The effect of hormone replacement therapy on the survival of UK women: a retrospective cohort study 1984-2017.

OBJECTIVE: To estimate the effect of estrogen-only and combined hormone replacement therapy (HRT) on the hazards of overall and age-specific all-cause mortality in healthy women aged 46-65 at first prescription. DESIGN: Matched cohort study. SETTING: Electronic primary care records from The Health Improvement Network (THIN) database, UK (1984-2017). POPULATION: 105 199 HRT users (cases) and 224 643 non-users (controls) matched on age and general practice. METHODS: Weibull-Double-Cox regression models adjusted for age at first treatment, birth cohort, type 2 diabetes, hypertension and hypertension treatment, coronary heart disease, oophorectomy, hysterectomy, body mass index, smoking and deprivation status. MAIN OUTCOME MEASURES: All-cause mortality. RESULTS: A total of 21 751 women died over an average of 13.5 years follow-up per participant, of whom 6329 were users and 15 422 non-users. The adjusted hazard ratio (HR) of overall all-cause mortality in combined HRT users was 0.91 (95% CI 0.88-0.94), and in estrogen-only users was 0.99 (0.93-1.07), compared with non-users. Age-specific adjusted HRs for participants aged 46-50, 51-55, 56-60 and 61-65 years at first treatment were 0.98 (0.92-1.04), 0.87 (0.82-0.92), 0.88 (0.82-0.93) and 0.92 (0.85-0.98) for combined HRT users compared with non-users, and 1.01 (0.84-1.21), 1.03 (0.89-1.18), 0.98 (0.86-1.12) and 0.93 (0.81-1.07) for estrogen-only users, respectively. CONCLUSIONS: Combined HRT was associated with a 9% lower risk of all-cause mortality and estrogen-only formulation was not associated with any significant changes. TWEETABLE ABSTRACT: Estrogen-only HRT is not associated with all-cause mortality and combined HRT reduces the risks.

Adult atopic eczema and the risk of dementia: A population-based cohort study.

BACKGROUND: Chronic inflammatory conditions have been linked to dementia, but little is known about the role of atopic eczema, an inflammatory condition recently recognized to be common among older adults. OBJECTIVE: To determine whether active atopic eczema is associated with incident dementia. METHODS: A longitudinal cohort study of 1,767,667 individuals aged 60 to 99 years registered with The Health Improvement Network, a primary care cohort in the United Kingdom. The diagnoses of atopic eczema and dementia were identified using medical record codes. RESULTS: The incidence of dementia was 57 per 10,000 person-years among those with atopic eczema during follow-up (12.1% of the population) compared with 44 per 10,000 person-years in the control group. This translated to a 27% increased risk of dementia (hazard ratio, 1.27; 95% CI, 1.23-1.30) in adjusted Cox proportional hazard models. Similar associations were observed in subgroup analyses of vascular dementia and Alzheimer's disease. The association persisted after additionally adjusting for the use of systemic corticosteroids (hazard ratio, 1.29; 95% CI, 1.26-1.33) and potential mediators (hazard ratio, 1.19; 95% CI, 1.16-1.22). More severe eczema was associated with a higher risk of dementia. LIMITATIONS: Lack of detailed data on severity. CONCLUSION: Atopic eczema was associated with a small but increased risk of incident dementia. The association increased with the severity of atopic eczema.

Long term survival after a first transient ischaemic attack in England: A retrospective matched cohort study.

