Journal of Rehabilitation Medicine 51-3 | Page 32

178 L. Aasdahl et al. linear regression was used. The 2 FABQ subscales were dicho- tomized into low risk and moderate/high risk using the cut-offs recommended by Wertli et al. (7). For the FABQ-work subscale a score of less than 21 was categorized as low risk and for the physical activity subscale a score of less than 14 was categorized as low risk. Based on the 2 categories, the participants were classified into 4 groups (for the 2 subscales separately) based on their scores at the start (T1) and the end of the rehabilitation programmes (T2): (i) consistently low fear-avoidance beliefs; (ii) increasing from low to high scores; (iii) decreasing from high to low scores; and (iv) consistently high fear-avoidance beliefs. The new categorical variable was included in the regression analyses. The analyses were performed both unadjusted and adjusted for age, sex and education. In addition, a sensitivity analysis adjusting for intervention programme was performed (in addition to the aforementioned variables). All analyses were performed separately for the 2 FABQ subscales. To evaluate the association between FABQ at baseline (T0) and future work participation for the different diagnosis groups, linear regression was used and the analyses performed separately for participants with musculoskeletal diagnoses and psychological diagnoses. As there were few participants with unspecific di- agnoses (chapter A in ICPC-2) they were not included in these analyses. For the association analyses, participants from both trials were included. p-values (2-tailed) < 0.05 were considered statistically signi- ficant. Precision was assessed using 95% confidence intervals (95% CI). All analyses were performed using STATA 14.1 (StataCorp. 2015. Stata Statistical Software: Release 14. Col- lege Station, TX, USA: StataCorp LP). RESULTS The flow of participants through the 2 trials is illustra- ted in Fig. 1. After screening, 168 participants remained in the short trial and were randomized to the short inpa- tient programme (n = 92) or the outpatient programme (n = 76). In the long trial, 166 participants were inclu- ded and randomized to the long inpatient programme (n = 86) or the outpatient programme (n = 80). The number of people who answered the questionnaires decreased steadily through the study (Fig. 1). Participant characteristics The mean age of the participants was 45 years and most were women (79%). Approximately half had a muscu- loskeletal sick-leave diagnosis (54%), while 37% had a psychological diagnosis, and 9% a diagnosis from the general and unspecified chapter of ICPC-2. Most participants (65%) worked full-time before they were sick-listed, 18% worked part-time, 12% did not have employment, and 5% had a graded disability pension. The median number of sickness absence days at inclu- sion was 217 (interquartile range (IQR) 179–268). Base- line characteristics of the participants in the intervention vs the comparator were similar in both trials (Table I). Table I. Baseline characteristics of participants Short trial Short inpatient programme (n  = 92) Age, years, mean (SD) Women, n (%) Higher education a , n (%) Work status, n (%) No work Long Long inpatient programme outpatient programme (n  = 86) (n  = 80) 45.0 (8.7) 71 (77) 45.1 (9.6) 62 (82) 46.3 (8.7) 70 (81) 45.2 (10.4) 61 (76) 45 (49) 31 (41) 32 (37) 34 (43) 15 (16) 7 (9) 11 (13) 6 (8) Full-time 57 (62) 52 (68) 54 (63) 53 (66) Part-time 15 (16) 16 (21) 12 (14) 18 (23) 5 (5) 1 (1) 41 (45) 35 (46) 35 (41) 36 (45) 45 (49) 36 (47) 48 (56) 38 (48) 6 (7) 5 (7) 3 (3) 6 (8) Graded disability pension Sick-leave status b , n (%) Full sick-leave Partial sick-leave Work assessment allowance Main diagnoses for sick-leave (ICPC-2) b , n (%) A – general and unspecified L – musculoskeletal P – psychological Length of sick leave at inclusion b,c , median days (IQR) HADS, mean (SD) Anxiety (0–21) Depression (0–21) Pain level, mean (SD) Mean pain (0–10) FABQ, mean (SD) Work (0–42) Physical activity (0–24) Long trial Short outpatient programme (n  = 76) a 9 (10) 48 (52) 35 (38) 9 (10) 7 (9) 5 (6) 40 (53) 54 (63) 29 (38) 27 (31) 3 (4) 9 (11) 40 (50) 31 (39) 224 (189–262) 229 (187–275) 204 (163–265) 216 (177–265) 7.8 (4.4) 7.4 (4.3) 7.4 (3.9) 8.6 (4.1) 6.7 (4.3) 6.0 (4.1) 5.7 (4.2) 6.6 (4.0) 4.7 (2.3) 4.6 (2.0) 5.0 (2.0) 4.8 (2.2) 20.9 (11.5) 19.9 (11.5) 21.4 (11.8) 23.2 (11.1) 9.1 (6.1) 8.1 (6.9) 8.8 (7.2) 9.5 (7.1) Higher (tertiary) education (college or university). Based on data in the medical certificate from the National Social Security System Registry. Number of days on sick leave during the last 12 months prior to inclusion. Measured as calendar days, not adjusted for graded sick leave or part-time job. SD: standard deviation; HADS: Hospital Anxiety and Depression scale; FABQ: Fear Avoidance Beliefs Questionnaire; IQR: interquartile range. b c www.medicaljournals.se/jrm