Cost-effectiveness of laboratory monitoring for management of HIV treatment in sub-Saharan Africa: a model-based analysis.

OBJECTIVE: To compare the cost-effectiveness of three different strategies for long-term monitoring of antiretroviral therapy (ART) failure and regimen switching in sub-Saharan Africa: a symptom-based approach, or monitoring of either CD4 cell counts or plasma viral load (pVL). DESIGN: Markov model. SETTING AND PARTICIPANTS: Hypothetical HIV-infected adult population who began first-line ART and subsequently had up to 6 years of follow-up. MAIN OUTCOME MEASURES: Total cost, life expectancy and incremental cost-effectiveness ratio (ICER). RESULTS: A symptom-based approach yielded a life expectancy of 64.0 months at a total cost of US$ 4028 per person. All laboratory-based strategies, at testing intervals of 6 or 12 months, were cost-saving and improved life expectancy, compared with a symptom-based approach. The life-expectancy gain was larger for pVL than for CD4 strategies at 6-monthly (2.3 and 0.9 months, respectively) and 12-monthly testing (2.0 and 0.8 months, respectively). Cost-savings of 6-monthly pVL or CD4 testing were similar (US$ 630 and 621, respectively), whereas 12-monthly CD4 cell counts were more cost-saving than 12-monthly pVL (US$ 1132 and 880, respectively). Testing every 12 months - rather than every 6 months - decreased the ICER by 102% for CD4 cell count and 67% for pVL. These findings were robust to a wide range of deterministic sensitivity analyses, but were sensitive to the specificity and costs of diagnostic tests. CONCLUSION: Additional diagnostic costs are balanced by cost-savings from avoiding unnecessary switching due to misdiagnosis of ART failure. Routine pVL monitoring may be preferred as a replacement for CD4 cell counts because of its additional public-health advantages in preventing drug-resistance, supporting adherence and reducing HIV transmission.

HIV-1 resistance testing influences treatment decision-making

OBJECTIVE: To investigates how the use of HIV-1 resistance tests influences physician decision-making. METHODS: Ten experienced reference physicians from the Brazilian Network for Drug Resistance each received ten patients' case histories. The selected patients had experienced at least two virological failures. First, reference physicians were asked to empirically select a new regimen for each patient. Second, after genotype report (ViroSeq 2.6) was provided, and physicians were again asked to select a new regimen considering this additional information. Finally, they were asked to select a regimen after receiving a virtual phenotype result (vircoTYPE 3.9.00). RESULTS: In 79 percent of the cases, physicians changed their empirical choice of regimen after receiving the genotype report, resulting in an increase in the mean number of active drugs from 1.8 to 2.2 (p = 0.0003), while the average number of drugs/regimen remained at 4.0. After receipt of the virtual phenotype report, additional changes were made in 75 percent of the patient cases, resulting in an increase in the number of active drugs to 2.8 (p < 0.0001), while the average number of drugs/regimen remained at 4.0. After receipt of the genotype report, 48 percent of the changes were in NRTIs, 29 percent were in NNRTIs and 60 percent were in PIs; after consideration of the virtual phenotype, 61 percent, 10 percent and 49 percent of the changes, respectively, were in these categories of drugs. Fourteen percent of the physicians rated the genotype report as "extremely useful", whereas 34 percent rated the subsequent virtual phenotype report as "extremely useful" (p = 0.0003). CONCLUSIONS: Resistance testing has a significant impact on physicians' choices of antiretroviral salvage therapies, and it promotes the selection of more active drugs.

HIV-1 resistance testing influences treatment decision-making.

OBJECTIVE: To investigates how the use of HIV-1 resistance tests influences physician decision-making. METHODS: Ten experienced reference physicians from the Brazilian Network for Drug Resistance each received ten patients' case histories. The selected patients had experienced at least two virological failures. First, reference physicians were asked to empirically select a new regimen for each patient. Second, after genotype report (ViroSeq 2.6) was provided, and physicians were again asked to select a new regimen considering this additional information. Finally, they were asked to select a regimen after receiving a virtual phenotype result (vircoTYPE 3.9.00). RESULTS: In 79% of the cases, physicians changed their empirical choice of regimen after receiving the genotype report, resulting in an increase in the mean number of active drugs from 1.8 to 2.2 (p = 0.0003), while the average number of drugs/regimen remained at 4.0. After receipt of the virtual phenotype report, additional changes were made in 75% of the patient cases, resulting in an increase in the number of active drugs to 2.8 (p < 0.0001), while the average number of drugs/regimen remained at 4.0. After receipt of the genotype report, 48% of the changes were in NRTIs, 29% were in NNRTIs and 60% were in PIs; after consideration of the virtual phenotype, 61%, 10% and 49% of the changes, respectively, were in these categories of drugs. Fourteen percent of the physicians rated the genotype report as "extremely useful", whereas 34% rated the subsequent virtual phenotype report as "extremely useful" (p = 0.0003). CONCLUSIONS: Resistance testing has a significant impact on physicians' choices of antiretroviral salvage therapies, and it promotes the selection of more active drugs.