Net benefits of resistance testing directed therapy compared with standard of care in HIV-infected patients with virological failure: A meta-analysis

Enferm Infecc Microbiol Clin. 2006 Apr;24(4):232-7. doi: 10.1016/s0213-005x(06)73768-5.


Background: We incorporated the latest available information to evaluate the net benefit of using resistance testing in HIV-infected patients with virological failure.

Methods: Meta-analysis of randomized controlled trials comparing the clinical impact of selecting antiretroviral therapy according to results of resistance testing (phenotype or genotype) or according to the standard of care. The population studied included HIV-infected patients with virological failure. The outcome measures were the proportion of patients with HIV-RNA below the detection limit, and the decline in HIV-RNA and increase in CD4 lymphocyte count at the end of follow-up (< or = 24 weeks). Clinical trials were identified through searches in MEDLINE, EMBASE and proceedings from major infectious diseases meetings.

Results: Eight trials including a total of 1810 patients were eligible. Therapy guided by resistance testing resulted in a higher percentage of patients with HIV-1 RNA below the detection limit at the end of follow-up (< or = 24 weeks) as compared with the standard of care (40.2% vs. 32.9%). The pooled risk ratio was 1.23; 95% CI 1.09-1.40, p = 0.0009; test for heterogeneity I(2)=0%; p = 0.46). The number needed to treat [NNT] was 13 (95% CI: 9-25). Subgroup analysis showed greater benefits in therapy guided by genotype testing with expert interpretation, when compared with standard of care (NNT: 5; 95% CI: 3-9; p = 0.06). The heterogeneity among trials for evaluating HIV-1 RNA decline and CD4 lymphocyte cell count increase made unfeasible pooling the results across studies.

Conclusion: Genotype testing with expert interpretation showed the greatest benefit for guiding therapy in patients with HIV infection and virological failure.

Publication types

  • Comparative Study
  • Meta-Analysis

MeSH terms

  • Anti-HIV Agents / pharmacology*
  • Anti-HIV Agents / therapeutic use
  • Antiretroviral Therapy, Highly Active*
  • CD4 Lymphocyte Count
  • Drug Resistance, Viral*
  • Follow-Up Studies
  • Genotype
  • HIV Infections / drug therapy*
  • HIV-1 / drug effects*
  • HIV-1 / genetics
  • Humans
  • Microbial Sensitivity Tests / methods*
  • Phenotype
  • RNA, Viral / blood
  • Randomized Controlled Trials as Topic
  • Retrospective Studies
  • Risk Factors
  • Treatment Failure
  • Treatment Outcome
  • Viral Load
  • Virology / methods*


  • Anti-HIV Agents
  • RNA, Viral