title: Retrospective study of adjunctive diode laser therapy for pain attenuation in 662 patients: detailed analysis by questionnaire.
abstract: OBJECTIVE
  The aim of this study was to assess the long-term effects of low-level laser therapy (LLLT) through a retrospective survey using questionnaires.
  
  
  BACKGROUND
  The use of LLLT for chronic pain attenuation has been reported in the international literature for over 20 years.
  
  
  METHODS
  We used a series of diode laser systems in which the most effective wavelength was consistently found to be 830 nm with an output power in continuous-wave of 60 mW. Subjects were 1,087 patients treated by LLLT at the Shiroto Clinic from April 1992 to August 1995. Questionnaires were sent to subjects in September and October 1996.
  
  
  RESULTS
  The reply rate was 60.9%, comprising 662 questionnaires (265 males, 397 females, mean age of 53.4 years). The total efficacy rating (excellent plus good) immediately after LLLT was 46.8% in men and 47% in women. At the time of the survey, this rose to 73.3% in men and 76.8% in women, with positive effects also recorded on psychosomatic factors such as well-being, physical energy, general fatigue, mental vigor, and emotional stability. LLLT effects continued for 1-3 days. No statistically significant difference in efficacy was seen between males and females. LLLT as used in the study is therefore considered safe, effective, and side-effect-free, making it an ideal adjunctive therapeutic modality for intractable chronic and other pain.
  
  
  CONCLUSIONS
  Infrared diode LLLT is therefore considered safe, effective, and side-effect-free, making it an ideal adjunctive therapeutic modality for intractable chronic pain.
authors.affiliation: Department of Hygiene, Hirosaki University School of Medicine, Aomori, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Nakaji
authors.forename: Chiyuki
authors.initials: C
authors.lastname: Shiroto
authors.forename: Misako
authors.initials: M
authors.lastname: Yodono
authors.forename: Takashi
authors.initials: T
authors.lastname: Umeda
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D028022:Low-Level Light Therapy; D008297:Male; D008875:Middle Aged; D010148:Intractable Pain / Q000532:radiotherapy*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires