Kwan’s arm problem scale: psychometric examination in a sample of stage II breast cancer survivors
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Arm/shoulder problems and lymphedema are common in patients treated for breast cancer. The Kwan’s arm problem scale (KAPS) is a 13 items self-rating form developed for examination of such problems. Since no such testing has been done, we wanted to examine the psychometric properties of the KAPS. At a median of 47 months (range 32–87 months) post-surgery, 256 stage II breast cancer survivors filled in the KAPS. Findings from physical examination of arm/shoulder function, assessment of lymphedema, and established measures of quality of life (QOL), mental distress and fatigue were used to study convergent and discriminant validity. Factor structure and internal consistency were tested in split-half samples. The total KAPS as well as its two subscales showed high internal consistency (α ≥ 0.92). A two factor solution explained 70% of the variance in the total KAPS score. Convergent validity was shown as the total KAPS score explained 32.5% of the variance in abduction of the ipsilateral shoulder. Discriminant validity was shown as the total KAPS score explained only 6.7% of the variance in abduction of the contralateral shoulder. Concurrent validity was confirmed since the total KAPS explained 54.8% of the variance in arm symptom subscale of breast cancer-specific QOL. Area under the curve was 0.80 for problems of using the arm at a cut-off of the total KAPS score of 21.5. The results show that the KAPS has good psychometric properties supported by high reliability and considerable convergent and discriminant validity.
KeywordsArm morbidity Breast cancer Kwan’s arm problem scale Lymphedema Patient based rating Shoulder problems
Center for shared Decision Making and Nursing Research, Rikshospitalet University Hospital has funded the first author during the writing up of this paper.
- 2.Haid A, Köberle-Wührer R, Knauer M, Burtscher J, Fritzsche H, Peschina W et al (2002) Morbidity of breast cancer patients following complete axillary dissection or sentinel node biopsy only: a comparative evaluation. Breast Cancer Res Treat 73:31–36. doi: 10.1023/A:1015234318582 PubMedCrossRefGoogle Scholar
- 8.Rietman JS, Dijkstra PU, Hoekstra HJ, Eisma WH, Szabo BG, Groothoff JW et al (2002) Late morbidity after treatment of breast cancer in relation to daily activities and quality of life: a systematic review. Eur J Surg Ca 29:229–238Google Scholar
- 10.Sprangers AG, Groenvold M, Arraras JI, Franklin J, te Velde A, Muller M et al (1996) The European Organization for research and treatment of cancer breast cancer-specific quality of life questionnaire module: first results from a three country field study. J Clin Oncol 10:2756–2768Google Scholar
- 12.Ware JE, Snow KK, Kosinski M et al (2000) SF-36® health survey: manual and interpretation guide. Quality Metric Inc., LincolnGoogle Scholar
- 14.Ware JE Jr, Gandek B, Kosinski M, Aaronson NK, Apolone G, Brazier J et al (1998) The equivalence of SF-36 summary health scores estimated using standard and country-specific algorithms in 10 countries: results from the IQOLA Project International Quality of Life Assessment. J Clin Epidemiol 51:1167–1170. doi: 10.1016/S0895-4356(98)00108-5 PubMedCrossRefGoogle Scholar
- 15.Loge JH, Kaasa S, Jensen Hjermstad M, Kvien TK (1998) Translation and performance of the Norwegian SF-36 health survey in patients with rheumatoid arthritis. I. Data quality, scaling assumptions, reliability, and construct validity. J Clin Epidemiol 51:1069–1076. doi: 10.1016/S0895-4356(98)00098-5 PubMedCrossRefGoogle Scholar