Table 3

Multivariable linear regression for SPADI at 6-month follow-up: n=804, adjusted R²=0.31 (baseline SPADI and QuickDASH not included in the model)

Independent predictor	Subgroup comparisons	Parameter estimate	95% CI	p Value
Patient expectation of change	Completely recover	0
	Much improve	5.21	1.80 to 8.61	0.003
	Slightly improve	12.43	8.20 to 16.67	<0.001
	No change/worse	−0.94	−8.53 to 6.66	0.809
Pain self-efficacy		−0.36	−0.50 to −0.22	<0.001
Number of additional health problems	None	0
	One	3.52	0.30 to 6.75	0.032
	Two or more	6.62	1.48 to 9.75	0.008
Anxiety or depression	None	0
	Moderate	2.19	−0.99 to 5.37	0.177
	Extreme	12.02	1.49 to 22.56	0.025
Frequency of pain medication	None/occasional	0
Frequency of pain medication	Most/every day/night	3.85	0.61 to 7.09	0.020
Most strenuous exercise	None	0
	Mild	−5.53	−10.32 to −0.74	0.024
	Moderate	−8.98	−13.86 to −4.11	<0.001
	Strenuous	−6.82	−12.17 to −1.47	0.013
Difference between passive and active abduction		0.07	0.004 to 0.142	0.038
Change during scapular facilitation	Yes	0
Change during scapular facilitation	No	4.93	2.13 to 7.74	0.001
Severity of pain at rest		1.89	1.26 to 2.51	<0.001
Duration of shoulder symptoms (weeks)		0.02	0.01 to 0.03	0.002
Paraesthesia in the arm	No	0
Paraesthesia in the arm	Yes	−10.08	−18.73 to −1.43	0.022
Current employment status	Employed	0
	Retired	2.96	0.10 to 6.02	0.058
	Unemployed	14.30	7.72 to 20.87	<0.001

The first row of prognostic factors with categorical data is the reference or comparator category.
SPADI, Shoulder Pain and Disability Index; QuickDASH, Quick Disability of the Arm, Shoulder and Hand Questionnaire.