The Medicines Intelligence Data Platform: A Population-Based Data Resource From New South Wales, Australia.

BACKGROUND: The Medicines Intelligence (MedIntel) Data Platform is an anonymised linked data resource designed to generate real-world evidence on prescribed medicine use, effectiveness, safety, costs and cost-effectiveness in Australia. RESULTS: The platform comprises Medicare-eligible people who are ≥18 years and residing in New South Wales (NSW), Australia, any time during 2005-2020, with linked administrative data on dispensed prescription medicines (Pharmaceutical Benefits Scheme), health service use (Medicare Benefits Schedule), emergency department visits (NSW Emergency Department Data Collection), hospitalisations (NSW Admitted Patient Data Collection) plus death (National Death Index) and cancer registrations (NSW Cancer Registry). Data are currently available to 2022, with approval to update the cohort and data collections annually. The platform includes 7.4 million unique people across all years, covering 36.9% of the Australian adult population; the overall population increased from 4.8 M in 2005 to 6.0 M in 2020. As of 1 January 2019 (the last pre-pandemic year), the cohort had a mean age of 48.7 years (51.1% female), with most people (4.4 M, 74.7%) residing in a major city. In 2019, 4.4 M people (73.3%) were dispensed a medicine, 1.2 M (20.5%) were hospitalised, 5.3 M (89.4%) had a GP or specialist appointment, and 54 003 people died. Anti-infectives were the most prevalent medicines dispensed to the cohort in 2019 (43.1%), followed by nervous system (32.2%) and cardiovascular system medicines (30.2%). CONCLUSION: The MedIntel Data Platform creates opportunities for national and international research collaborations and enables us to address contemporary clinically- and policy-relevant research questions about quality use of medicines and health outcomes in Australia and globally.

Assessing the Benefits and Harms of Pharmacotherapy in Older Adults with Frailty: Insights from Pharmacoepidemiologic Studies of Routine Health Care Data.

The objective of this review is to summarize and appraise the research methodology, emerging findings, and future directions in pharmacoepidemiologic studies assessing the benefits and harms of pharmacotherapies in older adults with different levels of frailty. Older adults living with frailty are at elevated risk for poor health outcomes and adverse effects from pharmacotherapy. However, current evidence is limited due to the under-enrollment of frail older adults and the lack of validated frailty assessments in clinical trials. Recent advancements in measuring frailty in administrative claims and electronic health records (database-derived frailty scores) have enabled researchers to identify patients with frailty and to evaluate the heterogeneity of treatment effects by patients' frailty levels using routine health care data. When selecting a database-derived frailty score, researchers must consider the type of data (e.g., different coding systems), the length of the predictor assessment period, the extent of validation against clinically validated frailty measures, and the possibility of surveillance bias arising from unequal access to care. We reviewed 13 pharmacoepidemiologic studies published on PubMed from 2013 to 2023 that evaluated the benefits and harms of cardiovascular medications, diabetes medications, anti-neoplastic agents, antipsychotic medications, and vaccines by frailty levels. These studies suggest that, while greater frailty is positively associated with adverse treatment outcomes, older adults with frailty can still benefit from pharmacotherapy. Therefore, we recommend routine frailty subgroup analyses in pharmacoepidemiologic studies. Despite data and design limitations, the findings from such studies may be informative to tailor pharmacotherapy for older adults across the frailty spectrum.

Power to the people: why person-generated health data are important for pharmacoepidemiology.

Person-generated health data (PGHD) are valuable for studying outcomes relevant to everyday living, for obtaining information not otherwise available, for long-term follow-up, and in situations where decisions cannot wait for traditional clinical research to be completed. While there is no dispute that these data are subject to bias, insights gained may be better than having an information void, provided the biases are understood and addressed. People will share information known uniquely to them about exposures that may affect drug tolerance, safety, and effectiveness (eg, nonprescription and complementary medications, alcohol, tobacco, illicit drugs, exercise, etc). Patients may be the best source of safety information when long-term follow-up is needed (eg, the 5- to 15-year follow-up required for some gene therapies). Validation studies must be performed to evaluate what people can accurately report and when supplementary confirmation information is needed. However, PGHD has already proven valuable in quantifying and contrasting COVID-19 vaccine benefits and risks and for evaluating disease transmission and the accuracy of COVID-19 testing. Going forward, PGHD will be used for patient-measured and patient-relevant outcomes, including for regulatory purposes, and will be linked to broader health data networks using tokenization, becoming a mainstay for signals about risks and benefits for diverse populations. This article is part of a Special Collection on Pharmacoepidemiology.

The application of lag times in cancer pharmacoepidemiology: a narrative review.

PURPOSE: With the increasing utilization of medications worldwide, coupled with the increasing availability of long-term data, there is a growing opportunity and need for robust studies evaluating drug-cancer associations. One methodology of importance in such studies is the application of lag times. METHODS: In this narrative review, we discuss the main reasons for using lag times. RESULTS: Namely, we discuss the typically long latency period of cancer concerning both tumor promoter and initiator effects and outline why cancer latency is a key consideration when choosing a lag time. We also discuss how the use of lag times can help reduce protopathic and detection bias. Finally, we present practical advice for implementing lag periods. CONCLUSIONS: In general, we recommend that researchers consider the information that generated the hypothesis as well as clinical and biological knowledge to inform lag period selection. In addition, given that latency periods are usually unknown, we also advocate that researchers examine multiple lag periods in sensitivity analyses as well as duration analyses and flexible modeling approaches.

Published registry-based pharmacoepidemiologic associations show limited concordance with agnostic medication-wide analyses.

OBJECTIVES: To assess how the results of published national registry-based pharmacoepidemiology studies (where select associations are of interest) compare with an agnostic medication-wide approach (where all possible drug associations are tested). STUDY DESIGN AND SETTING: We systematically searched for publications that reported drug associations with any, breast, colon/colorectal, or prostate cancer in the Swedish Prescribed Drug Registry. Results were compared against a previously performed agnostic medication-wide study on the same registry. PROTOCOL: https://osf.io/kqj8n. RESULTS: Most published studies (25/32) investigated previously reported associations. 421/913 (46%) associations had statistically significant results. 134 of the 162 unique drug-cancer associations could be paired with 70 associations in the agnostic study (corresponding drug categories and cancer types). Published studies reported smaller effect sizes and absolute effect sizes than the agnostic study, and generally used more adjustments. Agnostic analyses were less likely to report statistically significant protective associations (based on a multiplicity-corrected threshold) than their paired associations in published studies (McNemar odds ratio 0.13, P = 0.0022). Among 162 published associations, 36 (22%) showed increased risk signal and 25 (15%) protective signal at P < 0.05, while for agnostic associations, 237 (11%) showed increased risk signal and 108 (5%) protective signal at a multiplicity-corrected threshold. Associations belonging to drug categories targeted by individual published studies vs. nontargeted had smaller average effect sizes; smaller P values; and more frequent risk signals. CONCLUSION: Published pharmacoepidemiology studies using a national registry addressed mostly previously proposed associations, were mostly "negative", and showed only modest concordance with their respective agnostic analyses in the same registry.

Sex differences in adverse drug reactions: Are women more impacted?

Pharmacovigilance and pharmacoepidemiology studies regarding the sex difference in adverse drug reactions are numerous, and it is now a challenge to take them into account in order to increase drug safety. Here, we present an overview of this topic through data on epidemiology, mechanisms, and methods used for assessing sex differences in drug safety. Because the literature is extensive, we choose to expose a few examples of studies for cardiovascular drugs, anti-infectious, psychotropics, antidiabetics, anticancer drugs and some specific drugs to illustrate our purpose. Many studies show a higher risk in women for most of drugs involving in sex differences. However, physiological, methodological and subjective points have to be taken into account to interpret these results. Clinical trials must also enroll more women to better evaluate sex differences both in efficacy and pharmacovigilance. Nevertheless, when there is a pharmacological rationale underlying the observed association between sex and drug safety profile, it is now unavoidable to think about its consideration for a personalized prescription.

