1. Frequency of Pap testing in women aged 15-29 years in Alberta: A case of over-screening?
Sayeeda Amber Sayed MBBS MPH Christopher Naugler MD FRCPS
James A Dickinson MBBS PhD
Thanks to Maggie Guo MSc
Depts of Family Medicine
Community Health Sciences
Laboratory Medicine

2. Canadian Policy Began with annual smears
Walton report 1976: every 3 years
Stop after hysterectomy, or age 60
Canadian Task Force on Preventive Health Care (CTFPHC): 1991
Every 3 years from sexual debut
18 to 69
Sabotaged immediately

3. If a little is good, more must be better?

4. Sunnybrook and Women’s Health Sciences Centre http://www
All women should have regular Pap smears starting at the age of 18 or when they become sexually active. Many physicians believe that even virginal women should begin regular Pap tests at the age of 18. Women who have had a hysterectomy (surgical removal of the uterus) and those past menopause still need to have regular Pap tests. Women who have had four normal Pap tests in the previous ten years may discontinue Pap tests at the age of 70.
Accessed July 2004

5. Sunnybrook and Women’s Health Sciences Centre http://www
All women should have regular Pap smears starting at the age of 18 or when they become sexually active. Many physicians believe that even virginal women should begin regular Pap tests at the age of 18. Women who have had a hysterectomy (surgical removal of the uterus) and those past menopause still need to have regular Pap tests. Women who have had four normal Pap tests in the previous ten years may discontinue Pap tests at the age of 70.
Medical rape
Accessed July 2004

6. Sunnybrook and Women’s Health Sciences Centre http://www
All women should have regular Pap smears starting at the age of 18 or when they become sexually active. Many physicians believe that even virginal women should begin regular Pap tests at the age of 18. Women who have had a hysterectomy (surgical removal of the uterus) and those past menopause still need to have regular Pap tests. Women who have had four normal Pap tests in the previous ten years may discontinue Pap tests at the age of 70.
Uncomfortable and cruel
Because there is so little disease, then of course, pap testing is doing it!
Accessed July 2004

7. Effect on Mortality and Incidence
Good national data
Mortality: death register
National available from 1932
Incidence: Cancer registries
National available from 1972

8. Age-Specific Incidence of Invasive Cervical Cancer in Canada, 1972-200640 35 30 25
Rate per 100,000 20
When data is arranged by years.
Greatest effects in middle age. Incidence rates dropped to 1/3 for most women over 40.
Lower absolute reductions and prevented fractions at younger ages 15 10 5
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
Age of group (years)
Dickinson JA, Stankiewicz A, Popadiuk C, Pogany L, Onysko J Miller AB. BMC Public Health :992 8 8

9. Mortality from Invasive Cervical Cancer in Canada in Periods from 1972 to 200630 28 26 24 22 20 18 16
Rate per 100,000 14 12
For mortality: the reduction is steadily greater with older age, both proportional and absolute.
Problems at young and old end.
Young: minimal effect. Old: still rising mortality: why? 10 8 6 4 2
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
Age group
Dickinson JA, Stankiewicz A, Popadiuk C, Pogany L, Onysko J Miller AB. BMC Public Health :992 9 9

10. Guideline changes in Alberta
Pre 2009; start age 18, annual screening
2009 start age 21, 3 tests in 5 yrs then 3 yr
2013 CTFPHC based on epidemiology
Start age 25, every 3 years
2016 Alberta Guidelines
Follow CTFPHC

11. How did screening change in response to guidelines?
Calgary Lab Services
Services for city of Calgary: ~ 1 Mill
Unified database
Measure:
Pap tests
Major biopsies

12. Pap tests by age in Calgary 2006-2015
Alberta Guideline
CTFPHC

13. Changes Major reduction around 2009:
Alberta guidelines
No effect of 2013 Canadian Task Force
Rates dropping rapidly for Teenagers
But still too many
Rates still over 33% for >22 yrs
Implies many more often than 3 yearly

14. Rate of abnormal tests in the population

15. Effect on abnormal test rate?
Later start, longer intervals, fewer tests
Time to develop more severe abnormalities
Disease should be concentrated
Hypotheses
Higher abnormal rate among those tested
Higher biopsy rate among those tested

16. Rates of abnormal tests in women who had a test 2007-2015
Abnormal rates peak for yr old. Much lower for 25yrs.
Largely remains flat, despite reductions
Only effect for teenagers in last few years. Perhaps effect of CTFPHC 2013

17. Rates of abnormal tests in women who had a test 2007-2015
Abnormal rates peak for yr old. Much lower for 25yrs.
Largely remains flat, despite reductions
Only effect for teenagers in last few years. Perhaps effect of CTFPHC 2013

18. Biopsy rates among tested women
Note his set is only for the years after 2009.
Biopsy rates low for teenagers, peak 22/23, lower thereafter.

19. Outcomes Abnormal test rates steady
Except: Reducing in cohort with HPV vaccine
No concentration of disease
Peak in young 20s, lower with age
Biopsy rates dropping: before HPV reductions
? Change in disease
? Changes in diagnosis by pathologists
? Changes in practice: referrals, colposcopy

20. Conclusions Less testing does not concentrate disease
Suggests that rates of abnormalities in unimmunized cohorts are similar, regardless of testing rates.
Vast majority are false positives
Pap testing young women causes (random?) harm for 10-20%, for unmeasurably small benefit.

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23. How do we change Physicians? Patients?
James A. Dickinson, Gina Ogilvie, Dirk Van Niekerk, and Cathy Popadiuk. Evidence that supports policies to delay cervical screening until after age 25 years
CMAJ March 13, :E380-E381; doi: /cmaj

24. Frequency of Pap testing in women aged 15-29 years in Alberta: Clearly a case of over-screening.
Sayeeda Amber Sayed MBBS MPH Christopher Naugler MD FRCPS
James A Dickinson MBBS PhD
Thanks to Maggie Guo MSc
Depts of Family Medicine
Community Health Sciences
Laboratory Medicine