ALLHAT: a critical assessment

The ALLHAT study has attracted considerable attention in the media and in the research community, partly due to the study's unexpected and controversial conclusions. However, the study has several serious shortcomings. The primary end-points in ALLHAT were negative and the conclusions are based entirely on secondary end-points and subgroup analyses. Moreover, there is good reason for skepticism concerning the findings on heart failure in ALLHAT, because of ambiguity in the diagnosis, lack of information on blood pressure and absence of a "washout" period. The study design was severely flawed and does not reflect clinical reality. Also, blood pressure differences between groups severely complicate interpretation. From a patient perspective in ALLHAT, there are drug safety concerns with the thiazides, as there was evidence of excess diabetes development. The ALLHAT results are difficult to generalize and have limited relevance in European settings. Thus, the ALLHAT study suffers from several major shortcomings and there is a huge body of evidence that contradicts the ALLHAT interpretations.