High-risk pregnancy: characterization of medication use profile and association with clinical and sociodemographic factors / Gestação de alto risco: caracterização do perfil de utilização de medicamentos e associação com fatores clínicos e sociodemográficos

Abstract Objectives: describe the profile of medication use and adherence, and the association with clinical and sociodemographic characteristics of high-risk pregnant women attended at a university hospital. Methods: cross-sectional study with data collected through a questionnaire applied on 386 pregnant women. Results: most participants were seen only by the gynecologist (75.1%), started prenatal in the first gestational trimester (86.8%), did not plan the pregnancy (61.9%), and performed an average of 8.2 (SD=4.4) prenatal consultations. The most frequent diagnoses were arterial hypertension (20.5%) and diabetes mellitus (19.7%). Prevalence of medication use was 99.7%, with an average of 5.1 (SD=2.1) medication per woman and 12.7% self-medication. Antianemics (88.9%) and analgesics (63.2%) were the most prevalent classes and 17.9% of the women reported the use of medication with significant gestational risk. Only 36.5% were considered adherent, 32.9% declared they were unaware of the indication of the medication in use and 42% did not receive guidance on the use of the medication during pregnancy. There is no evidence of association between the number of the medication used and clinical and sociodemographic aspects. Conclusions: there is a need to develop strategies to improve the care of this population, with emphasis on strengthening multi-professional care.

Resumo Objetivos: descrever o perfil de utilização de medicamentos e de adesão, e a associação com as características clínicas e sociodemográficas de gestantes de alto risco atendidas em um hospital universitário. Métodos: trata-se de um estudo transversal com dados coletados mediante um questionário estruturado aplicado à 386 gestantes. Resultados: a maior parte das participantes era acompanhada apenas pelo ginecologista (75,1%), iniciou o pré-natal no primeiro trimestre gestacional (86,8%), não planejou a gravidez (61,9%) e realizou em média 8,2 (DP=4,4) consultas de pré-natal. Os diagnósticos mais frequentes foram hipertensão arterial (20,5%) e diabetes mellitus (19,7%). A prevalência de uso de medicamentos foi 99,7%, com média de 5,1 (DP=2,1) medicamentos por mulher e 12,7% de automedicação. Os antianêmicos (88,9%) e analgésicos (63,2%) foram as classes farmacológicas mais prevalentes e 17,9% das gestantes referiram uso de fármacos com risco gestacional relevante. Apenas 36,5% das gestantes foram consideradas aderentes ao tratamento, 32,9% declararam desconhecer a indicação dos medicamentos em uso e 42% não receberam orientações sobre o uso de medicamentos durante a gestação. Não há evidências de associação entre o número de medicamentos utilizados e os aspectos clínicos e sociodemográficos. Conclusão: é necessário desenvolver estratégias para melhorar o atendimento desta população e o uso racional de medicamentos, com ênfase no fortalecimento do cuidado multiprofssional.

Pharmacoepidemiology for oncology clinical practice: Foundations, state of the art and perspectives.

Since the early 2000s, the arrival of the so-called targeted therapies and immunotherapies have prolonged survival rates in many cancers. In parallel, post-marketing surveillance of anticancer drugs through pharmacoepidemiology has gradually developed. This paper provides (i) a detailed argumentation of the foundations for pharmacoepidemiology of anticancer drugs, (ii) an overview of pharmacoepidemiological studies currently available in this field, and (iii) some perspectives to improve pharmacoepidemiology for oncology practice. First of all, according to the existing literature, the development of pharmacoepidemiological studies for the clinical evaluation of anticancer drugs appears particularly justified based on common limitations of clinical trials in oncology regarding essential methodological principles such as adequate control groups, randomisation or double blinding. Many descriptive field cohort studies have investigated together treatment patterns, effectiveness, and safety to compare results from clinical trials with those of everyday practice. The utilisation of anticancer drugs has also been extensively described through cross-sectional or cohort studies by often using medico-administrative or medical databases. Such studies are useful to quantify and characterise use over time in the population, including clinically unvalidated use, and to evaluate adherence and persistence to increasingly available oral anticancer drugs. Despite their importance to increase knowledge, comparative effectiveness or safety studies remain uncommon. In a context of rapidly emerging therapies and personalised treatments, this may be due to methodological challenges especially related to the choice of a comparator or the consideration of confounding by indication. In the future, efforts must be pursued to provide real-time access to high-quality, large-scale clinical, biological and treatment data, and to improve record-linkage between hospital and outpatient databases. More research is also needed to better evaluate all medications, not only anticancer, as part of an overall cancer care pathway and to bring the evaluation of anticancer drugs closer to patients and society (social pharmacology).