OBJECTIVE: Transient ischaemic attacks (TIA) serve as warning signs for future stroke, and the impact of TIA on long term survival is uncertain. We assessed the long-term hazards of all-cause mortality following a first episode of a transient ischaemic attack (TIA). DESIGN: Retrospective matched cohort study. METHODS: Cohort study using electronic primary health care records from The Health Improvement Network (THIN) database in the United Kingdom. Cases born in or before 1960, resident in England, with a first diagnosis of TIA between January 1986 and January 2017 were matched to three controls on age, sex and general practice. The primary outcome was all-cause mortality. The hazards of all-cause mortality were estimated using a time-varying Double-Cox Weibull survival model with a random frailty effect of general practice, while adjusting for different socio-demographic factors, medical therapies, and comorbidities. RESULTS: 20,633 cases and 58,634 controls were included. During the study period, 24,176 participants died comprising of 7,745 (37.5%) cases and 16,431(28.0%) controls. In terms of hazards of mortality, cases aged 39 to 60 years at the first TIA event had the highest hazard ratio (HR) of mortality compared to their 39-60 years matched controls (HR = 3.04 (2.91 - 3.18)). The HR for cases aged 61-70 years, 71-76 years and 77+ years were 1.98 (1.55 - 2.30), 1.79 (1.20 - 2.07) and 1.52 (1.15 - 1.97) compared to their same-aged matched controls. Cases aged 39-60 at TIA onset who were prescribed aspirin were associated with reduced HR of 0.93 (0.84 - 1.01), 0.90 (0.82 - 0.98) and 0.88 (0.80 - 0.96) at 5, 10 and 15 years respectively, compared to the same aged cases who were not prescribed any antiplatelet. Statistically significant reductions in hazard ratios were observed with aspirin at 10 and 15 years in all age groups. Hazard ratio point estimates for other antiplatelets (dipyridamole or clopidogrel) and dual antiplatelet therapy were very similar to aspirin at 5, 10 and 15 years but with wider confidence intervals that included 1. There was no survival benefit associated with antiplatelet prescription in controls. CONCLUSIONS: The overall risk of death was considerably elevated in all age groups after a first-ever TIA event. Aspirin prescription was associated with a reduced risk. These findings support the use of aspirin in secondary prevention for people with a TIA. The results do not support the use of antiplatelet medication in people without TIA.

A descriptive epidemiological study of the incidence of newly diagnosed Lyme disease cases in a UK primary care cohort, 1998-2016.

BACKGROUND: Primary care is likely to see the highest number of Lyme disease patients. Despite this, there is limited published data regarding Lyme disease patients accessing primary care in the UK. We aim to describe trends in the incidence of a new diagnosis, and demographics of patients identified in a primary care electronic health database. METHODS: A descriptive epidemiological study of Lyme disease coded patients in UK primary care. 3725 patients coded for Lyme disease during 1998-2016 were identified within The Health Improvement Network (THIN). Incidence rates and the demographics of cases identified were described. Poisson regression was used to analyse socio-demographic characteristics of the cases. RESULTS: There was an increase in annual crude incidence rates, peaking in 2015 at 5.47 (95% CI 4.85-6.14) cases per 100,000 population per year. Multivariable analysis showed there were significant differences in the ages of those affected, incidence of a new diagnosis rose as deprivation levels improved, and that there was a higher incidence of cases living in rural areas compared to urban areas. There was no significant difference between sexes for the UK. Cases were significantly more likely to identify with being white compared to the national population. CONCLUSIONS: An increasing incidence of patients newly coded with Lyme disease related Read codes was identified using data from a UK national primary care database. By comparing these incidence figures with national laboratory-confirmed surveillance data, a multiplication factor of 2.35 (95%CI 1.81-2.88) can be calculated in order to estimate the annual number of cases seen in primary care. The significant socio-demographic variables associated with a Lyme disease diagnosis likely reflect a complex interplay of socio-economic issues, which needs to be further explored. Future work is needed to examine the treatment and management of patients within this database.

Seasonality of urinary tract infections in the United Kingdom in different age groups: longitudinal analysis of The Health Improvement Network (THIN).

Evidence regarding the seasonality of urinary tract infection (UTI) consultations in primary care is conflicting and methodologically poor. To our knowledge, this is the first study to determine whether this seasonality exists in the UK, identify the peak months and describe seasonality by age. The monthly number of UTI consultations (N = 992 803) and nitrofurantoin and trimethoprim prescriptions (N = 1 719 416) during 2008-2015 was extracted from The Health Improvement Network (THIN), a large nationally representative UK dataset of electronic patient records. Negative binomial regression models were fitted to these data to investigate seasonal fluctuations by age group (14-17, 18-24, 25-45, 46-69, 70-84, 85+) and by sex, accounting for a change in the rate of UTI over the study period. A September to November peak in UTI consultation incidence was observed for ages 14-69. This seasonality progressively faded in older age groups and no seasonality was found in individuals aged 85+, in whom UTIs were most common. UTIs were rare in males but followed a similar seasonal pattern than in females. We show strong evidence of an autumnal seasonality for UTIs in individuals under 70 years of age and a lack of seasonality in the very old. These findings should provide helpful information when interpreting surveillance reports and the results of interventions against UTI.

Risk of chronic kidney disease in young adults with impaired glucose tolerance/impaired fasting glucose: a retrospective cohort study using electronic primary care records.

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.

Evaluation of methods to estimate missing days' supply within pharmacy data of the Clinical Practice Research Datalink (CPRD) and The Health Improvement Network (THIN).

PURPOSE: The extent to which days' supply data are missing in pharmacoepidemiologic databases and effective methods for estimation is unknown. We determined the percentage of missing days' supply on prescription and patient levels for oral anti-diabetic drugs (OADs) and evaluated three methods for estimating days' supply within the Clinical Practice Research Datalink (CPRD) and The Health Improvement Network (THIN). METHODS: We estimated the percentage of OAD prescriptions and patients with missing days' supply in each database from 2009 to 2013. Within a random sample of prescriptions with known days' supply, we measured the accuracy of three methods to estimate missing days' supply by imputing the following: (1) 28 days' supply, (2) mode number of tablets/day by drug strength and number of tablets/prescription, and (3) number of tablets/day via a machine learning algorithm. We determined incidence rates (IRs) of acute myocardial infarction (AMI) using each method to evaluate the impact on ascertainment of exposure time and outcomes. RESULTS: Days' supply was missing for 24 % of OAD prescriptions in CPRD and 33 % in THIN (affecting 48 and 57 % of patients, respectively). Methods 2 and 3 were very accurate in estimating days' supply for OADs prescribed at a consistent number of tablets/day. Method 3 was more accurate for OADs prescribed at varying number of tablets/day. IRs of AMI were similar across methods for most OADs. CONCLUSIONS: Missing days' supply is a substantial problem in both databases. Method 2 is easy and very accurate for most OADs and results in IRs comparable to those from method 3.

Costs of vitamin D testing and prescribing among children in primary care.

Vitamin D has attracted considerable interest in recent years, with a marked increase in diagnosis of vitamin D deficiency seen among children in clinical practice in the UK. The economic implications of this change in diagnostic behaviour have not been explored. We performed a cohort study to examine longitudinal trends in healthcare expenditure arising from vitamin D testing and prescribing for children in primary care in England, using the electronic healthcare records of 722,525 children aged 0-17 years held in The Health Improvement Network database. Combined costs of vitamin D tests and prescriptions increased from £1647 per 100,000 person-years in 2008 (95% CI, £934 to £3007) to £28,913 per 100,000 person-years in 2014 (95% CI, £26,361 to £31,739). The total cost of vitamin D prescriptions and tests for children in primary care at the national level in England in 2014 was estimated to be £4.31 million (95% CI, £2.96-£6.48 million). CONCLUSION: There has been a marked increase in healthcare expenditure on vitamin D tests and prescriptions for children in primary care over the past decade. Future research should explore the drivers for this change in diagnostic behaviour and the reasons prompting investigation of vitamin D status in clinical practice. What is Known: • Vitamin D deficiency has attracted considerable interest in recent years, with a marked increase in diagnosis seen in children. • The economic implications of this change in diagnostic behaviour have not been explored. What is New: • There has been a large increase in healthcare expenditure on vitamin D tests and prescriptions for children in primary care in England over the past decade (> 15 fold between 2008 and 2013). • Screening of vitamin D status in children without specific risk factors or clinical features of deficiency may represent avoidable healthcare expenditure.

Incidence, treatment and recurrence of endometriosis in a UK-based population analysis using data from The Health Improvement Network and the Hospital Episode Statistics database.

PURPOSE: This retrospective study used medical records from The Health Improvement Network (THIN) and Hospital Episode Statistics (HES) database to evaluate endometriosis (incidence, treatment and need for recurrent invasive procedures) in the general UK population. MATERIALS AND METHODS: Women aged 12-54 years between January 2000 and December 2010, with a Read code for endometriosis, were identified in THIN. Cases were validated by manual review of free-text comments in medical records and responses to physician questionnaires. False-negative cases were identified among women with Read codes for hysterectomy or dysmenorrhea. Prescriptions of medical therapies for endometriosis were identified in THIN. Cases of single and recurrent invasive procedures were identified in women with medical records in both THIN and HES. RESULTS: Overall, 5087 women had a Read code for endometriosis, corresponding to an incidence of 1.02 (95% confidence interval [CI]: 0.99-1.05) per 1000 person-years. After case validation, the estimate was 1.46 (95% CI: 1.43-1.50) per 1000 person-years. Medical therapy was prescribed to 55.5% of women with endometriosis in the first year after diagnosis. In total, 48.3% of women received invasive treatment during the study period; approximately one-fifth of these women required further invasive treatment, mainly in the 3 years after the index procedure. CONCLUSIONS: Using Read codes as the only method to identify women with endometriosis underestimates incidence. Over half of women with recorded endometriosis are prescribed medical therapy in the first year after diagnosis. Women with diagnosed endometriosis are at risk of requiring recurrent invasive procedures.

The reporting and diagnosis of uterine fibroids in the UK: an observational study.

BACKGROUND: Uterine fibroids (UFs) are the most common benign tumour in women, and many undergo hysterectomy or uterus-preserving procedures (UPPs) to manage their symptoms. We aimed to validate the recording of UFs in a primary care database, The Health Improvement Network (THIN), and to determine the incidence of UFs in the UK. METHODS: In this observational study, women in THIN aged 15-54 years between January 2000 and December 2009 with no previous record of UFs, hysterectomy or UPPs were identified. Individuals were followed up until there was a Read code indicating UFs, they reached 55 years of age or died, or the study ended. Among those without a UF code, women were identified with a code for hysterectomy, UPPs or heavy menstrual bleeding (HMB). Anonymized patient profiles from each category were randomly selected and reviewed. Subsequently, primary care physicians were asked to complete questionnaires to verify the diagnosis for a randomly selected subgroup. RESULTS: In total, 737,638 women were identified who met the initial inclusion criteria. The numbers of women with a code for UFs, hysterectomy, UPPs and HMB were 9380, 11,002, 3220 and 60,915, respectively; the proportions of confirmed cases of UFs were 88.8, 29.7, 57.7 and 15.9 %. The estimated number of women with UFs was 23,140 (64.0 % without a recorded UF diagnosis). The overall incidence of UFs was 5.8 per 1000 woman-years. CONCLUSIONS: UFs were confirmed in a high proportion of women with UF Read codes. However, almost two-thirds of cases were identified among women with a code for hysterectomy, UPPs or HMB. These results show that UFs are under-recorded in UK primary care, and suggest that primary care physicians tend to code the symptoms of UFs more often than the diagnosis.

Use of demographic and pharmacy data to identify patients included within both the Clinical Practice Research Datalink (CPRD) and The Health Improvement Network (THIN).

PURPOSE: Pharmacoepidemiology researchers often utilize data from two UK electronic medical record databases, the Clinical Practice Research Datalink (CPRD) and The Health Improvement Network (THIN), and may choose to combine the two in an effort to increase sample size. To minimize duplication of data, previous studies examined the practice-level overlap between these databases. However, the proportion of overlapping patients remains unknown. We developed a method using demographic and pharmacy variables to identify patients included in both CPRD and THIN, and applied this method to measure the proportion of overlapping patients who initiated the oral anti-diabetic drug saxagliptin. METHODS: We conducted a cross-sectional study among patients initiating saxagliptin in CPRD and THIN between October 2009 and September 2012. Within both databases, we identified patients: (i) ≥18 years, (ii) newly prescribed saxagliptin, and (iii) with ≥180 days enrollment prior to saxagliptin initiation. Demographic data (birth year, sex, patient registration date, family number, and marital status) and prescriptions (including dates) for the first two oral anti-diabetic drugs prescribed within the study period were used to identify matching patients. RESULTS: Among 4202 CPRD and 3641 THIN patients initiating saxagliptin, 2574 overlapping patients (61% of CPRD saxagliptin initiators; 71% of THIN saxagliptin initiators) were identified. Among these patients, 2474 patients (96%) perfectly matched on all demographic and prescription data. CONCLUSIONS: Within each database, over 60% of patients initiating saxagliptin were included within both CPRD and THIN. Combined demographic and prescription data can be used to identify patients included in both CPRD and THIN.

The continuation rates of long-acting reversible contraceptives in UK general practice using data from The Health Improvement Network.

