Distribution of gestational age at birth by maternal and infant characteristics in U.S. birth certificate data: Informing gestational age assumptions when clinical estimates are not available.

PURPOSE: We aimed to describe the distribution of gestational age at birth (GAB) to inform the estimation of GAB when clinical or obstetric estimates are not available for perinatal pharmacoepidemiology studies. METHODS: We estimated GAB (median, mode, mean, and standard deviation) and percentage born at each gestational week in groups based on plurality and other variables for live births in CDC's U.S. birth data. RESULTS: In 2020, 3 617 213 newborns had birth certificates with nonmissing GAB. Among singletons (3 501 693), median and mode GAB were both 39 weeks. Births with lower median GAB were from women with eclampsia (37 weeks) or receiving intensive care (37 weeks); newborns receiving intensive care (37 weeks); newborns with birth weight <2500 g (35 weeks), <1500 g (28 weeks), or <1000 g (25 weeks); and newborns not discharged alive (23 weeks). Among twins (112 633), median GAB was 36 weeks (mode, 37 weeks). Additional noteworthy groups were women with 0-6 prenatal visits (median, 34 weeks) or 7-8 prenatal visits (median, 35 weeks) or aged 15-19 years (median, 35 weeks). CONCLUSIONS: Some maternal and infant groups had distinct GAB distributions in the United States. This information can be useful in estimating GAB when individual-level clinical estimates are not available, such as in database studies of medication use during pregnancy.

Perinatal pharmacoepidemiology: How often are key methodological elements reported in publications?

PURPOSE: Publications provide important information for clinicians, researchers, and patients. Key methodological elements must be reported for maximum transparency. We identified key methodological elements necessary for fully understanding perinatal pharmacoepidemiology research and quantified the proportion of studies that reported these elements in a sample of publications. METHODS: Key methodological elements were identified from guidelines from regulatory agencies, literature, and subject-matter knowledge: source of information to determine pregnancy start; mother- or father-infant linkages (process, success rate); unit of analysis; and whether non-live births and fetuses with various anomalies were included in the study population. We conducted a literature review for recent observational studies on medical product utilization or safety during pregnancy and estimated the prevalence of reporting these elements. RESULTS: Data were extracted from a random sample of 100 publications; 8% were published in epidemiology/pharmacoepidemiology journals; 85% were medical product-safety studies. Of publications for which each element was applicable, 43% reported the source for determining pregnancy start; 57%, whether the study population included multifetal pregnancies; 39%, whether it included more than one pregnancy per woman; 27%, whether it included fetuses with chromosomal abnormalities; 60%, fetuses with major congenital malformations; and 93%, non-live births. Of the 20 studies with mother-infant linkage, 35% described the process; 21% reported the linkage success rate. Among studies with more than one pregnancy/offspring per woman, 22% reported methods addressing sibling correlation. CONCLUSIONS: In this sample of pregnancy-related pharmacoepidemiology publications, completeness of reporting could have been improved. A pregnancy-specific checklist would increase transparency in the dissemination of study results.

Ivabradine drug utilization study in five European countries: A multinational, retrospective, observational study to assess effectiveness of risk-minimization measures.

PURPOSE: This drug utilization study of ivabradine evaluated prescriber compliance with the new risk minimization measures (RMMs), communicated starting 2014 following preliminary results from the SIGNIFY study. METHODS: This was a multinational (five European countries) chart review study with two study periods: pre-RMM and post-RMM. Patients initiating ivabradine for chronic stable angina pectoris in routine clinical practice were identified across general practitioners and specialists. The primary outcome analysis evaluated the compliance with the new RMMs, ie, use in patients with a heart rate greater than or equal to 70 bpm at initiation, no doses higher than those recommended in the summary of product characteristics (SmPC) at initiation and during 6 months of follow-up, and no concomitant use of verapamil or diltiazem. RESULTS: Overall, 711 and 506 eligible patients were included in the pre-RMM and post-RMM periods, respectively. The percentage of patients prescribed ivabradine according to the new RMMs increased significantly in the post-RMM period (70.6% and 78.4% in the pre- and post-RMM periods respectively; P value = .0035). The compliance to RMMs increased for all the criteria assessed independently: the proportions of patients with (a) heart rate ≥ 70 bpm at initiation (79.4% and 85.2%, respectively; P value = .0141), (b) no dose higher than the SmPC doses at initiation and during follow-up (92.8% and 94.1%, respectively; P value = .3957), and (c) no concomitance with verapamil or diltiazem (96.1% and 99.2%, respectively; P value = .0007). CONCLUSIONS: The RMMs for ivabradine were well implemented across the five participating European countries confirming a favorable benefit-risk balance of ivabradine in chronic stable angina pectoris.

