Interestingly, Paech and colleagues found comparable results in their study on adherence to HAART using a similar design as we did. Their findings add to the evidence that only about half of all patients take HAART as directed when skipping of antiretroviral pills as well as deviation from the recommended intake schedule are being considered.
Paech and colleagues found no effect on adherence of dosing frequency and number of pills prescribed. Because they investigated adherence in an observational study, this finding could have been owing to prescription bias. Most likely, physicians prescribe simpler regimens to patients known or suspected to have problems with adherence. Consequently, comparable levels of adherence are to be expected when comparing simple and more complex HAART regimens. Determining the effect of regimen complexity on adherence would require random allocation of therapy. Indeed, higher adherence rates have been reported for a HAART regimen with twice-daily dosing without mealtime instructions compared with a HAART regimen with 3 times–daily dosing in addition to mealtime instructions in a randomized clinical trial.1 Highly active antiretroviral therapy regimens are of the most complex therapies ever prescribed for an indefinite time. We believe that every effort should be made to simplify HAART regimens to facilitate patient adherence.
Nieuwkerk PT, Lange JMA, Sprangers MAG. Adherence to HAART: Why Is It So Difficult?—Reply. Arch Intern Med. 2002;162(10):1197-1198. doi: