Changes in the incidence and prevalence of systemic lupus erythematosus between 1990 and 2020: an observational study using the Clinical Practice Research Datalink (CPRD).

OBJECTIVE: To obtain updated estimates on the incidence and prevalence of systemic lupus erythematosus (SLE) in the UK, over the period 1990-2020, using the Clinical Practice Research Datalink (CPRD). METHODS: This was a retrospective cohort study using the CPRD covering the period 1990-2020. A case ascertainment algorithm was developed in line with best practice recommendations for observational research. Incidence was calculated per 100 000 person-years and point prevalence (at the mid-year point) calculated per 100 000. Results were stratified by sex. RESULTS: 9443 SLE cases were identified. 5278 incident cases were identified (4538 women, 740 men). The overall incidence rate was 5.47 (95% CI 5.33 to 5.62) cases per 100 000 person-years. Incidence rates decreased slightly across the study period, which was more pronounced for women than men. Point prevalence increased over time, from 21.4 (95% CI 17.68 to 25.67) per 100 000 in 1990 to 107.14 (95% CI 103.26 to 111.12) per 100 000 in 2020. CONCLUSIONS: The observed fivefold increase in prevalence of SLE over the last 30 years, in the context of a modest decline in incidence rate, may suggest improved outcomes in SLE and has important implications for healthcare service delivery and planning in the UK.

Tumor Necrosis Factor Inhibitor Monotherapy Versus Combination Therapy for the Treatment of Psoriatic Arthritis: Combined Analysis of European Biologics Databases.

OBJECTIVE: To investigate whether tumor necrosis factor inhibitor (TNFi) combination therapy with conventional synthetic disease-modifying antirheumatic drugs (csDMARD) is more effective for psoriatic arthritis (PsA) and/or improves TNFi drug survival compared to TNFi monotherapy. METHODS: Five PsA biologics cohorts were investigated between 2000 and 2015: the ATTRA registry (Czech Republic); the Swiss Clinical Quality Management PsA registry; the Hellenic Registry of Biologics Therapies (Greece); the University of Bari PsA biologics database (Italy); and the Bath PsA cohort (UK). Drug persistence was analyzed using Kaplan-Meier and equality of survival using log-rank tests. Comparative effectiveness was investigated using logistic regression with propensity scores. Separate analyses were performed on (1) the combined Italian/Swiss cohorts for change in rate of Disease Activity Score in 28 joints (DAS28); and (2) the combined Italian, Swiss, and Bath cohorts for change in rate of Health Assessment Questionnaire (HAQ). RESULTS: In total, 2294 patients were eligible for the drug survival analysis. In the Swiss (P = 0.002), Greek (P = 0.021), and Bath (P = 0.014) databases, patients starting TNFi in combination with methotrexate had longer drug survival compared to monotherapy, while in Italy the monotherapy group persisted longer (P = 0.030). In eligible patients from the combined Italian/Swiss dataset (n = 1056), there was no significant difference between treatment arms in rate of change of DAS28. Similarly, when also including the Bath cohort (n = 1205), there was no significant difference in rate of change of HAQ. CONCLUSION: Combination therapy of a TNFi with a csDMARD does not appear to affect improvement of disease activity or HAQ versus TNFi monotherapy, but it may improve TNFi drug survival.

Risk of Osteoarthritis in an Incident Cohort of People With Psoriatic Arthritis: A Population-based Cohort Study.

OBJECTIVE: To determine the risk of a diagnosis of osteoarthritis (OA) in patients with psoriatic arthritis (PsA) compared to patients with psoriasis and a general population cohort. METHODS: Incident PsA patients aged 18-89 years at diagnosis were identified from the United Kingdom Clinical Practice Research Datalink between 1998 and 2014. All patients with PsA were matched to 2 cohorts of patients, both at a 1:4 ratio. The first cohort included patients with psoriasis (and no PsA) and the second was a general population cohort (with no psoriasis or PsA). The baseline prevalence of OA was calculated for each study cohort. The incidence of OA was calculated, and adjusted relative risks (RRadj) were calculated using conditional Poisson regression. RESULTS: We identified 6783 incident PsA patients. The baseline prevalence of OA ranged from 22.1% (95% CI 21.1-23.1) in the PsA cohort to 12.6% (95% CI 12.2-13.0) and 11.0% (95% CI 10.6-11.3) in the psoriasis and general population cohorts, respectively. The incidence of OA was significantly higher in the PsA cohort compared to the psoriasis and general population cohorts after adjusting for BMI (RRadj 1.68, 95% CI 1.46-1.93, and RRadj 1.86, 95% CI 1.62-2.14, respectively). CONCLUSION: An increased risk of OA was observed in patients with PsA compared to patients with psoriasis alone and those in the general population. Further work is needed to determine whether this reflects a true increase in OA risk or misdiagnosed PsA, and the extent to which it can be explained by differences in the opportunity for OA diagnosis between cohorts.

