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Regulatory agencies are increasingly considering real-world evidence (RWE) to support label expansions of approved medicines. We conducted a comparative effectiveness study to emulate a proposed randomized trial of romiplostim vs. standard-of-care (SOC) therapy among patients with recently diagnosed (≤12 months) immune thrombocytopenia (ITP), that could support expansion of the romiplostim label. We discuss challenges that we encountered and solutions that were developed to address those challenges. Study size was a primary concern, particularly for romiplostim initiators, given the rarity of ITP and the stringent trial eligibility criteria. For this reason, we leveraged multiple data sources (Nordic Country Patient Registry for Romiplostim; chart review study of romiplostim initiators in Europe; Flatiron Health EMR linked with MarketScan claims). Additionally, unlike the strictly controlled clinical trial setting, platelet counts were not measured at regular intervals in the observational data sources, and therefore the end point of durable platelet response often used in trials could not be reliably measured. Instead, the median platelet count was chosen as the primary end point. Ultimately, while we observed a slightly higher median platelet count in the romiplostim group vs. SOC, precision was limited because of small study size (median difference was 11 × 10 9 /L (95% CI: -59, 81)). We underscore the importance of conducting comprehensive feasibility assessments to identify fit-for-purpose data sources with sufficient sample size, data elements, and follow-up. Beyond technical challenges, we also discuss approaches to increase the credibility of RWE, including systematic incorporation of clinical expertise into study design decisions, and separation between decision makers and the data., (© 2021 The Authors. Clinical Pharmacology & Therapeutics © 2021 American Society for Clinical Pharmacology and Therapeutics.)

Purpose: We examined safety outcomes of interest (SOI) and overall survival (OS) among lung cancer patients initiating crizotinib and erlotinib in routine clinical practice., Methods: This descriptive cohort study used routinely collected health data in Denmark, Finland, Sweden, the Netherlands, and the United States (US) during 2011-2017, following crizotinib commercial availability in each country. Among crizotinib or erlotinib initiators, we reported baseline characteristics and incidence rates and cumulative incidences of the SOI - hepatotoxicity, pneumonitis/interstitial lung disease, QT interval prolongation-related events, bradycardia, vision disorders, renal cysts, edema, leukopenia, neuropathy, photosensitivity, malignant melanoma, gastrointestinal perforation, cardiac failure and OS. Results from the European Union (EU) countries were combined using meta-analysis; results from the US were reported separately., Results: There were 456 patients in the crizotinib cohort and 2957 patients in the erlotinib cohort. Rates of the SOI per 1000 person-years in the crizotinib cohort ranged from 0 to 65 in the EU and from 0 to 374 in the US. Rates of the SOI per 1000 person-years in the erlotinib cohort ranged from 0 to 91 in the EU and from 3 to 394 in the US. In the crizotinib cohort, 2-year OS was ~50% in both EU and US. In the erlotinib cohort, 2-year OS was 21% in the EU and 35% in the US., Conclusions: This study describes clinical outcomes among lung cancer patients initiating crizotinib or erlotinib in routine clinical practice. Differences between SOI rates in EU and US may be partially attributable to differences in the underlying databases., (© 2021 John Wiley & Sons Ltd.)

Purpose: Lack of control for time-varying exposures can lead to substantial bias in estimates of treatment effects. The aim of this study is to provide an overview and guidance on some of the available methodologies used to address problems related to time-varying exposure and confounding in pharmacoepidemiology and other observational studies. The methods are explored from a conceptual rather than an analytical perspective., Methods: The methods described in this study have been identified exploring the literature concerning to the time-varying exposure concept and basing the search on four fundamental pharmacoepidemiological problems, construction of treatment episodes, time-varying confounders, cumulative exposure and latency, and treatment switching., Results: A correct treatment episodes construction is fundamental to avoid bias in treatment effect estimates. Several methods exist to address time-varying covariates, but the complexity of the most advanced approaches-eg, marginal structural models or structural nested failure time models-and the lack of user-friendly statistical packages have prevented broader adoption of these methods. Consequently, simpler methods are most commonly used, including, for example, methods without any adjustment strategy and models with time-varying covariates. The magnitude of exposure needs to be considered and properly modelled., Conclusions: Further research on the application and implementation of the most complex methods is needed. Because different methods can lead to substantial differences in the treatment effect estimates, the application of several methods and comparison of the results is recommended. Treatment episodes estimation and exposure quantification are key parts in the estimation of treatment effects or associations of interest., (© 2017 The Authors. Pharmacoepidemiology & Drug Safety Published by John Wiley & Sons Ltd.)

