Montreal, QC—Researchers analyzed studies of patient adherence to daily and weekly medications to evaluate the impact of dosing frequency on medication adherence. Osteoporosis was the condition selected by the investigators because there are many daily and weekly medications available for this indication. Their results showed that patients on weekly regimens are 90% more likely to be adherent than those on daily regimens.
“Weekly dosing is more convenient for patients and that is likely why they have a greater propensity to stick to weekly therapy,” said lead investigator Panagiotis Mavros, PhD, Executive Director, Outcomes Research, and Lead, Medical Data Analytics, Merck & Co, Inc, Whitehouse Station, NJ.
Dr Mavros, who presented the results in a presentation at the International Society for Pharmacoeconomics and Outcomes Research 19th Annual International Meeting, explained that the systematic review and meta-analysis included studies in the English language published between January 2002 and August 2013. They focused on 7 studies that measured the medication possession ratio in patients with osteoporosis; none of the articles included were crossover studies.
On average, patients taking an osteoporosis medication with once-weekly dosing had 12% more days on which they were taking the medication. This held true when they removed the data from 1 study that appeared to have erroneous data on record with extremely narrow confidence intervals. However, there was significant heterogeneity in the studies with respect to this measure. “We have to interpret this result with caution,” acknowledged Dr Mavros.
The researchers also found that the odds ratio for adherence was 1.90 on average for once-weekly versus once-daily dosing. There was a low level of heterogeneity between studies in this measure. “We trust this result even more,” concluded Dr Mavros. “We can say with confidence that patients on once-weekly osteoporosis medication were 90% more likely to be adherent to their medication than those on once-daily dosing.”