CE_Selftesting_BMGF_Feb2015.pdf

1. Assessment of the potential impact and cost‐
effectiveness of self‐testing for HIV in low
income countries
Valentina Cambiano, Deborah Ford, Travor Mabugu, Sue Napierala
Mavedzenge, Alec Miners, Owen Mugurungi, Fumiyo Nakagawa,
Paul Revill, Andrew Phillips
In press with Journal of Infectious Diseases

2. Question
Donors and stakeholders:
Should investment be made to support product
development, promotion and marketing of self‐
testing in low income countries?
Our aim: To evaluate whether the availability of
self‐testing (ST), in addition to standard testing
conducted by health care workers (“HCW‐
testing”) provides value.

3. Parameter Value Source
Accuracy of ST SE = 92%; SP = 99% FDA Approval Oraquick In‐
Home HIV test
Accuracy of HCWT SE = 98%; SP = 100% Pant Pai et al., Lancet Inf
Dis 2012
Increase in the rate of 1st
and repeat test due to ST
availability
20% ‐
Substitution of HCWT with
ST
30% of repeat tests;
10% of 1st time tests
‐
Reduction in the %
“resistant to testing”
From 5% to 2.5% ‐
Confirmatory HCWT
following positive ST
80% by 1 y from
positive ST
Evidence on disclosure from
Choko et al. CROI 2014
Linkage to care 60% by 1 year since
diagnosis
Rosen et al., AIDS 2011
Main assumptions

4. Parameter Value Source
Change in sexual
behaviour (SB) in those
who are tested HIV+ by
HCWT
with primary P: ‐13%,
with casual P: ‐17% in the
first 6 ms, ‐9% after
Kennedy et al. AIDS
Behav 2012; Fonner et al.
Cochrane 2012
Change in SB in those
tested HIV‐ by HCWT
No change Cremin et al. Aids
Behavior 2010
Change in SB after ST The same as HCWT ‐
Disability weights WHO 4 event: 0.55;
TB: 0.40;
WHO 3 event: 0.22
Salomon et al. Lancet
2012
Cost HCWT (fully loaded) Neg $9;
Pos $25
$10 in Eaton et al. Lancet
Global Health (2014)
Cost of ST $3 ‐
CD4 threshold for ART <500 cells/mm3 Zimbabwe MoH
Main assumptions on self‐testing

5. Summary of assumptions on testing if ST is not
introduced

6. Assumed effect of introduction of self‐testing:
impact on % tested in the last year and ever
50%
66%
79%
83%
28%
39%
50%
57%
0% 20% 40% 60% 80% 100%
Reference
Self‐testing
201120152035
% ever tested % tested for HIV in the last year
DHS data

7. Assumed effect of introduction of self‐testing:
impact on % diagnosed, % on ART
85%
93%
93%
56%
69%
69%
0% 20% 40% 60% 80% 100%
Reference
Self‐testing
20152035
% diagnosed % on ART (of those HIV+)

8. Impact on total cost and sources of costs
ART cost (1st line: TDF+3TC+NEV)1: $ 116 Visit: $ 20
WHO4: $ 200 CD4 measurement: $ 10
WHO3: $ 20 negative HCW‐test: $ 9
TB: $ 50 positive HCW‐test: $25
Cotrimoxazole (per year): $ 5 self‐test: $ 3
1 – Cost from MSF report 2013 increased by 20% to include supply chain costs;
consistency with Menzies et al PLOS One 2012;
Scenarios:
REFERENCE
SELF‐TESTING
HCWT

9. Overview of costs and health benefits
Zimbabwe estimated GDP:$500
http://www.indexmundi.com/zimbabwe/economy_profile.html
‐80
‐60
‐40
‐20
0
20
Difference in discounted cost in US$
millions over 20
Discounted DALYs averted over 20 years
No self‐testing
‐2000 0 2000 4000 6000 8000
Introduction of
self‐testing

10. Overview of costs and health benefits – introduction
of self‐testing vs NO self‐testing
Zimbabwe estimated GDP:$500
http://www.indexmundi.com/zimbabwe/economy_profile.html
‐80
‐60
‐40
‐20
0
20
Difference in discounted cost in US$
millions over 20
Discounted DALYs averted over 20 years
No self‐testing
‐2000 0 2000 4000 6000 8000
Introduction of
self‐testing
2.6% in cost
<0.005% in DALYs