Challenges of evaluating chronic heart failure and acute heart failure events in research studies using large health care databases.

Epidemiological studies on heart failure (HF) using large health care databases are becoming increasingly frequent, as they represent an invaluable opportunity to characterize the importance and risk factors of HF from a population perspective. Nevertheless, because of its complex diagnosis and natural history, the heterogeneous use of the relevant terminology in routine clinical practice, and the limitations of some disease coding systems, HF can be a challenging condition to assess using large health care databases as the main source of information. In this narrative review, we discuss some of the challenges that researchers may face, with a special focus on the identification and validation of chronic HF cases and acute HF decompensations. For each of these challenges, we present some potential solutions inspired by the literature and/or based on our research experience, aimed at increasing the internal validity of research and at informing its interpretation. We also discuss future directions on the field, presenting constructive recommendations aimed at facilitating the conduct of valid epidemiological studies on HF in the coming years.

Risk Assessment of Acute Myocardial Infarction and Stroke Associated with Long-Acting Muscarinic Antagonists, Alone or in Combination, versus Long-Acting beta2-Agonists.

Background: The long-acting muscarinic antagonist (LAMA) aclidinium was approved in Europe in 2012 to relieve symptoms in adult patients with chronic obstructive pulmonary disease (COPD). A post-authorization safety study was initiated to assess potential cardiovascular risks associated with LAMAs versus long-acting beta2-agonists. Purpose: To estimate incidence rates and adjusted incidence rate ratios (IRRs) for acute myocardial infarction (AMI), stroke, and major adverse cardiac events (MACE) in new users of aclidinium, aclidinium/formoterol, tiotropium, other LAMA, long-acting beta-agonists/inhaled corticosteroids (LABA/ICS), and LAMA/LABA compared with initiators of LABA. Patients and Methods: This population-based cohort study included patients with COPD aged ≥40 years initiating COPD medications in the UK Clinical Practice Research Datalink (CPRD) Aurum database from 2012 to 2019. Poisson regression models were used to estimate the IRR for AMI, stroke, and MACE in users of COPD medications versus LABA, adjusting for clinically relevant covariables. Results: The study included 11,121 new users of aclidinium, 4804 of aclidinium/formoterol, 56,198 of tiotropium, 23,856 of other LAMA, 17,450 of LAMA/LABA, 70,289 of LABA/ICS, and 13,716 of LABA. During periods of continuous medication use after initiation (current use), crude incidence rates per 1000 person-years for AMI ranged from 8.7 (aclidinium/formoterol) to 12.4 (LAMA/LABA), for stroke ranged from 4.8 (aclidinium/formoterol) to 7.2 (LAMA/LABA), and for MACE ranged from 13.5 (aclidinium/formoterol) to 19.3 (LAMA/LABA). Using LABA as reference, adjusted IRRs [95% confidence intervals] were close to 1 for all study drugs for AMI (lowest for aclidinium/formoterol, 0.95 [0.60-1.52], and highest for LAMA/LABA, 1.23 [0.91-1.67]), stroke (lowest for aclidinium/formoterol, 0.64 [0.39-1.06], and highest for tiotropium, 1.02 [0.81-1.27] for tiotropium) and for MACE (lowest for aclidinium, 0.93 [0.75-1.16], and highest for LAMA/LABA, 1.24 [0.97-1.59]). Conclusion: Risks of AMI, stroke, and MACE in current users of aclidinium, aclidinium/formoterol, tiotropium, other LAMA, LAMA/LABA, or LABA/ICS were similar to the risks among current users of LABA.

Characteristics of New Users of Aclidinium Bromide, Aclidinium/Formoterol, and Other COPD Medications in the United Kingdom, Denmark, and Germany.

