Health Improvement Network Database Research Articles

Intra-cluster and inter-period correlation coefficients for cross-sectional cluster randomised controlled trials for type-2 diabetes in UK primary care.

BackgroundClustered randomised controlled trials (CRCTs) are increasingly common in primary care. Outcomes within the same cluster tend to be correlated with one another. In sample size calculations, estimates of the intra-cluster correlation coefficient (ICC) are needed to allow for this nonindependence. In studies with observations over more than one time period, estimates of the inter-period correlation (IPC) and the within-period correlation (WPC) are also needed.MethodsThis is a retrospective cross-sectional study of all patients aged 18 or over with a diagnosis of type-2 diabetes, from The Health Improvement Network (THIN) database, between 1 October 2007 and 31 March 2010. We report estimates of the ICC, IPC, and WPC for typical outcomes using unadjusted and adjusted generalised linear mixed models with cluster and cluster by period random effects. For binary outcomes we report on the proportions scale, which is the appropriate scale for trial design. Estimated ICCs were compared to those reported from a systematic search of CRCTs undertaken in primary care in the UK in type-2 diabetes.ResultsData from 430 general practices, with a median [IQR] number of diabetics per practice of 241 [150–351], were analysed. The ICC for HbA1c was 0.032 (95 % CI 0.026–0.038). For a two-period (each of 12 months) design, the WPC for HbA1c was 0.035 (95 % CI 0.030–0.040) and the IPC was 0.019 (95 % CI 0.014–0.026). The difference between the WPC and the IPC indicates a decay of correlation over time. Following dichotomisation at 7.5 %, the ICC for HbA1c was 0.026 (95 % CI 0.022–0.030). ICCs for other clinical measurements and clinical outcomes are presented. A systematic search of ICCs used in the design of CRCTs involving type-2 diabetes with HbA1c (undichotomised) as the outcome found that published trials tended to use more conservative ICC values (median 0.047, IQR 0.047–0.050) than those reported here.ConclusionsThese estimates of ICCs, IPCs, and WPCs for a variety of outcomes commonly used in diabetes trials can be useful for the design of CRCTs. In studies with observations taken at different time-points, the correlation of observations may decay over time, as reflected in lower values for the IPC than for the ICC. The IPC and WPC estimates are the first reported for UK primary care data.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1532-9) contains supplementary material, which is available to authorized users.

Duration of oral tetracycline-class antibiotic therapy and use of topical retinoids for the treatment of acne among general practitioners (GP): A retrospective cohort study

Guidelines recommend limiting the duration of oral antibiotic therapy in acne to 3 to 6months and prescribing concomitant topical retinoids for all patients. We sought to evaluate the duration of therapy with oral tetracyclines and the use of topical retinoids among patients with acne treated primarily by general practitioners in the United Kingdom. We conducted a retrospective cohort study using the Health Improvement Network database. The mean duration of therapy was 175.1days. Of antibiotic courses, 62% were not associated with a topical retinoid; 29% exceeded 6months in duration. If all regions were to achieve uses similar to the region with the shortest mean duration of therapy, approximately 3.3 million antibiotic days per year could be avoided in the United Kingdom. The Health Improvement Network does not include information on acne severity and clinical outcomes. Prescribing behavior for oral antibiotics in the treatment of acne among general practitioners is not aligned with current guideline recommendations. Increasing the use of topical retinoids and considering alternative agents to oral antibiotics when appropriate represent opportunities to reduce antibiotic exposure and associated complications such as antibiotic resistance and to improve outcomes in patients treated for acne.

Ongoing impairments following transient ischaemic attack: retrospective cohort study.

