Healthcare databases in Europe for studying medicine use and safety during pregnancy.

PURPOSE: The aim of this study was to describe a number of electronic healthcare databases in Europe in terms of the population covered, the source of the data captured and the availability of data on key variables required for evaluating medicine use and medicine safety during pregnancy. METHODS: A sample of electronic healthcare databases that captured pregnancies and prescription data was selected on the basis of contacts within the EUROCAT network. For each participating database, a database inventory was completed. RESULTS: Eight databases were included, and the total population covered was 25 million. All databases recorded live births, seven captured stillbirths and five had full data available on spontaneous pregnancy losses and induced terminations. In six databases, data were usually available to determine the date of the woman's last menstrual period, whereas in the remainder, algorithms were needed to establish a best estimate for at least some pregnancies. In seven databases, it was possible to use data recorded in the databases to identify pregnancies where the offspring had a congenital anomaly. Information on confounding variables was more commonly available in databases capturing data recorded by primary-care practitioners. All databases captured maternal co-prescribing and a measure of socioeconomic status. CONCLUSION: This study suggests that within Europe, electronic healthcare databases may be valuable sources of data for evaluating medicine use and safety during pregnancy. The suitability of a particular database, however, will depend on the research question, the type of medicine to be evaluated, the prevalence of its use and any adverse outcomes of interest. © 2014 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons, Ltd.

Smoking and delay to diagnosis are associated with poorer functional outcome in psoriatic arthritis.

OBJECTIVE: To identify predictors of poorer physical function in established psoriatic arthritis (PsA). METHODS: PsA patients with disease duration of ≥10 years were identified from the Bath longitudinal cohort. Physical function was assessed using the Stanford Health Assessment Questionnaire (HAQ). Sex, age at diagnosis, duration of symptoms prior to diagnosis, smoking, treatment and year of diagnosis were included in a multivariable regression analysis to identify associations with HAQ. RESULTS: 267 patients were identified for inclusion. The median age was 56 years (IQR 45-63), median disease duration was 13 years (IQR 10-18) and median HAQ score was 0.63 (IQR 0.13-1.25). The model predicted significant increases in HAQ related to smoking (0.23, 95% CI 0.04 to 0.42), age >50 years at diagnosis (0.27, 95% CI 0.03 to 0.51), symptom duration of ≥1 year before diagnosis (0.22, 95% CI 0.02 to 0.42), female sex (0.39, 95% CI 0.20 to 0.57) and history of treatment with an anti-TNF agent (0.63, 95% CI 0.32 to 0.93) at follow-up. CONCLUSIONS: Smoking, delay to diagnosis, older age at diagnosis, female sex and a history of anti-TNF treatment are associated with worse physical function in established PsA.

Administrative complexities for a European observational study despite directives harmonising requirements.

PURPOSE: For pharmacoepidemiological studies in Europe, accessing data should require only authorisation by the relevant data protections committees, as expected from the 1995 Data Protection Directive (95/46/EC). Our experience from a multinational observational study across seven European countries shows that this is certainly not the case. METHODS: The study was a multicentre, multinational, case-population study in European liver transplant centres in seven countries, retrospectively evaluating a 3-year period. Before data collection started, the procedures to obtain the necessary authorisations for the participating countries were defined. REMARKS: In France, a single opinion from a single data protection committee was enough to start the study. In Italy, Portugal, Greece and the UK, there was a national authority, but the hospitals requested the approval by their local committees/bodies irrespective of whether the authorisation of the national committee came after or before that of local ones. In Ireland, only one hospital participated, and the opinion of its ethics committee was sufficient. In the Netherlands, the opinion of the institutional review board of the local coordinating centre was necessary to obtain the opinions from the institutional review boards of the other hospitals. The information requested by the different committees and the time to obtain the approvals varied, even within the same country. CONCLUSION: This degree of complexity and disharmony, and resulting cost, was observed in a simple retrospective study. Regulators will need to be aware that these time-consuming, expensive and useless complexities must be factored in when estimating the time and cost of a study.

The incidence of primary glomerulonephritis worldwide: a systematic review of the literature.