Sociodemographic and pharmacoepidemiological profile of people on antiretroviral therapy in the coast of the state of Paraná

The aim of this study was to investigate possible factors related to antiretroviral therapy (ART) that contribute to the understanding of the highest rate of Aids detection on the coast of the state of Paraná, a port region identified administratively as the 1stRegional Health Division (1stHD) in the state of Paraná. Data on the sociodemographic profile of the population undergoing antiretroviral treatment (ART), medication changes, dropout of therapy, proportion of the population undergoing treatment and viral load were obtained through computerized systems. Between July 1, 2018 and June 31, 2019, 1,393 people were on ART in the 1stRS. Of these, 57.6% were male. During this period, 110 people started ART with a predominance of the age group between 30 and 39 years old. ART was switched for169 people and 211 patient dropouts were detected. The proportion of people diagnosed with HIV without treatment (gap) is still high, however 92.7% people on ART have suppressed viral load. It can be concluded that the lower educational level of the population undergoing treatment, the late diagnosis of those infected and the treatment gapprobably contribute to the highest rate of Aids detection in the 1stRS.

Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives.

Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, ß-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.

Time-related biases in pharmacoepidemiology.

PURPOSE: Observational studies using computerized healthcare databases have become popular to investigate the potential effectiveness of old drugs for new indications. Many of these studies reporting remarkable effectiveness were shown to be affected by different time-related biases. We describe these biases and illustrate their effects using a cohort of patients treated for chronic obstructive pulmonary disease (COPD). METHODS: The Quebec healthcare databases were used to form a cohort of 124 030 patients with COPD, 50 years or older, treated between 2000 and 2015. Inhaled corticosteroids (ICS) and long-acting bronchodilators were used as exposures, with diverse outcomes, including lung cancer, acute myocardial infarction and death, to illustrate protopathic, latency time, immortal time, time-window, depletion of susceptibles, and immeasurable time biases. RESULTS: Protopathic bias affected bronchodilator-defined cohort entry with an incident rate of lung cancer of 23.9 per 1000 in the first year, compared with around 12.0 in the subsequent years. When latency and immortal times were misclassified, ICS were associated with decreased incidence of lung cancer (hazard ratio [HR] 0.32; 95% CI: 0.30-0.34), compared with 0.50 (95% CI: 0.48-0.53) after correcting for immortal time bias and 0.96 (95% CI: 0.91-1.02) after also correcting for latency time bias. Time-window, depletion of susceptibles and immeasurable time biases also affected the findings similarly. CONCLUSIONS: Many observational studies of new indications for older drugs reporting unrealistic effectiveness were affected by avoidable time-related biases. The apparent effectiveness often disappears with proper design and analysis. Future studies should consider these time-related issues to avoid severely biased results.

Empirical assessment of case-based methods for drug safety alert identification in the French National Healthcare System database (SNDS): Methodology of the ALCAPONE project.

OBJECTIVES: To introduce the methodology of the ALCAPONE project. BACKGROUND: The French National Healthcare System Database (SNDS), covering 99% of the French population, provides a potentially valuable opportunity for drug safety alert generation. ALCAPONE aimed to assess empirically in the SNDS case-based designs for alert generation related to four health outcomes of interest. METHODS: ALCAPONE used a reference set adapted from observational medical outcomes partnership (OMOP) and Exploring and Understanding Adverse Drug Reactions (EU-ADR) project, with four outcomes-acute liver injury (ALI), myocardial infarction (MI), acute kidney injury (AKI), and upper gastrointestinal bleeding (UGIB)-and positive and negative drug controls. ALCAPONE consisted of four main phases: (1) data preparation to fit the OMOP Common Data Model and select the drug controls; (2) detection of the selected controls via three case-based designs: case-population, case-control, and self-controlled case series, including design variants (varying risk window, adjustment strategy, etc.); (3) comparison of design variant performance (area under the ROC curve, mean square error, etc.); and (4) selection of the optimal design variants and their calibration for each outcome. RESULTS: Over 2009-2014, 5225 cases of ALI, 354 109 MI, 12 633 AKI, and 156 057 UGIB were identified using specific definitions. The number of detectable drugs ranged from 61 for MI to 25 for ALI. Design variants generated more than 50 000 points estimates. Results by outcome will be published in forthcoming papers. CONCLUSIONS: ALCAPONE has shown the interest of the empirical assessment of pharmacoepidemiological approaches for drug safety alert generation and may encourage other researchers to do the same in other databases.