Clinical management after transient ischaemic attack (TIA) is focused on stroke prevention; however, a number of small studies suggest that patients may experience ongoing residual impairments. This was a retrospective matched-cohort study using anonymized electronic primary care records from The Health Improvement Network database, which covers approximately 6% of the UK population. Adults (≥ 18 years old) who experienced a first TIA between 2009 and 2013 were matched in a ratio of 1:5 to controls by age, sex and general practice. The time to first consultation for fatigue, psychological impairment or cognitive impairment was estimated by Kaplan-Meier survivor functions and adjusted hazard ratios. A total of 9419 TIA patients and 46 511 controls were included. The Kaplan-Meier curves showed that TIA patients were more likely than controls to consult for all three impairments (P < 0.0001). Within 7.1 months (95% confidence interval (CI), 6.2-8.2), 25% of TIA patients consulted for psychological impairment compared with 23.5 months (95% CI, 22.5-24.6) for controls. Hazard ratios for TIA patients were 1.43 (95% CI, 1.33-1.54) for consulting for fatigue, 1.26 (95% CI, 1.20-1.31) for psychological impairment and 1.45 (95% CI, 1.28-1.65) for cognitive impairment. Transient ischaemic attack is associated with significantly increased subsequent consultation for fatigue, psychological impairment and cognitive impairment. These findings suggest that impairments exist after initial symptoms of TIA have resolved, which should be considered by clinicians when treating TIA patients.

Health economic burden that different wound types impose on the UK's National Health Service.

The aim of this study was to estimate the patterns of care and annual levels of health care resource use attributable to the management of different wound types by the UK's National Health Service (NHS) in 2012/2013 and the annual costs incurred by the NHS in managing them. This was a retrospective cohort analysis of the records of 2000 patients in The Health Improvement Network (THIN) Database. Patients' characteristics, wound-related health outcomes and all health care resource use were quantified, and the total NHS cost of patient management was estimated at 2013/2014 prices. The NHS managed an estimated 2·2 million patients with a wound during 2012/2013. Patients were predominantly managed in the community by general practitioners (GPs) and nurses. The annual NHS cost varied between £1·94 billion for managing 731 000 leg ulcers and £89·6 million for managing 87 000 burns, and associated comorbidities. Sixty-one percent of all wounds were shown to heal in an average year. Resource use associated with managing the unhealed wounds was substantially greater than that of managing the healed wounds (e.g. 20% more practice nurse visits, 104% more community nurse visits). Consequently, the annual cost of managing wounds that healed in the study period was estimated to be £2·1 billion compared with £3·2 billion for the 39% of wounds that did not heal within the study year. Within the study period, the cost per healed wound ranged from £698 to £3998 per patient and that of an unhealed wound ranged from £1719 to £5976 per patient. Hence, the patient care cost of an unhealed wound was a mean 135% more than that of a healed wound. Real-world evidence highlights the substantial burden that wounds impose on the NHS in an average year. Clinical and economic benefits to both patients and the NHS could accrue from strategies that focus on (a) wound prevention, (b) accurate diagnosis and (c) improving wound-healing rates.

Selection Bias When Using Instrumental Variable Methods to Compare Two Treatments But More Than Two Treatments Are Available

Instrumental variable (IV) methods are widely used to adjust for the bias in estimating treatment effects caused by unmeasured confounders in observational studies. It is common that a comparison between two treatments is focused on and that only subjects receiving one of these two treatments are considered in the analysis even though more than two treatments are available. In this paper, we provide empirical and theoretical evidence that the IV methods may result in biased treatment effects if applied on a data set in which subjects are preselected based on their received treatments. We frame this as a selection bias problem and propose a procedure that identifies the treatment effect of interest as a function of a vector of sensitivity parameters. We also list assumptions under which analyzing the preselected data does not lead to a biased treatment effect estimate. The performance of the proposed method is examined using simulation studies. We applied our method on The Health Improvement Network (THIN) database to estimate the comparative effect of metformin and sulfonylureas on weight gain among diabetic patients.

