Dalhousie dyspnea scales: construct and content validity of pictorial scales for measuring dyspnea.
BACKGROUND
Because there are no child-friendly, validated, self-report measures of dyspnea or breathlessness, we developed, and provided initial validation, of three, 7-item, pictorial scales depicting three sub-constructs of dyspnea: throat closing, chest tightness, and effort.


METHODS
We developed the three scales (Throat closing, Chest tightness, and Effort) using focus groups with 25 children. Subsequently, seventy-nine children (29 children with asthma, 30 children with cystic fibrosis. and 20 children who were healthy) aged 6 to 18 years rated each picture in each series, using a 0-10 scale. In addition, each child placed each picture in each series on a 100-cm long Visual Analogue Scale, with the anchors "not at all" and "a lot".


RESULTS
Children aged eight years or older rated the scales in the correct order 75% to 98% correctly, but children less than 8 years of age performed unreliably. The mean distance between each consecutive item in each pictorial scale was equal.


CONCLUSIONS
Preliminary results revealed that children aged 8 to 18 years understood and used these three scales measuring throat closing, chest tightness, and effort appropriately. The scales appear to accurately measure the construct of breathlessness, at least at an interval level. Additional research applying these scales to clinical situations is warranted.
McGrath
Patrick J
PJ
Department of Psychology, Dalhousie University, NS, B3H 4J1, Canada. Patrick.McGrath@dal.ca
Pianosi
Paul T
PT
Unruh
Anita M
AM
Buckley
Chloe P
CP
D000293:Adolescent; D001249:Asthma / Q000503:physiopathology*; D001296:Audiovisual Aids; D002648:Child; D004417:Dyspnea / Q000145:classification / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D012720:Severity of Illness Index