Psychometric evaluation of a coping questionnaire in two independent samples of people with diabetes

The study examines internal item/scale structure and concurrent validity of a newly developed 48-item questionnaire [General Coping Questionnaire (GCQ)] that measures 10 aspects of coping with chronic illness (self-trust, problem-reducing actions, change of values, social trust, minimization, fatalism, resignation, protest, isolation and intrusion). The tests were performed in two independent samples of persons with diabetes mellitus. The first sample consisted of 119 subjects with type I diabetes and the second sample of 184 subjects with type II diabetes. Concurrent validity was examined by comparisons with measures of health-related quality of life (SF-36), a measure of metabolic control (HbA1c) and incidence of diabetic complications. The item/scale structure was found to be similar and very good in both samples. The 10 dimensions correlated as expected with the measure of mental health, although the 'negative' dimensions of the GCQ correlated higher compared with the 'positive' dimensions. Weaker relations with metabolic control were also found in one of the samples. These tests provide further evidence that GCQ is a well-structured, relevant and reliable instrument for assessing coping reactions in chronic somatic conditions.