Important differences in the durability of glycaemic response among second-line treatment options when added to metformin in type 2 diabetes: a retrospective cohort study

Importance There is limited information about the durability of glycaemic control when different oral glucose-lowering therapies (GLTs) are used as add-on treatments to metformin (MET) in patients with type 2 diabetes mellitus (T2DM).Objective To compare time to treatment failure between different classes of oral GLT when used as second line (add-on) treatments to MET monotherapy at HbA1c ≥ 7.5%.Design, setting and participants A retrospective cohort study on 20,070 patients who were newly treated with a sulphonylurea (SU), dipeptidyl-peptidase-4 (DPP-4) inhibitor or thiazolidinedione (TZD) following MET therapy failure (2007–2014). Patients’ data was sourced from UK General Practices via The Health Improvement Network (THIN) database. The risk of dual therapy failure was compared between three treatment groups: MET + SU (reference group, n = 15,508), MET + DPP-4 inhibitor (n = 3,080) and MET + TZD (n = 1,482). Follow-up was until treatment substitution or intensification with a 3rd GLT, or for up to 5 years (totalling 46,430 person-years). Propensity score weighting and Cox proportional hazard regression analyses were employed.Main outcomes and measures Risk of dual therapy failure was compared between treatment groups while adjusting for baseline covariates.Results Unadjusted survival analysis showed the incidence of dual therapy failure at 1 year was 15% with SU, 23% with DPP-4 inhibitor and 8% with TZD. Corresponding failure rates at 2 years were 26, 38 and 12%, respectively. Adjusted multivariate models showed that, compared to the SU group, adding a DPP-4 inhibitor was associated with an increased risk of treatment failure (adjusted hazard ratio, aHR, 1.58; 95% CI: 1.48–1.68), while adding a TZD was associated with a reduced hazard (aHR, 0.45; 95% CI: 0.41–0.50). Baseline parameters associated with an increased hazard of intensification included HbA1c, diabetes duration, gender, smoking status and the use of statins.Conclusions and relevance In routine clinical practice, adding a DPP-4 inhibitor to MET is associated with an increased, earlier requirement for treatment intensification compared to adding an SU or TZD. Adding a TZD to MET resulted in the most durable glycaemic response.Key messagesThe Agency for Healthcare Research and Quality has suggested that the durability of glycaemic response after treatment intensification is best investigated using well-designed long-term observational studies.In routine clinical practice, among patients with T2DM receiving a second line glucose lowering treatment as add-on to MET, the addition of a Thiazolidinediones is associated with the most durable glycaemic response, followed by a Sulfonylurea and then a DPP-4 inhibitor.Factors associated with earlier dual therapy failure included concomitant use of statin therapy, being female, a smoker, those with longer diabetes duration and higher baseline HbA1c levels.The addition of a Thiazolidinediones was associated with significant weight gain (1.8 kg, p < 0.001), while add-on DPP-4 inhibitor produced a significant weight reduction (−1.8 kg, p < 0.001). A very small reduction in body weight was observed with the SU (−0.2 kg, p < 0.001).

Effectiveness and cost-effectiveness of a cardiovascular risk prediction algorithm for people with severe mental illness

IntroductionCardiovascular risk prediction tools are important for cardiovascular disease (CVD) prevention, however, which algorithms are appropriate for people with severe mental illness (SMI) is unclear.Objectives/aimsTo determine the cost-effectiveness using the net monetary benefit (NMB) approach of two bespoke SMI-specific risk algorithms compared to standard risk algorithms for primary CVD prevention in those with SMI, from an NHS perspective.MethodsA microsimulation model was populated with 1000 individuals with SMI from The Health Improvement Network Database, aged 30–74 years without CVD. Four cardiovascular risk algorithms were assessed; (1) general population lipid, (2) general population BMI, (3) SMI-specific lipid and (4) SMI-specific BMI, compared against no algorithm. At baseline, each cardiovascular risk algorithm was applied and those high-risk (&gt; 10%) were assumed to be prescribed statin therapy, others received usual care. Individuals entered the model in a ‘healthy’ free of CVD health state and with each year could retain their current health state, have cardiovascular events (non-fatal/fatal) or die from other causes according to transition probabilities.ResultsThe SMI-specific BMI and general population lipid algorithms had the highest NMB of the four algorithms resulting in 12 additional QALYs and a cost saving of approximately £37,000 (US$ 58,000) per 1000 patients with SMI over 10 years.ConclusionsThe general population lipid and SMI-specific BMI algorithms performed equally well. The ease and acceptability of use of a SMI-specific BMI algorithm (blood tests not required) makes it an attractive algorithm to implement in clinical settings.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Kawasaki disease incidence in children and adolescents: an observational study in primary care

