THE IMPLEMENTATION OF PREP WILL IMMEDIATELY REDUCE COSTS WITH COMPLEX TREATMENTS IN THE FUTURE.
Note from the editor of seropositivo.org: A Canadian dollar is worth R $ 2.42 in 23 / 03 / 2015
A Canadian document assessing the cost of using Pre-Exposure Prophylaxis (PrEP) to prevent HIV infection in relation to the total cost of maintaining the life of a patient under antiretroviral treatment, by the life expectancy of a single HIV-infected patient, based on the values available for Quebec and Ontario, PrEP would be the largest cost reduction in most scenarios, even if the overall cost-of-living of care for HIV-positive patients will decline in the future.
The document, published in January of 2015, prior to the Conference on Retroviruses and Opportunistic Infections (CROI 2015), in fact almost certainly underestimates the potential benefits of PrEP costs. The researchers, at the time of writing, had access to estimates of the cost of PrEP and HIV + (seropositive) patient care but did not have access to the actual efficacy of PrEP as seen in the Ipergay study, the study they used for modeling of their study.
They therefore based their estimate on the cost of an infection avoided according to the efficacy observed in the previous iPrEx study - 44%. In fact, the effectiveness seen in Ipergay was 86% - meaning that the cost per infection avoided would be considerably less.
In addition, the researchers use a high estimate of the overall cost of drugs used to take a regimen that is modeled on the Ipergay study. In this case, the average cost per person was about half of this.
The costs of preparation and treatment.
To calculate the cost of PrEP, the researchers added the cost of the emtricitabine / tenofovir (Truvada) regimen to indirect costs, such as lost work time for clinic visits, staff salaries, free condoms, and one year. The cost of Truvada was CA 9,505 dollars (US $) per year and other costs were $ 2.497 US dollars, or CA 12,001 dollars in total.
The cost of infection from an HIV life was based on diagnosis at 30 years (the average in Quebec) and on the current additional life expectancy (excluding people who inject drugs) from someone diagnosed at that age - 35,2 years. Researchers assume that the person with HIV begins antiretroviral therapy (ART) immediately. They cost two antiretroviral (ART) regimens an inexpensive (efavirenz / emtricitabine / tenofovir [Atripla]) and one expensive (darunavir [Prezista] plus [Truvada]). They also assume the 10% failure rate for these two early regimens and a second-line regimen of raltegravir or etravirine plus supportive medications.
Annual drug costs are $ 14093 or CA $ 22.040 in the lower cost and the higher cost scenario. Hospital costs were actually slightly lower than the annual cost of PrEP care: R $ 2016,00 per year. This is because trial participants in Ipergay were seen every two months, while HIV clinical visits are, as a rule, quarterly. This leads to a cost per patient, per year, of CA $ 16.109 for the cheapest drug regimen.
However, the modelers also added, something that is not always added to the cost models of HIV infection: its cost to the economy in terms of unemployment and lost productivity. Taking estimates from Quebec with the unemployment rate in people with HIV and lost time with productivity due to hospitalizations and clinical consultations, they calculated that the non-medical cost to the economy of each case of HIV was CA 11.550 dollars per year . The total annual cost to the economy of every person with HIV was therefore CA 27659 dollars in total for the cheapest drug regime.
The modelers noted that while there is clearly a higher unemployment rate among people with HIV in Canada compared to the general population, this is not the case with gay men in general, as they have similar employment rates with of people using PrEP.
(Editor's note: This is a fact which, as I have observed, maintains this disparity, that of proportional unemployment, which is always higher among people with HIV)
Given the expected life expectancy expected for the average person diagnosed with HIV, this would mean that the lifetime cost of an HIV infection would be 1.439.984 (Canadian) dollars for the cheaper regime.
The researchers then used a figure called the "number needed to treat". This represents the number of people who need to be given PrEP to avoid an HIV infection. In iPrEx this number was just under 52 years, leading to a cost per infection averted from CA 621.390 dollars.
This means that PrEP would save CA $ 818.594 per infection prevented.
Discounting future costs
However, future costs of HIV treatment are likely to be lower than they are now. This is because the situation of HIV-positive people may change: for example in the future it is likely that, less HIV-positive are unemployed. In addition, some people with HIV will die early from other causes, so the cost of their HIV infection will disappear from the model. Because of this, it is standard practice in modeling the long-term effects of health interventions to apply discounts to avoided future costs.
