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Development of a Short Version of the Modified Yale Preoperative Anxiety Scale

Jenkins, Brooke N. MS*†; Fortier, Michelle A. PhD*†; Kaplan, Sherrie H. PhD*‡§; Mayes, Linda C. MD; Kain, Zeev N. MD, MBA*‖

doi: 10.1213/ANE.0000000000000350
Pediatric Anesthesiology: Research Report

BACKGROUND: The modified Yale Preoperative Anxiety Scale (mYPAS) is the current “criterion standard” for assessing child anxiety during induction of anesthesia and has been used in >100 studies. This observational instrument covers 5 items and is typically administered at 4 perioperative time points. Application of this complex instrument in busy operating room (OR) settings, however, presents a challenge. In this investigation, we examined whether the instrument could be modified and made easier to use in OR settings.

METHODS: This study used qualitative methods, principal component analyses, Cronbach αs, and effect sizes to create the mYPAS-Short Form (mYPAS-SF) and reduce time points of assessment. Data were obtained from multiple patients (N = 3798; M age = 5.63) who were recruited in previous investigations using the mYPAS over the past 15 years.

RESULTS: After qualitative analysis, the “use of parent” item was eliminated due to content overlap with other items. The reduced item set accounted for 82% or more of the variance in child anxiety and produced the Cronbach α of at least 0.92. To reduce the number of time points of assessment, a minimum Cohen d effect size criterion of 0.48 change in mYPAS score across time points was used. This led to eliminating the walk to the OR and entrance to the OR time points.

CONCLUSIONS: Reducing the mYPAS to 4 items, creating the mYPAS-SF that can be administered at 2 time points, retained the accuracy of the measure while allowing the instrument to be more easily used in clinical research settings.

Published ahead of print July 9, 2014.

From the *Department of Anesthesiology & Perioperative Care, †Department of Psychology and Social Behavior, ‡Health Policy Research Institute, and §Department of Medicine, University of California, Irvine, Irvine, California; and ‖Child Study Center, School of Medicine, Yale University, New Haven, Connecticut.

Published ahead of print July 9, 2014.

Accepted for publication May 9, 2014.

Funding: This research was funded by National Institutes of Health grant numbers: R01HD37007-01, R01HD37007-02, R01HD037007-04, 2R01HD037007-06, and R01HD048935-01A1.

The authors declare no conflicts of interest.

Reprints will not be available from the authors.

Address correspondence to Michelle A. Fortier, PhD, Department of Anesthesiology & Perioperative Care, University of California, Irvine, 505 S. Main St. Suite 940, Orange, CA 92868. Address e-mail to

© 2014 International Anesthesia Research Society