Dalhousie dyspnea scales: construct and content validity of pictorial scales for measuring dyspnea
1 Departments of Psychology, Pediatrics, and Psychiatry, Dalhousie University, NS, B3H 4J1, Canada
2 IWK Health Centre, Halifax, NS, B3K 6R8, Canada
3 Department of Pediatrics Dalhousie University and IWK Health Centre, Halifax, NS, B3K 6R8, Canada
4 School of Health and Human Performance and School of Occupational Therapy, Dalhousie University, 1459 Oxford Street, Halifax, NS, B3H 4R2, Canada
BMC Pediatrics 2005, 5:33 doi:10.1186/1471-2431-5-33Published: 30 August 2005
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.
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".
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.
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.