Cohen 2002.

Methods	A prospective open‐label randomized controlled clinical trial conducted at 25 university and private practice centres in the USA
Participants	272 participants Inclusion: at least 13 years of age; documented HIV‐1 infection; HIV‐ 1‐RNA plasma levels ≥ 2000 copies/mL; antiretroviral experience; experiencing virological failure on antiretroviral treatment consisting of ≥ 2 NRTIs and only 1 PI, taken for at least 1 month before screening Exclusion: history of alcohol or drug use judged as likely to interfere with therapy; previous phenotypic resistance testing; had participated in an antiretroviral drug trial within 30 days of selection or during the trial; had a life expectancy < 6 months; had disease that could interfere with assessments NB: Patients with previous NNRTI therapy were later allowed to participate.
Interventions	Intervention: phenotypic resistance testing (PRT) (i.e. antiretroviral regimens chosen with PRT and external expert advice coupled with access to published treatment guidelines and participants' treatment histories) Control: standard of care (SOC) (i.e. antiretroviral regimens chosen on the basis of access to published treatment guidelines and participants' treatment histories)
Outcomes	Virological success (< 400 copies/mL), change in viral load, change in CD4 cell count Follow‐up: 16 weeks
Notes	All participants provided informed consent. Study was funded by Glaxo Wellcome, Inc. (primary) and Virco NV.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomly assigned to intervention and control groups.
Allocation concealment (selection bias)	Low risk	Centrally located randomization was used with block size of 4.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Arm assignments were not blinded (knowledge of allocation is unlikely to introduce bias).
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Trial authors did not report this information (knowledge of allocation is unlikely to introduce bias).
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses to follow‐up were balanced between groups. Trial authors performed ITT analyses.
Selective reporting (reporting bias)	Low risk	Trial authors reported all outcomes of interest.
Other bias	High risk	Study was supported by manufacturers of resistance tests.
Overall risk assessment	High risk	Risk is due to the uncertainties raised above.