Research design issues in pain clinical trials

The science of conducting randomized clinical trials to investigate treatments for pain began with landmark studies in the 1950s and 1960s by Henry Beecher, Raymond Houde, Louis Lasagna, Abraham Sunshine, and Stanley Wallenstein. These studies focused on acute pain, and not until the 1980s did the attention of the field turn to treatments for chronic pain. The end of the field’s infancy was marked by the publication in 1991 of “The design of analgesic clinical trials ,” a volume that comprehensively reviewed methods for evaluating the efficacy of analgesic medications for treatment of different types of acute and chronic pain.1 Although clearly related, acute and chronic pain are distinct phenomena. Chronic pain has been defined as pain that persists beyond the normal time of healing,2 but pain can also …