title: Net benefits of resistance testing directed therapy compared with standard of care in HIV-infected patients with virological failure: A meta-analysis.
abstract: 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.
  
  
  CONCLUSIONS
  Genotype testing with expert interpretation showed the greatest benefit for guiding therapy in patients with HIV infection and virological failure.
authors.affiliation: HIV Unit, Department of Internal Medicine, Hospital Marina Baixa, Avda. Alcalde En Jaime Botella Mayor 7, 03570 Villajoyosa, Alicante, Spain. ena.jav@gva.es
authors.forename: Javier
authors.initials: J
authors.lastname: Ena
authors.forename: Rosa F
authors.initials: RF
authors.lastname: Ruiz de Apodaca
authors.forename: Concepción
authors.initials: C
authors.lastname: Amador
authors.forename: Concepción
authors.initials: C
authors.lastname: Benito
authors.forename: Francisco
authors.initials: F
authors.lastname: Pasquau
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology* / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D024882:Drug Resistance, Viral; D005500:Follow-Up Studies; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010641:Phenotype; D012367:RNA, Viral / Q000097:blood; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D016896:Treatment Outcome; D019562:Viral Load; D014773:Virology / Q000379:methods*
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral