Scientific
publications

OBJECTIVES: To determine the effectiveness of live attenuated influenza vaccine (LAIV) in reducing amoxicillin prescribing in preschool children in primary care. PATIENTS AND METHODS: We used The Health Improvement Network (THIN), a large primary care database from the United Kingdom. We included children aged 2 to 4 years old at the start of either the 2013/14 or the 2014/15 winter season, with at least one amoxicillin prescription between September and May, irrespective of LAIV vaccination status. We used the self-controlled case series method to estimate influenza vaccine effectiveness (VE). RESULTS: The total study sample included 33 137 children from 378 general practices during the two winter seasons. Of these children, 43.4% with at least one amoxicillin prescription had been vaccinated. The rate of amoxicillin prescribing was significantly reduced during periods of influenza vaccine immunity. The associated VE for amoxicillin prescribing was 12.8% (95% CI 6.9%, 18.3%) in 2013/14 and 14.5% (9.6%, 19.2%) in 2014/15. Given a VE of 14.5%, we estimated that amoxicillin prescribing could have been reduced by 5.6% if LAIV uptake in children aged 2-4 years increased to 50% in the 2014/15 winter season. CONCLUSIONS: Influenza vaccination of young children may contribute to a reduction in the prescribing of amoxicillin, one of the most commonly prescribed antibiotics in primary care. Further studies are required to confirm the size of the effect.

BACKGROUND AND PURPOSE: Primary prevention of stroke and transient ischemic attack (TIA) is important to reduce the burden of these conditions; however, prescribing of prevention drugs is suboptimal. We aimed to identify individual clinical and demographic characteristics associated with potential missed opportunities for prevention therapy with lipid-lowering, anticoagulant, or antihypertensive drugs before stroke/TIA. METHODS: We analyzed anonymized electronic primary care records from a UK primary care database that covers 561 family practices. Patients with first-ever stroke/TIA, ≥18 years, with diagnosis between January 1, 2009, and December 31, 2013, were included. Missed opportunities for prevention were defined as people with clinical indications for lipid-lowering, anticoagulant, or antihypertensive drugs but not prescribed these drugs before their stroke/TIA. Mixed-effect logistic regression models evaluated the relationship between missed opportunities and individual clinical/demographic characteristics. RESULTS: The inclusion criteria were met by 29 043 people with stroke/TIA. Patients with coronary heart disease, chronic kidney disease, peripheral arterial disease, or diabetes mellitus were at less risk of a missed opportunity for prescription of lipid-lowering and antihypertensive drugs. However, patients with a 10-year cardiovascular disease risk ≥20% but without these diagnoses had increased risk of having a missed opportunity for prescription of lipid-lowering drugs or antihypertensive drugs. Women were less likely to be prescribed anticoagulants but more likely to be prescribed antihypertensive drugs. The elderly (≥85 years of age) were less likely to be prescribed all 3 prevention drugs, compared with people aged 75 to 79 years. CONCLUSIONS: Knowing the patient characteristics predictive of missed opportunities for stroke prevention may help primary care identify and appropriately manage these patients. Improving the management of these groups may reduce their risk and potentially prevent large number of future strokes and TIAs in the population.

The aim of this study was to estimate the patterns of care and annual levels of health care resource use attributable to managing venous leg ulcers (VLUs) in clinical practice by the UK's National Health Service (NHS) and the associated costs of patient management. This was a retrospective cohort analysis of the records of 505 patients in The Health Improvement Network (THIN) Database. Patients' characteristics, wound-related health outcomes and health care resource use were quantified, and the total NHS cost of patient management was estimated at 2015/2016 prices. Overall, 53% of all VLUs healed within 12 months, and the mean time to healing was 3·0 months. 13% of patients were never prescribed any recognised compression system, and 78% of their wounds healed. Of the 87% who were prescribed a recognised compression system, 52% of wounds healed. Patients were predominantly managed in the community by nurses with minimal clinical involvement of specialist clinicians. Up to 30% of all the VLUs may have been clinically infected at the time of presentation, and only 22% of patients had an ankle brachial pressure index documented in their records. The mean NHS cost of wound care over 12 months was an estimated £7600 per VLU. However, the cost of managing an unhealed VLU was 4·5 times more than that of managing a healed VLU (£3000 per healed VLU and £13 500 per unhealed VLU). This study provides important insights into a number of aspects of VLU management in clinical practice that have been difficult to ascertain from other studies and provides the best estimate available of NHS resource use and costs with which to inform policy and budgetary decisions.

