Data drawn from patients’ self-reports about their medication use are most useful and valid for classifying their use of long-term, regularly used medications, according to new research drawing on the Sax Institute’s 45 and Up Study.
The researchers from The University of Sydney and Australian National University said self-reported data on medication use could capture information that was not always revealed in official pharmaceutical claims or prescription data, because it covers a wide range of prescription and non-prescription, complementary and alternative medicines.
However, there are well-documented concerns about the accuracy of self-reported medication-use, as it relies on patients’ recall.
The study aimed to compare the accuracy of data from people’s self-reported use of a wide-range of prescriptions medications with the gold-standard method of linking routine data claims for dispensed prescription-only medications.
The researchers examined self-reported medication use relating to a four-week period among a random sample of 500 participants in the 45 and Up Study, Australia largest study of healthy ageing. They compared the self-reported data with Pharmaceutical Benefits Scheme (PBS) prescription medicine claims data.
Data validity varies depending on medication type
The findings, published in the latest issue of Public Health Research & Practice, showed that overall, the participants’ self-reported data on their use of prescription-only medications compared well with the PBS claims data.
Positive predictive values were higher than 75% for almost four in five medication classes examined. However, the validity of self-reported data varied depending on the type of medication.
Participants’ self-reported information on long-term prescription medications for chronic conditions, such as cardiovascular medications, was excellent when compared with the claims data, the study found.
There was lower validity for medications used in the short term or intermittently, such as analgesics, anxiolytics, sedatives and antibiotics, the study suggested.
The authors concluded that self-reported data on medication use such as those studied were likely to be particularly “useful and valid” for classifying exposure to long-term, regularly used medications.
“These findings have important implications for design and interpretation of pharmacoepidemiological studies using self-reported data to examine use and safety of prescription medication in real-world settings,” the authors wrote.
Find out more
- Read the full study: Ascertainment of self-reported prescription medication use compared with pharmaceutical claims data
- Read other News from the 45 and Up Study