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).


METHODS
Markov model.


METHODS
Hypothetical HIV-infected adult population who began first-line ART and subsequently had up to 6 years of follow-up.


METHODS
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.


CONCLUSIONS
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.
PharmAccess Foundation, Department of Global Health, Academic Medical Center of the University of Amsterdam and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands. r.hamers@aighd.org
Raph L
RL
Hamers
A W
AW
Sawyer
Martin
M
Tuohy
Wendy S
WS
Stevens
Tobias F
TF
Rinke de Wit
Andrew M
AM
Hill
D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000191:economics* / Q000453:epidemiology; D017954:Africa South of the Sahara / Q000453:epidemiology; D019380:Anti-HIV Agents / Q000191:economics* / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count / Q000191:economics; D019411:Clinical Laboratory Techniques / Q000191:economics*; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008390:Markov Chains; D019057:Quality-Adjusted Life Years; D018571:Sentinel Surveillance; D017211:Treatment Failure; D019562:Viral Load / Q000191:economics
D019380:Anti-HIV Agents