BACKGROUND: Severe mental illness (SMI) is associated with excess cardiovascular disease (CVD) morbidity, but little is known on provision of preventative interventions. We investigated statin initiation for primary CVD prevention in individuals with and without SMI. METHODS: We used primary care data from The Health Improvement Network from 2006 to 2015 for UK patients aged 30-99years with no pre-existing CVD conditions and selected individuals with schizophrenia (n=13,252) or bipolar disorder (n=11,994). In addition, we identified samples of individuals without schizophrenia (n=66,060) and bipolar disorder (n=59,765), but with similar age and gender distribution. Missing data on CVD covariates were estimated using multiple imputation. Statin prescribing differences between individuals with and without SMI were investigated using multivariable Poisson regression models. RESULTS: Initiation of statin prescribing was between 2 and 3 fold higher in people aged 30-59years with SMI than in those without after adjusting for CVD covariates. The rates in those aged 60-74years with SMI were similar or slightly higher relative to those without SMI. The incidence rate ratio (IRR) was 1.15 (95% CI 1.03-1.28) for bipolar disorder and 1.00 (0.91-1.11) for schizophrenia. The rate of statin prescribing was lower (IRR 0.81 (0.66-0.98)) amongst the oldest (aged 75+years) with schizophrenia relative to those without schizophrenia. CONCLUSIONS: Despite higher rates of new statin prescriptions to younger individuals with SMI relative to individuals without SMI, there was evidence of lower rates of statin initiation for older individuals with schizophrenia, and this group may benefit from additional measures to prevent CVD.

OBJECTIVES: UK primary care databases (PCDs) are used by researchers worldwide to inform clinical practice. These databases have been primarily tied to single clinical computer systems, but little is known about the adoption of these systems by primary care practices or their geographical representativeness. We explore the spatial distribution of clinical computing systems and discuss the implications for the longevity and regional representativeness of these resources. DESIGN: Cross-sectional study. SETTING: English primary care clinical computer systems. PARTICIPANTS: 7526 general practices in August 2016. METHODS: Spatial mapping of family practices in England in 2016 by clinical computer system at two geographical levels, the lower Clinical Commissioning Group (CCG, 209 units) and the higher National Health Service regions (14 units). Data for practices included numbers of doctors, nurses and patients, and area deprivation. RESULTS: Of 7526 practices, Egton Medical Information Systems (EMIS) was used in 4199 (56%), SystmOne in 2552 (34%) and Vision in 636 (9%). Great regional variability was observed for all systems, with EMIS having a stronger presence in the West of England, London and the South; SystmOne in the East and some regions in the South; and Vision in London, the South, Greater Manchester and Birmingham. CONCLUSIONS: PCDs based on single clinical computer systems are geographically clustered in England. For example, Clinical Practice Research Datalink and The Health Improvement Network, the most popular primary care databases in terms of research outputs, are based on the Vision clinical computer system, used by <10% of practices and heavily concentrated in three major conurbations and the South. Researchers need to be aware of the analytical challenges posed by clustering, and barriers to accessing alternative PCDs need to be removed.

Adverse events are anticipated during a clinical development program. Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We describe here the process undertaken by Pfizer to investigate a safety signal for pancreatic cancer with tofacitinib. Potential cases of pancreatic cancer across indications from Pfizer's clinical trials and safety databases were identified and underwent in-depth case review and external expert consultation. The magnitude of the signal was quantified. The feasibility of formal signal evaluation via a hypothesis-testing study was explored. As of July 2016, 14 cases of potential pancreatic cancer were identified: eight cases in clinical development trials (psoriasis n = 6; RA n = 1; psoriatic arthritis n = 1), four cases in a postmarketing study in RA patients in Japan, and two spontaneous reports. Incidence rates (95% confidence intervals) per 100 patient-years ranged from 0 (0, 0.02) to 0.14 in RA, 0.05 (0.01, 0.15) to 0.07 (0.02, 0.16) in psoriasis, and 0.25 (0.01, 1.37) in psoriatic arthritis. The majority of patients had established risk factors for pancreatic cancer. The pharmaceutical industry's rapid and transparent response to safety signals is essential for ensuring patient safety and enabling physicians and patients to adequately assess a drug's risk:benefit. Safety signals emerging through pharmacovigilance may be true or false indicators of a causative association with drug exposure. In this example, it was determined that tofacitinib exposure was unlikely to be related to induction and promotion of pancreatic cancer; however, a relationship with pancreatic cancer promotion could not be excluded.