BACKGROUND: Little is known about the worldwide variation in incidence of primary glomerulonephritis (GN). The objective of this review was to critically appraise studies of incidence published in 1980-2010 so that an overall view of trends of these diseases can be found. This would provide important information for determining changes in rates and understanding variations between countries. METHODS: All relevant papers found through searches of Medline, Embase and ScienceDirect were critically appraised and an assessment was made of the reliability of the reported incidence data. RESULTS: This review includes 40 studies of incidence of primary GN from Europe, North and South America, Canada, Australasia and the Middle East. Rates for the individual types of disease were found to be in adults, 0.2/100,000/year for membrano-proliferative GN, 0.2/100,000/year for mesangio-proliferative GN, 0.6/100,000/year for minimal change disease, 0.8/100,000/year for focal segmental glomerulosclerosis, 1.2/100,000/year for membranous nephropathy and 2.5/100,000/year for IgA nephropathy. Rates were lower in children at around 0.1/100,000/year with the exception of minimal change disease where incidence was reported to be 2.0/100,000/year in Caucasian children with higher rates in Arabian children (9.2/100,000/year) and Asian children (6.2-15.6/100,000/year). CONCLUSIONS: This study found that incidence rates of primary GN vary between 0.2/100,000/year and 2.5/100,000/year. The incidence of IgA nephropathy is at least 2.5/100,000/year in adults; this disease can exist subclinically and is therefore only detected by chance in some patients. In addition, referral policies for diagnostic biopsy vary between countries. This will affect the incidence rates found.

Strengthening regulatory science in academia: STARS, an EU initiative to bridge the translational gap.

Truly disruptive medicine innovation and new treatment paradigms tend to start in non-commercial research institutions. However, the lack of mutual understanding between medicine developers and regulators when it comes to medicine development significantly delays or even prevents the access of patients to these innovations. Here, we outline what regulatory-related barriers hamper the translational development of novel products or new treatment paradigms initiated in academia, and propose key steps towards improved regulatory dialogue among academia, funding bodies and regulatory authorities. Moreover, we briefly describe how the STARS (Strengthening Training of Academia in Regulatory Science) project aims to reach out to medicine innovators in academia to bridge the regulatory knowledge gap and enhance this dialogue to facilitate the implementation of academic research findings in clinical practice.

The incidence of myasthenia gravis: a systematic literature review.

BACKGROUND: A systematic review of literature published between 1980 and 2007, on the incidence of myasthenia gravis, was undertaken. METHODS: All relevant papers found through searches of Medline, Embase and Science Direct were critically appraised and an assessment was made of the reliability of the reported incidence data. RESULTS: Thirty-one studies were included in the review, the majority of which investigated populations in Europe. The incidence rates reported were between 3.0 and 30.0/1,000,000/year. However, it is thought that the rates at the upper end of this range, reported by the prospective studies, provided the most accurate estimates. Overall, incidence rates have increased over time owing to a greater awareness of the disease and improved methods of diagnosis. CONCLUSIONS: The most accurate estimate of incidence of myasthenia gravis was around 30/ 1,000,000/year. The incidence in children and adolescents aged 0-19 years was found to be between 1.0 and 5.0/ 1,000,000/year. The rates presented in this review are likely to be an underestimate of the true incidence rates, as mild cases will have been missed and cases in the elderly will have been misdiagnosed.

The epidemiology of Guillain-Barré syndrome worldwide. A systematic literature review.

BACKGROUND: This systematic literature review of the epidemiology of Guillain-Barré syndrome (GBS) identifies trends in incidence rates by age, study method and cause of disease. It is important to have a reliable estimate of incidence to determine and investigate any changes: no previous systematic reviews of GBS have been found. METHODS: After critical assessment of the reliability of the reported data, incidence rates were extracted from all relevant papers published between 1980 and 2008, identified through searches of Medline, Embase and Science Direct. RESULTS: Sixty-three papers were included in this review; these studies were prospective, retrospective reviews of medical records or retrospective database studies. Ten studies reported on the incidence in children (0-15 years old), and found the annual incidence to be between 0.34 and 1.34/100,000. Most studies investigated populations in Europe and North America and reported similar annual incidence rates, i.e. between 0.84 and 1.91/100,000. A decrease in incidence over the time between the 1980s and 1990s was found. Up to 70% of cases of GBS were caused by antecedent infections. CONCLUSIONS: Our best estimate of the overall incidence of GBS was between 1.1/100,000/year and 1.8/100,000/year. The incidence of GBS increased with age after 50 years from 1.7/100,000/year to 3.3/100,000/year.