Kawasaki disease is reported to be increasing in incidence and is the commonest childhood cause of acquired heart disease in the Western world. To determine the current UK incidence of Kawasaki disease across childhood and adolescence; and investigate trends over time and season. An observational, descriptive study in the UK. The Health Improvement Network (THIN) database of primary healthcare records was searched for codes or text indicating Kawasaki disease. Identified records were compared with a study case definition and a date of onset was assigned to cases. The incidence, age/sex distribution, and trend in seasonal and temporal distribution were estimated (2008-2012). A total of 110 episodes of Kawasaki disease in 109 children were identified from 3.9 million person-years observation. The incidence of Kawasaki disease was 2.8 per 100 000 person-years (95% confidence interval [CI] = 2.3 to 3.4) when aged <20 years; 9.1 (95% CI = 7.3 to 11.2) aged <5 years, and 3.0 per 100 000 (95% CI = 2.0 to 4.3) across the age groups when possible cases were included. More cases were identified in males (55%) with one-fifth of cases diagnosed after 5 years of age. There was no statistically significant trend in incidence over the study years (P = 0.10 adjusted for sex and month), or between seasons (P = 0.65 adjusted for year and sex). Although the incidence of Kawasaki disease remains low and has stabilised in the UK, GPs should recognise that the condition occurs throughout childhood and across the seasons.

Risk factors for diabetic retinopathy in people with Type 2 diabetes: A case–control study in a UK primary care setting

AimTo identify risk factors of diabetic retinopathy (DR) among people with Type 2 diabetes mellitus in UK primary care. MethodsA case–control study nested in a cohort of incident Type 2 diabetes identified in The Health Improvement Network database from 2000 to 2007. Cases were people with DR (N=7735) and controls were a DR-free sample (N=9395). No age restrictions were applied. Adjusted odds ratios and 95% CIs were estimated. Results21% of DR cases were identified during the first semester after Type 2 diabetes diagnosis. After controlling for delay on the Type 2 diabetes diagnosis, the DR risk increased with the duration of diabetes. DR increased with a mean systolic BP ≥150mmHg (1.18; 1.10–1.27), high alcohol consumption (1.34; 1.11–1.61), glycated haemoglobin (≥75 to <86: 1.14; 1.00–1.31; ≥86 to <97mmol/mol: 1.25; 1.07–1.45; ≥97mmol/mol: 1.21; 1.07–1.37), microalbuminuria (1.16; 1.06–1.27), and retinal vein occlusion (2.47; 1.67–3.66). Glaucoma and retinal arterial occlusion showed an OR of 0.71 (0.60–0.84) and 0.63 (0.40–1.01), respectively. HDL ≥1.55mmol/l (0.88; 0.80–0.98), high triglycerides (2.3–5.6mmol/l: 0.90; 0.82–0.99; >5.6mmol/l: 0.85; 0.64–1.13) or smoking (0.89; 0.81–0.97) had a slightly reduced DR risk. Users of hypoglycaemic agents had an increased DR risk. ConclusionSome DR cases were identified near the diabetes diagnosis date suggesting that a delayed diabetes diagnosis is still common. Glaucoma, retinal arterial occlusion and high HDL levels were inversely associated with DR, while retinal vein occlusion, alcohol and other well-known risk factors were positively associated.

Antibiotic Exposure, Infection, and the Development of Pediatric Psoriasis: A Nested Case-Control Study.

