Publications
scientifiques

AIMS: To assess whether glycaemic control is associated with a lifelong increased risk of fracture in people with newly diagnosed Type 1 diabetes. METHODS: People with newly diagnosed Type 1 diabetes between 1 January 1995 and 10 May 2016 were identified in The Health Improvement Network database. Longitudinal HbA measurements from diagnosis to fracture or study end or loss to follow-up were collected. A Cox proportional hazards model with HbA included as a time-dependent variable was fitted to these data. RESULTS: Some 5368 people with newly diagnosed Type 1 diabetes were included. The estimated adjusted hazard ratio (aHR) for HbA was statistically significant [aHR 1.007; 95% confidence interval (CI) 1.002-1.011 (mmol/mol) and aHR 1.07; 95% CI 1.03-1.12 (%)]. An incremental higher risk of fracture was observed with increasing levels of HbA . CONCLUSIONS: In people with newly diagnosed Type 1 diabetes, higher HbA is associated with an increased risk for fractures.

OBJECTIVE: To estimate the contemporary epidemiology of systemic sclerosis (SSc) in the UK and to explore the validity of using The Health Improvement Network (THIN) primary care database to study SSc. METHODS: 4,520,299 individuals (2000-2012) aged 1-99 years were followed to identify potential incident cases of SSc; potential prevalent cases were identified at start of follow-up. Patient profiles, including free-text comments, were manually reviewed to verify cases of SSc, and case validation was undertaken for a sample (n = 100) using questionnaires to primary care physicians. Incidence, prevalence and mortality rates were calculated. RESULTS: Following manual review, we identified 1321 cases of SSc (689 incident and 632 prevalent) over a mean follow-up of 7.6 years; mean age at diagnosis 59.1 years. Using information from 91/100 valid questionnaires returned, the positive predictive value of SSc diagnoses in THIN following manual review was 94%. Incidence rates of SSc per 100,000 person-years (95% CI) were 2.02 (1.87-2.17) overall, [3.36 (3.09-3.64) in females, 0.61 (0.49-0.74) in males], ranging from 1.53 (1.11-2.06) to 2.56 (1.78-3.56) across calendar years. Prevalence of SSc per 100,000 (95% CI) increased from 17.13 (14.97-19.51) to 25.38 (23.68-27.16) over the study period, and was higher in females. Using Poisson regression, the adjusted mortality rate ratio was 2.82 (95% CI: 2.55-3.13) among SSc cases versus the general population. CONCLUSIONS: THIN enables precise and valid estimates of SSc occurrence to be determined. The observed increase in SSc prevalence has not been driven by increasing incidence.

BACKGROUND: Anal fistula is a pathological connection between the anal canal and perianal skin, which most commonly develops from an infected anal crypt. While the majority of anal fistulas are idiopathic, they are also associated with Crohn's disease (CD) and other inflammatory conditions. The prevalence of anal fistula is estimated to be 1-2 per 10000 patients, but population-based studies on anal fistula epidemiology are limited and outdated. AIM: To assess the prevalence of anal fistula and relevant comorbidities, with and without CD in the United Kingdom and Europe. METHODS: A retrospective population-representative observational cohort study was performed in The Health Improvement Network (THIN), a United Kingdom primary care database. Mid-year point prevalence of anal fistula was calculated on the first of July for each year between 2014 and 2017. Estimates were calculated for anal fistula overall and by CD status and standardized to the United Kingdom and European population. Prevalence of relevant comorbidities including lymphogranuloma venereum, hidradenitis suppurativa, anal presentation of sexually transmitted diseases, diabetes mellitus, and radiation in the pelvic area was reported. RESULTS: The United Kingdom-standardized overall point prevalence of anal fistula was 1.80 (95%CI: 1.65-1.94) per 10000 patients in 2017, while the Europe standardized estimate was 1.83 (95%CI: 1.68-1.98) per 10000 patients. Both these standardized point prevalence estimates ranged from 1.89 to 2.36 between 2014-2016. The United Kingdom-standardized point prevalence of anal fistula without CD was 1.35 (95%CI: 1.23-1.48) per 10000 patients, while the Europe-standardized estimate was 1.39 (95%CI: 1.26-1.52) per 10000 patients. In contrast, the standardized point prevalence estimate of anal fistula with CD was lower for both United Kingdom and Europe (0.44; 95%CI United Kingdom: 0.37-0.52, 95%CI Europe: 0.37-0.51) per 10000 patients in 2017. In 2017, 19% of anal fistula patients without CD and 13% of anal fistula patients with CD had at least one relevant comorbidity. These results show that anal fistulas are infrequent in the general population. 24.5% of prevalent anal fistulas are associated with CD, but other potentially etiological comorbidities are rare. CONCLUSION: This real-world evidence study estimated the United Kingdom-standardized prevalence of anal fistula was 1.80 per 10000 patients in 2017. Approximately 25% of cases may be associated with CD, while other comorbidities are rare.

OBJECTIVES: Hypotension is of particular relevance for patients with heart failure (HF), since almost all HF drugs cause lowering of blood pressure (BP) and it is associated with a poor prognosis. We aimed to investigate hypotension incidence and risk factors in patients with incident HF in the UK. DESIGN: Retrospective cohort study including nested case-control analyses. SETTING: The Health Improvement Network UK primary care database. PARTICIPANTS: 18 677 adult patients with incident HF during 2000-2005 were followed and cases of hypotension (systolic BP ≤90 mm Hg) were identified. Controls were age-matched, sex-matched and date-matched to cases (1:2). PRIMARY AND SECONDARY OUTCOME MEASURES: We estimated hypotension incidence in the full study population and relevant subgroups (eg, sex and age). Potential risk factors for hypotension overall and for multiple versus single hypotensive episodes were evaluated using conditional logistic regression and unconditional regression models, respectively. RESULTS: During a mean follow-up of 3.31 years, 2565 patients (13.7%) developed hypotension. The incidence of hypotension was 3.17 cases per 100 patient years (95% confidence interval (CI): 3.05-3.30), and was markedly increased in women aged 18-39 years (n=32; 17.72 cases per 100 patient-years; 95% CI: 9.69-29.73). Hypotension risk factors included high healthcare utilisation (proxy measure for HF severity and general comorbidity; eg, ≥10 primary care physician visits versus none, odds ratio (OR): 2.29; 95% CI: 1.34-3.90), previous hypotensive episodes (OR: 2.32; 95% CI: 1.84-2.92), renal failure and use of aldosterone antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Risk factors identified for hypotension generally overlapped with those for multiple versus single hypotensive episodes. CONCLUSIONS: Hypotension occurs frequently in patients with incident HF. Our findings may help identify patients most likely to benefit from close BP monitoring. The increased incidence of hypotension in young women with HF requires investigation.

IMPORTANCE: Peripheral neuropathy has been associated with systemic fluoroquinolone exposure, but risk has been poorly quantified. OBJECTIVE: To calculate relative and absolute risk estimates for the association of fluoroquinolone exposure with peripheral neuropathy and to examine how risk may be affected by timing of fluoroquinolone exposure and by other risk factors. DESIGN, SETTING, AND PARTICIPANTS: This nested case-control study used anonymized data from all patients routinely registered with general practices in The Health Improvement Network database, a large primary care population database in the United Kingdom, from January 1, 1999, to December 31, 2015. Data analyses were conducted January 8, 2018. The cohort consisted of 1 338 900 adults issued 1 or more prescriptions of fluoroquinolone (34.3%) or amoxicillin-clavulanate (65.7%) antibiotics. Adults with incident peripheral neuropathy were matched (on age, sex, general practice, and calendar time) with up to 4 controls by using incidence density sampling selected from a cohort prescribed oral fluoroquinolone or amoxicillin-clavulanate antibiotics. Incidence rate ratios of peripheral neuropathy were calculated for fluoroquinolone and for amoxicillin-clavulanate exposure and compared with nonexposure among patients without diabetes, with sensitivity analyses testing the consistency of the results. Population mean-adjusted rate differences were then estimated, including the number needed to harm for various durations of fluoroquinolone therapy. EXPOSURES: Current and cumulative exposure to oral fluoroquinolone or amoxicillin-clavulanate antibiotics. MAIN OUTCOMES AND MEASURES: Incident peripheral neuropathy cases recorded in electronic medical records. RESULTS: In total, 5357 patients with incident peripheral neuropathy (mean [SD] age, 65.6 [14.7] years; 2809 women [52.4%]) were matched to 17 285 controls (mean [SD] age, 64.4 [15.2] years; 9485 women [54.9%]) without diabetes. Current oral fluoroquinolone exposure was associated with an increased relative incidence of peripheral neuropathy compared with nonexposure (adjusted incident rate ratio, 1.47; 95% CI, 1.13-1.92). Risk increased by approximately 3% for each additional day of current fluoroquinolone exposure and persisted for up to 180 days following exposure. No significant increased risk was observed with oral amoxicillin-clavulanate exposure. The absolute risk with current oral fluoroquinolone exposure was 2.4 (95% CI, 1.8-3.1) per 10 000 patients per year of current use. The number needed to harm for a 10-day course was 152 083 patients (95% CI, 117 742-202 778) and was greatest among men and among patients older than 60 years. CONCLUSIONS AND RELEVANCE: The results of the present study suggested that oral fluoroquinolone therapy was associated with an increased risk of incident peripheral neuropathy that may depend on the timing of the exposure and the cumulative dose. Health care professionals should consider these potential risks when prescribing fluoroquinolone antibiotics.

PURPOSE: The aim of the present study was to describe antipsychotic utilization patterns among patients with schizophrenic disorder in Italy, Spain, the UK, and the USA. METHODS: A retrospective cohort study was conducted. Patients aged 15 and over with schizophrenic disorder were identified in the Caserta claims database (Italy), the Valencia electronic medical record (EMR) database (Spain), in The Health Improvement Network EMR database (UK), and in databases of publicly and privately insured populations in the United States (US). RESULTS: The frequency of first-generation or second-generation antipsychotic use and of long-acting or other formulations was described. Persistence to antipsychotics was estimated. Overall, 1,403,240 patients with schizophrenic disorder having a total of 765,573 new antipsychotic treatment episodes were identified. The median follow-up time ranged from 0.8 (IQR 0.2-1.9) years in the US commercially-insured population to 1.2 (IQR 0.1-1.7) years in the Spanish population. Second-generation antipsychotics were more frequently used than first-generation antipsychotics in all countries (on average, from 64.4% in the UK to 87% in US): the use of this class increased over time in Italy, Spain, and US (Medicaid). The use of long-acting formulations was heterogeneous across countries, but generally much lower than other formulations. Persistence to antipsychotic treatment at 1 year was low in all countries, ranging from 40 in Spain to 30% in Italy. CONCLUSIONS: Antipsychotic utilization was heterogeneous among persons with schizophrenic disorder. Nevertheless, low persistence was an issue in all the countries, as less than half of the patients continued their treatment beyond 1 year.

INTRODUCTION: Chronic kidney disease (CKD) management in the UK is usually primary care based, with National Institute for Health and Care Excellence (NICE) guidelines defining criteria for referral to secondary care nephrology services. Estimated glomerular filtration rate (eGFR) is commonly used to guide timing of referrals and preparation of patients approaching renal replacement therapy. However, eGFR lacks sensitivity for progression to end-stage renal failure; as a consequence, the international guideline group, Kidney Disease: Improving Global Outcomes has recommended the use of a risk calculator. The validated Kidney Failure Risk Equation may enable increased precision for the management of patients with CKD; however, there is little evidence to date for the implication of its use in routine clinical practice. This study will aim to determine the impact of the Kidney Failure Risk Equation on the redesignation of patients with CKD in the UK for referral to secondary care, compared with NICE CKD guidance. METHOD AND ANALYSIS: This is a cross-sectional population-based observational study using The Health Improvement Network database to identify the impact of risk-based designation for referral into secondary care for patients with CKD in the UK. Adult patients registered in primary care and active in the database within the period 1 January 2016 to 31 March 2017 with confirmed CKD will be analysed. The proportion of patients who meet defined risk thresholds will be cross-referenced with the current NICE guideline recommendations for referral into secondary care along with an evaluation of urinary albumin-creatinine ratio monitoring. ETHICS AND DISSEMINATION: Approval was granted by The Health Improvement Network Scientific Review Committee (Reference number: 18THIN061). Study outcomes will inform national and international guidelines including the next version of the NICE CKD guideline. Dissemination of findings will also be through publication in a peer-reviewed journal, presentation at conferences and inclusion in the core resources of the Think Kidneys programme.

OBJECTIVE: To investigate trends in the incidence of testing for vitamin D deficiency and the prevalence of patients with circulating concentrations of 25-hydroxyvitamin D (25(OH)D) indicative of deficiency (<30 nmol/L) between 2005 and 2015. DESIGN: Longitudinal analysis of electronic health records in The Health Improvement Network primary care database. SETTING: UK primary care. INTERVENTION: None. PARTICIPANTS: The analysis included 6 416 709 participants aged 18 years and older. PRIMARY OUTCOMES: Incidence of having a blood test for vitamin D deficiency between 2005 and 2015, the prevalence with blood 25(OH)D <30 nmol/L and the effects of age, ethnicity and socioeconomic status on these measures were assessed. RESULTS: After a mean follow-up time of 5.4 (SD 3.7) years, there were 210 502 patients tested for vitamin D deficiency. The incidence of vitamin D testing rose from 0.29 per 1000 person-years at risk (PYAR) (95% CI 0.27 to 0.31) in 2005 to 16.1 per 1000 PYAR (95% CI 15.9 to 16.2) in 2015. Being female, older, non-white ethnicity and more economically deprived were all strongly associated with being tested. One-third (n=69 515) had 25(OH)D <30 nmol/L, but the per cent deficient among ethnic minority groups ranged from 43% among mixed ethnicity to 66% in Asians. Being male, younger and more economically deprived were also all associated with vitamin D deficiency (p<0.001). CONCLUSIONS: Testing for vitamin D deficiency increased over the past decade among adults in the UK. One-third of UK adults who had a vitamin D test performed in primary care were vitamin D deficient, and deficiency was much higher among ethnic minority patients. Future research should focus on strategies to ensure population intake of vitamin D, particularly in at-risk groups, meets recommendations to reduce the risk of deficiency and need for testing.

BACKGROUND: NICE Clinical Guidelines (CG) 168, published in July 2013, recommend specialist vascular referral for all leg ulcers, defined as a break in the skin below the knee that has not healed within two weeks. AIM: To examine the impact of CG168 on the primary care management of leg ulcers using The Health Improvement Network database. METHODS: An eligible population of approximately two million adult patients was analysed over two 18-month periods before and after publication of CG168. Those with a new diagnosis of leg ulcers in each time period were analysed in terms of demographics, specialist referral and superficial venous ablation. RESULTS: We identified 7532 and 7462 new diagnoses of leg ulcers in the pre- and post-CG168 cohorts, respectively. Patients with a new diagnosis of leg ulcers were elderly (median age: 77 years both cohorts) and less likely to be male (47% both cohorts). There were 2259 (30.0%) and 2329 (31.2%) vascular service referrals in the pre- and post-CG168 cohorts, respectively (hazard ratio, 1.05, 95% CI: 0.99, 1.11, p = 0.096). The median interval between general practitioner diagnosis and referral was 1.5 days in both cohorts. Patients from both cohorts who were referred for a new diagnosis of leg ulcers were equally likely to receive superficial venous ablation. CONCLUSIONS: Disappointingly, we have been unable to demonstrate that publication of NICE CG168 has been associated with a meaningful change in leg ulcer management in primary care in line with guideline recommendations.

OBJECTIVES: To measure the rates of lower respiratory tract infection (LRTI) and mortality following feeding gastrostomy (FG) placement in patients with learning disability (LD). Following this to compare these rates between those having LRTI prior to FG placement and those with no recent LRTI. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: The study population included patients with LD undergoing FG placement in the 'The Health Improvement Network' database. Patients with LRTI in the year prior (LYP) to their FG placement were compared with patients without a history of LRTI in the year prior (non-LYP) to FG placement. FG placement and LD were identified using Read codes previously developed by an expert panel. MAIN OUTCOME MEASURES: Incidence rate ratio (IRR) of developing LRTI and mortality following FG, comparing patients with LRTI in the year prior to FG placement to patients without a history of LRTI. RESULTS: 214 patients with LD had a FG inserted including 743.4 person years follow-up. 53.7% were males and the median age was 27.6 (IQR 19.6 to 38.6) years. 27.1% were in the LYP patients. 18.7% had a LRTI in the year following FG, with an estimated incidence rate of 254 per 1000-person years. Over the study period the incidence rate of LRTI in LYP patients was 369 per 1000-person years, in non-LYP patients this was 91 per 1000-person years (adjusted IRR 4.21 (95% CI 2.68 to 6.63) p<0.001). 27.1% of patients died during study follow-up. Incidence rate of death was 80 and 45 per 1000-person year for LYP and non-LYP patients, respectively (adjusted IRR 1.80 (1.00 to 3.23) p=0.05). CONCLUSION: In LD patients, no clinically meaningful reduction in LRTI incidence was observed following FG placement. Mortality and LRTI were higher in patients with at least one LRTI in the year preceding FG placement, compared with those without a preceding LRTI.

Background Ischemic heart disease (IHD) has been considered the top cause of mortality globally. However, countries differ in their rates and there have been changes over time. Methods and Results We analyzed mortality data submitted to the World Health Organization from 2005 to 2015 by individual countries. We explored patterns in relationships with age, sex, and income and calculated age-standardized mortality rates for each country in addition to crude death rates. In 5 illustrative countries which provided detailed data, we analyzed trends of mortality from IHD and 3 noncommunicable diseases (lung cancer, stroke, and chronic lower respiratory tract diseases) and examined the simultaneous trends in important cardiovascular risk factors. Russia, United States, and Ukraine had the largest absolute numbers of deaths among the countries that provided data. Among 5 illustrative countries (United Kingdom, United States, Brazil, Kazakhstan, and Ukraine), IHD was the top cause of death, but mortality from IHD has progressively decreased from 2005 to 2015. Age-standardized IHD mortality rates per 100 000 people per year were much higher in Ukraine (324) and Kazakhstan (97) than in United States (60), Brazil (54), and the United Kingdom (46), with much less difference in other causes of death. All 5 countries showed a progressive decline in IHD mortality, with a decline in smoking and hypertension and in all cases a rise in obesity and type II diabetes mellitus. Conclusions IHD remains the single largest cause of death in countries of all income groups. Rates are different between countries and are falling in most countries, indicating great potential for further gains. On the horizon, future improvements may become curtailed by increasing hypertension in some developing countries and more importantly global growth in obesity.

Prescription of direct oral anticoagulants (DOAC) compared to warfarin for treating atrial fibrillation patients have increased substantially since their introduction in the England's National Health Service. Assessment of the risk of strokes and bleeds in relation to the large-scale uptake in DOACs compared to warfarin at the clinical commissioning group (CCG) level needs to be carried out. Publicly available- aggregated, CCG level, multi-source health and prescription records data were interrogated to investigate the association between prescription rate of DOACs and stroke/ bleed events during the period of 2013 to 2016. Variability of prescription rates and patient numbers across 208 CCGs were used to infer the effect of DOACs on stroke and bleed risk. Relative risk (RR) and 95% credible intervals (CI) were estimated using Markov chain Monte Carlo approach in JAGS. During the study period, the proportion of DOAC prescriptions increased at an average rate of 122% per annum. DOAC prescription was association with a 50% reduction in ischaemic (RR = 0.48, 95% CI = 0.39, 0.57) and haemorrhagic stroke (RR = 0.50, 95% CI = 0.26-0.77). In contrast, DOAC prescription reached significant association with reduction in gastrointestinal bleeds (RR = 0.86, 95% CI = 0.73-0.98) but not clinically relevant bleeds (RR = 0.95, 95% CI = 0.85-1.05). Sex stratified data showed significant association between DOAC prescription and reduction in haemorrhagic stroke risk (RR = 0.40, 95% CI = 0.28-0.52) and gastrointestinal bleeds (RR = 0.76, 95% CI = 0.63-0.93) in males only. Age stratified data suggested significant association with reduction in risk of both ischaemic and haemorrhagic strokes in patients aged 70 years and above, and reduction in risk of clinically relevant and gastrointestinal bleeds in patients aged 70-79 years only. Publicly available health and prescription data for the English population indicates reduction in stroke and bleed risk in specific age and sex sub-groups with the uptake of DOACs compared to warfarin between 2013 and 2016.