Uptake of HIV testing among pregnant women in Ontario: Results from the HIV seroprevalence study to June 2002

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Uptake of HIV testing among pregnant women in
Ontario Results from the HIV seroprevalence
study to June 2002

• Robert S. Remis, Carol Swantee, Carol Major,
  Margaret Fearon, Evelyn Wallace, Peggy Millson,
  Liviana Calzavara, Elizabeth Rea, Susan King,
  Marion Vermeulen, Elaine Whittingham and
• Robert Palmer
• Department of Public Health Sciences, University
  of Toronto
• Laboratories Branch and Public Health Branch,
  Ontario Ministry of Health and Long Term-Care
• Toronto Public Health Hospital for Sick
  Children
• Ontario HIV Treatment Network, 4th Annual
  Research Day,
• Toronto, Ontario, November 28, 2002

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Acknowledgments

• Central Public Health Laboratory, Ontario
  Ministry of Health and Long-Term Care
• Keyi Wu, programming
• Mark Fisher, systems consulting and custom
  download
• Prenatal Screening Evaluation Committee
• Frank McGee, co-ordinator
• Janis Tripp, consultant
• Funding
• AIDS Bureau, Ontario Ministry of Health and
  Long-Term Care
• Bureau of HIV/AIDS, STD and TB, Health Canada

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Background

• 1989-91 Ontario HIV seroprevalence study
• (Coates et al), 0.23 / 1,000
• February 1994 ACTG 076 showed ZDV reduced
• mother-infant HIV transmission by 67
• 1997 Modelled HIV prevalence, 0.70/1,000 and
  estimated uptake of prenatal HIV testing 1994-96,
  2025

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Ontario HIV screening program

• Spring 1995 Advisory to physicians to consider
  HIV testing of pregnant women at increased HIV
  risk
• August 1997 Committee formed to plan program
• December 1998 Minister announced program to
  offer HIV testing to all pregnant women
• January 1999 Promotional materials and
  requisitions sent to physicians
• September 2001 Memo included with prenatal test
  report to physicians who had not prescribed an
  HIV test

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Study objectives

• Quantify and characterize HIV prevalence among
  women of childbearing age in Ontario
• Evaluate the Ontario universal HIV screening
  program

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Data management

• Data extracted from LAByrinth (prenatal and HIV
  diagnostic databases)
• Study period January 3, 1999 to June 30, 2002
• Records from HIV prenatal database matched to
  records in
• HIV diagnostic database
• Matching allowed for different spelling and
  structure of
• name (double-barrelled first and last names)
  and reversal
• of month/day in birth date
• Separate prenatal tests aggregated into episode
  equivalent to the gestation period HIV uptake
  analysed for each pregnancy

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Data analysis

• Number of women tested at prenatal visit
  included
• Women for whom HIV test ordered on prenatal
  requisition, or tested though HIV diagnostic
  service
• Tests categorized as current or previous to
  pregnancy
• Analysis in SAS of
• Trends over time in proportion tested
• Testing rates by health region and age group
• HIV-positive women number and rates by type of
  test, region and quarter

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Number of pregnancies by health regionJanuary
1999 to June 2002
Number pregnancies Proportion
Toronto Central East, other Southwest Central West Ottawa Eastern, other Northern N/A or OFP 130,604 108,237 64,171 76,455 37,696 40,215 31,649 2,045 27 22 13 16 8 8 6
Total 491,072 100
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HIV testing among pregnancies by timing of HIV
test, Ontario
Proportion of pregnancies ()
10
HIV testing among pregnancies forselected health
regions
100
90
80
70
60
Proportion of pregnancies ()
50
40
30
Metro Toronto
Central East, other
20
Southwest
10
Central West
0
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Quarter (1999-2002)
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HIV testing among pregnancies forselected health
regions
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Proportion of pregnancoes tested for HIV by
health region, Quarter 2, 2002
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Number of PHUs in each region by proportion
tested for HIV, Quarter 2, 2002
Total PHUs
Number of PHUs by proportion of HIV testing uptake
50-59
90-100
80-89
70-79
60-69
1
1
Toronto
6
1
5
Central East, other
9
1
1
4
2
1
Southwest
7
6
1
Central West
1
Ottawa
1
5
5
Eastern, other
3
8
3
2
Northern
37
1
11
19
5
1
Total
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Number of HIV-positive pregnancies
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HIV-positive pregnancies by time of diagnosis
and quarter
15
Current
13
Previous
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Number of pregnancies
9
7
5
3
1
-1
Q1
Q3
Q1
Q3
Q1
Q3
Q1
1999
1999
2000
2000
2001
2001
2002
By Quarter
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Interpretation

• Actual uptake of HIV testing is somewhat higher
  due to false non-matches (especially in anonymous
  and coded HIV testing)
• Study does not indicate why HIV test uptake is
  less than ideal (qualitative research of pregnant
  women and physician survey have been done)
• Study does not indicate number of HIV-infected
  women undiagnosed
• Unlinked component of HIV seroprevalence study
  among women not HIV tested is (finally!) under way

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Conclusions 1

• Critical to capture data from HIV diagnostic
  database as well as from prenatal database
• HIV testing increased from 40 to 50 from
  January to May 1999, with modest increase until
  September, 2001
• Impact of memo from 60 to 76!
• Important regional differences in HIV test uptake
• Over 3.5 years, 113 women identified as
  HIV-positive, 35 previously diagnosed, 78 newly
  diagnosed
• Data suggests more high risk pregnant women are
  being offered and accepting HIV testing

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Conclusions 2

• According to model (not presented)
• Birth rate among diagnosed HIV-infected women is
  low
• 40 of HIV-infected women undiagnosed at
  conception remain undiagnosed
• An estimated 8-10 preventable mother-infant HIV
  transmissions occurred in 2001