Prescription of antiepileptic medicines including valproate in pregnant women: A study in three European countries.

PURPOSE: To study patterns of antiepileptic drugs (AED) prescribing, particularly valproate, during pregnancy over a 10-year period in the UK, Italy, and France. METHODS: Data on pregnancies conceived after 1 January 2007 with outcomes before 31 December 2016 were extracted from four European electronic health care databases (380 499 in the United Kingdom (UK), 66 681 in France, and 649 918 in Italy [355 767 in Emilia Romagna and 294 151 in Tuscany]). Prevalence of AEDs with an ATC code starting N03A and clobazam (N05BA09) were stratified by country and calendar year. RESULTS: AED prescribing during pregnancy varied from 3.0 (2.8-3.1) per 1000 pregnancies in Emilia Romagna to 7.8 (7.5-8.0) in the UK, 5.9 (5.6-6.1) in Tuscany, and 6.3 (5.7-6.9) in France. Lamotrigine was commonly prescribed in all regions with a third of women exposed to an AED during pregnancy taking lamotrigine in the UK and France. Valproate was prescribed to 28.6% of AED exposed pregnant women in Tuscany, 21.6% in France, 16.7% in Emilia Romagna, and 11.9% in the UK. Over the study period, the prevalence of AED prescribing increased in the UK mainly due to increases in pregabalin and gabapentin, declined in France mainly related to decreases in clonazepam, and remained constant in Italy. Valproate prescriptions declined to a prevalence <1 per 1000 pregnancies in 2015 to 2016 in the UK, France, and Emilia Romagna. CONCLUSIONS: Variations in AED prescribing during pregnancy indicate the potential for further reductions, particularly of valproate. Increases in pregabalin/gabapentin prescribing, for which risks are not well known, are a cause for concern.

Did advice on the prescription of sodium valproate reduce prescriptions to women? An observational study in three European countries between 2007 and 2016.

OBJECTIVES: In November 2014, the CMDh (a regulatory body representing EU Member States) advised doctors not to prescribe sodium valproate for epilepsy or bipolar disorder in preg nant women, in women who can become pregnant, or in girls unless other treatments are ineffective or not tolerated. This study aimed to determine if this warning led to changes in prescription patterns. DESIGN AND SETTING: Cohort of 5.4 million women aged between 10 and 50 years identified in electronic health care data from United Kingdom, France, and Italy (2007-2016). MAIN OUTCOME MEASURES: Anti-epileptic drug (AED) prescriptions. RESULTS: The prevalence of women receiving AED prescriptions in 2016 varied from 12.2 per 1000 to 29 per 1000 in the four regions. The incidence of prescribing any AED (excluding clonazepam, gabapentin, and pregabalin) fell each year on average by 7.5% (95% CI, 7.0%-8.0%; Emilia Romagna), 9.6% (8.3%-11.0%; France), 7.1% (6.7%-7.6%; Tuscany), and 0.4% (0.2%-1.0%; United Kingdom). The relative odds of prescribing sodium valproate rather than any other AED decreased more after 2014 compared with before the end of 2014 in France (OR = 0.77; 95% CI, 0.60-0.98), Tuscany (0.81; 0.76-0.86), Emilia Romagna (0.83; 0.76-0.90), and the United Kingdom (0.92; 0.80-1.06; not statistically significant). CONCLUSIONS: There is evidence that the CMDh warning did lead to changes in prescription patterns of sodium valproate in women of childbearing age. There were considerable differences in prescribing practice amongst regions of Europe.

Risk of type 2 diabetes and cardiovascular disease in an incident cohort of people with psoriatic arthritis: a population-based cohort study.

