The development of supportive care needs scale for Thai women with breast cancer undergoing chemotherapy

Abstract

Assessment of supportive care needs before setting up care plans plays significant role in conducting patient-centered care, particularly supportive care needs of Thai women with breast cancer undergoing chemotherapy whose treatment process is specifically different from other group of cancer patients. It was found that supportive care needs scales constructed in western countries had certain limitations of some question items concerning difference in context, ways of life, and culture. Hence they could not assess consistently with all needs of Thai context.

This study aims to develop supportive care needs scale for Thai women with breast cancer undergoing chemotherapy with two stage instrumental development process. In Stage I, the scale was constructed by determining operational definition and attributes of supportive care needs by interviewing 10 Thai women with breast cancer undergoing chemotherapy. Data were analyzed to provide a framework for development of 62 question items. Content validity was checked by seven experts and was found to have content validity by version of 0.91. Questions were edited and the remaining 55 items were tried out with 30 samples. Cronbach’s Alpha was found to be 0.886. In Stage II, the instrument’s quality was examined. Psychometric properties of the proposed scale was tested by Exploratory Factor Analysis with 350 samples and Confirmatory Factor Analysis with 352 samples at eight super tertiary cancer care units, from all four regions of Thailand, in order to assess construct validity and reliability of the instrument.

Results of the Exploratory Factor Analysis using common factor method which was a Principle Components Analysis (PCA) and Varimax with Kaiser Normalization method determined value of factor loading at 0.3. The resulting final version of the questionnaire had 43 items in eight components that could explain data variation at 69.66 percent of cumulative. These components were: 1) financial support (6 items), 2) self-care advice (5 items), 3) family support (7 items), 4) awareness of disease and treatment (7 items), 5) family involvement activities (5 items), 6) consult with professional (4 items), 7) information on complementary care (3 items), and 8) symptomatic relieving and care concern (6 items). The questionnaire used four-point rating scale (1-4) to assess level of importance and necessity of each supportive care need from the lowest, low, high, to the highest.

Results of Confirmatory Factor Analysis showed Chi-Square = 862.74, df = 591, p-value = 0.000, RMSEA = 0.036, SRMR = 0.060, CFI = 0.941, and GFI = 0.902. Results indicated that empirical data were closely consistent with results of Exploratory Factor Analysis. Errors of the questionnaire were in standard level, reliability after by-aspect analysis was between 0.705 - 0.817, and reliability by version was 0.941.