Incremental cost per newly diagnosed HIV infection (NDHI): routine (RTS), targeted (TTS), and current clinical practice testing strategies (CPTS)

INTRODUCTION Although RTS as HIV Diagnosis was considered cost effectiveness [1], overall budget may be unaffordable for some countries. We explore Incremental cost per NDHI associated with different TS. MATERIALS AND METHODS From a health care perspective, using direct costs and Euros currency, we calculated budget and cost per NDHI of RTS (all patients were tested), TTS (Universal risk practices and clinical conditions-RP&CC - only positive were tested), and CPTS (Only patients physicians considered were tested). We considered DRIVE (Spanish acronym of HIV infection Rapid Diagnosis) study and clinical Practice outcomes. Population between 18-60 years, attending to a Hospital Emergency Room or to a Primary Care Center performed an HIV RP&CC questionnaire (Q) and an HIV rapid test (HIV RT). Unitary costs considered were: HIV RT, nurse, registry, transport and HIV confirmation when necessary, imputed to all population in RTS and CPTS and only in HIV RP&CC-Q positive in TTS analysis, while HIV RP&CC-Q costs were added to all population in TTS. Sensitivity analyses were performed with varying rates of NDHI and of positive HIV RP&CC-Q population, and different RP&CC Q sensitivity (SE) to predict HIV infection. RESULTS 5,329 HIV RP&CC-Q and HIV RT were performed to 49.64% women, median age 37 years old, 74.9% Spaniards. In DRIVE and CP, NDHI were 4.1‰, and 1.6‰, while HIV RP&CC-Q was positive in 51.2%. HIV RP&CC-Q SE was 100%. Overall budget employed in HIV testing was in RTS 43,503€, in TTS 24,472€ and in CPTS 5,032€. Cost per 1 NDHI was 1,977€, 1,112€ and 5,032€, respectively. A reduction in cost of 865€, favouring TTS vs. RTS, while an increased cost of 824€ in CPTS vs. RTS was obtained. Considering NDHI rate of 2.6‰ saving costs increased to 1379€ in TTS, while were reduced to 576€ if NDHI rate increases 6.2‰. Effect of RP&CC-Q positivity rate was similar, if 25% saving costs were 1368€, while if 75% were reduced to 399€. Varying SE of RP&CC-Q to 95%, 91% and 50% cost saving was 810€, 754€, and 208€, and number of MHI one, two and 11. CONCLUSIONS In DRIVE study Targeted TS with universal screening of RP&CC before an HIV rapid test is cost saving, without missing NDHI, with respect to Routine TS. Lower rates of HIV infection and RP&CC in the population, increase costs savings.