BACKGROUND AND OBJECTIVES: Aclidinium bromide was approved in the European Union for the treatment of chronic obstructive pulmonary disease (COPD) in adult patients in 2012 and in a fixed-dose combination with formoterol in 2014. We characterised new users of aclidinium, aclidinium/formoterol and other COPD medications and evaluated off-label prescribing of these medications in three European populations. METHODS: We described demographic characteristics, comorbidities, comedications, COPD severity and off-label prescribing of new users of aclidinium, aclidinium/formoterol and other COPD medications in patients with COPD aged ≥ 40 years in the Clinical Practice Research Datalink (CPRD, UK), Danish National Health Databases, and German Pharmacoepidemiological Research Database (GePaRD) between 2015 and 2017. RESULTS: We included 17,668 new users of aclidinium (CPRD, 4871; Denmark, 2836; GePaRD, 9961) and 14,808 new users of aclidinium/formoterol (CPRD, 2153; Denmark, 2586; GePaRD, 10,069). Study patients were of similar age, except in GePaRD, where users of long-acting beta2-agonists (LABA)/inhaled corticosteroids were younger. Patients had multiple comorbidities and used multiple comedications-most frequently hypertension (50-79%) and short-acting beta2-agonists (26-84%). Aclidinium users in CPRD and long-acting anticholinergics/LABA users in Denmark and GePaRD had the highest frequency of severe/very severe COPD. Off-label prescribing of aclidinium (5.0% [CPRD]-8.9% [Denmark]) and aclidinium/formoterol (2.6% [GePaRD]-3.2% [CPRD]) was low, and the main reason was asthma without a COPD diagnosis. CONCLUSIONS: Aclidinium and aclidinium/formoterol were mostly prescribed according to label, with preference given to older patients with more severe COPD and to patients with a high prevalence of comorbidities and comedication use.

A Cohort Study to Evaluate the Risk of Hospitalisation for Congestive Heart Failure Associated with the Use of Aclidinium and Other Chronic Obstructive Pulmonary Disease Medications in the UK Clinical Practice Research Datalink.

BACKGROUND: The long-acting anticholinergic (LAMA) aclidinium was approved in Europe in 2012 to relieve symptoms in adults with chronic obstructive pulmonary disease (COPD). A Post-Authorisation Safety Study (PASS) was initiated to assess potential cardiovascular safety concerns for aclidinium. OBJECTIVE: To estimate the adjusted incidence rate ratio (IRR) for hospitalisation for heart failure in patients with COPD who were new users of aclidinium, tiotropium, other LAMA, long-acting beta-agonists/inhaled corticosteroids (LABA/ICS), and LAMA/LABA were compared with initiators of LABA. METHODS: This population-based cohort study included patients with COPD aged ≥40 years initiating COPD medications in the Clinical Practice Research Datalink (CPRD) GOLD in the United Kingdom from 2012 to 2017. Medications were identified via general practice prescriptions. The first-ever hospitalisations for heart failure were identified in the Hospital Episode Statistics, and general practitioner records from the CPRD. Poisson regression models were used to estimate the IRR for hospitalisation for heart failure in users of COPD medications versus LABA, adjusting for clinically relevant covariates. RESULTS: The study included 4350 new users of aclidinium, 23,405 of tiotropium, 6977 of other LAMAs, 3122 of LAMA/LABA, 26,093 of LABA/ICS, and 5678 of LABA. Mean age was 69-70 years across medication groups. Aclidinium users had the highest proportion of severe COPD, and LABA users had the lowest (35% vs 19%, respectively). Crude incidence rates per 1000 person-years for the first-ever hospitalisation for heart failure ranged from 6.9 in LABA to 9.5 in aclidinium. Using LABA as reference, adjusted IRRs (95% confidence interval) for first-ever hospitalisation for heart failure were 0.90 (0.53-1.53) for aclidinium, 1.02 (0.69-1.51) for tiotropium, 0.86 (0.50-1.47) for other LAMAs, 1.09 (0.41-2.92) for LAMA/LABA, and 1.01 (0.69, 1.48) for LABA/ICS. CONCLUSION: The study did not find increased risks of hospitalisations for heart failure in new users of aclidinium, tiotropium, other LAMAs, LAMA/LABA, and LABA/ICS compared with LABA.

Evaluating the Safety of Medication Exposures During Pregnancy: A Case Study of Study Designs and Data Sources in Multiple Sclerosis.

BACKGROUND: Regulatory agencies often request prospective, product-specific post-authorization pregnancy exposure registries to monitor safety during pregnancy, even though studies using existing health databases could also be employed. OBJECTIVES: Using multiple sclerosis (MS) as a case study, we evaluated various study designs and data sources previously used to study medication exposure in pregnancy. METHODS: We examined (1) strengths and limitations of study designs used for pregnancy safety studies in women exposed to MS-specific medications during pregnancy and (2) existing data sources used to conduct such studies in other disease areas. For the data sources identified, we contacted data custodians to determine the feasibility of assessing the risk of adverse outcomes in women with MS exposed to disease-modifying therapies (DMTs) during pregnancy. RESULTS: Of 43 MS-specific studies identified, most of which were prospective registries, very few, regardless of design and study population, produced timely and robust results for spontaneous abortions and major congenital malformations, considering study duration, achievement of target enrollment numbers, inclusion of internal comparators, and publication of results. Building on the successful use of existing healthcare databases to investigate drug safety during pregnancy in other disease areas, we identified 13 data sources that could be used to study intravenous DMT exposures in women with MS. CONCLUSIONS: Prospective, treatment-specific registries have generally failed to deliver robust information. For this reason, other study approaches, in particular cohort studies using existing healthcare databases, should be considered for evaluating the safety of drug exposure in pregnancy, including in MS.

