The Pharmacoepidemiology of antidepressant prescribing in Canada

1. The Pharmacoepidemiology of antidepressant prescribing in Canada Rachael Morkem This publication was made possible through funding from the Public Health Agency of Canada. The views expressed here do not necessarily reflect those of the Public Health Agency of Canada.

2. Background • Depression is the leading cause of disability worldwide and is a major contributor to the global burden of disease • Antidepressant drugs (ATDs) are part of the first line of treatment for those suffering from depression • In the last decade there has been a lot of enthusiasm for the efficacy of antidepressants • In the last five years extensive reviews of published and unpublished trials have shows that the superior efficacy of ATDs to placebo only remained true for severely depressed patients • New guidelines recommend ATDs not be used for sub-threshold depressive symptoms or mild depression due to poor risk-benefit ratio.

3. Objective • To describe the current landscape of antidepressant prescribing in primary care • For children (1-14), youth (15-24), adults (25-64) and seniors (65+) • For males and females

4. Methods • Data Source: Canadian Primary Care Sentinel Surveillance Network • A collaboration of primary care practice based research networks (PBRNs) across the country that works with family physicians to maintain a database of primary healthcare information. • Data Holdings: 475 primary care providers contribute data on 600, 000 patients • Data Elements: socio-demographic data, provider demographics, health condition data, billing/encounter data, medications, lab data, encounter data, risk factor data, allergies/adverse drug reactions, referral data, procedural data, examination data

5. 8 Provinces, 11 EMRs British Columbia - BCPCReN, Vancouver - Wolf, OSCAR (1) Alberta - SAPCReN, Calgary - Med Access, Wolf - NAPCReN, Edmonton - Med Access, Wolf Manitoba - MaPCReN, Winnipeg - JonokeMed Ontario - DELPHI, London - Optimed-Accuro, OSCAR - UTOPIAN, Toronto - Nightingale, Practice Solutions, Bell EMR - EON, Kingston - P&P (4), OSCAR, Bell EMR, Practice Solutions (1), Nightingale (1) Québec - RRSPUM, Montréal - Da Vinci, Purkinje (2) Nova Scotia/New Brunswick - MaRNet, Halifax - Nightingale, Purkinje (3) Newfoundland - APBRN, St. John's - Wolf, Nightingale (1) = recruited but not yet operational (2) = nearly operational (3) = available (4) = supported as legacy 10 PBRNs across Canada

6. Methods • Study Population: Yearly Contact Groups from 2006 to 2012 • Yearly Contact Groups (YCG): All patients who had a recorded encounter in the year of study. • Prevalence Rates were determined using a yearly cross sectional analysis (YCG=denominator) • Antidepressant prescriptions: • SSRIs, SNRIs, TCAs, MAOIs, atypicals • It should be noted that antidepressants are used to treat depression as well as other disorders such as anxiiety and chronic pain.

7. YCG Age and Sex Distribution(2006 – 2012) Results - Denominator

8. Results: General Prescribing Rates

9. CPCSSN – Preliminary Findings on Incidence of Antidepressant Prescribing

10. Results: Gender Differences

11. CPCSSN – Preliminary Findings on Incidence of Antidepressant Prescribing

12. Results: Age Group Differences

13. Duration of Antidepressant Use: Methods • Drug Era: a span of time that a given person has been persistently exposed to a Drug Concept (drug name, brand name, class, or group) • Drug Era= Era end – Era start • Persistence window: the allowable span of time after a prescription is scheduled to be completed within which another prescription of the same drug needs to be filled in order to maintain persistence. • Persistence window = 30 days • Based on the Observational Medical Outcomes Partnership (OMOP) conservative approach * Reisinger SJ, Ryan PB, O’Hara DJ, Powell GE, Painter JL, Pattishall EN, Morris JA. Development and evaluation of a common data model enabling active drug safety surveillance using disparate healthcare databases. J Am Med Inform Assoc2010;17:652-662.

14. Duration of Antidepressant Use: 2006-2012

15. Time to end of Drug Era: all patients with an antidepressant Rx 1 year 2 years 3 years 4 years 5 years

16. Time to end of Drug Era: Patients with Drug Era <1 year 1 month 2 months 3 months 4 months 5 months 6 months

17. Discussion and Conclusions • Rates of antidepressant prescribing by primary care providers is increasing in both males and females and in youth, adults and seniors. • UK primary care study suggests that this is due to an increase in the proportion receiving long term treatment and not new ‘users’.+ This is supported by Canada survey data.++ • Preliminary incidence analysis using CPCSSN data supports these findings • Youth (15-24), Adults (25-64) and Seniors (65+) all have similar rates of increasing prevalence while antidepressant prescribing for children is relatively stable (<0.5%) • This suggests that guidelines are being followed as it is generally agreed that pre-pubescent depression is markedly different than depression seen after puberty. +Moore M, Yuen HM, Dunn N, et al. Explaining the rise in antidepressant prescribing: a descriptive study using the general practice research database. BMJ 2009;339:b3999 ++ Patten SB, Wang JL, Williams JV, et al. Frequency of antidepressant use in relation to recent and past major depressive episodes. Can J Psychiatry 2010 Aug;55(8):532-5.

18. Discussion and Conclusions • Duration of Use: 60% of patients prescribed (not incident cases) did not get their prescription renewed beyond 1 year. • Within this group: • 50% did not get their prescription renewed beyond 3months • 80% do not get their prescription renewed beyond 6months • By five years less than 5% are still taking the antidepressant

19. Some Cautions • Generalizability • Primary care population • Representativity of CPCSSN to the Canadian population • Prescriptions • No data on whether prescription was filled or antidepressant was taken • Incidence • misclassification

20. Our Team • Rachael Morkem Research Associate, Eastern Ontario Network (EON), CPCSSN • Dr. David Barber Network Direction, Eastern Ontario Network (EON), CPCSSN • Dr. Tyler Williamson Senior Epidemiologist, CPCSSN • Dr. Scott Patten Professor, University of Calgary

21. thanks to all funders, stakeholders, partners AND sentinel physicians Funding for this publication was provided by the Public Health Agency of Canada The views expressed herein do not necessarily represent the views of the Public Health Agency of Canada. Cette publication a été réalisée grâce au financement de l'Agence de la santé publique du Canada. Les opinions exprimées ici ne reflètent pas nécessairement celles de l'Agence de la santé publique du Canada.

23. Results: Children

24. Results: Youth

25. Results: Adults

26. Results: Seniors

27. Results: Age Group Differences

28. Results: Age Group Differences

29. Time to end of Drug Era: by Age Group 1 year

30. Time to end of Drug Era: by Gender 1 year

31. Time to end of Drug Era: by Drug Class aty = atypical ATD mao = monoamine oxidase inhibitors (MAOI) snr = selective norepinephrine reuptake inhibitors (SNRI) ssri = selective serotonin reuptake inhibitors (SSRI) tca = tricycle antidepressants (TCA) 1 year

32. Effect of Regulatory Warnings on Antidepressant Prescription Rates among children, adolescents and young adults • 2007 Paper

33. Effect of Regulatory Warnings on Antidepressant Prescription Rates among children, adolescents and young adults UK CA US

34. Results - Denominator Mean Age and Sex Distribution (2006-2012)