Study on potentially inappropriate prescriptions (only available in French)

Retrospective study from 2000 to 2006

The Canadian Institute for Health Information (CIHI) reports that the proportion of people aged 65 and over in the four Canadian provinces of Alberta, Saskatchewan, Manitoba and New Brunswick who have had at least one potentially inappropriate prescription (PIP) varied between 30.6% and 41.2% in 2000-2001 and between 25.2% and 31.3% in 2005-2006. Accordingly, the Conseil du médicament and the Régie de l’assurance maladie du Québec (RAMQ) carried out this study to determine the prevalence of PIPs, between 2000 and 2006, in people aged 65 and over in the province of Québec.

A retrospective descriptive study was performed using the RAMQ’s data banks. For each fiscal year between 2000-2001 and 2005-2006, the population studied consisted of all users aged 65 and over, i.e. everyone who had had at least one prescription paid for through the Public Prescription Drug Insurance Plan. The proportion of users having had at least one PIP, regardless of their diagnosis or health condition, was determined using the 2002 Beers criteria. The prevalence of PIPs of any type, in chronic use, and for medications with a high risk of serious adverse effects was calculated for each fiscal year.

The percentage of users having had at least one PIP of any type fell from 35.4% to 30.0% during the period studied. For chronic-use drugs, the prevalence of PIPs also dropped, from 26.7% in 2000-2001 to 21.7% in 2005-2006. The percentage of users with at least one PIP for a high-risk drug declined far less significantly, from 24.5% in 2000-2001 to 22.8% in 2005-2006. Oral conjugated estrogens showed the most marked decrease among the drugs looked at between 2000 and 2006. However, they remained the second drug most commonly seen in PIPs of any type in 2005-2006, with a prevalence among users of 3.9%. Only clonazepam had a higher prevalence, of 4.2%. Ferrous sulfate is the drug associated with PIPs that saw the greatest average annual increase during the period studied. However, it ranked only as the fourth most common drug related to PIPs of any type, with 2.5% of users in 2005-2006.
 
The percentage of users aged 65 and over having had at least one PIP of any type remains significant in Québec, despite a decrease between 2000 and 2006. This is comparable to the proportion observed elsewhere in Canada. PIPs associated with chronic-use drugs, however, were higher in Québec than in any of the compared provinces in 2005-2006. This gap may be due to different prescribing or prescription-filling practices in Québec. In 2005-2006, nearly 30% of Québec seniors were given at least one PIP. Considering the effects PIPs may have had on their health, it is important to develop and implement effective strategies to improve the quality of care given to seniors.