ArticlePharmacoepidemiology and drug safety2025
Determining Drug Exposure Based on Medication Dispensing Data: A Validation Study of Vitamin K Antagonist Treatment Episodes Against INR Records.
Article in Pharmacoepidemiology and drug safety, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
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.
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.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
18 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIn pharmaco-epidemiological studies using vitamin K antagonist (VKA) exposure, constructing treatment episodes based on dispensed prescriptions is challenging, particularly due to the large variability in therapeutic dose.
objectivesTo validate different methods of constructing VKA treatment episodes based on dispensed prescriptions, using VKA exposure based on international normalized ratio (INR) measurements as a reference.
methodsData from five Dutch anticoagulation clinics were linked to VKA dispensing data from Statistics Netherlands. Three random samples of 10 000 VKA users between 2013 and 2019 were used to compare the construction of VKA treatment episodes based on dispensings, applying fixed or dynamic methods, against the reference of exposure based on INR measurements. A total of 60 different methods were validated by computing the percentage of INR measurements occurring outside dispensing-based VKA treatment episodes, the ratio of VKA-exposed person-time based on dispensings vs. INR measurements, and the number of dispensing-based episodes.
resultsDepending on the method used to construct treatment episodes, 14.8%-42.2% of the INR measurements were not covered by a dispensing-based episode. The VKA-exposed person-time ratio ranged between 0.73 and 1.13, and there was substantial variability in the number of dispensing-based episodes. Fixed methods resulted in a lower percentage of INR measurements outside the dispensing-based episodes, a VKA-exposed person-time ratio closer to 1.0, and a lower number of constructed episodes.
conclusionFixed methods performed better than dynamic methods when classifying VKA exposure based on dispensing data. Our findings may guide other researchers working with VKA dispensing data, especially when the tablets dispensed or the prescribed dose are unavailable.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.