ASSESSING QUALITY-OF-LIFE IN PATIENTS WITH CANCER - A COMPARISON OF AVISUAL-ANALOG AND A CATEGORICAL MODEL

A simple instrument for self-assessment of quality of life (QL) in pat ients with cancer was elaborated using a linear analogue scale (LAS). The instrument was based on five questions, exploring different functi onal areas; the same questions were also addressed in a parallel forma l, where problems were seen from an opposite point of view (positive/n egative). The LAS was given to 222 patients, fur a total of 372 tests collected, Internal consistency was satisfactory (Cronbach's alpha = 0 .75); QL score was significantly correlated to parameters of disease. Concordance between scales, as judged by comparison of parallel format s, was statistically significant but poor. A questionnaire was then el aborated with similar items, based on a categorical scale. A direct co mparison between LAS and our questionnaire was made on a group of 41 p atients. Internal consistency was poor For the LAS (alpha = 0.58) and good for the questionnaire (alpha = 0.93): Spearman's rank correlation coefficients were disappointing for the LAS and good For the question naire; the questionnaire was judged reliable in 82.9% of cases, the LA S in 29.3% only: the questionnaire score, and not the LAS score, was s ignificantly correlated with PS and disease status. In conclusion, man y patients appeared unable to correctly interpret the visual-analogue scale; the categorical scale was more immediate and correctly understo od by the large majority of patients, the correlation between score an d important parameters of QL was maintained, and internal consistency was excellent, indicating a satisfactory reliability of this instrumen t.