Risk factors for diabetic retinopathy in people with Type 2 diabetes: A case-control study in a UK primary care setting.

AIM: To identify risk factors of diabetic retinopathy (DR) among people with Type 2 diabetes mellitus in UK primary care. METHODS: A case-control study nested in a cohort of incident Type 2 diabetes identified in The Health Improvement Network database from 2000 to 2007. Cases were people with DR (N=7735) and controls were a DR-free sample (N=9395). No age restrictions were applied. Adjusted odds ratios and 95% CIs were estimated. RESULTS: 21% of DR cases were identified during the first semester after Type 2 diabetes diagnosis. After controlling for delay on the Type 2 diabetes diagnosis, the DR risk increased with the duration of diabetes. DR increased with a mean systolic BP ≥150mmHg (1.18; 1.10-1.27), high alcohol consumption (1.34; 1.11-1.61), glycated haemoglobin (≥75 to <86: 1.14; 1.00-1.31; ≥86 to <97mmol/mol: 1.25; 1.07-1.45; ≥97mmol/mol: 1.21; 1.07-1.37), microalbuminuria (1.16; 1.06-1.27), and retinal vein occlusion (2.47; 1.67-3.66). Glaucoma and retinal arterial occlusion showed an OR of 0.71 (0.60-0.84) and 0.63 (0.40-1.01), respectively. HDL ≥1.55mmol/l (0.88; 0.80-0.98), high triglycerides (2.3-5.6mmol/l: 0.90; 0.82-0.99; >5.6mmol/l: 0.85; 0.64-1.13) or smoking (0.89; 0.81-0.97) had a slightly reduced DR risk. Users of hypoglycaemic agents had an increased DR risk. CONCLUSION: Some DR cases were identified near the diabetes diagnosis date suggesting that a delayed diabetes diagnosis is still common. Glaucoma, retinal arterial occlusion and high HDL levels were inversely associated with DR, while retinal vein occlusion, alcohol and other well-known risk factors were positively associated.

Incidence of retinal complications in a cohort of newly diagnosed diabetic patients.

PURPOSE: We aimed at estimating the incidence of diabetic retinopathy (DR) and maculopathy (DMP) among newly diagnosed type 1 (t1DM) and type 2 diabetic patients (t2DM) in the United Kingdom primary care system. The incidence of DMP among patients with DR was also estimated. METHOD: We conducted a cohort study using The Health Improvement Network database. The cohort included 64,983 incident diabetic patients (97.3% were t2DM) aged 1-84 years diagnosed between 2000 and 2007. This cohort was followed from the date of diabetes diagnosis until recording of DR or DMP in two separate follow-ups. Follow-up was censored at 85 years of age, death, or end of 2008. An additional follow-up was conducted from DR to DMP diagnosis using similar censoring reasons. DR and DMP cumulative incidences were calculated as well as incidence rates (IR; cases per 1,000 person-years) per calendar period (2000-2001 and 2006-2007). RESULTS: Follow-up for DR: 9 years after diabetes diagnosis, 28% of t2DM and 24% of t1DM patients had developed DR (7,899 incident DR cases). During the first 2 years with diabetes, the IR was almost 2 times higher in patients diagnosed with diabetes in 2006-2007 (47.7) than among those diagnosed in 2000-2001 (24.5). Follow-up for DMP: 9 years after diabetes diagnosis, 3.6% of t2DM and 4.4% of t2DM patients had developed DMP (912 incident DMP cases). During the first 2 years with diabetes, the IR was three times higher in patients diagnosed with diabetes in 2006-2007 (5.8) than among those diagnosed in 2000-2001 (1.8). Macular oedema occurred in 0.8% of patients. CONCLUSIONS: In a cohort of incident diabetes, 28% of patients developed retinopathy and 4% maculopathy within the first 9 years. The 2-year IRs of DR and DMP were higher in patients diagnosed with diabetes during the period 2006-2007 than in those diagnosed during the 2000-2001 period.