Table 1. Demographic and clinical characteristics of the participants.
| Treatment group | ||||||
| Total (n = 104) | ICBT (n = 50) | GCBT (n = 54) | ||||
| Age, years: mean (SD) | 34.2 | (9.4) | 33.8 | (9.7) | 34.6 | (9.2) |
| Gender: female, % | 62% | 64% | 59% | |||
| Age of initial onset of panic symptoms, mean (SD) | 25.6 | (9.1) | 25.6 | (8.9) | 25.6 | (9.4) |
| Duration of illness (PD), mean years (SD) | 6.7 | (9.4) | 6.0 | (9.3) | 7.3 | (9.6) |
| Severity of panic disorder (PDSS), mean (SD) | 14.2 | (4.1) | 14.1 | (4.3) | 14.2 | (4.0) |
| Functional impairment in work/school (SDS1), mean (SD) | 5.7 | (3.1) | 5.5 | (3.3) | 5.9 | (2.9) |
| Functional impairment in social life (SDS2),mean (SD) | 5.8 | (2.6) | 5.6 | (2.8) | 5.9 | (2.5) |
| Functional impairment in family life/home responsibilities (SDS3), mean (SD) | 4.4 | (2.7) | 4.1 | (2.9) | 4.6 | (2.5) |
| Impaired Performance Days (WQ2), mean (SD) | 4.7 | (6.4) | 3.4 | (5.0) | 5.8 | (7.3) |
| Number of sick-leave days (WQ1), mean (SD) | 5.5 | (8.1) | 5.5 | (8.3) | 5.6 | (7.9) |
| Anxiety Sensitivity Index (ASI), mean (SD) | 32.9 | (12.0) | 32.5 | (11.6) | 33.2 | (12.4) |
| Psychotropic medication, % | 45% | 44% | 46% | |||
| Agoraphobia, % | 85% | 86% | 83% | |||
| Any anxiety disorder, % | 17% | 16% | 18% | |||
| Depression, % | 10% | 8% | 11% | |||
| Generalised anxiety disorder, % | 11% | 12% | 9% | |||
| Health anxiety (hypochondriasis), % | 3% | 0% | 6% | |||
| Social anxiety disorder, % | 6% | 4% | 7% | |||
| Specific phobia, % | 2% | 0% | 4% | |||
| Obsessive compulsive disorder, % | 1% | 0% | 2% | |||
| Posttraumatic stress disorder, % | 1% | 0% | 2% | |||
Abbreviations: ICBT, Internet-based cognitive behaviour therapy; GCBT, group-based cognitive behaviour therapy; WQ, work questionnaire; ASI, Anxiety Sensitivity Index; SDS, Sheehan Disability Scale.