Antibiotics disrupt human microbiota and have been associated with several pediatric autoimmune diseases. Psoriasis activity has been linked to group A streptococcal and viral infections. To determine whether antibiotic exposure and infections are independently associated with incident psoriasis in children. This nested case-control study used data from the Health Improvement Network database, a population-representative electronic health records database from the United Kingdom, from June 27, 1994, through January 15, 2013. Data were analyzed from September 17, 2014, through August 12, 2015. Children aged 1 to 15 years with newly diagnosed psoriasis (n = 845) were compared with age- and sex-matched controls (n = 8450) randomly chosen at the time of psoriasis diagnosis from general practices with at least one case, excluding children with immunodeficiency, inflammatory bowel disease, and juvenile arthritis. Systemic antibacterial prescriptions and infections of the skin and other sites within 2 years before psoriasis diagnosis. Incident psoriasis as determined by validated diagnostic codes. The association of antibiotic exposure and infections with incident psoriasis was determined by conditional logistic regression, adjusting for confounders. After adjusting for matching, country, socioeconomic deprivation, outpatient visits, and infections within the past 2 years, antibiotic exposure in the last 2 years was weakly associated with incident psoriasis (adjusted odds ratio [aOR], 1.2; 95% CI, 1.0-1.5). The associations for infections of skin (aOR, 1.5; 95% CI, 1.2-1.7) and other sites (aOR, 1.3; 95% CI, 1.1-1.6) were similar. Untreated nonskin infections (aOR, 1.5; 95% CI, 1.3-1.8) but not antibiotic-treated nonskin infections (aOR, 1.1; 95% CI, 0.9-1.4) were associated with psoriasis. Results were similar when using a lifetime exposure window. Different classes of antibiotics and age of first antibiotic exposure were also not associated with psoriasis. The findings did not substantively change when excluding periods of varying length before diagnosis. Infections are associated with the development of pediatric psoriasis, but antibiotics do not appear to contribute substantially to that risk.

Kidney disease in moderate-to-severe psoriasis: a critical appraisal.

Using a population-based cohort, Wan etal. examined the risk of moderate-to-advanced (stage 3-5) chronic kidney disease (CKD) in patients with psoriasis. A population-based cohort was constructed using The Health Improvement Network (THIN) database. THIN is an electronic primary healthcare records database containing routinely collected medical diagnosis and drug prescribing data on >9million patients in the U.K. Data were collected prospectively on 143883 adults (aged 18-90years) with psoriasis. Of these, 7354 had severe psoriasis, as defined by prescription codes for systemic medication or treatment codes for phototherapy. Patients with psoriasis were matched with up to five nonpsoriasis age- and practice-matched controls. Patients with a diagnosis of CKD before study entry were excluded. In addition, baseline data from the Incident Health Outcomes and Psoriasis Events (iHOPE) study, a cohort of 8731 primary care patients aged 25-64years with psoriasis, was included. Psoriasis severity was categorized according to body surface area (BSA) involvement as estimated by general practitioners. A similar method using a patient-reported BSA assessment tool was previously validated by the same group. Patients were matched by age and practice with 10 nonpsoriasis controls. Psoriasis, identified on the basis of a recorded diagnostic code for psoriasis. Incident CKD was defined as the presence of a recorded diagnostic code consistent with moderate-to-advanced (stage 3-5) CKD or laboratory parameters consistent with the diagnosis (estimated glomerular filtration rate <60mLmin(-1) 1·73m(-2) ) during follow-up. Prevalent CKD (as defined above) in the cross-sectional data from the iHOPE study. The adjusted hazard ratios for incident CKD were 1·05 [95% confidence interval (CI) 1·02-1·07], 0·99 (95% CI 0·97-1·02) and 1·93 (95% CI 1·79-2·08) in the overall, mild and severe psoriasis groups, respectively. In the nested cross-sectional study (iHOPE) the adjusted prevalence odds ratios for CKD were 0·89 (95% CI 0·72-1·10), 1·36 (95% CI 1·06-1·74) and 1·58 (95% CI 1·07-2·34) in the mild, moderate and severe psoriasis groups, respectively. Moderate-to-severe psoriasis is associated with an increased risk of moderate-to-advanced CKD, independently of traditional risk factors.

Predicting dementia risk in primary care: development and validation of the Dementia Risk Score using routinely collected data.