Objectives: To determine the risk of type 2 diabetes (T2D) and cardiovascular diseases in PsA patients compared with the general population and patients with psoriasis. Methods: Incident PsA patients aged 18-89 years were identified in the UK Clinical Practice Research Datalink between 1998 and 2014 and were matched (1:4 ratio) to a general population cohort and psoriasis cohort. The incidence of T2D, cerebrovascular disease, ischaemic heart disease and peripheral vascular disease (PVD) was calculated for each study cohort. Conditional Poisson regression was used to calculate adjusted relative risks. Results: We identified 6783 incident cases of PsA. The risk of T2D was significantly higher in the PsA cohort than in the general population and the psoriasis cohorts [adjusted relative risk 1.40 (CI95 1.15, 1.70) and adjusted relative risk 1.53 (CI95 1.19, 1.97), respectively]. The incidence of ischaemic heart disease, peripheral vascular disease and the three cardiovascular outcomes combined in the PsA cohort was significantly higher than in the general population. No significant differences in risk were observed between the PsA and psoriasis cohorts for any cardiovascular outcome. Conclusion: The development of T2D in an incident population of PsA is significantly higher than in psoriasis alone or in a general population, whereas the increased risk of cardiovascular disease in PsA and psoriasis is similar.

Risk of uveitis and inflammatory bowel disease in people with psoriatic arthritis: a population-based cohort study.

OBJECTIVES: To determine the risk of uveitis and inflammatory bowel disease (IBD) in patients with psoriatic arthritis (PsA) compared with the general population and patients with psoriasis. METHODS: A cohort study using data from the UK Clinical Practice Research Datalink between 1998 and 2014. Patients with incident PsA aged 18-89 years were identified and matched to a cohort of patients with psoriasis and a general population cohort. The incidence of uveitis, all IBD, Crohn's disease and ulcerative colitis was calculated for each study cohort and adjusted relative risks (RRadj) were calculated using conditional Poisson regression. RESULTS: 6783 incident cases of PsA were identified with a median age of 49 years. The risk of uveitis was significantly higher in the PsA cohort than in the general population and psoriasis cohorts (RRadj 3.55, 95% CI 2.21 to 5.70 and RRadj 2.13, 95% CI 1.40 to 3.24, respectively). A significant increase was observed for Crohn's disease (RRadj 2.96, 95% CI 1.46 to 6.00 and RRadj3.60, 95% CI 1.83 to 7.10) but not for ulcerative colitis (RRadj1.30, 95% CI 0.66 to 2.56 and RRadj0.98, 95% CI 0.50 to 1.92). CONCLUSIONS: In a primary care-based incidence cohort of patients with PsA, there were substantial risks of developing uveitis and/or Crohn's disease, but not ulcerative colitis, when compared with the general population and psoriasis controls.

Interval between onset of psoriasis and psoriatic arthritis comparing the UK Clinical Practice Research Datalink with a hospital-based cohort.

Objectives: To describe the time interval between the onset of psoriasis and PsA in the UK primary care setting and compare with a large, well-classified secondary care cohort. Methods: Patients with PsA and/or psoriasis were identified in the UK Clinical Practice Research Datalink (CPRD). The secondary care cohort comprised patients from the Bath PsA longitudinal observational cohort study. For incident PsA patients in the CPRD who also had a record of psoriasis, the time interval between PsA diagnosis and first psoriasis record was calculated. Comparisons were made with the time interval between diagnoses in the Bath cohort. Results: There were 5272 eligible PsA patients in the CPRD and 815 in the Bath cohort. In both cohorts, the majority of patients (82.3 and 61.3%, respectively) had psoriasis before their PsA diagnosis or within the same calendar year (10.5 and 23.8%), with only a minority receiving their PsA diagnosis first (7.1 and 14.8%). Excluding those who presented with arthritis before psoriasis, the median time between diagnoses was 8 years [interquartile range (IQR) 2-15] in the CPRD and 7 years (IQR 0-20) in the Bath cohort. In the CPRD, 60.1 and 75.1% received their PsA diagnosis within 10 and 15 years of their psoriasis diagnosis, respectively; this was comparable with 57.2 and 67.7% in the Bath cohort. Conclusion: A similar distribution for the time interval between psoriasis and arthritis was observed in the CPRD and secondary care cohort. These data can inform screening strategies and support the validity of data from each cohort.

Statins during pregnancy: a cohort study using the General Practice Research Database to investigate pregnancy loss.

