Level 4:Efficacious. In order to be considered “efficacious,” a treatment must meet the following criteria:In a comparison with a no-treatment control group, alternative treatment group, or sham (placebo) control utilizing randomized assignment, the investigational treatment is shown to be statistically significantly superior to the control condition or the investigational treatment is equivalent to a treatment of established efficacy in a study with sufficient power to detect moderate differences;The studies have been conducted with a population treated for a specific problem, from whom inclusion criteria are delineated in a reliable, operationally defined manner;The study used valid and clearly specified outcome measures related to the problem being treated;The data are subjected to appropriate data analysis;The diagnostic and treatment variables and procedures are clearly defined in a manner that permits replication of the study by independent researchers, andThe superiority or equivalence of the investigational treatment have been shown in at least two independent studies” (LaVaque et al. 2002, p. 280).