BackgroundExisting dementia risk scores require collection of additional data from patients, limiting their use in practice. Routinely collected healthcare data have the potential to assess dementia risk without the need to collect further information. Our objective was to develop and validate a 5-year dementia risk score derived from primary healthcare data.MethodsWe used data from general practices in The Health Improvement Network (THIN) database from across the UK, randomly selecting 377 practices for a development cohort and identifying 930,395 patients aged 60–95 years without a recording of dementia, cognitive impairment or memory symptoms at baseline. We developed risk algorithm models for two age groups (60–79 and 80–95 years). An external validation was conducted by validating the model on a separate cohort of 264,224 patients from 95 randomly chosen THIN practices that did not contribute to the development cohort. Our main outcome was 5-year risk of first recorded dementia diagnosis. Potential predictors included sociodemographic, cardiovascular, lifestyle and mental health variables.ResultsDementia incidence was 1.88 (95 % CI, 1.83–1.93) and 16.53 (95 % CI, 16.15–16.92) per 1000 PYAR for those aged 60–79 (n = 6017) and 80–95 years (n = 7104), respectively. Predictors for those aged 60–79 included age, sex, social deprivation, smoking, BMI, heavy alcohol use, anti-hypertensive drugs, diabetes, stroke/TIA, atrial fibrillation, aspirin, depression. The discrimination and calibration of the risk algorithm were good for the 60–79 years model; D statistic 2.03 (95 % CI, 1.95–2.11), C index 0.84 (95 % CI, 0.81–0.87), and calibration slope 0.98 (95 % CI, 0.93–1.02). The algorithm had a high negative predictive value, but lower positive predictive value at most risk thresholds. Discrimination and calibration were poor for the 80–95 years model.ConclusionsRoutinely collected data predicts 5-year risk of recorded diagnosis of dementia for those aged 60–79, but not those aged 80+. This algorithm can identify higher risk populations for dementia in primary care. The risk score has a high negative predictive value and may be most helpful in ‘ruling out’ those at very low risk from further testing or intensive preventative activities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-016-0549-y) contains supplementary material, which is available to authorized users.

Carpal Tunnel Syndrome Associated with Oral Bisphosphonates. A Population-Based Cohort Study

BackgroundBisphosphonates are widely used to prevent osteoporotic fractures. Some severe musculoskeletal reactions have been described with this medication; among them, some cases of carpal tunnel syndrome. Thus, the aim of this study was to explore whether bisphosphonates may be associated with this syndrome.MethodsA cohort study was conducted to compare exposed to unexposed women; the exposed group was that composed of women having received at least one prescription of an oral bisphosphonate. For the purpose, we used information from The Health Improvement Network (THIN) database. The outcome of interest was defined as those women diagnosed with carpal tunnel syndrome. A survival analysis was performed; the Cox proportional hazard model was used to calculate hazard ratios and 95% confidence intervals, and to adjust for identified confounding variables.ResultsOut of a sample of 59,475 women older than 51 years, 19,825 were treated with bisphosphonates during the period studied. No differences in age distribution or mean follow-up time were observed between the two groups in comparison. Overall, there were 572 women diagnosed with carpal tunnel syndrome, 242 (1.2%) in the group exposed to bisphosphonates, and 330 (0.8%) in the unexposed. An adjusted hazard ratio of developing carpal tunnel syndrome of 1.38 (95%CI, 1.15–1.64) was found for women exposed to bisphosphonates; no significant changes in the hazard ratios were found when considering different levels of bisphosphonate exposure.ConclusionsAn increased risk of carpal tunnel syndrome is associated with the use of bisphosphonates in postmenopausal women.

Health economic burden that wounds impose on the National Health Service in the UK

ObjectiveTo estimate the prevalence of wounds managed by the UK's National Health Service (NHS) in 2012/2013 and the annual levels of healthcare resource use attributable to their management and corresponding...

Methods of defining hypertension in electronic medical records: validation against national survey data.