PURPOSE: The aim of this study was to determine if there are any differences between the types of pregnancy loss experienced by women who have been prescribed a statin just before or early in pregnancy compared with those who have not. METHODS: A retrospective cohort study using the General Practice Research Database was carried out. Women aged 10-49 years at pregnancy start who received a prescription for a statin in the 3 months before and/or during the first trimester of pregnancy were matched to up to 10 pregnancies on age at start date, diabetes and hypertension status before pregnancy. Pregnancies occurring between 1/1/1992 and 31/3/2009 were included. Pregnancy losses were identified and categorised as spontaneous (including miscarriage), induced for medical, other or unknown reasons. Freetext was used to determine the type of loss where this was not clear from the coded medical records. RESULTS: Two hundred eighty-one pregnancies potentially exposed to statins were identified and matched to 2643 unexposed pregnancies. About 54.45% of pregnancies potentially exposed to a statin resulted in a delivery compared with 62.81% of those not exposed. 25.27% of all pregnancies potentially exposed to a statin resulted in a spontaneous loss compared with 20.81% in those not exposed. Using a time to event analysis with exposure as a time-dependent covariate gave an adjusted hazards ratio of 1.64 (95%CI 1.10 to 2.46) of spontaneous pregnancy loss in the statin exposed group. CONCLUSIONS: This study is the first to report the differences in types of pregnancy loss following the potential exposure to a statin just before or early in pregnancy. Copyright © 2017 John Wiley & Sons, Ltd.

Prescribing of Antidiabetic Medicines before, during and after Pregnancy: A Study in Seven European Regions.

AIM: To explore antidiabetic medicine prescribing to women before, during and after pregnancy in different regions of Europe. METHODS: A common protocol was implemented across seven databases in Denmark, Norway, The Netherlands, Italy (Emilia Romagna/Tuscany), Wales and the rest of the UK. Women with a pregnancy starting and ending between 2004 and 2010, (Denmark, 2004-2009; Norway, 2005-2010; Emilia Romagna, 2008-2010), which ended in a live or stillbirth, were identified. Prescriptions for antidiabetic medicines issued (UK) or dispensed (non-UK) during pregnancy and/or the year before or year after pregnancy were identified. Prescribing patterns were compared across databases and over calendar time. RESULTS: 1,082,673 live/stillbirths were identified. Pregestational insulin prescribing during the year before pregnancy ranged from 0.27% (CI95 0.25-0.30) in Tuscany to 0.45% (CI95 0.43-0.47) in Norway, and increased between 2004 and 2009 in all countries. During pregnancy, insulin prescribing peaked during the third trimester and increased over time; third trimester prescribing was highest in Tuscany (2.2%) and lowest in Denmark (0.5%). Of those prescribed an insulin during pregnancy, between 50.5% in Denmark and 88.8% in the Netherlands received an insulin analogue alone or in combination with human insulin, this proportion increasing over time. Oral products were mainly metformin and prescribing was highest in the 3 months before pregnancy. Metformin use during pregnancy increased in some countries. CONCLUSION: Pregestational diabetes is increasing in many areas of Europe. There is considerable variation between and within countries in the choice of medication for treating pregestational diabetes in pregnancy, including choice of insulin analogues and oral antidiabetics, and very large variation in the treatment of gestational diabetes despite international guidelines.

Asthma medication prescribing before, during and after pregnancy: a study in seven European regions.

OBJECTIVES: To explore utilisation patterns of asthma medication before, during and after pregnancy as recorded in seven European population-based databases. DESIGN: A descriptive drug utilisation study. SETTING: 7 electronic healthcare databases in Denmark, Norway, the Netherlands, Italy (Emilia Romagna and Tuscany), Wales, and the Clinical Practice Research Datalink representing the rest of the UK. PARTICIPANTS: All women with a pregnancy ending in a delivery that started and ended between 2004 and 2010, who had been present in the database for the year before, throughout and the year following pregnancy. MAIN OUTCOME MEASURES: The percentage of deliveries where the woman received an asthma medicine prescription, based on prescriptions issued (UK) or dispensed (non-UK), during the year before, throughout or during the year following pregnancy. Asthma medicine prescribing patterns were described for 3-month time periods and the choice of asthma medicine and changes in prescribing over the study period were evaluated in each database. RESULTS: In total, 1,165,435 deliveries were identified. The prevalence of asthma medication prescribing during pregnancy was highest in the UK and Wales databases (9.4% (CI95 9.3% to 9.6%) and 9.4% (CI95 9.1% to 9.6%), respectively) and lowest in the Norwegian database (3.7% (CI95 3.7% to 3.8%)). In the year before pregnancy, the prevalence of asthma medication prescribing remained constant in all regions. Prescribing levels peaked during the second trimester of pregnancy and were at their lowest during the 3-month period following delivery. A decline was observed, in all regions except the UK, in the prescribing of long-acting ß-2-agonists during pregnancy. During the 7-year study period, there were only small changes in prescribing patterns. CONCLUSIONS: Differences were found in the prevalence of prescribing of asthma medications during and surrounding pregnancy in Europe. Inhaled ß-2 agonists and inhaled corticosteroids were, however, the most popular therapeutic regimens in all databases.

