Restarting ART via re-testing

[jennifersmith203]

People who were previously on ART may choose to restart ART via re-testing and referral rather than returning directly to clinic. We should consider adding this route explicitly to the code.

[jennifersmith203]

For info - this modelling study estimated that 58% of positive tests in 2020 were people who had tested positive previously (doesn't necessarily mean they were on ART but still a huge proportion):

https://www.thelancet.com/journals/lanhiv/article/PIIS2352-3018(20)30315-5/fulltext

"As knowledge of status increased from 2000 to 2020, the median time to diagnosis decreased from 9·6 years (9·1–10) to 2·6 years (1·8–3·5), HIV testing positivity declined from 9·0% (7·7–10) to 2·8% (2·1–3·9), and the proportion of first-time diagnoses among all positive tests dropped from 89% (77–96) to 42% (30–55)."

[andrew-phillips-1]

Thanks - I will look again at that paper.

[andrew-phillips-1]

I gave this more thought and I think we probably don't need to explicitly model hiv tests in people who are already diagnosed. I think it will be sufficient that we model an increased rate_return when the person has access to any form of easy access testing. We will have to think about and discuss with others what types of testing qualify as "easy access". We will need to consider a range of possible values for the effect size given the uncertainty and probable variability in the effect. This is a much smaller change than I had been envisaging. I was earlier thinking that we might need to consider having tested = 1 in some people who are already registd=1 but I don't think this is needed and would confuse things. We do need to be careful when comparing our outputs on new diagnoses with data on "new" positive tests, as the paper Jenny highlights indicates. What do you all think ?