Electronic medical records (EMR) can be a cost-effective source for hypertension surveillance. However, diagnosis of hypertension in EMR is commonly under-coded and warrants the needs to review blood pressure and antihypertensive drugs for hypertension case identification. We included all the patients actively registered in The Health Improvement Network (THIN) database, UK, on 31 December 2011. Three case definitions using diagnosis code, antihypertensive drug prescriptions and abnormal blood pressure, respectively, were used to identify hypertension patients. We compared the prevalence and treatment rate of hypertension in THIN with results from Health Survey for England (HSE) in 2011. Compared with prevalence reported by HSE (29.7%), the use of diagnosis code alone (14.0%) underestimated hypertension prevalence. The use of any of the definitions (38.4%) or combination of antihypertensive drug prescriptions and abnormal blood pressure (38.4%) had higher prevalence than HSE. The use of diagnosis code or two abnormal blood pressure records with a 2-year period (31.1%) had similar prevalence and treatment rate of hypertension with HSE. Different definitions should be used for different study purposes. The definition of 'diagnosis code or two abnormal blood pressure records with a 2-year period' could be used for hypertension surveillance in THIN.

Incidence and recurrence of boils and abscesses within the first year: a cohort study in UK primary care.

Boils and abscesses are common in primary care but the burden of recurrent infection is unknown. To investigate the incidence of and risk factors for recurrence of boil or abscess for individuals consulting primary care. Cohort study using electronic health records from primary care in the UK. The Health Improvement Network (THIN) database was used to identify patients who had consulted their GP for a boil or abscess. Poisson regression was used to examine the relationship between age, sex, social deprivation, and consultation and to calculate the incidence of, and risk factors for, repeat consultation for a boil or abscess. Overall, 164 461 individuals were identified who consulted their GP for a boil or abscess between 1995 and 2010. The incidence of first consultation for a boil or abscess was 512 (95% CI = 509 to 515) per 100 000 person-years in females and 387 (95% CI = 385 to 390) per 100 000 person-years in males. First consultations were most frequent in younger age groups (16-34 years) and those with the greatest levels of social deprivation. The rate of repeat consultation for a new infection during follow up was 107.5 (95% confidence interval [CI] = 105.6 to 109.4) per 1000 person-years. Obesity (relative risk [RR] 1.3, 95% CI = 1.2 to 1.3), diabetes (RR 1.3, 95% CI = 1.2 to 1.3), smoking (RR 1.3, 95% CI = 1.2 to 1.4), age <30 years (RR 1.2, 95% CI = 1.2 to 1.3), and prior antibiotic use (RR 1.4, 95% CI = 1.3-1.4) were all associated with repeat consultation for a boil or abscess. Ten percent of patients with a boil or abscess develop a repeat boil or abscess within 12 months. Obesity, diabetes, young age, smoking, and prescription of an antibiotic in the 6 months before initial presentation were independently associated with recurrent infection, and may represent options for prevention.

Statin Therapy and Risk of Acute Memory Impairment

Reports on the association between statins and memory impairment are inconsistent. To assess whether statin users show acute decline in memory compared with nonusers and with users of nonstatin lipid-lowering drugs (LLDs). Using The Health Improvement Network database during January 13, 1987, through December 16, 2013, a retrospective cohort study compared 482,543 statin users with 2 control groups: 482,543 matched nonusers of any LLDs and all 26,484 users of nonstatin LLDs. A case-crossover study of 68,028 patients with incident acute memory loss evaluated exposure to statins during the period immediately before the outcome vs 3 earlier periods. Analysis was conducted from July 7, 2013, through January 15, 2015. When compared with matched nonusers of any LLDs (using odds ratio [95% CI]), a strong association was present between first exposure to statins and incident acute memory loss diagnosed within 30 days immediately following exposure (fully adjusted, 4.40; 3.01-6.41). This association was not reproduced in the comparison of statins vs nonstatin LLDs (fully adjusted, 1.03; 0.63-1.66) but was also present when comparing nonstatin LLDs with matched nonuser controls (adjusted, 3.60; 1.34-9.70). The case-crossover analysis showed little association. Both statin and nonstatin LLDs were strongly associated with acute memory loss in the first 30 days following exposure in users compared with nonusers but not when compared with each other. Thus, either all LLDs cause acute memory loss regardless of drug class or the association is the result of detection bias rather than a causal association.