Antiepileptic drug prescribing before, during and after pregnancy: a study in seven European regions.

PURPOSE: The aim of this study was to explore antiepileptic drug (AED) prescribing before, during and after pregnancy as recorded in seven population-based electronic healthcare databases. METHODS: Databases in Denmark, Norway, the Netherlands, Italy (Emilia Romagna/Tuscany), Wales and the Clinical Practice Research Datalink, representing the rest of the UK, were accessed for the study. Women with a pregnancy starting and ending between 2004 and 2010, which ended in a delivery, were identified. AED prescriptions issued (UK) or dispensed (non-UK) at any time during pregnancy and the 6 months before and after pregnancy were identified in each of the databases. AED prescribing patterns were analysed, and the choice of AEDs and co-prescribing of folic acid were evaluated. RESULTS: In total, 978 957 women with 1 248 713 deliveries were identified. In all regions, AED prescribing declined during pregnancy and was lowest during the third trimester, before returning to pre-pregnancy levels by 6 months following delivery. For all deliveries, the prevalence of AED prescribing during pregnancy was 51 per 10 000 pregnancies (CI95 49-52%) and was lowest in the Netherlands (43/10 000; CI95 33-54%) and highest in Wales (60/10 000; CI95 54-66%). In Denmark, Norway and the two UK databases lamotrigine was the most commonly prescribed AED; whereas in the Italian and Dutch databases, carbamazepine, valproate and phenobarbital were most frequently prescribed. Few women prescribed with AEDs in the 3 months before pregnancy were co-prescribed with high-dose folic acid: ranging from 1.0% (CI95 0.3-1.8%) in Emilia Romagna to 33.5% (CI95 28.7-38.4%) in Wales. CONCLUSION: The country's differences in prescribing patterns may suggest different use, knowledge or interpretation of the scientific evidence base. The low co-prescribing of folic acid indicates that more needs to be done to better inform clinicians and women of childbearing age taking AEDs about the need to offer and receive complete preconception care.

The incidence of childhood and adolescent seizures in the UK from 1999 to 2011: A retrospective cohort study using the Clinical Practice Research Datalink.

BACKGROUND: In postmarketing vaccine surveillance, adverse events observed in a vaccinated population are compared to the number expected based on a background incidence rate. The background rate should be accurate and obtained from a population comparable to the one vaccinated. Such rates are often not available. METHODS: The incidence rate of generalised convulsive, febrile and afebrile seizures was estimated in individuals born after 01-January-1998 and aged between 2 months and 15 years of age using the UK Clinical Practice Research Datalink (1999-2011). RESULTS: The study population consisted of 1532,992 individuals (4917,369 person years (PY) of follow up). A total of 28,917 generalised convulsive seizure events were identified during follow-up, the overall incidence rate was 5.88 per 1000PY. Age specific rates increased sharply from 4/1000PY at 2 months of age, peaked at 19/1000PY at 16 months and decreased until approximately 6 years of age at which point they became relatively stable at 2/1000PY. 67% of GCSs were categorised as febrile: 56% using Read codes, 11% using free text. Febrile seizures accounted for the age trend in GCS, with rates peaking at 16.1/1000PY at 16 months of age while afebrile seizure rates remained relatively stable across all ages (24 seizures per 1000PY). Analysis by first occurrence of febrile seizure showed a similar pattern, comparable to published studies on the incidence of seizures in childhood. DISCUSSION: The rates reported in this study could be used in the postmarketing surveillance of infant vaccines. However, given the variation across strata, and the potential underascertainment of seizure events presenting to A&E, care must be taken when interpreting and using these rates.

