Development and validation of the Basal and Squamous Cell Carcinoma Quality of Life (BaSQoL) Questionnaire

Health-related quality of life (HRQoL) is important in the management of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Disease-specific questionnaires exist, but with important shortcomings. The aim of this study was to develop and validate a questionnaire suitable for use in all patients with BCC and those with SCC. In a 4-phase trajectory, a preliminary questionnaire was created and population-based testing (1,173 patients) carried out. The questionnaire was reduced using exploratory factor analysis and item response theory. Individual item performance was assessed using classical test theory. A total of 721 patients completed the questionnaire. The number of items was reduced to 16, covering 5 scales. Confirmatory factor analysis showed a good fit. Cronbach's αs (range 0.67-0.82) were reasonable to high with good internal consistency. In conclusion, the Basal and Squamous Cell Carcinoma Quality of Life questionnaire has good face, content and construct validity. It is useful in the wide range of BCC and SCC patients and captures HRQoL impact over different time-frames