Incidence and Predictors of Hemorrhagic Stroke in Users of Low-Dose Acetylsalicylic Acid

The use of antithrombotic drugs (anticoagulants and antiplatelet drugs) has been reported to increase the risk of hemorrhagic stroke (HS) relative to no treatment. This study was performed to characterize the incidence and predictors of HS in users of acetylsalicylic acid (ASA) for the secondary prevention of cardiovascular events. A cohort of 36,775 ASA users aged 50-84 years in 2000-2007 was identified from The Health Improvement Network database. The incidence of HS was calculated, and a nested case-control analysis, adjusted for potential confounding factors, was performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association of potential risk factors with HS in current users of ASA. The overall incidence of HS was 5.70 cases per 10,000 person-years and increased with age. In current ASA users, the incidence of HS was 4.91 cases per 10,000 person-years. Predictors of HS in patients taking ASA for secondary prevention included a history of HS (OR, 4.84; 95% CI, 1.48-15.88), a history of atrial fibrillation (OR, 4.03; 95% CI, 1.53-10.62), and hypnotic/anxiolytic drug use (OR, 2.67; 95% CI, 1.17-6.05). The small number of patients using warfarin also had an increased risk of HS (OR, 23.42; 95% CI, 4.89-112.10). Physicians should consider additional risk factors for HS, such as a history of HS or atrial fibrillation, and the use of warfarin, before prescribing ASA for the secondary prevention of cardiovascular events.

An algorithm to improve diagnostic accuracy in diabetes in computerised problem orientated medical records (POMR) compared with an established algorithm developed in episode orientated records (EOMR)

BackgroundAn algorithm that detects errors in diagnosis, classification or coding of diabetes in primary care computerised medial record (CMR) systems is currently available. However, this was developed on CMR systems...

Comparative Efficacy of Adding Sitagliptin to Metformin, Sulfonylurea or Dual Therapy: A Propensity Score-Weighted Cohort Study.

IntroductionThe aim of this study was to assess the efficacy of co-administering sitagliptin to patients with inadequate glycemic control following treatment with metformin (MET), sulfonylurea (SU), or MET + SU.MethodsA cohort of 25,386 patients with type 2 diabetes mellitus (hemoglobin A1c [HbA1C] >53 mmol/mol or 7%), newly treated with sitagliptin between 2007 and 2013, was sourced from UK general practices via The Health Improvement Network database. Among these, eligible patients were segregated into three groups: MET (n = 3364), SU (n = 509), or MET + SU therapy (n = 5929). The relative efficacy of sitagliptin added to SU or MET + SU compared with sitagliptin added to MET monotherapy was assessed with regards to HbA1c and body weight changes from baseline up to 52 weeks. The glycemic efficacy was a measure of average treatment effects obtained from multivariable linear regression models and propensity score-matching analysis.ResultsA total of 9802 patients were included in the study. Overall, addition of sitagliptin 100 mg once daily resulted in 5.5 mmol/mol (0.5%) HbA1c reduction (P < 0.001) and 0.8 kg weight reduction at 1 year (P < 0.001). Efficacy was similar across the treatment groups, but in patients with baseline HbA1c ≥9% adding sitagliptin to MET + SU produced a significantly smaller reduction in HbA1c when compared to the reference group MET (MET + SU vs. MET only: −0.5% vs. −0.7%, P < 0.001). The mean HbA1c reduction from baseline within this subgroup of patients was not significantly different between SU and MET monotherapies (−0.8% vs. −0.7%, respectively, P = 0.4). Across treatment groups, HbA1c reductions with add-on sitagliptin occurred after 24 weeks of treatment with a peak reduction occurring between 36 and 48 weeks, and receded after week 48.ConclusionIn a real-world general practice setting, sitagliptin was effective in patients with suboptimal glycemic control with MET, SU or dual therapy, maximum between 36 and 48 weeks, but in patients with HbA1c of >9% receiving MET + SU therapy, adding sitagliptin, as a third agent, conferred minimal benefit.Electronic supplementary materialThe online version of this article (doi:10.1007/s13300-015-0110-6) contains supplementary material, which is available to authorized users.