Diagnóstico precoz de la infección por VIH. Evaluación de la viabilidad, el impacto clínico y el coste de dos estrategias diferentes

Laburpena

Background. In Spain, the number of people living with HIV infections (PLWHIV) increases every year. Around 45-50% of the patients have a delayed diagnosis (CD4 <350 cells/mcl), and 30% advanced disease (CD4 <200 cells/mcl). Also, up to 30% of the HIV patients are unaware of their own status1. European Guidelines recommend testing HIV in persons with risk practices and/or clinical conditions associated with HIV infection, but in the clinical practice this is not routinely investigated or considered2. The revised CDC Guidelines on HIV screening in 2006 recommended routine HIV testing in a variety of Health Care settings3. This strategy is cost-effective in populations with HIV prevalence of at least 0.1%4. An European study exploring routine HIV “opt-out” diagnostic strategy has observed low prevalence of hidden HIV diagnoses, identifying only high risk and usually advanced HIV patients, thus not supporting this unselected HIV screening strategy5. It is still not clear which is the best screening strategy for HIV infection, but the increase of diagnoses in early stage of the infection must be a priority for Health Care Systems. Objectives. The main objective of this study is to evaluate the viability, the clinical impact and the incremental cost of two different HIV-screening strategies (routine versus risk practice and clinical conditions guided), in a Health area of Madrid. The secondary objectives are: to evaluate the rate of new HIV-infections in a population attended in an Emergency Department and a Primary Care Center, to describe the characteristics of the HIV-positive patients, the clinical impact of being attended by the Health System, the missed opportunities for previous diagnosis, to validate an HIV-risk practice and clinical conditions questionnaire (HIV-R Quest), and to purpose the best HIV-screening strategy according to the viability, the diagnostic profitability, the efficiency, and the economic impact. Methods. From 1st July 2012 to 31st May 2013, patients between 18-60 years of age, attending to a Hospital Emergency Room (ER) or a Primary Care Center (PCC) were included in a prospective, opened, one-arm study. Inclusion criteria were: age 18-60, attend to ER o PCC and written informed consent. The exclusion criteria were: prior HIV-infection diagnosis, not written informed consent or being already included in the study. All the patients were evaluated with both an HIV-R Quest and the HIV whole blood rapid test (HIV-RT) INSTI®. Results. 5,329 valid paired of HIV-R Quest and HIV-RT were performed, 69.3% in PCC; 50.36% were women, and the median age was 37 years (28-47); 74.92% were Spaniards. New HIV-infections rate was 4.1‰, and even higher in men, non Spaniards and in the ER. We identified 22 people with hidden HIV infection, and the median of CD4 was 232 cells/mcl with a median viral load of 5.1 Log; Most of the HIV-positive patients (90.9%) have had previous sanitary contact in the last two months. Missed opportunities for HIV diagnosis were estimated as a minimum of 31.8% and a maximum of 90.9%. HIV-R Quest was positive in 51.2% of the studied population, with a difference of 6% more in men (p<0.00). Sensitivity (SE) and Predictive Negative Value (PNV) of HIV-R Quest to predict HIV-infection were 100%. In PCC the screening coverage (ratio between screening and attended population) was higher than in ER. In DRIVE study, universal screening of risk practice and clinical conditions (RP&CC) before an HIV rapid test is cost saving, without missing newly diagnosed HIV infection, with respect to universal testing. Conclusions. The high Newly Diagnosed HIV infection rate found in DRIVE study supports the implementation of some more extended HIV screening strategies in Spain. Missed opportunities for HIV diagnosis were observed in one third of our population. A reliable and feasible HIV Risk Practice and Clinical Conditions self-Questionnaire identify people with no risk for HIV-infection, without missing any HIV diagnosis. Universal screening of RP&CC and HIV-RT in patients with RP&CC (HIV-R Quest positive), offers a more efficient strategy to recommend HIV-testing.