Observational studies help us understand how to treat pandemic influenza and other emerging virus diseases

In his editorial, Zhang (1) comments on my earlier article that suggested inexpensive and widely available generic drugs might be used to reduce mortality from pandemic influenza, Ebola and other emerging virus diseases (2). He notes that several earlier studies explored the possibility that statins might be used to treat patients with sepsis and acute respiratory distress syndrome (ARDS) (1). Many individual observational studies [for example, (3)] and their meta-analyses (4) have suggested that statins might be effective in these patients, but several randomized controlled trials (RCTs) have failed to demonstrate their efficacy (5,6). Critical care specialists, many of them involved in these RCTs, have expressed different opinions on whether statins should still be considered potentially useful (7-9). In my view, the question is still open; the RCTs were conducted in mechanically ventilated ICU patients, and many of these patients were started on treatment late in the course of illness. Thus, statin treatment by itself may have been “too little, too late”. Nonetheless, the experimental and clinical rationale for this general approach to treating the host response in patients with critical illness is still persuasive. For many reasons, it must be further explored (2).