The incidence of autoimmune thyroid disease: a systematic review of the literature.

OBJECTIVE: To undertake a systematic review of literature published between 1980 and 2008 on the incidence of autoimmune thyroid disease. DESIGN: All relevant papers found through searches of Medline, EMBASE and ScienceDirect were critically appraised and an assessment was made of the reliability of the reported incidence data. RESULTS: The reported incidence of autoimmune hypothyroidism varied between 2.2/100 000/year (males) and 498.4/100 000/year (females) and for autoimmune hyperthyroidism, incidence ranged from 0.70/100 000/year (Black males) to 99/100 000/year (Caucasian females). Higher incidence rates were found in women compared to men for all types of autoimmune thyroid disease. The majority of studies included in the review investigated Caucasian populations mainly from Scandinavia, Spain, the UK and the USA. It is possible that nonautoimmune cases were included in the incidence rates reported here, which would give an overestimation in the incidence rates of autoimmune disease presented. CONCLUSION: To our knowledge this is the most comprehensive systematic review of autoimmune thyroid disease conducted in the past two decades. Studies of incidence of autoimmune thyroid disease have only been conducted in a small number of mainly western countries. Our best estimates of the incidence of hypothyroidism is 350/100 000/year in women and 80/100 000/year in men; the incidence of hyperthyroidism is 80/100 000/year in women and 8/100 000/year in men.

Data resources for investigating drug exposure during pregnancy and associated outcomes: the General Practice Research Database (GPRD) as an alternative to pregnancy registries.

Pregnancy registries are the most commonly used data resource for the post-marketing surveillance of drug teratogenicity. However, the limited sample size and potential selection bias in these registries has led us to investigate the potential of the UK General Practice Research Database (GPRD) as an alternative data source for monitoring drug safety during pregnancy. In addition, a literature review identified further observational data sources that monitor pregnancy outcomes for future evaluation. Initial feasibility studies focused on the ability of the GPRD to capture pregnancy outcomes for a range of drug class exposures, all of which are currently under investigation in pregnancy registries, during pregnancy. The comparator pregnancy registries were identified via a MEDLINE search, whilst eligible pregnancies, in which women received one or more prescriptions for the drug of interest during pregnancy, were identified in the GPRD using the mother-baby link. The number of pregnancy outcomes following exposure to medication for a range of conditions with varying prevalence, including depression, migraine, epilepsy, herpes simplex and HIV, captured by the two data sources were compared. For depression, a relatively prevalent condition, the GPRD recorded the same number of mean annual intrauterine exposures to fluoxetine as the pregnancy registry (118 exposures/year). Ascertainment of intrauterine exposure to drug treatments for less prevalent conditions was found to be higher for the pregnancy registries than the GPRD; for the older antiepileptic drugs (valproate and carbamazepine), the pregnancy registry recorded between four and five times as many mean annual exposures as the GPRD. Virtually no antiretroviral exposures (three) were identified during the time period of interest on the GPRD, compared with 3946 in the Antiretroviral Pregnancy Registry. Data from the GPRD meet established criteria for evaluating outcomes of pregnancy. For prevalent conditions, it has the potential to replace or work alongside standard pregnancy registries and the alternative data sources identified. Further studies are now needed to assess its ability to replicate known teratogenic associations.

Hormone replacement therapy and risk of acute myocardial infarction : a review of the literature.

Many animal studies and studies on intermediate clinical endpoints have shown hormone replacement therapy (HRT) to be associated with both favourable and unfavourable cardiovascular effects. We reviewed the literature regarding HRT and the distinct endpoint of acute myocardial infarction (AMI) in peri- and postmenopausal women. Searches of the MEDLINE and EMBASE databases were conducted. Fifty papers were identified as eligible for inclusion: eight randomised controlled trials, 18 cohort studies, 23 case-control studies and one case-control and cohort study. The single large primary prevention randomised controlled trial on HRT and the risk of AMI in generally healthy women (Women's Health Initiative trial) reported a small yet significantly increased risk of AMI in postmenopausal women receiving combined HRT. This contrasts with a large number of observational studies that suggested a protective effect, although in many of these studies the results were not statistically significant. Inconclusive evidence on the effect of duration of use does not support the notion that a possible protective association is causal. Detection bias and residual confounding are alternative explanations for the associations observed in the randomised controlled trial and observational studies. No studies on groups of women with existing cardiovascular disease or with diabetes mellitus, including the only large secondary prevention trial (Heart and Estrogen/Progestin Replacement Study), reported a significant change in AMI risk between HRT users and non-users. There is insufficient evidence to suggest that HRT is associated with a change in the risk of AMI in the majority of women. However, certain subgroups of women with specific genetic polymorphisms may be more susceptible to a change in the risk of AMI with HRT use.

