Background
Rationale for Modeling HIV Self-Testing
Issues: | Data required (including format of estimate) | Possible source of data (if available) |
---|---|---|
1. What proportion of population is resistant to HTC (i.e. they will be tested only if symptomatic)? |
\(\frac{{\# {\text{ Of people resistant to HTC}}}}{{\# {\text{ Of people in the entire population}}}}\)
| – |
2. Would people who would not have accessed HTC opt to self-test? |
\(\frac{{\# \;{\text{Of people resistant to HTC who self-test}}}}{{\# {\text{ Of people resistant to HTC}}}}\)
| |
3. Would people who would have accessed HTC to test for the first time instead opt for HIVST? |
\(\frac{{\# {\text{ Of first-time testers using HIVST}}}}{{\# {\text{ Of all first-time testers}}}}\)
| – |
4. Would people who would have accessed HTC for repeat HIV testing instead opt for HIVST? |
\(\frac{{\# {\text{ Of HIVST conducted in people who tested before}}}}{{\# {\text{ Of tests }}\left( {\text{HIVST or HTC}} \right){\text{ conducted among people who tested for HIV before}}}}\)
| |
5. Is the subgroup of those who choose HIVST different from the population who access HTC? | Characteristics (including demographics and sexual behaviour) of people who choose HIVST, who choose HTC and who choose not to test for HIV | – |
6. Would the availability of HIVST Increase the chance that people who have never tested (who are non-resistant to testing) of testing for the first time? If so, by how much? |
\(\frac{{\# {\text{ Of first-time testers}},{\text{ when HIVST is available}}}}{{\# {\text{ Of first-time testers}},{\text{ when HIVST is not available}}}}\)
Data on total # of HTC administered and HIVST kits distributed, if possible broken down by whether first or repeat test, could help inform these parameters | – |
7. Would the availability of HIVST increase the frequency of repeat testing? If so, by how much? |
\(\frac{\text{Rate of testing when HIVST is available}}{{{\text{Rate of testing when HIVST is not available}}}}\)
Data on total # of HTC administered and HIVST kits distributed, if possible broken down by whether first or repeat tests, could help informing these parameters | [42] |
8. Are the characteristics of people whose rate of testing increases with the availability of HIVST different from those for whom the frequency does not increase? | Data on characteristics of people with increased rate of testing and for whom the rate of testing does not increase (including demographics and sexual behaviour) | – |
9. Do people seek confirmatory HTC following a positive HIVST? |
\(\frac{{\# {\text{ Of people who receive a positive HIVST and seek confirmatory HTC}}}}{{\# {\text{ Of people who receive a positive HIVST}}}}\)
| |
10. What is the sensitivity of HIVST when conducted by lay people? |
\(\frac{{\# {\text{ Of people with a positive result using HIVST and using the gold standard HTC}}}}{{\# {\text{ Of people with a positive result using gold standard HTC}}}}\)
| |
11. What is the specificity of HIVST when conducted by lay people? |
\(\frac{{\# {\text{ Of people with a negative result using HIVST and using the gold standard HTC}}}}{{\# {\text{ Of people with a negative result using gold standard HTC}}}}\)
| |
12. What, if any, change in sexual behaviour occurs following a positive and negative HIVST? |
\(\frac{{\#{\text{ Of condom-less partners or condom-less sex acts after a positive HIVST result}}}}{{\#{\text{ Of condom-less partners or condom-less sex acts before HIVST}}}}\)
\(\frac{{\# {\text{ Of condom-less partners or condom-less sex acts after a negative HIVST result}}}}{{ \# {\text{ Of condom-less partners or condom-less sex acts before HIVST }}\left( {{\text{and how this differs}},{\text{ if at all}},{\text{ from change after HTC}}} \right)}}\)
| [38] |
13. What is the cost of implementing HIVST in RLS? | Cost of implementing a HIVST program if self-test kits are free to the end user (including kit and distribution and support costs) | – |
14. What is the quality of life following a positive or a negative HIVST as compared to the same result communicated by a provider? |
\(\frac{\text{Quality of life after reading a positive HIVST result}}{\text{Quality of life before HIVST}}\)
\(\frac{\text{Quality of life after reading a negative HIVST result}}{\text{Quality of life before HIVST}}\)
To compare against:
\(\frac{\text{Quality of life after a positive result communicated by a health care provider}}{\text{Quality of life before HTC}}\)
\(\frac{\text{Quality of life after a negative result communicated by a health care provider}}{{{\text{Quality of life before HTC }}}}\)
| [39] |
15. How well do people link to post-test care after being diagnosed HIV-positive following HIVST, as compared to being diagnosed following HTC? |
\(\frac{{\# {\text{ Of people diagnosed with HIV who link to care }}\left( {\text{defined as evaluation of eligibility for ART initiation}} \right){\text{ following a positive HIVST}}}}{{\# {\text{ Of people who are diagnosed }}\left( {\text{have a confirmatory HTC}} \right){\text{ following a positive HIVST}}}}\)
To compare against:
\(\frac{{\# {\text{ Of people diagnosed with HIV who link to care following a diagnosis not as a consequence of a positive HIVST}}}}{{\# {\text{ Of people who are diagnosed with HIV not as a consequence of a positive HIVST}}}}\)
| |
16. How well are people retained in care after being diagnosed HIV-positive following HIVST, as compared to being diagnosed following HTC? |
\(\frac{{\# {\text{ Of people who are retained in care }}\left( {\text{among those eligible and ineligible for ART}} \right){\text{ at 1 and n years since diagnosis prompted by a positive HIVST}}}}{{\# {\text{ Of people who were diagnosed as a consequence of a positive HIVST 1 and n years ago}}}}\)
To compare against:
\(\frac{{\# {\text{ Of people who are retained in care }}\left( {\text{among those eligible and ineligible for ART}} \right){\text{ at 1 and n years since diagnosis not prompted by a positive HIVST}}}}{{\# {\text{ Of people who were diagnosed with HIV}},{\text{ not as a consequence of a positive HIVST}},{\text{ 1 and n years ago}}}}\)
| – |
Other considerations (which cannot be captured by the current model and have not been discussed due to the limited space) | ||
17. For people who have never tested for HIV, or do not attend regular repeat testing, what are the reasons for not testing? Which barriers, if any, might be overcome with the availability of HIVST? How can HIVST programming be designed to help overcome these barriers? | Some reasons for not having tested before: -Not wanting to know the result of the HIV test -Inconvenience/opportunity cost including: waiting time to have an HIV test, distance to the facility which provide HIV test, cost -Real or perceived lack of confidentiality -Stigma associated with testing -Not believing oneself to be at risk -Poor treatment by testing staff | [13] |
18. Would people use HIVST to test new partners for HIV, and would they act on these results (by either using protection or not having sex)? |
\( \frac {{\text{ People who would use HIVST to test new partners}}}{\text{ People with new partners}} \)
| [32] |