Measurement of psychosocial adjustment to breast cancer: a unidimensional or multidimensional construct?

Using data from a longitudinal study of Hoskins' 'Patterns of Adjustment to Breast Cancer among Women and their Partners', a conceptually derived multidimensional formulation of psychosocial adjustment was empirically tested. The Psychosocial Adjustment to Illness Scale was administered to both patients and partners at six times post-definitive surgery, i.e., 7-10 days, 30 days, 60 days, 90 days, 180 days, and one year. Extensive factor analytic studies were performed on data from the Psychosocial Adjustment to Illness Scale at four of the collection times when complete data sets were available for 128 patients and 121 partners. Results of the principal components analysis with varimax rotation were compared to factor analyses reported by the developers of the scale. The seven-factor matrix reported by Derogatis was not reproduced; instead, one factor was consistently identified at each of the four time periods as the best solution. Although items from all seven domains of the scale loaded on the single factor, items pertaining to psychological distress and role performance in the domestic and social environments were most prominent. These data support the need to validate empirically hypothesized separate dimensions of psychosocial adjustment to breast cancer in both patients and partners as proposed in a number of widely used tests.