Tibolone and endometrial cancer: a cohort and nested case-control study in the UK.

OBJECTIVE: Case series and spontaneous reports of endometrial cancer have raised the question as to whether the use of tibolone (introduced into the UK in 1991) is associated with an increased risk of endometrial cancer. This study set out to evaluate whether tibolone use is associated with an increased risk of endometrial cancer. METHODS: Age-adjusted incidence rate ratios (IRRs) of endometrial cancer were calculated for tibolone use compared with the use of other hormone replacement therapy (HRT). Separate sets of controls, matched for age and general practice, were compared with cases, all nested within a cohort of HRT users identified from the UK General Practice Research Database (GPRD). Conditional logistic regression analysis, adjusted for potential confounders, was used to study the association between tibolone use and the risk of endometrial cancer. RESULTS: 4995 women used tibolone as their first HRT product; 10 783 (4.3%) of the users of combined HRT had changed to tibolone at some time during the study period. Amongst women whose HRT began with tibolone, the age-adjusted IRR relative to those who started with combined sequential HRT was 1.83 (95% CI 1.19, 2.82). The nested case-control study comprised 162 cases, each matched to two sets of 972 controls. There were 43 tibolone-exposed subjects, 28 of whom had used other HRT before or after tibolone. The adjusted odds ratio of the risk of endometrial cancer in women who had ever used tibolone, compared with users of combined sequential HRT, was 1.54 (95% CI 1.03, 2.32) in the age-matched set and 1.58 (95% CI 1.01, 2.47) in the practice-matched set. Sensitivity analyses did not decrease the risk estimates found. DISCUSSION: Tibolone may be associated with an increased risk of endometrial cancer compared with conventional forms of HRT, but our data are fragile. Residual bias and uncontrolled confounding cannot be excluded, and follow-up time is insufficient to draw any firm conclusions with respect to the endometrial safety of tibolone.

How do we best detect toxic effects of drugs taken during pregnancy? A EuroMap paper.

It is a major clinical and public health problem that there is no clear strategy as to how we best make use of information obtained when pregnant women take drugs. For this reason, some pregnant women are not treated as they should be and some are given drugs they should not use. We suggest a monitoring system that combines some of the available datasets in Europe. Using these sources as a starting point, one can develop a system that has sufficient power to detect even rare diseases like congenital malformations and sufficient diversity to detect several possible outcomes from spontaneous abortions to childhood disorders. We also suggest that case-crossover designs should be used in case-control monitoring systems that carry a high risk of recall bias. These considerations are based upon our results from a European Union-funded concerted action called EuroMaP (Medicine and Pregnancy).

Guillain-Barré syndrome and adjuvanted pandemic influenza A (H1N1) 2009 vaccines: a multinational self-controlled case series in Europe.

BACKGROUND: The risk of Guillain-Barré syndrome (GBS) following the United States' 1976 swine flu vaccination campaign in the USA led to enhanced active surveillance during the pandemic influenza (A(H1N1)pdm09) immunization campaign. This study aimed to estimate the risk of GBS following influenza A(H1N1)pdm09 vaccination. METHODS: A self-controlled case series (SCCS) analysis was performed in Denmark, Finland, France, Netherlands, Norway, Sweden, and the United Kingdom. Information was collected according to a common protocol and standardised procedures. Cases classified at levels 1-4a of the Brighton Collaboration case definition were included. The risk window was 42 days starting the day after vaccination. Conditional Poisson regression and pooled random effects models estimated adjusted relative incidences (RI). Pseudo likelihood and vaccinated-only methods addressed the potential contraindication for vaccination following GBS. RESULTS: Three hundred and three (303) GBS and Miller Fisher syndrome cases were included. Ninety-nine (99) were exposed to A(H1N1)pdm09 vaccination, which was most frequently adjuvanted (Pandemrix and Focetria). The unadjusted pooled RI for A(H1N1)pdm09 vaccination and GBS was 3.5 (95% Confidence Interval (CI): 2.2-5.5), based on all countries. This lowered to 2.0 (95% CI: 1.2-3.1) after adjustment for calendartime and to 1.9 (95% CI: 1.1-3.2) when we accounted for contra-indications. In a subset (Netherlands, Norway, and United Kingdom) we further adjusted for other confounders and there the RI decreased from 1.7 (adjusted for calendar month) to 1.4 (95% CI: 0.7-2.8), which is the main finding. CONCLUSION: This study illustrates the potential of conducting European collaborative vaccine safety studies. The main, fully adjusted analysis, showed that the RI of GBS was not significantly elevated after influenza A(H1N1)pdm09 vaccination (RI = 1.4 (95% CI: 0.7-2.8). Based on the upper limits of the pooled estimate we can rule out with 95% certainty that the number of excess GBS cases after influenza A(H1N1)pdm09 vaccination would be more than 3 per million vaccinated.

Pandemic influenza vaccination during pregnancy: an investigation of vaccine uptake during the 2009/10 pandemic vaccination campaign in Great Britain.

BACKGROUND: Pregnant women in Great Britain were recommended to receive influenza A(H1N1)pdm09 vaccines during the 2009/10 influenza pandemic, however uptake of the vaccines by pregnant women was reported to have been very low. AIM: We sought to estimate uptake of influenza A(H1N1)pdm09 vaccines and to investigate predictors of vaccine uptake in pregnant women in Great Britain during the 2009/10 pandemic. RESULTS: Uptake of influenza A(H1N1)pdm09 vaccines by pregnant women was 21.6%. Pregnant women with an underlying health condition increasing the risk of influenza-related complications had a higher vaccination rate than pregnant women without such conditions. The hazard ratio comparing these two groups decreased logarithmically throughout pregnancy from 9.3 in the first week to 1.3 by the end of pregnancy. Increasing maternal age (HR 1.01, CI 95 1.01-1.01), having a previous delivery recorded (HR 1.21, CI95 1.16-1.27) and living in Scotland (HR 2.58, CI95 2.34-2.85) or Wales (HR 1.37, CI95 1.20-1.57) as opposed to England were all also associated with an increase in vaccination uptake rates throughout pregnancy. DISCUSSION: Uptake of influenza A(H1N1)pdm09 vaccines by pregnant women was low. None of the potential predictors evaluated in this study were strong enough to account for this, however information on health beliefs and GP recommendation were not available. If the low rates reported here are to be improved new strategies to increase uptake of influenza vaccine in pregnant women need to be identified, evaluated and implemented. METHODS: Uptake rates were calculated using data from the UK General Practice Research Database (GPRD). Predictors of vaccination were identified using a Cox proportional hazards model.

Asthma management in pregnancy.

BACKGROUND: Asthma is common during pregnancy, however research is limited regarding the extent and timing of changes in asthma management associated with pregnancy. OBJECTIVE: To determine the prevalence of asthma during pregnancy and identify changes in treatment and asthma exacerbation rates associated with pregnancy, while controlling for seasonal influences. METHODS: Pregnant women with asthma were identified from the UK General Practice Research Database between 2000 and 2008. For each woman asthma medication prescribed during the study period was identified; for each product combination the British Thoracic Society medication-defined asthma treatment step was identified. Asthma exacerbations were identified during pregnancy and in the corresponding 12 months prior. Analyses of changes in asthma treatment and exacerbation rates during pregnancy relative to the corresponding period 12 months prior, to control for seasonality, were stratified by trimester and asthma treatment intensity level. RESULTS: The prevalence of treated asthma in pregnancies resulting in a delivery was 8.3%. From 14,141 pregnancies, in 12,828 women with asthma, 68.4% received prescriptions for a short-acting ß2-agonist and 41.2% for inhaled corticosteroids; 76.5% were managed with asthma treatment Step 1 or 2. Poor persistence to inhaled corticosteroids, defined as a gap of up to 60 days between prescriptions, was common. In 45.0% of pregnancies, an increase in average treatment step was observed whereas in 25.6% the treatment step decreased. Treatment intensity remained the same in 29.5% of pregnancies. Exacerbations occurred in 4.8% of pregnancies compared to 5.9% in the same season the year before (p<0.001). CONCLUSION: Exacerbation rates during pregnancy were slightly lower than in the year before. However, treatment patterns and exacerbation rates in this study suggest asthma control during pregnancy is variable, and women may require close monitoring especially in those with evidence of poor control before pregnancy.