Pharmacoepidemiology of the antiglaucoma drugs in Brazil from 2012 to 2018 / Farmacoepidemiologia das drogas antiglaucomatosas no Brasil de 2012 a 2018

Abstract Purpose: To outline the epidemiological profile of clinical treatments for glaucoma provided by the Brazilian Unified Health System (SUS, acronym in Portuguese) between January 2012 and December 2018. Methods: A quantitative and descriptive study was conducted using available data based on the outpatient information system from SUS (SIA/SUS, acronym in Portuguese). The variables were monocular treatment with first, second, and third-line drugs; monocular treatment with combinations of two drugs and three drugs from different lines; binocular treatment with first, second, and third-line drugs; and binocular treatment with combinations of two drugs and three drugs from different lines. Results: During the analysis period, the prevalence of clinical therapies for glaucoma increased from 2012 to 2017 and decreased from 2017 to 2018. Of the clinically treated patients, 96% were carriers of binocular glaucoma. Among the regions of Brazil, the Northeast had the highest prevalence of binocular glaucoma (about 60% of the number of cases), and the most common therapy was combinations of two drugs from different lines. The Southeast region had the highest concentration of monocular glaucoma (53% of cases), and the predominant therapy was combinations of three drugs from different lines. The Midwest region had the lowest prevalence of monocular-treatments for glaucoma (less than 6%). Conclusion: In Brazil, the highest number of treatments offered by the public health system was in the Northeast and Southeast regions. There is a high national prevalence and potential for the morbidity of this disease. Therefore, it is necessary to strengthen programs aimed at early diagnosis and appropriate treatment to reduce adverse outcomes.

Resumo Objetivo: Traçar o perfil epidemiológico do tratamento clínico para o glaucoma no Brasil fornecido pelo Sistema Único de Saúde (SUS), no período de janeiro de 2012 a dezembro de 2018. Métodos: Estudo quantitativo e descritivo, utilizando a base de dados disponível no Sistema de Informações Ambulatoriais do SUS (SIA/SUS). As variáveis utilizadas foram: tratamento monocular com drogas de primeira, de segunda e de terceira linha; tratamento monocular com combinações de duas drogas e de três drogas de diferentes linhas; tratamento binocular com drogas de primeira, de segunda e de terceira linha; e tratamento binocular com combinações de duas drogas e de três drogas de diferentes linhas. Resultados: Durante o período analisado, a prevalência de terapias clínicas para o glaucoma aumentou entre 2012 e 2017 e diminuiu entre 2017 e 2018. Dos pacientes tratados clinicamente, 96% eram portadores de glaucoma binocular. Entre as regiões do Brasil, o Nordeste teve a maior prevalência de glaucoma binocular (cerca de 60% do número de casos), e a terapia mais comum foi a combinação de duas drogas de diferentes linhas. A região Sudeste teve a maior concentração de glaucoma monocular (53% dos casos), e a terapia predominante foi a combinação de três drogas de diferentes linhas. A região Centro-Oeste apresentou a menor prevalência de tratamentos monoculares para o glaucoma (menos de 6%). Conclusão: No Brasil, o maior número de tratamentos oferecidos pelo sistema público de saúde foi nas regiões Nordeste e Sudeste. Existe uma alta prevalência nacional e um alto potencial para morbidade desta doença. Portanto, é necessário fortalecer programas voltados para o diagnóstico precoce e para o tratamento adequado a fim de reduzir os resultados adversos.

Using nationally representative survey data for external adjustment of unmeasured confounders: An example using the NHANES data.

PURPOSE: To evaluate the use of data from population-based surveys such as the National Health and Nutrition Examination Survey (NHANES) for external adjustment for confounders imperfectly measured in health care databases in the United States. METHODS: Our example study used Medicaid Analytic eXtract (MAX) data to estimate the relative risk (RR) for prenatal serotonin-norepinephrine reuptake inhibitors (SNRIs) exposure and cardiac defects. Smoking and obesity are known confounders poorly captured in databases. NHANES collects information on lifestyle factors, depression, and prescription medications. External adjustment requires information on the prevalence of confounders and their association with SNRI use; which was obtained from the NHANES. It also requires estimates of their association with the outcome, which were based on the literature and allowed us to correct the RR using sensitivity analyses. RESULTS: In MAX, the RR for the association between prenatal SNRI exposure and cardiac defects was 1.51 unadjusted and 1.20 adjusted for measured confounders and restricted to women with depression. In NHANES, among women of childbearing age with depression, the prevalence of smoking was 60.2% (95% Confidence Interval 43.2, 74.3) for SNRI users and 44.1% (39.6, 48.8) for nonusers of antidepressants. The corresponding estimates for obesity were 59.2% (43.2, 74.3) and 40.5% (35.9, 45.0), respectively. If the associations between smoking and obesity with cardiac defects are independent from each other and from other measured confounders, additional adjustment for smoking and obesity would move the RR from 1.20 to around 1.10. CONCLUSION: National surveys like NHANES are readily available sources of information on potential confounders and they can be used to assess and improve the validity of RR estimates from observational studies missing data on known risk factors.

