Evidence map›Paper›PMID 41885329›Full record

ArticleJournal of managed care & specialty pharmacy2026

The impact of data source on real-world medication adherence and exposure measures: From prescription to sold.

Yifan Zheng, Karen B Farris, Antoinette B Coe, Michael P Dorsch, Kayvan Najarian, Corey A Lester

Abstract read
In one paragraph

Article in Journal of managed care & specialty pharmacy, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Yifan Zheng
Karen B FarrisClinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor.
Antoinette B CoeClinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor.
Michael P DorschClinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor.
Kayvan NajarianDepartment of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor.
Corey A LesterClinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundMedication adherence is central to evaluating treatment effectiveness, reducing preventable complications, and informing value-based care. The proportion of days covered (PDC) is widely used but inconsistently calculated across studies because of variations in data sources and methods. Prescription timestamps (written, filled, and sold) capture different stages of the medication journey; however, their impact on adherence measures has not been systematically compared.

objectiveTo evaluate how different prescription data sources and calculation methods influence medication adherence estimates in real-world practice.

methodsWe conducted a retrospective cohort study of cardiovascular prescriptions (2009-2019) using longitudinal transaction data. Each prescription included written, fill, and medication sold (pickup) dates. Adults with at least 12 months of follow-up and 3 or more prescriptions in the same class (angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers [ARBs], calcium channel blockers, or diuretics) were included (N = 7,226). Two adherence measures were calculated: (1) exposure PDC, reflecting raw coverage without gap adjustments, and (2) adherence PDC, which excluded prolonged gaps using dynamic patient-specific thresholds. PDC was calculated using 5 source definitions (written, fill, sold, written-sold, and fill-sold). Adherent classification agreement at the 0.80 threshold was assessed using cross-tabulations and visualized with Sankey diagrams.

resultsPatients contributed more than 230,000 fills. Median fill and sold lags were both 0 days, and the 90th percentile delays were longer for fills (29 days) than for sold (3 days). Exposure PDC varied substantially across sources (median = 0.747-0.794;

conclusionsAdherence measurement is not fixed but shaped by data source and methodology. Both timestamp choice and gap-handling substantially influence adherence estimates and patient classification. Our dynamic, patient-specific approach to gap adjustment yielded stable metrics, and exposure-based measures remained more source-sensitive. Standardizing and transparently reporting adherence definitions is essential to avoid misclassification. Future work should evaluate the prognostic value of gap-adjusted vs exposure PDC in predicting cardiovascular outcomes to guide more meaningful quality measures and value-based care.

Indexed as

Cardiovascular AgentsDrug MonitoringDrug PrescriptionsAgedAngiotensin-Converting Enzyme InhibitorsCardiovascular DiseasesFemaleHumansMaleMiddle AgedRetrospective StudiesAngiotensin-Converting Enzyme InhibitorsCardiovascular Agents

Identifiers

PMID41885329
PMCPMC13020390

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.