To compare three anxiety scales; the anxiety visual analogue scale (VAS), the anxiety component of the Amsterdam preoperative anxiety and information scale (APAIS), and the state portion of the Spielburger state-trait anxiety inventory (STAI), for assessment of preoperative anxiety levels in same day admission patients. Patients completed the three anxiety assessment scales both before and after seeing the anesthesiologist preoperatively. The scales used were the STAI, the six-question APAIS, and the VAS. APAIS was further subdivided to assess anxiety about anesthesia (sum A), anxiety about surgery (sum S) and a combined anxiety total (i.e., sum C = sum A + sum S). These scales were compared to one another. Pearson's correlation (pair-wise deletion) was used for validity testing. Cronbach's alpha analysis was used to test internal validity of the various components of the APAIS scale. A correlation co-efficient (r) > or = 0.6 and P < 0.05 were considered significant. Four hundred and sixty three scale sets were completed by 197 patients. There was significant and positive correlation between VAS and STAI r = 0.64, P < 0.001), VAS and APAIS r = 0.6, P < 0.001), sum C and STAI r = 0.63, P < 0.001) and between VAS and sum C r = 0.61, P < 0.001). Sum C and STAI r value were consistent with repeated administration. Cronbach's alpha-levels for the anxiety components of the APAIS (sum C) and desire for information were 0.84 and 0.77 respectively. In addition to VAS, the anxiety component of APAIS (sum C) is a promising new practical tool to assess preoperative patient anxiety levels.
