The Pharmacoepidemiology of antidepressant prescribing in CanadaRACHAEL 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.

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efficacy of antidepressants In the last five years extensive reviews of published and unpublished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.

Objective

To describe the current landscape of antidepressant prescribing in primary careFor children (1-14), youth (15-24), adults (25-64) and

seniors (65+)For males and females

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

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 10 PBRNs across Canada

(1) = recruited but not yet operational(2) = nearly operational(3) = available(4) = supported as legacy

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.

YCG Age and Sex Distribution(2006 – 2012)

Results - Denominator

Patient Characteristics    2006 2007 2008 2009 2010 2011 2012    n % N % n % n % n % n % n %Gender

  Male 41047 40% 68825 41% 86811 41%10202

1 41%11533

0 41%12586

2 41%13173

1 42%

  Female 61234 60% 99761 59%12439

1 59%14584

3 59%16371

7 59%17809

2 59%18590

2 59%Age (group)  1-14 15384 15% 24637 15% 30148 14% 35860 14% 38905 14% 42281 14% 44104 14%  15-24 10768 11% 20628 12% 25029 12% 28607 11% 31249 11% 33282 11% 32292 10%

  24-64 57794 56% 93435 55%11813

1 56%13810

6 55%15541

9 55%16785

4 55%17371

3 55%  65+ 18365 18% 31032 18% 39515 19% 46408 19% 54498 19% 61000 20% 65767 21%

TOTAL10231

116973

221282

324898

128007

130441

731587

6

Results: General Prescribing Rates

2006 2007 2008 2009 2010 2011 20120.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%Yearly Antidepressant Prescription Rates

CPCSSN – Preliminary Findings on Incidence of Antidepressant Prescribing

Results: Gender Differences

2005 2006 2007 2008 2009 2010 2011 2012 20130.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%Yearly Antidepressant Prescription Rates by Gender

Male

CPCSSN – Preliminary Findings on Incidence of Antidepressant Prescribing

Results: Age Group Differences

2005 2006 2007 2008 2009 2010 2011 2012 20130.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%Antidepressant Prescribing Rates by Age Group

Children Linear (Children) Youth Linear (Youth)Adults Linear (Adults) Seniors Linear (Seniors)

Duration of Antidepressant Use: Methods

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

• 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)

* 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 Assoc 2010;17:652-662.

Duration of Antidepressant Use: 2006-2012 Age Group

Duration (days)Number

Mean Confidence Limits Median

Children 1-14 345 [208, 482] 148 47

Youth 15-24 328 [316, 339] 165 4657

Adults 25-64 391 [386, 397] 203 26974

Seniors 65+ 384 [374, 394] 202 7360

Time to end of Drug Era: all patients with an antidepressant Rx

1 year

2 years

3 years 4

years 5 years

1 month

3 months

2 months

4 months

5 months 6

months

Time to end of Drug Era: Patients with Drug Era <1 year

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.

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

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

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

thanks to all funders, stakeholders, partners AND sentinel physicians

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.

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.

Results: Children

2005 2006 2007 2008 2009 2010 2011 2012 20130.00%

0.05%

0.10%

0.15%

0.20%

0.25%

0.30%

0.35%

0.40%

Children (1-11) Yearly Antidepressant Prescribing Rates

Results: Youth

2005 2006 2007 2008 2009 2010 2011 2012 20130.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

Youth (12-24) Antidepressant Prescribing Rate

Results: Adults

2005 2006 2007 2008 2009 2010 2011 2012 20130.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

Adult (25-64) Antidepressant Prescribing Rate

Results: Seniors

2005 2006 2007 2008 2009 2010 2011 2012 20130.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

Seniors (65+) Antidepressant Prescribing Rates

Results: Age Group Differences

2005 2006 2007 2008 2009 2010 2011 2012 20130.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

18.00%

Female Antidepressant Prescription Rates by Age Group

Children Linear (Children) Youth Linear (Youth)Adults Linear (Adults) Seniors Linear (Seniors)

Results: Age Group Differences

2005 2006 2007 2008 2009 2010 2011 2012 20130.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

Male Antidepressant Prescribing Rates by Age Group

Children Linear (Children) Youth Linear (Youth)Adults Linear (Adults) Seniors Linear (Seniors)

1 year

Time to end of Drug Era: by Age Group

1 year

Time to end of Drug Era: by Gender

Time to end of Drug Era: by Drug Class

1 year

aty = atypical ATD

mao = monoamine oxidase inhibitors (MAOI)

snr = selective norepinephrine reuptake inhibitors (SNRI)

ssri = selective serotonin reuptake inhibitors (SSRI)

tca = tricycle antidepressants (TCA)

Effect of Regulatory Warnings on Antidepressant Prescription Rates among children, adolescents and young adults

2007 Paper

2004 2005 2006 2007 2008 2009 2010 2011 20120

20

40

60

80

100

120

Prevalence of Antidepressant Prescriptions per 1000 children (5-11), adolescents (12-17) and young adults (19-24)

Children Adolescents Young Adults

Prev

alen

ce p

er 1

000

Effect of Regulatory Warnings on Antidepressant Prescription Rates among children, adolescents and young adults

UK CA US

Mean Age and Sex Distribution (2006-2012)

Results - Denominator

Mean Std Dev Min Max

FemaleChildren 6.4 4.5 1 14

Youth 19.7 2.8 15 24Adults 44.9 11.2 25 64Seniors 75.5 7.8 65 113MaleChildren 6.9 4.1 1 14

Youth 19.2 2.8 15 24Adults 46.8 10.9 25 64Seniors 74.5 7.1 65 112

16%

10%

53%

20%

Males

1-14 15-24 24-64 65+

10.97

11.39

58.37

19.26

Females