Psychological distress. The Hopkins Symptom
Check List-25 (HSCL-25)33 was used to measure
psychological distress. The HSCL was chosen because
it provides information about psychological distress in nonpsychiatric populations, and because previous studies have reported the questionnaire to have satisfactory validity and reliability as a measure of psychological distress. The HSCL exists in various forms and has different numbers of items. From a 25-item, validated Norwegian version of the HSCL,3two items
regarding suicidal ideation and loss of sexual interest were excluded on the basis of earlier recommendations of the Regional National Committee for Research Ethics.39 Respondents were asked how bothered they had been by various symptoms during the previous 2 weeks. The HSCL-23 items, which included anxiety and depressive symptoms, rated on a 4-point scale, from
0 _ “not bothered” to 3 _ “extremely bothered.” In the present study, a global score was calculated for each patient, based on the mean of their 23 responses. Recent research has found the optimal cutoff for HSCL to be lower for men than for women when the Composite International Diagnostic Interview is used as the external criterion, and it has been suggested that mean scores above the threshold of .67 for men and .75 for women
indicate psychological distress.40 Therefore these
values were used to define the presence or absence
of psychological distress for patients in this study. The HSCL has been widely used in different settings inside and outside Norway, and with various populations, including elderly and patients with COPD. The reliability of the HSCL-23 was satisfactory in this study, with a Cronbach’s alpha coefficient of .92.