTING

United Kingdom Health Improvement Network database, which contains electronic primary care medical records of more than six million patients.

PARTICIPANTS

Every patient starting a statin between 1995 and 2006 (129,288) matched with up to five non-statin users (n = 600,241); 9073 patients had a recorded diagnosis of pneumonia, of whom 1398 were using a statin.

MAIN OUTCOME MEASURE

All cause mortality within six months of diagnosis of pneumonia.

RESULTS

Among users and non-users of statins with comparable propensity scores, 95/942 users and 686/3615 non-users died on the day that pneumonia was diagnosed. In the following six month period, 109/847 statin users died compared with 578/2927 non-users, giving an adjusted hazard ratio of 0.67 (0.49 to 0.91). If these observed benefits translated into clinical practice, 15 patients would need to be treated with a statin for six months after pneumonia to prevent one death.

CONCLUSIONS

Compared with people who were not taking statins, the risk of dying in the six month period after pneumonia was substantially lower among people who were already established on long term statin treatment when the pneumonia occurred. Whether some or all of this protective effect would be obtained if statin treatment begins when a patient first develops pneumonia is not known. However, given that statins are cheap, safe, and well tolerated, a clinical trial in which people with pneumonia are randomised to a short period of statin treatment is warranted.

Eosinophil chemotaxis inhibited by 5-lipoxygenase blockade and leukotriene receptor antagonism

We studied the effects of the 5-lipoxygenase inhibition and sulfidopeptidyl leukotriene receptor antagonism on lumenal chemotaxis of eosinophils in 124 guinea pig tracheal explant preparations from 62 animals. Cell migration was assessed histologically and by differential cell count, and airway narrowing was measured by calibrated micrometry. Intralumenal instillation of the chemotaxin, formyl-met-leu-phe (FMLP) caused migration of 163,509 +/- 18,103 eosinophils/cm segment (eos/cm) versus 15,443 +/- 3,557 eos/cm for segments receiving vehicle only (p < 0.001). Coincubation of FMLP with zileuton, a selective inhibitor of 5-lipoxygenase, caused a concentration-related inhibition of eosinophil migration. At 10(-10) M zileuton, cell migration caused by FMLP was decreased by 57% and nearly complete reduction to 17,200 +/- 3,620 eos/cm resulted after 10(-6) M zileuton (p < 0.001 versus FMLP). Lumenal narrowing caused by FMLP (15.3 +/- 3.4%) was attenuated maximally to 1.15 +/- 2.51% after 10(-8) M zileuton (p < 0.02). In 36 preparations, concentration of leukotriene B4 (LTB4) was measured in treated tracheal perfusate. LTB4 secretion caused by FMLP was 6.4 +/- 0.48 pg/ml versus 3.32 +/- 0.89 pg/ml for buffer control at 5 min (p < 0.02) and was undetectable 120 min after activation with FMLP. Blockade of LTB4-receptor with the selective antagonist, LTB4 dimethyl amide, caused > 90% inhibition of eosinophil migration (p < 0.001). Comparable results were obtained with zafirlukast, an LTD4-receptor antagonist. Our data demonstrate that both LTB4 and LTD4 facilitate eosinophil migration from lamina propria to lumen caused by the chemotaxin, FMLP, and that LTB4-induced eosinophil migration is accompanied by initial lumenal secretion of LTB4.