Safety of Fluticasone Propionate Prescribed for Asthma During Pregnancy: A UK Population-Based Cohort Study.

BACKGROUND: Asthma is commonly treated during pregnancy, yet data on the safety of asthma medicines used during pregnancy are sparse. OBJECTIVE: The objective of this study was to evaluate the safety of the inhaled corticosteroid (ICS) fluticasone propionate (FP), alone and in fixed-dose combination with salmeterol (FSC) in terms of the risk of all major congenital malformations (MCMs), compared with all other non-FP ICS. METHODS: Women with asthma who had a pregnancy between January 1, 2000, and December 31, 2010, were identified in the United Kingdom's Clinical Practice Research Datalink. Exposure to asthma medicines during the first trimester of pregnancy was based on issued prescriptions. The mothers' and infants' medical records were linked where possible, and pregnancy outcomes with an MCM diagnosed by age 1 year were identified based on medical codes in the mother's and infant's medical records, including those MCMs prenatally diagnosed that ended in an induced pregnancy termination. The absolute and relative risks of an MCM after different ICS exposures, stratified by the asthma treatment intensity level, were calculated. RESULTS: A total of 14,654 mother-infant pairs were identified, of which 6,174 received an ICS prescription during the first trimester, in addition to 13 first trimester ICS exposed pregnancies that ended in an induced termination after a prenatal MCM diagnosis. In total, 5,362 pregnancies were eligible for the primary analysis at age 1 year. The absolute risk of an MCM after any first trimester FP exposure was 2.4% (CI95 0.8-4.1) and 2.7% (CI95 1.8-3.6) for the "moderate" and "considerable/severe" asthma treatment intensity levels, respectively. The adjusted odds ratios when compared with non-FP ICS were 1.1 (CI95 0.5-2.3) and 1.2 (CI95 0.7-2.0) for the "moderate" and "considerable/severe" intensity levels; risks for any FP and for FSC did not differ substantially. CONCLUSION: No increase in the overall risk of MCMs was identified after first trimester FP exposure compared with non-FP ICS.

Beginning and duration of pregnancy in automated health care databases: review of estimation methods and validation results.

PURPOSE: To describe methods reported in the literature to estimate the beginning or duration of pregnancy in automated health care data, and to present results of validation exercises where available. METHODS: Papers reporting methods for determining the beginning or duration of pregnancy were identified based on Pubmed searches, by consulting investigators with expertise in the field and by reviewing conference abstracts and reference lists of relevant papers. From each paper or abstract, we extracted information to characterize the study population, data sources, and estimation algorithm. We then grouped these studies into categories reflecting their general methodological approach. RESULTS: Methods were classified into 5 categories: (i) methods that assign a uniform duration for all pregnancies, (ii) methods that assign pregnancy duration based on preterm-delivery or health care related codes, or codes for other pregnancy outcomes, (iii) methods based on the timing of prenatal care, (iv) methods based on birth weight, and (v) methods that combine elements from 2 and 3. Validation studies evaluating these methods used varied approaches, with results generally reporting on the mistiming of the start of pregnancy, incorrect estimation of the duration of pregnancy, or misclassification of drug exposure during pregnancy or early pregnancy. CONCLUSIONS: In the absence of accurate information on the beginning or duration of pregnancy, several methods of varying complexity are available to estimate them. Validation studies have been performed for many of them and can serve as a guide for method selection for a particular study.

The Clinical Practice Research Datalink for drug safety in pregnancy research: an overview.

Medicine use during pregnancy is common; however the safety of medicine use during pregnancy is largely unknown when a medicine comes to market. Electronic healthcare databases, including the Clinical Practice Research Datalink (CPRD), are increasingly being used for post-marketing surveillance in this field. The CPRD contains anonymised, longitudinal medical records routinely collected in primary care. Using CPRD data it is possible to identify medical records indicative of pregnancy, including pregnancy losses. Data on prescriptions issued can be used to determine maternal exposure and for about 80% of pregnancies it is possible to link the mother's medical record to the medical record of the child. Data in the medical records of the mother and child can then be used to identify adverse pregnancy outcomes, including congenital malformations. This paper describes some of the complexities involved in using CPRD data for pregnancy related research and discusses some of its strengths and limitations.

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.

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.

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.