Highlights
- •Historic cohorts suggested that supply of inhaled medicines may exceed actual use.
- •This is the first study to directly compare medicine supply (MPR) against adherence.
- •Among 275 adults in 12 CF centres, MPR over-estimates adherence by a median of 14%.
- •Even with 20% contingency, mean annual cost of excess supply was £1,124/patient.
- •Excess supply cost was higher in those with adherence <50% (mean £2,017/patient).
Abstract
Background
Studies in separate cohorts suggest possible discrepancies between inhaled medicines
supplied (median 50-60%) and medicines used (median 30-40%). We performed the first
study that directly compares CF medicine supply against use to identify the cost of
excess medicines supply.
Methods
This cross-sectional study included participants from 12 UK adult centres with ≥1
year of continuous adherence data from data-logging nebulisers. Medicine supply was
measured as medication possession ratio (MPR) for a 1-year period from the first suitable
supply date. Medicine use was measured as electronic data capture (EDC) adherence
over the same period. The cost of excess medicines was calculated as whole excess
box(es) supplied after accounting for the discrepancy between EDC adherence and MPR
with 20% contingency.
Results
Among 275 participants, 133 (48.4%) were females and mean age was 30 years (95% CI
29-31 years). Median EDC adherence was 57% (IQR 23-86%), median MPR was 74% (IQR 46-96%)
and the discrepancy between measures was median 14% (IQR 2-29%). Even with 20% contingency,
mean potential cost of excess medicines was £1,124 (95% CI £855-1,394), ranging from
£183 (95% CI £29-338) for EDC adherence ≥80% to £2,017 (95% CI £1,507-2,526) for EDC
adherence <50%.
Conclusions
This study provides a conservative estimate of excess inhaled medicines supply cost
among adults with CF in the UK. The excess supply cost was highest among those with
lowest EDC adherence, highlighting the importance of adherence support and supplying
medicine according to actual use. MPR provides information about medicine supply but
over-estimates actual medicine use.
Keywords
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Article Info
Publication History
Published online: September 23, 2021
Accepted:
September 4,
2021
Received in revised form:
September 1,
2021
Received:
April 22,
2021
Identification
Copyright
© 2021 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
ScienceDirect
Access this article on ScienceDirectLinked Article
- Corrigendum to “Using a learning health system to understand the mismatch between medicines supply and actual medicines use among adults with cystic fibrosis” [J Cyst Fibros (2022), 21/2, 323-331]Journal of Cystic FibrosisVol. 21Issue 5
- PreviewThe authors regret an error has occurred in the description and calculation of dose-weighted composite MPR (dwcMPR) for participants on multiple medicines. We described dose-weighting according to the number of dispensed inhaled medications. In fact, the dose-weighting should be based on the number of prescribed inhaled medications to ensure there is no gap between the cMPR and electronic data capture (EDC) adherence if someone has indeed used all the medicines that were supplied. Therefore, the first step to calculate dwcMPR should have been: calculate the total prescribed doses of medicine by adding up of all individual values of daily prescribed dose × days.
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