Abstract
An increasing number of clinical reports on the application of low reactive-level laser therapy (LLLT) in pain attenuation are appearing in the literature, but very few of these reports include a blinding procedure to offset the possible placebo effect of laser therapy, especially with smaller patient populations. The present study describes a protocol set up to remove as much as possible any skewing of the data by the placebo effect. The trial is set up in two (or more) geographically distant institutes under similar environmental conditions. Patients with a variety of pain complaints are selected for the study with similar demographic characteristics in all trial sites, and are each assigned a patient number for trial identification purposes. Treatment parameters are standardized for a single LLLT session using the same laser system at the same parameters (in the present study a GaAlAs diode laser, 830 nm, c/w, 60 mW was used). A computer is programmed to assign real or sham laser treatment randomly to each patient number, every time the number changes as sensed in the computer by the use of the laser therapy system main power switch. The same computer, located distantly from the treatment room, controls the laser system directly to produce real and sham laser therapy, and neither the patient, the therapist nor the computer operator is thus aware to which group the patient has been assigned by the computer, which stores these data to be retrieved after the trial and assessment are complete. A comprehensive record chart is used to record pre- and post therapy subjective and objective evaluations for both individual pain groups and the population as a whole, including any adverse side effects and machine safety, with a series of scores being finally compiled to give an overall efficacy rate. The last stage of the trial involves subjecting the results for the real and sham groups to direct statistical analysis using a combination of χ2 and Fischer’s tests. A value of p= <0.01 is significant with a level of confidence of less than 1%. These data are examined for each pain group and for the population as a whole site by site, and finally similar data for the total population in all the sites is compiled.
