title: Validity, reliability, and responsiveness of a digital version of the visual analog scale.
abstract: The design used in this study was a prospective cohort. Pain intensity levels recorded by the digital version of the visual analog scale (VAS-D) are easy to both score and share with other health care professionals. The purpose of the study was to examine the test-retest reliability, concurrent validity, and responsiveness of the VAS-D. Thirty-three people with upper extremity injuries reported pain intensity levels before and after performing four maximal grip contractions (pre- and postgripping). Our version of the VAS-D had high test-retest reliability (r=0.96) and good concurrent validity (r=0.84-0.97) with both the paper version of the VAS (VAS-P) and the verbal numerical rating scale (NRS-V). Responsiveness of the VAS-D was indicated by a significant increase in pain levels from pre- to postgripping. Similar responsiveness to that of the VAS-P and NRS-V was indicated by similar effect size coefficients and analysis of variance of pain change scores. In conclusion, the VAS-D is a reliable, valid, and responsive measure of pain intensity for people with upper extremity injuries. However, differences in accuracy (resolution) among the VAS-D, VAS-P, or NRS-V may render the three pain scales not fully compatible.
  
  
  METHODS
  Not applicable.
authors.affiliation: Department of Occupational Science and Technology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA. sindhu@uwm.edu
authors.forename: Bhagwant S
authors.initials: BS
authors.lastname: Sindhu
authors.forename: Orit
authors.initials: O
authors.lastname: Shechtman
authors.forename: Laura
authors.initials: L
authors.lastname: Tuckey
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001134:Arm Injuries / Q000175:diagnosis*; D015331:Cohort Studies; D003936:Diagnosis, Computer-Assisted; D004185:Disability Evaluation; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000175:diagnosis*; D010147:Pain Measurement / Q000295:instrumentation* / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results