PURPOSE: The purpose of this study was to determine the continuation rates of new users of long-acting reversible contraceptive (LARC) methods in the UK, using data from general practice. METHODS: We conducted an observational study using a general practitioner (GP) database, The Health Improvement Network (THIN). The methods studied were copper intrauterine devices (Cu-IUDs), levonorgestrel-releasing intrauterine system (LNG-IUS), progestogen-only implants and progestogen-only injections. The study population comprised women in THIN aged 18-44 years during the period 2004-2009 who had been registered with their GP for at least 5 years, with a computerized prescription history of at least 1 year. Using computer algorithms, the database was searched for the Read and Multilex codes for each LARC method. New LARC users were identified and followed until there was a record indicating termination of use or the study period ended. RESULTS: The proportion of women who discontinued use during the same year of administration was 7.5% for Cu-IUDs, 10.6% for LNG-IUS, 13.2% for progestogen-only implants and 54.4% for progestogen-only injections. By the end of the study, a higher proportion of Cu-IUD and LNG-IUS users (21.1 and 18.6%, respectively) undertook consecutive use of the same method than progestogen-only implant users (10.7%). Manual review of computerized profiles demonstrated the validity of this approach. CONCLUSIONS: In the UK, the continuation rates of LARCs are high, and approximately one fifth of women chose to have a second intrauterine device fitted after expiry of the first device. A validation step demonstrated the reliability of the methodology and computer algorithms used.

Use of prescription contraceptive methods in the UK general population: a primary care study.

OBJECTIVE: To determine prescription contraceptive use in the UK. DESIGN: Observational study using a primary care database. SETTING: The Health Improvement Network (THIN). POPULATION: Women in THIN aged 12-49 years in 2008, registered with their primary care doctor for at least 5 years, and with a prescription history of at least 1 year were included. METHODS: THIN was searched using the Read and MULTILEX codes for the following methods: combined oral contraceptives (COCs), progestogen-only pills (POPs), copper intrauterine devices (Cu-IUDs), the levonorgestrel-releasing intrauterine system (LNG-IUS), progestogen-only implants, progestogen-only injections, and contraceptive patches. MAIN OUTCOME MEASURES: Prevalence, switching, and duration of prescriptions. RESULTS: A cohort of 194 054 women was identified. The prevalence of contraceptive use was: COCs, 16.2% (95% confidence interval, 95% CI 16.1-16.3%); POPs, 5.6% (95% CI 5.5-5.6%); Cu-IUD, 4.5% (95% CI 4.4-4.5%); LNG-IUS, 4.2% (95% CI 4.1-4.2%); progestogen-only implants, 1.5% (95% CI 1.5-1.6%); progestogen-only injections, 2.4% (95% CI 2.3-2.4%); and contraceptive patches, 0.1% (95% CI 0.1-0.2%). Within 1 year, 9.8% of new COC users switched to alternative COCs, and 9.0% changed to a different method. Among new COC users who did not switch method, 34.8% did not continue use beyond 3 months, and were no longer using a prescription contraceptive. CONCLUSIONS: Among users of oral contraceptives who did not switch method, over one-third did not continue use beyond 3 months. This supports current UK guidelines recommending a follow-up consultation with a healthcare professional 3 months after the first prescription of COCs.

Validity of psoriatic arthritis and capture of disease modifying antirheumatic drugs in the health improvement network.

PURPOSE: The aims of this study are to examine the validity of diagnostic codes for psoriatic arthritis in The Health Improvement Network (THIN) and to examine the agreement between General Practitioner (GP) report and prescription records for disease modifying antirheumatic drugs (DMARDs). METHODS: Questionnaires were sent to the GPs of 100 randomly selected patients with at least one medical record code for psoriatic arthritis. The positive predictive value (PPV) for a GP confirmed diagnosis was calculated, and alternative algorithms were examined to determine which method resulted in the highest PPV. RESULTS: The PPV for a single code for psoriatic arthritis was 85% (95%CI: 75.8-91.7%). Adding a prescription for a DMARD increased the PPV to 91% but with a substantial loss in sensitivity. Agreement between GPs and prescription data for use of an oral DMARD was 69%. CONCLUSIONS: The diagnosis codes for psoriatic arthritis used in THIN are valid. All prescriptions for DMARDs may not be accounted for in THIN.

Use of long-acting reversible contraceptives in the UK from 2004 to 2010: analysis using The Health Improvement Network Database.

OBJECTIVES: To determine the use of long-acting reversible contraceptives (LARCs) in the UK over the period 2004 to 2010, using the general practice database The Health Improvement Network (THIN). METHODS: Women in THIN, aged 18 to 44 years during 2004 to 2010, who had been registered with their general practitioner for at least five years, with a prescription history of at least one year were included. THIN was searched using the Read and MULTILEX codes for: copper intrauterine devices (Cu-IUDs), the levonorgestrel releasing-intrauterine system (LNG-IUS), progestogen-only implants, and progestogen-only injections. RESULTS: The prevalence of progestogen-only implant use rose from 0.5 to 3.4%, and that of the LNG-IUS from 3.1 to 5.2%. The annual incidence and prevalence of progestogen-only implant use increased for all age groups but was most marked in younger women, whereas the use of the LNG-IUS augmented with increasing age. For all women, there was a small decrease in the prevalence of use of Cu-IUDs (from 5.4 to 4.8%) and progestogen-only injections (from 3.6 to 3.2%). CONCLUSIONS: Uptake of progestogen-only implants and the LNG-IUS increased over the period 2004 to 2010 in the UK, but LARC use in young women remains low.

Post-bariatric surgery nutritional follow-up in primary care: a population-based cohort study.

BACKGROUND: Bariatric surgery is the most effective treatment for severe obesity. However, without recommended follow-up it has long-term risks. AIM: To investigate whether nutritional and weight monitoring in primary care meets current clinical guidance, after patients are discharged from specialist bariatric care. DESIGN AND SETTING: Retrospective cohort study in primary care practices contributing to IQVIA Medical Research Data in the UK (1 January 2000 to 17 January 2018). METHOD: Participants were adults who had had bariatric surgery with a minimum of 3 years' follow-up post-surgery, as this study focused on patients discharged from specialist care (at 2 years post-surgery). Outcomes were the annual proportion of patients from 2 years post-surgery with a record of recommended nutritional screening blood tests, weight measurement, and prescription of nutritional supplements, and the proportions with nutritional deficiencies based on blood tests. RESULTS: A total of 3137 participants were included in the study, and median follow-up post-surgery was 5.7 (4.2-7.6) years. Between 45% and 59% of these patients had an annual weight measurement. The greatest proportions of patients with a record of annual nutritional blood tests were for tests routinely conducted in primary care, for example, recorded haemoglobin measurement varied between 44.9% (n = 629/1400) and 61.2% (n = 653/1067). Annual proportions of blood tests specific to bariatric surgery were low, for example, recorded copper measurement varied between 1.2% (n = 10/818) and 1.5% (n = 16/1067) where recommended. Results indicated that the most common deficiency was anaemia. Annual proportions of patients with prescriptions for recommended nutritional supplements were low. CONCLUSION: This study suggests that patients who have bariatric surgery are not receiving the recommended nutritional monitoring after discharge from specialist care. GPs and patients should be supported to engage with follow-up care. Future research should aim to understand the reasons underpinning these findings.

Comorbidity phenotypes and risk of mortality in patients with ischaemic heart disease in the UK.

OBJECTIVES: The objective of this study is to use latent class analysis of up to 20 comorbidities in patients with a diagnosis of ischaemic heart disease (IHD) to identify clusters of comorbidities and to examine the associations between these clusters and mortality. METHODS: Longitudinal analysis of electronic health records in the health improvement network (THIN), a UK primary care database including 92 186 men and women aged ≥18 years with IHD and a median of 2 (IQR 1-3) comorbidities. RESULTS: Latent class analysis revealed five clusters with half categorised as a low-burden comorbidity group. After a median follow-up of 3.2 (IQR 1.4-5.8) years, 17 645 patients died. Compared with the low-burden comorbidity group, two groups of patients with a high-burden of comorbidities had the highest adjusted HR for mortality: those with vascular and musculoskeletal conditions, HR 2.38 (95% CI 2.28 to 2.49) and those with respiratory and musculoskeletal conditions, HR 2.62 (95% CI 2.45 to 2.79). Hazards of mortality in two other groups of patients characterised by cardiometabolic and mental health comorbidities were also higher than the low-burden comorbidity group; HR 1.46 (95% CI 1.39 to 1.52) and 1.55 (95% CI 1.46 to 1.64), respectively. CONCLUSIONS: This analysis has identified five distinct comorbidity clusters in patients with IHD that were differentially associated with risk of mortality. These analyses should be replicated in other large datasets, and this may help shape the development of future interventions or health services that take into account the impact of these comorbidity clusters.

Publication of UK NICE Clinical Guidelines 168 has not significantly changed the management of leg ulcers in primary care: An analysis of The Health Improvement Network database.

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.

Trends in the incidence of testing for vitamin D deficiency in primary care in the UK: a retrospective analysis of The Health Improvement Network (THIN), 2005-2015.

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.