A literature search up to April 2007 identified controlled studies with tumor necrosis factor alpha (TNF-alpha) inhibitors infliximab, etanercept and adalimumab in treating psoriasis. The analysis focused on calculating the number needed to treat (NNT) and number needed to harm (NNH) and compared the risk of serious adverse events with those of dying in a car accident. The NNT values were 2.1, 1.4 and 1.6 for etanercept, infliximab and adalimumab, respectively. Depending on the adverse event (lymphoma, tuberculosis or demyelinating disease), the NNHs ranged from 380-360,000 treated patients/year. Based on 2005 U.S. traffic data, there were 21 fatalities/100,000 licensed drivers giving an NNH for one fatality of 4,700 drivers. Patients' risk ...