DOES THE CLINICALLY SIGNIFICANT DIFFERENCE IN VISUAL ANALOG SCALE PAIN SCORES VARY WITH GENDER, AGE, OR CAUSE OF PAIN

Objectives: To determine the minimum clinically significant difference in visual analog scale (VAS) pain scores for acute pain in the ED set ting and to determine whether this difference varies with gender, age, or cause of pain. Methods: A prospective, descriptive study of 152 ad ult patients presenting to the ED with acute pain. At presentation and at 20-minute intervals to a maximum of three measurements, patients m arked the level of their pain on a 100-mm, nonhatched VAS. At each fol low-up they also gave a verbal rating of their pain as ''a lot better, '' ''much the same,'' ''a little worse,'' or ''much worse.'' The minim um clinically significant difference in VAS pain scores was defined as the mean difference between current and preceding scores when pain wa s reported as a little worse or a little better. Data were compared ba sed on gender, age more than or less than 50 years, and traumatic vs n ontraumatic causes of pain. Results: The minimum clinically significan t difference in VAS pain scores is 9 mm (95% CI, 6 to 13 mm). There is no statistically significant difference between the minimum clinicall y significant differences in VAS pain scores based on gender (p = 0.17 2), age (p = 0.782), or cause of pain (p = 0.84). Conclusions: The min imum clinically significant difference in VAS pain scores was found to be 9 mm. Differences of less than this amount, even if statistically significant, are unlikely to be of clinical significance. No significa nt difference in minimum significant VAS scores was found between gend er, age, and cause-of-pain groups.