The Perceived Adjustment to Chronic Illness Scale (PACIS): a global indicator of coping for operable breast cancer patients in clinical trials. Swiss Group for Clinical Cancer Research (SAKK) and the International Breast Cancer Study Group (IBCSG).

Subjective well-being is a major aspect of quality of life and is therefore increasingly used as an endpoint in clinical trials. It is influenced to a great extent by the complex process of coping with the disease and its treatment. Assessment of coping is methodologically demanding, especially in large clinical trials. We therefore developed a single-item measure, the Perceived Adjustment to Chronic Illness Scale (PACIS), as an indicator of coping, complementary to other scales related to quality of life. We sought to validate this instrument in a subgroup of 121 Swiss patients participating in the International Breast Cancer Study Group (IBCSG) adjuvant trials. At months 3 and 6 of adjuvant treatment PACIS showed a distinct pattern of highly significant rank correlations with several disease- and treatment-related problem areas from the Herschbach coping inventory (FBBK); 42% of the variance of PACIS at month 3 was explained by the FBBK (P = .0001). The portion of explained variance was considerably higher for the Italian- (70%) than for the German-speaking (30%) subgroups. Patients who rated more effort to cope with their disease on PACIS indicated more frequent use of 3 of 15 coping strategies in relation to psychological distress. These were "crying and becoming desperate", "taking tranquillizers and alcohol" and "other people are far worse off". These three coping strategies may define a high-risk group for poor psychosocial outcome. Patients whose PACIS scores showed that it required less effort to cope tended to use the strategy "seeing a positive side of the problem". We conclude that PACIS can be used as a global indicator of the coping process in large multicultural clinical trials of adjuvant therapy for breast cancer.