<prompt> Translate the following text to EnglishHaijulikani wazi kama matokeo mazuri ya muda mrefu yalitokea kutokana na majaribio haya, kwani kuelekezwa kwa matibabu ndiyo iliyokuwa variable ya matokeo iliyochunguzwa mara nyingi.  <response>: It is not always clear whether there were long-term positive outcomes from these trials since referral has been the outcome variable most often studied. 