What do systematic reviews say?

TDF vs AZT

It is very uncertain whether TDF changes drug resistance compared with AZT (very low certainty).

• Tenofovir or zidovudine in three‐drug combination therapy with one nucleoside reverse transcriptase inhibitor and one… 2010 · Cochrane Headline outcomes only
  RR 20.43 [1.24, 335.9]
  1 study · 71 participants
  Very low