BACKGROUND: The risk of chronic kidney disease (CKD) is known to be elevated in patients with diabetes mellitus but the risk of young adults aged 18 to 40 years with impaired glucose tolerance/impaired fasting glucose (IGT/IFG) developing CKD is not well characterised. Furthermore, progression of IGT/IFG to diabetes and subsequent CKD development is not well understood. METHODS: A retrospective cohort study was undertaken using The Health Improvement Network (THIN) database, a large dataset of electronic patient records. THIN database is jointly managed by IMS Health Real World Evidence Solution ( http://www.epic-uk.org/index.html ) and In Practice System (InPs). Cases were aged 18 to 40, with a diagnosis of IGT/IFG and registered at a practice contributing to THIN between 2000 and 2015. The study population consisted of 40,092 patients, including 21,454 (53.5%) female and 18,638 (46.5%) male. The median follow-up was approximately 2 years. The outcome was a diagnosis of CKD determined from either clinical coding or laboratory results. For the primary analysis the unadjusted and adjusted relative risk of CKD in IGT/IFG was compared to age, sex and practice matched controls with normoglycaemia. For the secondary analysis we compared the incidence of CKD before to after a diagnosis of type 2 diabetes (T2DM) in the IGT/IFG study cohort. RESULTS: The Incidence Rate Ratio (IRR) for CKD for IGT/IFG compared to normoglycaemia was 4.0 [95% confidence interval (CI), 3.2 to 5.1, P < 0.001]. The adjusted IRR was 2.6 [95% CI, 2.0 to 3.4, P < 0.001]. The unadjusted IRR was 8.8 [95% CI, 7.7 to 10.0, P < 0.001] after IGT/IFG patients had developed T2DM and the adjusted IRR was 6.3 [95% CI, 5.5 to 7.2, P < 0.001]. CONCLUSION: Our results show that young IGT/IFG subjects are also at higher risk of developing CKD. This risk is modulated by the degree of baseline renal function and glucose tolerance, being higher in those developing T2DM.

BACKGROUND: Data evaluating the impact of objectively measured psoriasis severity on type 2 diabetes mellitus (T2DM) risk are lacking. OBJECTIVE: To determine the risk for T2DM in patients with psoriasis compared with that in adults without psoriasis, stratified by categories of directly assessed body surface area (BSA) affected by psoriasis. METHODS: A prospective, population-based, cohort study from the United Kingdom in which 8124 adults with psoriasis and 76,599 adults without psoriasis were followed prospectively for approximately 4 years. RESULTS: There were 280 incident cases of diabetes in the psoriasis group (3.44%) and 1867 incident cases of diabetes in those without psoriasis (2.44%). After adjustment for age, sex and body mass index, the hazard ratios for development of incident diabetes were 1.21 (95% confidence interval [CI], 1.01-1.44), 1.01 (95% CI, 0.81-1.26), and 1.64 (95% CI, 1.23-2.18) in the groups with 2% or less of their BSA affected, 3% to 10% of their BSA affected, and 10% or more of their BSA affected compared with in the groups without psoriasis, respectively (P = .004 for trend). Worldwide, we estimate an additional 125,650 new diagnoses of T2DM per year in patients with psoriasis as compared with in those without psoriasis. LIMITATIONS: Relatively short-term follow-up and exclusion of prevalence cases, which may have masked associations in patients with less extensive psoriasis. CONCLUSION: Clinicians may measure BSA affected by psoriasis to target diabetes prevention efforts for patients with psoriasis.

OBJECTIVES: To identify and quantify inappropriate systemic antibiotic prescribing in primary care in England, and ultimately to determine the potential for reduction in prescribing of antibiotics. METHODS: Primary care data from 2013-15 recorded in The Health Improvement Network (THIN) database were used. Potentially inappropriate prescribing events in the database were identified by: (i) comparing prescribing events against treatment guidelines; (ii) comparing actual proportions of consultations resulting in prescription for a set of conditions with the ideal proportions derived from expert opinion; and (iii) identifying high prescribers and their number of prescriptions above an age- and body-system-specific benchmark. RESULTS: Applying the most conservative assumptions, 8.8% of all systemic antibiotic prescriptions in English primary care were identified as inappropriate, and in the least conservative scenario 23.1% of prescriptions were inappropriate. All practices had non-zero reduction potentials, ranging from 6.4% to 43.5% in the middle scenario. The four conditions that contributed most to inappropriate prescribing were sore throat (23.0% of identified inappropriate prescriptions), cough (22.2%), sinusitis (7.6%) and acute otitis media (5.7%). One-third of all antibiotic prescriptions lacked an informative diagnostic code. CONCLUSIONS: This work demonstrates (i) the existence of substantial inappropriate antibiotic prescribing and (ii) poor diagnostic coding in English primary care. All practices (not just the high prescribers) should engage in efforts to improve antimicrobial stewardship. Better diagnostic coding, more precise prescribing guidelines and a deeper understanding of appropriate long-term uses of antibiotics would allow identification of further potential for reductions.

AIM: To investigate determinants of change in glycated haemoglobin (HbA1c) in patients with type 2 diabetes mellitus (T2DM) at 6 months after initiating uninterrupted second-line glucose-lowering therapies. MATERIALS AND METHODS: This cohort study utilized retrospective data from 10 256 patients with T2DM who initiated second-line glucose-lowering therapy (switch from or add-on to metformin) between 2011 and 2014 in Germany and the UK. Effects of pre-specified patient characteristics on 6-month HbA1c changes were assessed using analysis of covariance. RESULTS: Patients had a mean (standard error [SE]) baseline HbA1c of 8.68% (0.02); 28.5% of patients discontinued metformin and switched to an alternative therapy and the remainder initiated add-on therapy. Mean (SE) unadjusted 6-month HbA1c change was -1.27% (0.02). When adjusted for baseline HbA1c, 6-month changes depended markedly on the magnitude of the baseline HbA1c (HbA1c <9%, -0.45% per unit increase in HbA1c; HbA1c ≥9%, -0.87% per unit increase in HbA1c). Adjusted mean 6-month HbA1c reductions showed slight treatment differences (range, 0.92-1.09%; P < .001). Greater reductions in HbA1c were associated with second-line treatment initiation within 6 months of T2DM diagnosis (1.36% vs 1.03% [P < .001]) and advanced age (≥70 years, 1.13%; <70 years, 1.02% [P < .001]). CONCLUSIONS: Many patients with T2DM have very high HbA1c levels when initiating second-line therapy, indicating the need for earlier treatment intensification. Patient-specific factors merit consideration when making treatment decisions.

OBJECTIVES: Primary care practices in England differ in antibiotic prescribing rates, and, anecdotally, prescribers justify high prescribing rates based on their individual case mix. The aim of this paper was to explore to what extent factors such as patient comorbidities explain this variation in antibiotic prescribing. METHODS: Primary care consultation and prescribing data recorded in The Health Improvement Network (THIN) database in 2013 were used. Boosted regression trees (BRTs) and negative binomial regression (NBR) models were used to evaluate associations between predictors and antibiotic prescribing rates. The following variables were considered as potential predictors: various infection-related consultation rates, proportions of patients with comorbidities, proportion of patients with inhaled/systemic corticosteroids or immunosuppressive drugs, and demographic traits. RESULTS: The median antibiotic prescribing rate was 65.6 (IQR 57.4-74.0) per 100 registered patients among 348 English practices. In the BRT model, consultation rates had the largest total relative influence on antibiotic prescribing rate (53.5%), followed by steroid and immunosuppressive drugs (31.6%) and comorbidities (12.2%). Only 21% of the deviance could be explained by an NBR model considering only comorbidities and age and gender, whereas 57% of the deviance could be explained by the model considering all variables. CONCLUSIONS: The majority of practice-level variation in antibiotic prescribing cannot be explained by variation in prevalence of comorbidities. Factors such as high consultation rates for respiratory tract infections and high prescribing rates for corticosteroids could explain much of the variation, and as such may be considered in determining a practice's potential to reduce prescribing.

BACKGROUND: Combining a GLP-1 receptor agonist (GLP-1RA) with insulin is often an effective treatment strategy for overweight patients with type 2 diabetes (T2D), but little is known about the longer-term effects on cardiovascular and mortality outcomes in routine clinical practice in the United Kingdom. We therefore compared the times to a major nonfatal cardiovascular (CV) event and all-cause mortality among overweight patients with T2D treated with insulin alone versus insulin+GLP-1RA in a large UK database. METHODS: A retrospective cohort study was conducted in 18,227 patients with insulin-treated T2D from UK General Practices using The Health Improvement Network database. The 5-year risk of mortality and a 3-point composite of all-cause mortality and nonfatal CV outcomes (myocardial infarction or stroke) was compared between a propensity score-matched cohort of those on insulin alone (n=1,793) and insulin+GLP-1RA (n=1,793), irrespective of other diabetes therapies, providing a total of 12,682 person-years of follow-up. Cox proportional hazard models were used to estimate the hazard ratios of the outcomes. RESULTS: Hemoglobin A1c reduction was similar between both groups (-0.42 vs -0.33%, P=.089 at 12 months). Overall, 3-point composite events of all-cause mortality and CV events (major adverse cardiovascular even) were 98 versus 55 for the insulin alone versus insulin+GLP-1RA groups, respectively (14.7 vs 9.2 per 1,000 person-years; adjusted hazard ratio [aHR]: 0.64; 95% CI: 0.42-0.98; P=.038). Corresponding composite nonfatal CV events were 33 versus 28 (6.0 vs 5.6 per 1,000 person-years; aHR: 0.76; 95% CI: 0.41-1.42; P=.393), whereas all-cause mortality events were 49 versus 13 (6.9 vs 2.0 per 1,000 person-years; aHR: 0.35; 95% CI: 0.17-0.73; P=.005). CONCLUSION: Based on a large UK cohort in routine clinical practice, adding a GLP-1RA to insulin therapy is associated with a reduction in risk of composite CV events and all-cause mortality but a nonsignificant higher risk of hospitalization for heart failure in overweight patients with T2D.

The aim of this study was to estimate the patterns of care and annual levels of health care resource use attributable to managing diabetic foot ulcers (DFUs) in clinical practice by the UK's National Health Service (NHS), and the associated costs of patient management. This was a retrospective cohort analysis of the records of 130 patients with a newly diagnosed DFU in The Health Improvement Network (THIN) database. Patients' characteristics, wound-related health outcomes and health care resource use were quantified, and the total NHS cost of patient management was estimated at 2015-2016 prices. Patients were predominantly managed in the community by nurses, with minimal clinical involvement of specialist physicians. 5% of patients saw a podiatrist, and 5% received a pressure-offloading device. Additionally, 17% of patients had at least one amputation within the first 12 months from initial presentation of their DFU. 14% of DFUs were documented as being clinically infected at initial presentation, although an additional 31% of patients were prescribed an antimicrobial dressing at the time of presentation. Of all the DFUs, 35% healed within 12 months, and the mean time to healing was 4·4 months. Over the study period, 48% of all patients received at least one prescription for a compression system, but significantly more patients healed if they never received compression (67% versus 16%; P < 0·001). The mean NHS cost of wound care over 12 months was an estimated £7800 per DFU (of which 13% was attributable to amputations), ranging from £2140 to £8800 per healed and unhealed DFU, respectively, and £16 900 per amputated wound. Consolidated medical records from a primary care held database provided 'real-world evidence' highlighting the consequences of inefficient and inadequate management of DFUs in clinical practice in the UK. Clinical and economic benefits to both patients and the NHS could accrue from strategies that focus on (i) wound prevention, (ii) improving wound-healing rates and (iii) reducing infection and amputation rates.

