Table IV. —Day 1-7/10 test-retest reliability of the WIP questionnaire.

Item	ICC	95% CI
Item 1 – Pain intensity	0.93	0.90-0.96
Item 2 – Pain interference	0.88	0.82-0.92
Item 3 – Temporal aspects of pain	0.89	0.82-0.92
Item 4 – Physical functioning	0.92	0.88-0.95
Item 5 – Psychological functioning	0.93	0.90-0.96
Item 6 – Leisure	0.93	0.89-0.95
Item 7 – Well-being	0.91	0.86-0.93
Item 8 – Work ability	0.89	0.83-0.93
Item 9 – Work productivity	0.89	0.83-0.93
Item 10 – Health-care services	0.86	0.76-0.92
Whole scale	0.93	0.83-0.96
Factor 1	0.94	0.89-0.97
Factor 2	0.91	0.82-0.95

WIP: Work in Progress; Factor 1: Self-drivenness to return to normal personal life with pain; Factor 2: Self-drivenness to return to work and reduce the dependence of health services; ICC: intraclass correlation coefficient; CI: confidence interval.