11. Sensitivity analysis ‐ most cost‐effective options
Cost effectiveness threshold in
US $
Total
discounted Δ in
costs in US$
millions*
Total discounted
DALYs averted in
thousands**
(95% CI)
0 500 1,000 5,000 10,000
Base case (B) STS STS STS STS STS ‐75 (‐77; ‐73) 7 (1; 13)
Cost of ST (B: US$3) = cost of
negative HCWT (US$9)
RS RS RS RS RS 136 (134; 137) 7 (1; 13)
Sensitivity of ST = 0.55 (B: 0.92) STS STS STS STS RS ‐81 (‐84; ‐79) ‐11 (‐22; ‐1)
Probability of diagnosis (HCWT)
following a +ve ST = 0.37 (B: 0.8)
STS STS STS STS STS ‐87 (‐90; ‐84) 0.1 (‐11; 11)
Linkage to care following
diagnosis for those who had a ST
0.4 by 1 year (B: 0.6)
STS STS STS RS RS ‐105 (‐112; ‐97) ‐19 (‐32; ‐6)
ART initiation at CD4<350
cells/mm3 (vs <350 cells/mm3
without introduction of ST)
STS STS STS RS RS ‐69 (‐74; ‐64) ‐21 (‐40; ‐2)
No reduction in risk behaviour
following a positive ST
STS STS STS STS STS ‐74 (‐77; ‐70) 19 (6; 33)
STS = self‐testing scenario; RS = reference scenario;

12. Sensitivity analysis ‐ most cost‐effective options
Cost effectiveness threshold in US $ Total discounted
Δ in costs in US$
millions
Total
discounted
DALYs averted
in thousands*
0 500 1,000 5,000 10,000
Increase in rate
of 1st test due to
ST (B: 20%)
2.5% STS STS STS STS STS ‐82 (‐85; ‐79) 10 (‐1; 20)
7.5% STS STS STS STS STS ‐81 (‐85; ‐78) 13 (‐1; 26)
Increase in rate
of repeat test
due to ST (B:
20%)
2.5% STS STS STS STS STS ‐102 (‐105; ‐99) 4 (‐6; 14)
7.5% STS STS STS STS STS ‐82 (‐86; ‐78) 13 (‐1; 26)
Substitution (B:
30% of repeat
test, 10% 1st
test)
5% of repeat,
2% 1st test
RS RS STS STS STS 38 (34; 41) 39 (20;57)
15% of repeat,
5% 1st test
STS STS STS STS STS ‐12 (‐17; ‐7) 22 (5; 39)
25% of repeat,
8% 1st test
STS STS STS STS STS ‐52 (‐57; ‐47) 20 (1; 39)
STS = self‐testing scenario; RS = reference scenario;

13. Conclusions
Given the characteristics of self‐testing specified in our base
scenario, introduction of self‐testing is cost‐effective at any cost –
effectiveness thresholds between $0 and $10,000.
Introduction of ST will allow modest savings in healthcare costs of
$75 million over 20 years in Zimbabwe, with a small (7,000)
number of DALYs averted.
If we assume a CET of $500 (similar to Zimbabwe GDP per capita in
2012), the US$75 million saving could be used to avert at least
150,000 DALYs by introduction of interventions with ICERs ≤ $500
per DALY averted.

14. Conclusions
Considering a cost‐effectiveness threshold of $1,000 or below, the
only circumstances in our univariate sensitivity analysis where
self‐testing may not be cost‐effective are:
• when the cost of the self‐test is the same as the cost of a
negative HCW‐test ($9).
• If the substitution is less than 1/3 of that assumed in the base
scenario (~5% of repeat and ~2% of 1st test).

15. Conclusions
Considering a cost‐effectiveness threshold of $1,000 or below, the
only circumstances in our univariate sensitivity analysis where
self‐testing may not be cost‐effective are:
• when the cost of the self‐test is the same as the cost of a
negative HCW‐test ($9).
• If the substitution is less than 1/3 of that assumed in the base
scenario (~5% of repeat and ~2% of 1st test).
The parameters that we found were most influential in
determining the cost‐effectiveness of introducing ST are:
• Cost of ST
• Linkage to care following self‐testing
• Level of substitution of HCWT with self‐testing
• Sensitivity of self‐testing

16. Considerations
• We investigated the introduction of HIV self‐testing in the
context of Zimbabwe, it is plausible the benefit is even greater
in settings with lower level of HIV testing and higher HIV
prevalence in the populations not tested for HIV.
• The model is set up to evaluate the cost‐effectiveness of
introduction of self‐testing in the general population and
specific sub‐populations, but we need better data to give us a
precise idea of DALYs actually averted and cost effectiveness.

17. Acknowledgements
Andrew Phillips
Debbie Ford
Fumiyo Nakagawa
Paul Revill
Alec Miners
Supported by: Bill and Melinda Gates
Foundation (Global Health Grant
Number OPP1064862
Stefano Bertozzi
Michael Borowitz
Charlene Brown
Augustine Choko
Liz Corbett
Cari Courtenay‐Quirk
Frances Cowan
Geoff Garnett
Sue Mavedzenge
Cheryl Johnson,
Christine Rousseau
Mickey Urdea