Accuracy of the days’ supply and the number of refills allowed recorded in Québec prescription claims databases for inhaled corticosteroids

Abstract

Objectives and hypothesesAdherence to inhaled corticosteroids (ICS) is a major issue in asthma. This study aimed to estimate the accuracy of the days’ supply and number of refills allowed, variables recorded in Québec claims databases and used to estimate adherence, and to develop correction factors, if required. We hypothesised that the accuracy of the days’ supply for ICS would be low whereas the accuracy of the number of refills allowed would be high.Setting40 community pharmacies in Québec (Canada) and a medication registry.ParticipantsWe collected data for 1108 ICS original prescriptions stored in the 40 pharmacies (sample 1), and we obtained a second sample of 2676 ICS prescriptions selected from reMed, a medication registry (sample 2).Primary and secondary outcomesWe estimated the concordance of the days’ supply and number of refills between Québec claims databases and the original prescription from sample 1. We developed a correction factor for the days’ supply in sample 1 and validated it in sample 2. Analyses were stratified by age: 0–11 and 12–64 years.ResultsIn sample 1, the concordance for the days’ supply was 39.6% (95% CI 37.6% to 41.6%) in those aged 0–11 years and 56% (54.9% to 57.2%) in those aged 12–64 years. The concordance increased to 59.4% (58.2% to 60.5%) in those aged 0–11 years and 74.2% (73.5% to 74.9%) in those aged 12–64 years after applying the correction factors in sample 2. The concordance for the refills allowed was 92.1% (91% to 93.1%) in those aged 0–11 years and 93.1% (92.5% to 93.7%) in those aged 12–64 years in sample 1.ConclusionsThe accuracy of the days’ supply was moderate among those aged 0–11 years and substantial among those aged 12–64 years after applying the correction factors. The accuracy of the number of refills was almost perfect in both groups.

Pneumonia risk in asthma patients using inhaled corticosteroids: a quasi‐cohort study

“…As a result, the people of highest income may be underrepresented in this database, as they tend to have private plans; nevertheless, the RAMQ still includes a large number of people of average socioeconomic status . Furthermore, the RAMQ databases have previously been used extensively to conduct epidemiological studies of the risk and benefits of ICSs , and have been proven valid and comprehensive .…”

Association between the timing of asthma diagnosis and medication use during pregnancy

“…Because women might use an inhaler of a controller medication for a longer period of time than it was prescribed 37 and because a SABA inhaler might be used for more than 3 months, we used the last filled prescription in the 3 months prior to cohort entry as a proxy for use after cohort entry. 38 The use of LTRA, THEO, and short-acting anticholinergics (SAAC) was not reported because of the low percentages of women using these medications (0.1%-0.3%) during follow-up. OCS use was defined as the number of days' supply dispensed during follow-up.…”

“…The use of ICS, ICS/LABA, any controller medication (ICS, ICS/LABA, leukotriene‐receptor antagonists [LTRA], or theophylline [THEO]), and SABA was measured as the number of filled prescriptions recorded in the RAMQ prescription claims database from the 20th week of gestation until delivery. Because women might use an inhaler of a controller medication for a longer period of time than it was prescribed 37 and because a SABA inhaler might be used for more than 3 months, we used the last filled prescription in the 3 months prior to cohort entry as a proxy for use after cohort entry 38 . The use of LTRA, THEO, and short‐acting anticholinergics (SAAC) was not reported because of the low percentages of women using these medications (0.1%–0.3%) during follow‐up.…”

“…March 31, 2010. At first, we applied correction factors to the days' supply of ICS in order to overcome data entry mistakes in pharmacy files (92). Briefly, ICS are provided in canisters containing a fixed number of puffs, hence the canister's lifespan may vary depending on the prescribed number of puffs per day.…”

Tiotropium Bromide As Adjunct Therapy In Children With Asthma: A Clinical Experience

“…Brie y, the PADB, described in another study (20), is a structured electronic medical record with systematic documentation of sociodemographic characteristics; asthma diagnosis, phenotype, severity and control; pulmonary function tests results, when applicable; comorbidities and environmental asthma triggers, as well as maintenance and/or rescue therapy reported on arrival to, and prescribed on discharge from, the clinic. The Data Registry for Prescribed Medications (reMed) provided data on all prescriptions served by any of Quebec's pharmacies, claimed by privately or publicly insured patients was used to document pharmacy dispensing of tiotropium (21).…”