Validity of hospital ICD-10-GM codes to identify acute liver injury in Germany.

PURPOSE: Acute liver injury (ALI) is an important adverse drug reaction. We estimated the positive predictive values (PPVs) of ICD-10-GM codes of ALI used in an international postauthorisation safety study (PASS). METHODS: Analyses used routine data (2007 to 2016, adults) from a German academic hospital in a cross-sectional design. Two algorithms from the PASS were applied to extract potential cases from the hospital information system: specific end point (A) (discharge diagnosis of liver disease-specific codes) and less specific end point (B) (discharge and outpatient-specific and nonspecific codes suggestive of liver injury). ALI cases were confirmed on the basis of plasma liver enzyme activity elevation. Secondary analysis was performed following exclusion of cases with known cancer, chronic liver, biliary and pancreatic disease, heart failure, and alcohol-related disorders, as applied in the PASS. RESULTS: On the basis of ICD codes: outcome A, 154 cases (143 with case notes and lab data for case verification); outcome B, 485 cases (357 with case notes and lab data). ALI was confirmed in 71 outcome A cases, PPV of 49.7% (95% confidence interval [CI], 41.2%-58.1%), and 100 outcome B cases, PPV of 28.0% (95% CI, 23.4%-33.0%). Applying exclusion criteria increased PPV (95% CI) to 62.7% (50.0%-74.2%) for outcome A and 45.7% (37.2%-54.3%) for outcome B. CONCLUSIONS: In safety studies on hepatotoxicity based on routine data using ICD-10-GM discharge codes and when validation of potential cases is not feasible, only the more specific codes should be used to describe ALI, and competing diagnoses for liver injury should be excluded to avoid substantial misclassification.

Analyzing patient-reported outcome data when completion differs between arms in open-label trials: an application of principal stratification.

PURPOSE: Cancer trials are often open-label and include patient-reported outcomes (PROs). Previous work has demonstrated that patients may complete PRO assessments less frequently in the control arm compared with the experimental arm in open-label trials. Such differential completion may affect PRO results. This paper sought to explore principal stratification methodology to address potential bias caused by the posttreatment intermediate variable of questionnaire completion. METHODS: We evaluated six randomized trials (five open-label and one double-blind) of anticancer therapies with varying levels of PRO completion submitted to the Food and Drug Administration (FDA). We applied complete case analysis (CCA), multiple imputation (MI), and principal stratification to evaluate PRO results for quality of life (QOL) and the domains of physical, role, and emotional function (PF, RF, and EF). Assignment to potential principal strata was by the expectation maximization algorithm using patient baseline characteristics. RESULTS: Completion rates in the experimental arm ranged from 66% to 94% and 51% to 95% in the control arm. Four trials had negligible completion differences between arms (1%-2%), and two had large differences favoring the experimental arm (15%-17%). For trials with negligible completion differences, principal stratification results were similar to CCA and MI results for all domains. Notable differences in point estimates may be observed in trials with large differences in completion rates. However, in the examined trials, the confidence intervals for the principal stratification estimates overlapped with the ones obtained using CCA. CONCLUSIONS: The principal stratification estimand may be a useful additional analysis, especially if PRO completion differs between arms.

Individual mortality information in the German Pharmacoepidemiological Research Database (GePaRD): a validation study using a record linkage with a large cancer registry.