Colorectal cancer risk reduction following macrogol exposure: a cohort and nested case control study in the UK.

BACKGROUND AND AIMS: Animal studies have demonstrated macrogol laxatives may reduce colorectal cancer (CRC) risk. This study aimed to investigate the association between macrogol prescribing and CRC risk. METHODS: A case-control study nested within a cohort of laxative users was conducted using data from the UK General Practice Research Database. Six controls per case were identified and to account for the lead time of CRC, additional control sets were selected on the index date backdated by 1 to 5 years. Exposure to macrogols and covariate status before each of the backdated index dates was established. Conditional logistic regression was used to calculate the risk of CRC following macrogol prescribing adjusted for potential confounders. RESULTS: 4734 incident CRC cases were identified; 2722, 2195, 1789, 1481 and 1214 had received a laxative prescription before the index dates backdated by 1 to 5 years. A suggestion of a non-significant reduction in CRC risk associated with 'macrogol after other laxative' prescribing was observed when the index date was backdated by 1 and 2 years, ORadj = 0.87 (CI950.74-1.03) and ORadj = 0.80 (CI950.65-1.00) compared to non-macrogol laxative exposure. The odds ratios reduced further and were significant when backdated by 3, 4 and 5 years, ORadj = 0.68 (CI950.50-0.92), ORadj = 0.60 (CI950.40-0.90) and ORadj = 0.30 (CI950.14-0.64) respectively. This reduction in risk was not observed, however, for 'macrogol only' and 'macrogol before other laxative' exposure categories. CONCLUSIONS: In this study we observed a reduced CRC risk associated with macrogol prescribing after accounting for the lead time for CRC. Further studies are required to determine whether the association is causal and whether it can partly be explained by selective prescribing.

Evaluating the hazard of foetal death following H1N1 influenza vaccination; a population based cohort study in the UK GPRD.

BACKGROUND: To evaluate the risk of foetal loss associated with pandemic influenza vaccination in pregnancy. Retrospective cohort study. UK General Practice Research Database Pregnancies ending in delivery or spontaneous foetal death after 21 October 2009 and starting before 01 January 2010. METHODOLOGY/PRINCIPAL FINDINGS: Hazard ratios of foetal death for vaccinated compared to unvaccinated pregnancies were estimated for gestational weeks 9 to 12, 13 to 24 and 25 to 43 using discrete-time survival analysis. Separate models were specified to evaluate whether the potential effect of vaccination on foetal loss might be transient (for ~4 weeks post vaccination only) or more permanent (for the duration of the pregnancy). 39,863 pregnancies meeting our inclusion criteria contributed a total of 969,322 gestational weeks during the study period. 9,445 of the women were vaccinated before or during pregnancy. When the potential effect of vaccination was assumed to be transient, the hazard of foetal death during gestational weeks 9 through 12 (HR(unadj) 0.56; CI(95) 0.43 to 0.73) and 13 through 24 (HR(unadj) 0.45; CI(95) 0.28 to 0.73) was lower in the 4 weeks after vaccination than in other weeks. Where the more permanent exposure definition was specified, vaccinated pregnancies also had a lower hazard of foetal loss than unvaccinated pregnancies in gestational weeks 9 through 12 (HR(unadj) 0.74; CI(95) 0.62 to 0.88) and 13 through 24 (HR(unadj) 0.59; CI(95) 0.45 to 0.77). There was no difference in the hazard of foetal loss during weeks 25 to 43 in either model. Sensitivity analyses suggest the strong protective associations observed may be due in part to unmeasured confounding. CONCLUSIONS/SIGNIFICANCE: Influenza vaccination during pregnancy does not appear to increase the risk of foetal death. This study therefore supports the continued recommendation of influenza vaccination of pregnant women.

Factors associated with uptake of seasonal and pandemic influenza vaccine among clinical risk groups in the UK: an analysis using the General Practice Research Database.

BACKGROUND: Influenza vaccine uptake rates are low compared with uptake rates of many other vaccines. It is unclear how this differs between risk groups in the population and between pandemic and non-pandemic influenza vaccines. AIM: This study sought to estimate uptake rates of pandemic and seasonal influenza vaccines among clinical risk groups in the UK during the 2009/2010 influenza season and to identify predictors of vaccine uptake in this cohort. METHODS: Uptake rates were calculated using data from the UK General Practice Research Database (GPRD). Predictors of vaccination were identified using a modified Poisson regression with robust standard error estimates. RESULTS: Uptake of pandemic influenza vaccine in clinical risk groups was 40.3% and uptake of seasonal influenza vaccine was 61.3%. Factors found to be predictive of seasonal and pandemic influenza vaccination included age and the total number of underlying health conditions an individual had. At risk individuals in those age groups in which universal vaccination of the general population was recommended were more likely to have been vaccinated than individuals in age groups in which only clinical risk groups were recommended for vaccination; hence children in clinical risk groups were more likely to receive pandemic than seasonal influenza vaccine. In older people, having a history of Guillain Barré syndrome was associated with a reduced likelihood of receipt of both seasonal (IRR(adj) 0.83, CI(95) 0.77-0.90) and pandemic influenza vaccines (IRR(adj) 0.82, CI(95) 0.73-0.92). DISCUSSION: Uptake of pandemic influenza vaccine was lower than that of seasonal influenza vaccine among those at a clinically high risk of influenza related morbidity. This suggests that vaccination strategies may need to be altered during future pandemics. Recommending universal vaccination within age categories in which there is a large proportion of high risk individuals could be considered as this may result in higher uptake among clinical risk groups.

Comparing the General Practice Research Database and the UK Epilepsy and Pregnancy Register as tools for postmarketing teratogen surveillance: anticonvulsants and the risk of major congenital malformations.

BACKGROUND: Use of pregnancy registries is a common method of postmarketing surveillance of pregnancy outcomes to identify potential teratogens. However, with the increase in electronic capture of healthcare data for administrative, audit and research purposes, data generated during routine clinical practice might be used to address questions similar to those explored using pregnancy registries. OBJECTIVES: To establish how data from the UK General Practice Research Database (GPRD) compares with data from the UK Epilepsy and Pregnancy Register and to assess how it can contribute to postmarketing surveillance of pregnancy outcomes. METHODS: Pregnancy outcomes were identified from the GPRD for women aged 14-49 years with a diagnosis of epilepsy and supporting evidence. Outcomes with a major congenital malformation (MCM) were identified and the relative risks (RRs) of an MCM following a range of first-trimester antiepileptic drug (AED) exposures were calculated and compared with those reported by the UK Epilepsy and Pregnancy Register. In addition, we also evaluated whether the known association between valproate and spina bifida could be identified using data from the GPRD. The study period ran from 1 January 1990 until 31 December 2006. RESULTS: A total of 1766 live mother-baby pairs were identified, as well as 551 pregnancy terminations, 13 stillbirths and 1 neonatal death. Including those that resulted in a termination, there were 62 unique pregnancy outcomes with an MCM. An increased risk of spina bifida was identified using the GPRD following first-trimester monotherapy exposure to valproate when compared with those with no AED exposure (RR 8.02; 95% CI 1.5, 43.5). More generally, comparing the GPRD with the UK register, the GPRD ascertained a lower number of first-trimester AED exposures: monotherapy 711 versus 2468; polytherapy 156 versus 718. We reproduced the UK register results of an increased MCM risk following first-trimester polytherapy AED exposure compared with no AED exposure (RR 2.89; 95% CI 1.43, 5.84). Using the GPRD, we identified similar point estimates to the UK register following monotherapy and polytherapy exposures (4.1% vs 3.7% and 7.1% vs 6.0%, respectively) but we were unable to reproduce the level of statistical significance. For individual AEDs, the MCM rate following valproate exposure was 4.9% (11/225) in the GPRD compared with 6.2% (44/715) in the UK register. CONCLUSIONS: The GPRD has potential for the identification of malformations and of a teratogenic association. For epilepsy, the GPRD does, however, identify fewer exposed pregnancies than a pregnancy registry. Therefore, in many circumstances pregnancy registries are likely to remain preferable as a method of surveillance. The GPRD may be better suited to monitoring medicines used in the treatment of more prevalent conditions, such as depression, or for monitoring medicines that have been on the market for a long time and for which no registry has been set up.