Table 2.

Summary of factors that explain differences in conclusions between randomized control trials and cohort studies

Variable	Clinical Trial	Cohort Study
Selected patients	Patients are often selected; no kidney dysfunction before treatment	Unselected patients who can have CKD before TDF initiation
Therapeutic history	Frequently naive patients	Frequently ARV-experienced patients
Associated ARVs	Frequently NNRTI	Frequently boosted PI
HIV disease	Often, recent diagnosis of HIV infection	Patients more susceptible to having advanced HIV disease
Studied kidney measure	Decrease of GFR <90 ml/min per 1.72 m2 or even <60 ml/min per 1.72 m2	Modification of eGFR that can significantly decrease while remaining >90 ml/min per 1.72. m2
Follow-up and duration of TDF exposure	Short follow-up (<1 yr) and duration of TDF treatment	Frequently, longer follow-up and exposure duration
Study finding	More commonly financed by pharmaceutical companies	More commonly independent studies
Resulting effect	Patients whose kidney function is very likely to benefit from the antiviral effect of TDF	Patients more at risk of cardiovascular and kidney complications of long-term HIV infection and ARV treatment

NNRTI, non-nucleoside reverse transcription inhibitor.