Adherence, therapeutic intensity, and the number of dispensed drugs
Article first published online: 13 SEP 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Pharmacoepidemiology and Drug Safety
Volume 20, Issue 12, pages 1255–1261, December 2011
How to Cite
Hovstadius, B. and Petersson, G. (2011), Adherence, therapeutic intensity, and the number of dispensed drugs. Pharmacoepidem. Drug Safe., 20: 1255–1261. doi: 10.1002/pds.2230
- Issue published online: 22 NOV 2011
- Article first published online: 13 SEP 2011
- Manuscript Accepted: 18 JUL 2011
- Manuscript Revised: 22 JUN 2011
- Manuscript Received: 3 FEB 2011
- therapeutic intensity;
- multiple medication
To estimate non-adherence in relation to the therapeutic intensity (TI) and the number of dispensed drugs per individual and study whether the TI can be used as an estimator of non-adherence with an increasing number of drugs.
The study comprised an individual-based register of all dispensed outpatient prescriptions in Sweden in 2006, including 6.2 million individuals. The applied definition of drug was the chemical entity or substance comprising the fifth level in the World Health Organisation's Anatomic, Therapeutic, Chemical classification. The defined daily dosage per individual during 12 months was applied as an indicator of the TI.
We found a positive linear relation between the TI and the increasing number of dispensed drugs per individual, both for men and women. We found a slightly diminishing TI with an increasing number of drugs only for the age groups above 70 years, at a level above 13 drugs per individual.
The linear relationship between the TI and the increasing number of dispensed drugs per individual provides poor support for using decreasing TI as an estimator of non-adherence. The low rate of cost-related non-adherence in Sweden might contribute to explaining the linear relationship. Copyright © 2011 John Wiley & Sons, Ltd.