Measurement of quality of life in women with breast cancer. Development of a life satisfaction questionnaire (LSQ-32) and a comparison with the EORTC QLQ-C30

The purpose was to develop and validate a new instrument suitable for measuring perceived quality of life in women with breast cancer. The instrument is to be used within conventional cancer therapy as well as in complementary care, and is called the LSQ-32 (Life Satisfaction Questionnaire). The subjects were 362 women with breast cancer in all cancer stages. Cronbach's alpha reliability coefficient of the LSQ was 0.89. The construct validity was estimated by a principal component analysis. Six orthogonal factors were identified: (1) 'Quality of family relation', (2) 'Physical symptoms', (3) 'Socioeconomic situation', (4) 'Quality of daily activities', (5) 'Sickness impact' and (6) 'Quality of close friend relation'. The criterion-related validity was estimated by comparing the LSQ-32 and the EORTC QLQ-C30. The scales/items of the EORTC QLQ-C30 were represented in the LSQ-32, but the factors 'Quality of family relation' and 'Quality of close friend relation' were not found in the EORTC QLQ-C30. It was concluded that the LSQ-32 as well as the EORTC QLQ-C30 are valuable tools in the measurement of quality of life in women with breast cancer. The LSQ-32, however, also contains an existential factor.