Why do a large-size cohort study ?

Although randomized controlled trials are the optimal methodology to assess the issue of efficacy and safety of drug interventions, there are several arguments in favour of carefully performed large prospective cohort studies as a much needed supplement, including:

1. until now controlled trials of antiretroviral drugs have usually had a rather short follow-up time (median follow-up time < 9-12 months), this does not allow for an assessment of the long-term effect of new antiretroviral drugs;
2. the usual strict in- and exclusion criteria in controlled trials may exclude a significant portion of HIV-infected patients otherwise seen and treated in the clinics around Europe and in other parts of the world;
3. the rate of rare, late-onset adverse drug reactions of antiretroviral therapy might not be assessed in controlled trials.

For more information o­n the use of cohort studies in HIV/AIDS, please see The Forum for Collaborative HIV Research. This Forum is an independent public/private partnership which facilitates and enhances HIV research.http://www.hivforum.org/

Updated: 15 Jun 2011