In the case of this model and in accordance with Canadian recommendations, modelers deduct the cost of an HIV infection from 3% to 5% per year per year of infection. In the case of a discount of 3%, this brings the lifetime cost of HIV infection up to $ 662,295 and PrEP still saves 40,905 dollars per infection avoided. But at a discount of 5%, the lifetime HIV cost becomes $ 448.901 and then PrEP costs $ 172.489 per infection averted - it may not be profitable under certain country guidelines. Adding in subsidies for improved quality of life, a possible "immune herd", effect of PrEP and other benefits reduces this cost to $ 60.223, but it is still not a cost reduction. That is, as far as this model achieves.
However, the cost per infection avoided by giving PrEP becomes much lower, using the number needed to treat (NNT) to prevent an HIV infection that was actually seen in the Ipergay study. This had 18 years, not 52 as in iPrEx. The annual cost per infection avoided from PrEP then becomes CA $ 216.018. If the NNT observed in PROUD is applied (13), then it is $ 156.013. This is a value still clearly seen in the discount rate of 5%, saving CA 232.883 dollars per HIV infection avoided even at the discount of 5% with the Ipergay NNT cost reduction - or $ 292,888 using the NNT PROUD figure.
In addition, as we have said above, the researchers have made conservative estimates that people who received PrEP under the Ipergay regimen actually reported sexually so many times that they ended up taking PrEP every day. In fact, Ipergay participants have used 50% of the drugs that total daily use would involve globally. This means that the cost per infection averted from an Ipergay annual scheme would be 108,009 dollars and the 5 savings% discount / lifetime would be $ 340.892. Even if the unemployment rate suddenly equalizes, and only direct medical costs due to HIV are allowed, which means that the 5% discount rate of the cost of living of an HIV infection becomes about $ 260,000 - and even less than the cost per infection avoided from an Ipergay regimen, even if taken daily.
It may be objected that the cost of each person putting in PrEP $ 12.001 is just an annual cost and this is being weighed against the cost of a lifetime's HIV treatment - while PrEP may also be taken for many years. The assumption is, however, that the incidence of HIV in the same people, if they did not receive PrEP would not change. In other words, for each year, PrEP in the amount of HIV infections for an additional year is avoided, to balance the annual cost of PrEP.
If the average risk behavior of the population who were in need of PrEP but who did not get to take it was decreasing, it would mean that they would experience fewer HIV infections and the PrEP savings would be lower. Likewise, if the risk behavior in people taking PrEP were rising relative to people who did not take it - a fear often expressed - then PrEP would become relatively more expensive and save less money. If the mean age at diagnosis was to rise by ten years for 40, then it is clear that the lifetime value of an HIV treatment would cost less - about 40% lower, based on the researchers' calculations - but PrEP there would still be cost savings for iPrEx NNT if costs incurred with HIV are not discounted and for the Ipergay and NUDs PROUDs at all discounts.
Finally, the estimate used for the cost-of-living of an HIV infection is greater in this role than in some roles. The US CDC estimates that the direct medical costs of HIV life infection are $ 618.900. That would raise the cost per HIV infection to under $ 200.000 at 5% off - but even so PrEP on the NNTs seen at Ipergay and PROUD would still be profitable.
Clearly, PrEP has considerable start-up costs and does not start saving money for short-term health systems. Large economies, compared to the cost of not implementing PrEP, will only accumulate over decades, and will only be significant if a significant proportion of the highly at-risk population decides to take PrEP - and while people with low risk do not. It can be a challenge to promote PrEP for those in need, while concealing that of low-risk people.
However, given the results of the new studies, it is difficult to devise scenarios in which PrEP based on Truvada does not produce long-term cost savings - something that health system managers should consider when deciding whether to implement it, it.
Posted on: March 20, 2015
Ouellet E et al. Cost effectiveness of 'on demand' HIV pre-exposure prophylaxis for non-drug-using men who have sex with men in Canada. Canadian Journal of Infectious Disease Medicine and Microbiology 26 (1): 23-29. 2015
Translated from the original in English Canada: PrEP use now could save considerable sums in the future by: Cláudio Santos de Souza in 22 of May of 2015
I think a research like this, based on the Brazilian reality would be very useful and, importantly, would optimize the work of prevention in closed systems submerged in vulnerability to HIV.
Reviewer Information: I have reviewed this text 11 times and I always remain in doubt about it being well drafted. I kindly ask that, in finding me incongruities, I will post in the comments the error so that I can correct it. By the way: My peripheral neuropathy becomes much worse on cold days, and a good part of this text has been typed only with the indicators and the middle finger of the left hand, since the right hand still has the aggravation of a reconstruction (sic) in as a result of an "accident of consumption" generated by the use of an office chain bought in a "chic decoration shop" as a birthday present. I need a sotware capable of listening to what I say and typing for me.