Conducting Privacy-Preserving Multivariable Propensity Score Analysis When Patient Covariate Information Is Stored in Separate Locations.

Distributed networks of health-care data sources are increasingly being utilized to conduct pharmacoepidemiologic database studies. Such networks may contain data that are not physically pooled but instead are distributed horizontally (separate patients within each data source) or vertically (separate measures within each data source) in order to preserve patient privacy. While multivariable methods for the analysis of horizontally distributed data are frequently employed, few practical approaches have been put forth to deal with vertically distributed health-care databases.

Do patients trust the FDA?: a survey assessing how patients view the generic drug approval process.

Purpose: Skepticism about the safety and effectiveness of certain generic drugs remains, particularly related to generic drugs that are approved by the Food and Drug Administration (FDA) using product-specific bioequivalence studies that differ from the standard testing pathway. The current study was designed to assess patient knowledge and perceptions of the generic drug approval process.

Methods: We conducted a survey of patients with 10 different chronic diseases.

Comparing the performance of propensity score methods in healthcare database studies with rare outcomes.

Nonrandomized studies of treatments from electronic healthcare databases are critical for producing the evidence necessary to making informed treatment decisions, but often rely on comparing rates of events observed in a small number of patients. In addition, studies constructed from electronic healthcare databases, for example, administrative claims data, often adjust for many, possibly hundreds, of potential confounders. Despite the importance of maximizing efficiency when there are many confounders and few observed outcome events, there has been relatively little research on the relative performance of different propensity score methods in this context.

Variable Selection for Confounding Adjustment in High-dimensional Covariate Spaces When Analyzing Healthcare Databases.

Background: Data-adaptive approaches to confounding adjustment may improve performance beyond expert knowledge when analyzing electronic healthcare databases and have additional practical advantages for analyzing multiple databases in rapid cycles. Improvements seemed possible if outcome predictors were reliably identified empirically and adjusted.

Methods: In five cohort studies from diverse healthcare databases, we implemented a base-case high-dimensional propensity score algorithm with propensity score decile-adjusted outcome models to estimate treatment effects among prescription drug initiators.

Physicians' Trust in the FDA's Use of Product-Specific Pathways for Generic Drug Approval.

Background: Generic drugs are cost-effective versions of brand-name drugs approved by the Food and Drug Administration (FDA) following proof of pharmaceutical equivalence and bioequivalence. Generic drugs are widely prescribed by physicians, although there is disagreement over the clinical comparability of generic drugs to brand-name drugs within the physician community. The objective of this survey was to assess physicians' perceptions of generic drugs and the generic drug approval process.

Prediction of rates of thromboembolic and major bleeding outcomes with dabigatran or warfarin among patients with atrial fibrillation: new initiator cohort study.

Objectives:  To compare stratified event rates from randomized controlled trials with predicted event rates from models developed in observational data, and assess their ability to accurately capture observed rates of thromboembolism and major bleeding for patients treated with dabigatran or warfarin as part of routine care.

Design:  New initiator cohort study.

Setting:  Data from United Health (October 2009 to June 2013), a commercial healthcare claims database in the United States.

Did FDA Decisionmaking Affect Anti-Psychotic Drug Prescribing in Children?: A Time-Trend Analysis.

Background: Following Food and Drug Administration (FDA) approval, many drugs are prescribed for non-FDA-approved ("off-label") uses. If substantial evidence supports the efficacy and safety of off-label indications, manufacturers can pursue formal FDA approval through supplemental new drug applications (sNDAs). We evaluated the effect of FDA determinations on pediatric sNDAs for antipsychotic drugs on prescribing of these products in children.

Impact of the U.S. Food and Drug Administration's Safety-Related Announcements on the Use of Bisphosphonates After Hip Fracture.

The U.S. Food and Drug Administration (FDA) issued several announcements related to potential risk of bisphosphonates including osteonecrosis of the jaw (2005), atrial fibrillation (2007), and atypical femur fracture (2010).

Variations in Patients' Perceptions and Use of Generic Drugs: Results of a National Survey.

Background: Over 84 % of all prescriptions in the US are filled as generic drugs, though in prior surveys, patients reported concerns about their quality.

Objective: We aimed to survey patients' perceptions and use of generic drugs.

Design: Our survey (administered August 2014) assessed patients' skepticism about generic drug safety and effectiveness and how often they requested brand-name drugs.

Brief Report: Utilization of the First Biosimilar Infliximab Since Its Approval in South Korea.

Objective: The US Food and Drug Administration is considering an application for a biosimilar version of infliximab, which has been available in South Korea since November 2012. The aim of the present study was to examine the utilization patterns of both branded and biosimilar infliximab and other tumor necrosis factor (TNF) inhibitors in South Korea before and after the introduction of this biosimilar infliximab.

Methods: Using claims data from April 2009 to March 2014 from the Korean Health Insurance Review and Assessment Service database, which includes the entire South Korean population, the number of claims for biosimilar infliximab was assessed.

Geographic patterns in patient demographics and insulin use in 18 countries, a global perspective from the multinational observational study assessing insulin use: understanding the challenges associated with progression of therapy (MOSAIc).

Background: Among patients with type 2 diabetes, insulin intensification to achieve glycemic targets occurs less often than clinically indicated. Barriers to intensification are not well understood. We present patients' baseline characteristics from MOSAIc, a study investigating patient-, physician-, and healthcare environment-based factors affecting insulin intensification and subsequent health outcomes.

Regularized Regression Versus the High-Dimensional Propensity Score for Confounding Adjustment in Secondary Database Analyses.

Selection and measurement of confounders is critical for successful adjustment in nonrandomized studies. Although the principles behind confounder selection are now well established, variable selection for confounder adjustment remains a difficult problem in practice, particularly in secondary analyses of databases. We present a simulation study that compares the high-dimensional propensity score algorithm for variable selection with approaches that utilize direct adjustment for all potential confounders via regularized regression, including ridge regression and lasso regression.

Incorporating linked healthcare claims to improve confounding control in a study of in-hospital medication use.

Introduction: The Premier Perspective hospital billing database provides a promising data source for studies of inpatient medication use. However, in-hospital recording of confounders is limited, and incorporating linked healthcare claims data available for a subset of the cohort may improve confounding control. We investigated methods capable of adjusting for confounders measured in a subset, including complete case analysis, multiple imputation of missing data, and propensity score (PS) calibration.

Disease-modifying antirheumatic drug use and the risk of incident hyperlipidemia in patients with early rheumatoid arthritis: a retrospective cohort study.

Objective: To compare the risk of incident hyperlipidemia in early rheumatoid arthritis (RA) patients after initiation of various disease-modifying antirheumatic drugs (DMARDs).

Methods: We conducted a cohort study using insurance claims data (2001-2012) in early RA patients. Early RA was defined by the absence of any RA diagnosis or DMARD prescriptions for 12 months.