INTRODUCTION: The European Medical Information Framework consortium has assembled electronic health record (EHR) databases for dementia research. We calculated dementia prevalence and incidence in 25 million persons from 2004 to 2012. METHODS: Six EHR databases (three primary care and three secondary care) from five countries were interrogated. Dementia was ascertained by consensus harmonization of clinical/diagnostic codes. Annual period prevalences and incidences by age and gender were calculated and meta-analyzed. RESULTS: The six databases contained 138,625 dementia cases. Age-specific prevalences were around 30% of published estimates from community samples and incidences were around 50%. Pooled prevalences had increased from 2004 to 2012 in all age groups but pooled incidences only after age 75 years. Associations with age and gender were stable over time. DISCUSSION: The European Medical Information Framework initiative supports EHR data on unprecedented number of people with dementia. Age-specific prevalences and incidences mirror estimates from community samples in pattern at levels that are lower but increasing over time.

OBJECTIVES: To assess the appropriateness of prescribing systemic antibiotics for different clinical conditions in primary care, and to quantify 'ideal' antibiotic prescribing proportions in conditions for which antibiotic treatment is sometimes but not always indicated. METHODS: Prescribing guidelines were consulted to define the appropriateness of antibiotic therapy for the conditions that resulted in antibiotic prescriptions between 2013 and 2015 in The Health Improvement Network (THIN) primary care database. The opinions of subject experts were then formally elicited to quantify ideal antibiotic prescribing proportions for 10 common conditions. RESULTS: Of the antibiotic prescriptions in THIN, 52.5% were for conditions that could be assessed using prescribing guidelines. Among these, the vast majority of prescriptions (91.4%) were for conditions where antibiotic appropriateness is conditional on patient-specific indicators. Experts estimated low ideal prescribing proportions in acute, non-comorbid presentations of many of these conditions, such as cough (10% of patients), rhinosinusitis (11%), bronchitis (13%) and sore throat (13%). Conversely, antibiotics were believed to be appropriate in 75% of non-pregnant women with non-recurrent urinary tract infection. In impetigo and acute exacerbation of chronic obstructive pulmonary disease, experts clustered into distinct groups that believed in either high or low prescribing. CONCLUSIONS: In English primary care, most antibiotics are prescribed for conditions that only sometimes require antibiotic treatment, depending on patient-specific indicators. Experts estimated low ideal prescribing proportions in many of these conditions. Incomplete prescribing guidelines and disagreement about prescribing in some conditions highlight further research needs.

BACKGROUND: To examine the intensity of glycemic and blood pressure control in British adults with diabetes mellitus and whether control levels or treatment deintensification rates differ across health states. METHODS: Retrospective cohort study using primary care electronic medical records (the United Kingdom Health Improvement Network Database) for adults with diabetes diagnosed at least 6 months before the index HbA1C and systolic blood pressure (SBP) measurements (to give their primary care physicians time to achieve treatment goals). We used prescribing records for 6 months pre/post the index measurements to determine who had therapy subsequently deintensified (based on "glycemic therapy score" and "antihypertensive therapy score" derived from number and dosage of medications). RESULTS: Of 292,170 individuals with diabetes, HbA1C < 6% or SBP < 120 mmHg after at least 6 months of management was less common in otherwise fit patients (15.0 and 12.7%) than in those who were mildly frail (16.6 and 13.2%) or moderately-severely frail (20.2 and 17.0%, both p < 0.0001). In the next 6 months, only 44.7% of those with HbA1C < 6% had glycemic therapy reduced (44.4% of fit, 47.1% of mildly frail, and 41.5% of moderate-severely frail patients) and 39.8% of those with SBP < 120 had their antihypertensives decreased (39.3% of fit, 43.0% of mildly frail, and 46.7% of moderate-severely frail patients). On the other hand, more individuals exhibited higher than recommended levels for HbA1C or SBP after the first 6 months of therapy (37.3, 33.4, and 31.3% of fit, mildly frail, and moderately-severely frail patients had HbA1C > 7.5% and 46.6, 51.4, and 48.5% had SBP > 140 mmHg). The proportions of patients with HbA1C or SBP out of recommended treatment ranges changed little 6 months later despite frequent (median 14 per year) primary care visits. CONCLUSIONS: Glycemic and hypertensive control exhibited statistically significant but small magnitude differences across frailty states. Medication deintensification was uncommon, even in frail patients below SBP and HbA1C targets. SBP levels were more likely to be outside recommended treatment ranges than glycemic levels. Trial registration As this study is a retrospective secondary analysis of electronic medical record data and not a health care intervention trial it was not registered.