Table 3

Effects of the intervention on the outcome measures

Outcome	Baseline	3 Months	6 Months	12 Months	B overall	95% CI	p Values
DASH
SG	22.28	17.76	14.04	14.32	−1.75²	−3.85 to 0.34	0.10
UCG	22.27	19.55	17.39	15.05
DASH work
SG	28.77	19.56	15.69	12.88	−3.82	−7.46 to −0.19	0.04
UCG	30.22	22.24	20.83	17.61
Days absent from work in the past month*
SG	1.63	4.21	2.45	3.42	–	–	0.56
UCG	3.70	4.02	7.84	7.27
Days absent from work in the past month due to CANS*
SG	0.81	0.74	0.38	1.08	–	–	0.29
UCG	3.64	2.62	3.51	5.27
SPS-6
SG	22.23	22.96	23.30	23.71	0.12^1,2	−0.81 to 1.05	0.80
UCG	22.12	22.93	22.30	23.27
Work Limitations Questionnaire
SG	7.15	7.56	7.53	6.09	0.07²	−0.70 to 0.84	0.86
UCG	7.73	7.66	7.03	7.53
NPRS last week
SG	4.80	4.21	3.96	4.19	−0.13	−0.48 to 0.27	0.47
UCG	4.76	4.30	4.16	3.56
PCS
SG	10.42	10.37	9.09	9.25	0.47	−0.83 to 1.78	0.48
UCG	13.25	10.56	12.30	9.03
General Self-Efficacy Scale #
SG	31.16	31.60	32.53	32.91	0.12	−0.63 to 0.88	0.75
UCG	32.58	32.81	32.95	33.85
Self-efficacy at work scale #
SG	8.62	15.07	11.53	13.58	2.32	−0.49 to 5.14	0.11
UCG	6.17	9.59	9.22	9.39
Checklist Individual Strength
SG	81.05	80.10	81.36	82.69	−1.19¹	−2.55 to 0.17	0.09
UCG	79.89	82.61	82.27	81.82
Utrecht Burnout Scale
U scale SG	2.40	2.48	2.40	2.34	0.05	−0.14 to 0.26	0.61
U scale UCG	2.32	2.29	2.30	2.38	0.05^1,2		0.58
D scale SG	1.46	1.66	1.72	1.51	0.08²	−0.14 to 0.25	0.37
D scale UCG	1.59	1.63	1.65	1.96
C scale SG	2.09	4.14	4.10	4.03		−0.09 to 0.25
C scale UCG	4.23	4.17	4.00	4.16
Workstyle Short Form
SG	33.05	28.96	27.02	27.64	−1.28²	−4.16 to 1.59	0.38
UCG	33.85	31.81	33.27	30.61
Pace and amount of work
SG	27.72	27.90	26.56	37.73	0.22^1,2	0.31 to 0.75	0.41
UCG	29.08	26.01	25.04	42.86
Relations with colleagues
SG	24.07	25.67	22.65	20.44	−1.37	−3.99 to 1.24	0.30
UCG	22.85	25.75	24.72	23.09
Relations with supervisors
SG	22.22	25.09	22.71	23.65	−1.45^1,2	−4.33 to 1.42	0.32
UCG	22.38	23.90	24.82	25.82
Participation in work
SG	53.51	52.44	49.21	50.48	−0.49²	−3.21 to 2.24	0.73
UCG	50.44	50.29	52.59	49.75
Autonomy at work
SG	38.92	38.14	35.79	36.71	−0.35^1,2	−2.34 to 1.63	0.73
UCG	36.69	26.58	38.25	36.71
Need for recovery
SG	51.98	47.18	46.99	45.28	−4.95^1,2	−10.62 to 0.71	0.09
UCG	44.29	51.51	51.35	49.20
Attitude towards self-management #
Importancy SG	26.67	–	–	25.66	−0.43¹	−3.68 to 2.82	0.79
Importancy UCG	26.29	–	–	25.32	0.10²		0.96
Enjoyment SG	23.06	–	–	23.20		−3.70 to 3.91
Enjoyment UCG	23.80	–	–	24.09
SF-12v2 #
PCSc SG	45.65	47.45	48.36	47.30	1.17¹	−0.18 to 2.53	0.09
PCSc UCG	44.51	45.07	45.52	47.46	−0.62²		0.45
MCSc SG	48.44	45.45	43.60	43.87		−2.23 to 0.99
MCSc UCG	47.85	47.19	44.67	42.14
Self-Reflection and Insight Scale #
SG	86.48	87.43	86.32	87.79	−0.20^1,2	−2.05 to 1.64	0.83
UCG	83.96	85.12	85.92	86.44
Limitations experienced in work-related activities
SG	3.53	–	–	2.13	−1.01	−1.97 to −0.04	0.04
UCG	3.95	–	–	3.06
Work capacity
SG	7.30	–	–	7.56	−0.038	−0.89 to 0.81	0.93
UCG	6.69	–	–	7.26
Performing sports/physical activities/exercises #
Number of days/week >30 min physical activity SG	3.56	–	–	4.46	0.07^1,2	−0.81 to 0.68	0.86
Number of days/week >30 min physical activity UCG	3.49	–	–	4.26
Number of days/week >20 min intensive physical activity SG	1.17	–	–	2.02	0.02^1,2	−0.70 to 0.73	0.96
Number of days/week >20 min intensive physical activity UCG	1.30	–	–	1.85
Number of days/week performing exercises SG	2.08	–	–	2.79	0.47^1,2	−0.45 to 1.39	0.32
Number of days/week performing exercises UCG	2.09	–	–	2.15
Hours/week performing sport activities in past 3 months SG	2.85	–	–	2.38	−1.00³	−1.90 to −0.12	0.03
Hours/week performing sport activities in past 3 months UCG	2.81	–	–	3.32

B, overall treatment effect of the SG compared with the UCG, adjusted for baseline values and possible confounders: (1) adjusted for duration of symptoms; (2) adjusted for gender; and (3) adjusted for age. All lower scores represent a better outcome, except for scores marked with #.
*Data with regard to absenteeism were asked on baseline, T1 and T2 with regard to the previous 3 months and on T3 with regard to the previous 6 months, and were analysed using Mann-Whitney U tests.
**Bold typeface: the significant differences are given between SG compared to UCG, adjusted for baseline values and possible confounders.
CANS, complaints of the arm, neck or shoulder; DASH, Disabilities of the Arm, Shoulder and Hand questionnaire; MCSc, Mental Component Scale; NPRS, Numeric Pain Rating Scale; PCS, Pain Catastrophizing Scale; PCSc, Physical Component Scale; SG, self-management group; SPS-6, Stanford Presenteeism Scale; UCG, usual care group.