OBJECTIVE: Claims data need to be validated to assess their use for epidemiological research. This study aimed to examine the validity of mortality information in the German Pharmacoepidemiological Research Database (GePaRD). DESIGN: Validation study, secondary data, medical claims. SETTING: Claims data of two German nationwide acting statutory health insurance providers (SHIs) contributing data for GePaRD; record linkage with epidemiological cancer registry providing individual official mortality information. PARTICIPANTS: All women insured with the two SHIs whose insurance coverage ended in the period 2006-2013 and who were residents of North Rhine Westphalia. MEASURES: Descriptive statistics were used to analyse the performance of the linkage procedure. Further, we calculated measures of agreement between the official and the GePaRD-based vital status and assessed differences between the official and the GePaRD-based date of death. RESULTS: Of the 256 111 women of the linkage sample, 25 528 were classified as 'deceased' in GePaRD and the others as 'alive'. Compared with the official data, the GePaRD-based vital status showed a sensitivity of 95.9% and a specificity of 99.4%. The negative predictive value was 99.6% and the positive predictive value 94.3%. The date of death agreed in 96.3% between both data sources. CONCLUSIONS: The vital status recorded in GePaRD was of high accuracy and discrepancies between dates of death in GePaRD and official dates were rare. This underlines the potential of the database for conducting large cohort studies with mortality as the endpoint.

Identification of potential carcinogenic and chemopreventive effects of prescription drugs: a protocol for a Norwegian registry-based study.

INTRODUCTION: Surveillance of unintended effects of pharmaceuticals (pharmacovigilance or drug safety) is crucial, as knowledge of rare or late side effects is limited at the time of the introduction of new medications into the market. Side effects of drugs may involve increased or decreased risk of cancer, but these typically appear after a long induction period. This fact, together with low incidences of many cancer types, limits the usefulness of traditional pharmacovigilance strategies, primarily based on spontaneous reporting of adverse events, to identify associations between drug use and cancer risk. Postmarketing observational pharmacoepidemiological studies are therefore crucial in the evaluation of drug-cancer associations. METHODS AND ANALYSIS: The main data sources in this project will be the Norwegian Prescription Database and the Cancer Registry of Norway. The underlying statistical model will be based on a multiple nested case-control design including all adult (~200 000) incident cancer cases within the age-range 18-85 years from 2007 through 2015 in Norway as cases. 10 cancer-free population controls will be individually matched to these cases with respect to birth year, sex and index date (date of cancer diagnosis). Drug exposure will be modelled as chronic user/non-user by counting prescriptions, and cumulative use by summarising all dispensions' daily defined doses over time. Conditional logistic regression models adjusted for comorbidity (National Patient Register), socioeconomic parameters (Statistics Norway), concomitant drug use and, for female cancers, reproduction data (Medical Birth Registry), will be applied to identify drug-use-cancer-risk associations. ETHICS AND DISSEMINATION: The study is approved by the regional ethical committee and the Norwegian data protection authority. Results of the initial screening step and analysis pipeline will be described in a key paper. Subsequent papers will report the evaluation of identified signals in replication studies. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

The value of a health insurance database to conduct pharmacoepidemiological studies in oncology.

Some concerns have emerged about the evidence of benefits on survival outcomes or quality of life of new anticancer drugs. In parallel, the decreased cancer mortality leads to an increased number of patients exposed to cancer treatment-related consequences. In this context, pharmacoepidemiology is crucial to assess anticancer drug use, effectiveness and safety in real life conditions. We aimed to describe strengths, limitations and considerations associated with the use of the French national health insurance database (système national des données de santé [SNDS]) to conduct pharmacoepidemiological studies in oncology. The SNDS represents a powerful tool in pharmacoepidemiology owing to its extensive coverage, accurate description and quantification of drug exposure and individual data on patients. The main limitations of this database ensue from the administrative nature resulting in technical difficulties in its management and gaps in availability of data. Another limitation is the lack of accurate identification of diseases, comorbidities or outcomes and potential confounding with notably the lack of data regarding cancer stage, prognosis or risk factors. Finally, the accurate identification of the nature of chemotherapy received by patients is sometimes complex. To minimize these limitations, several approaches and statistical methods could be used as highlighted by national or international initiatives. First, the SNDS may be linked with cancer registry or clinical data. Then, several data sources could be combined using meta-analytical methods. The development of methodological tools and the use of standardized methods are crucial to enhance the quality of studies that can impact clinical practice and guide public decision. Pharmacoepidemiological approaches and pharmacovigilance represent an important cornerstone in oncology for signal detection or long-term follow up of cancer patients. In this context, validated methods to identify cancer patients and to describe chemotherapy regimens within these data should be promoted and remain too scarce despite international guidelines. Moreover, limits and strength of each data sources should be systematically discussed according to the research question. Optimized and framed use of claims database represents a future challenge in onco-pharmacoepidemiology.