Variation in adherence to medications across the healthcare system in two comparative effectiveness research cohorts

Protocol for studying racial/ethnic disparities in depression care using joint information from participant surveys and administrative claims databases: an observational cohort study

INTRODUCTION

Current evidence indicates that older racial/ethnic minorities encounter disparities in depression care. Because late-life depression is common and confers major adverse health consequences, it is imperative to reduce disparities in depression care. Thus, the primary objectives of this protocol are to: (1) quantify racial/ethnic disparities in depression treatment and (2) identify and quantify the magnitude of these disparities accountable for by a multifactorial combination of patient, provider and healthcare system factors.

METHODS AND ANALYSIS

Data will be derived from the Vitamin D and Omega-3 Trial-Depression Endpoint Prevention (VITAL-DEP) study, a late-life depression prevention ancillary study to the VITAL trial. A total of 25 871 men and women, aged 50+ and 55+ years, respectively, were randomised in a 2×2 factorial randomised trial of heart disease and cancer prevention to receive vitamin D and/or fish oil for 5 years starting from 2011. Most participants were aged 65+ years old at randomisation. Medicare claims data for over 19 000 VITAL/VITAL-DEP participants were linked to conduct our study.The major study outcomes are depression treatment (antidepressant use and/or receipt of psychotherapy services) and adherence to medication treatment (antidepressant adherence and acceptability). The National Academy of Medicine framework for studying racial disparities was leveraged to select patient-level, provider-level and healthcare system-level variables and to address their potential roles in depression care disparities. Blinder-Oaxaca regression decomposition methods will be implemented to quantify and identify correlates of racial/ethnic disparities in depression treatment and adherence.

ETHICS AND DISSEMINATION

This study received Institutional Review Board (IRB) approval from the Partners Healthcare (PHS) IRB, protocol# 2010P001881. We plan to disseminate our results through publication of manuscripts patient engagement activities, such as study newsletters regularly sent out to VITAL participants, and presentations at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT01696435.

Real-world adherence to oral anticoagulants in atrial fibrillation patients: a study protocol for a systematic review and meta-analysis

INTRODUCTION

Atrial fibrillation (AF) is one of the leading causes of cerebrovascular mortality and morbidity. Oral anticoagulants (OACs) have been shown to reduce the incidence of cardioembolic stroke in patients with AF, adherence to treatment being an essential element for their effectiveness. Since the release of the first non-vitamin K antagonist oral anticoagulant, several observational studies have been carried out to estimate OAC adherence in the real world using pharmacy claim databases or AF registers. This systematic review aims to describe secondary adherence to OACs, to compare adherence between OACs and to analyse potential biases in OAC secondary adherence studies using databases.

METHODS AND ANALYSIS

We searched on PubMed, SCOPUS and Web of Science databases (completed in 26 September 2018) to identify longitudinal observational studies reporting days' supply adherence measures with OAC in patients with AF from refill databases or AF registers. The main study endpoint will be the percentage of patients exceeding the 80% threshold in proportion of days covered or the medication possession ratio. Two reviewers will independently screen potential studies and will extract data in a structured format. A random-effects meta-analysis will be carried out to pool study estimates. The risk of bias will be assessed using the Newcastle-Ottawa Scale for observational studies and we will also assess some study characteristics that could affect days' supply adherence estimates.

ETHICS AND DISSEMINATION

This systematic review using published aggregated data does not require ethics approval according to Spanish law and international regulations. The final results will be published in a peer-review journal and different social stakeholders, non-academic audiences and patients will be incorporated into the diffusion activities.

PROSPERO REGISTRATION NUMBER

CRD42018095646.