Introduction: Consanguineous marriage is associated with increased risks for congenital anomalies, low birthweight, and other adverse perinatal outcomes. In this population-based, case-control study we investigated the association between consanguineous marriage (first-cousin marriage) and stillbirth risk, using prospectively collected information from prepregnancy visits., Material and Methods: From 2007 to 2009, we identified 283 stillbirths (cases) and 2088 randomly selected live control births through prepregnancy visits in rural Golestan, Iran. The associations between consanguinity and prepregnancy maternal characteristics and stillbirth risk were examined using multivariate logistic regression., Results: The rate of consanguineous marriage was 19.4% among cases and 13.6% among controls. Consanguinity was associated with increased stillbirth risk [odds ratio (OR) 1.53; 95% CI 1.10-2.14]. The association was significantly increased for preterm stillbirth (< 37 gestational weeks) (OR 2.43; 95% CI 1.46-4.04) but not for term stillbirth (≥ 37 weeks) (OR 1.14; 95% CI 0.75-1.74). Low and high maternal age, underweight, obesity, nulliparity, a history of infertility or miscarriage, previous obstetric complications (preeclampsia, preterm delivery, and stillbirth in previous pregnancies) were also associated with increased stillbirth risks., Conclusions: Consanguineous marriage is associated with increased risk of stillbirth, particularly preterm stillbirth. Findings for other maternal risk factors for stillbirth in rural Iran are consistent with previously reported findings from high-income countries., (© 2015 Nordic Federation of Societies of Obstetrics and Gynecology.)

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) might increase the risk of venous thromboembolism (VTE), and risks might differ by type of NSAID. Compared with men, women have a higher incidence of VTE at younger age, and they more often use NSAIDs., Objectives: To assess risks of VTE in young and middle-aged women in association with use of NSAIDs., Patients/methods: In a nationwide case–control study (Thrombo Embolism Hormone Study) performed in Sweden 2003–2009, we included as cases 1433 women, 18 to 64 years of age with a first time VTE. Controls were 1402 randomly selected women, frequency matched by age. Information was obtained by telephone interviews and DNA analyses of blood samples. We calculated adjusted odds ratios (ORs) with 95% confidence intervals (CIs) adjusting for degree of immobilization, chronic disease, smoking, body mass index, use of hormonal contraception, hormone therapy or other NSAIDs., Results: Use of NSAIDs was not associated with increased risks of VTE (OR = 0.98, 95% CI 0.80–1.19). The OR was 0.88 for propionic acid derivatives (95% CI 0.72–1.10), 1.18 for acetic acid derivatives (95% CI 0.82–1.70) and 1.76 for coxibs (95% CI 0.73–4.27). For users of acetic acid derivatives and coxibs, the ORs increased by cumulative dose. Carriership of the prothrombin gene mutation or factor V Leiden had only minor effects on the results., Conclusions: We found no increased risks of VTE in association with use of NSAIDs. Users of high cumulative doses of acetic acid derivatives and coxibs had the highest risks, suggesting a relationship with cyclooxygenase selectivity and dose.

Background: Appendicectomy for acute appendicitis, but not for other causes, is inversely associated with immune-mediated diseases such as ulcerative colitis, suggesting appendicitis is a marker of immune characteristics influencing immune-mediated disease risk. This study investigated the association of appendectomy and its underlying diagnosis with multiple sclerosis (MS)., Methods: Swedish general population registers and the Swedish MS register provided information on 20,542 cases with MS diagnosed between 1964-2006 and 204,157 controls matched for age, sex, period and region. Appendicectomy prior to MS diagnosis was identified in 673 cases and 6518 controls. Conditional logistic regression, with adjustment for socio-economic index, assessed the association of diagnosis underlying appendicitis with MS risk., Results: A perforated appendix, the best indicator of acute appendicitis in this material, was inversely associated with MS, although not statistically significantly, with an odds ratio (and 95% confidence interval of 0.86 (0.70-1.04). The odds ratios are 1.04 (0.94-1.16) for appendicitis without perforation and 1.14 (0.98-1.33) for appendectomy without appendicitis., Conclusion: Although inconclusive in terms of assessing the hypothesis, these results may help to explain why earlier studies of appendicitis and MS risk have been inconsistent, as there may be variation in association by diagnosis underlying appendicectomy., (© 2010 The Author(s). European Journal of Neurology © 2010 EFNS.)