Measuring exercise adherence in patients with low back pain: development, validity, and reliability of the EXercise Adherence Scale (EXAS)

Figures & data

Table 1. Quality of performance score matrix

Excellent	Good	Reasonable	Moderate	Poor
Score 1	Score 0.8	Score 0.6	Score 0.4	Score 0.2
All parts of the home-based exercise are performed perfectly according to the recommendations by the therapist. There is no room for improvement. It is certain the desired effect of the exercise has been achieved.		Most parts of the exercise are performed well according to the recommendations by the therapist. Important parts of the exercise can be improved. The desired effect of the exercise is likely to have been achieved.		The majority or all of the parts of the exercise are not performed according to the recommendations by the therapist. It is very unlikely that the desired effect of the exercise has been achieved.

Table 2. Patient characteristics of the validity study of the exercise adherence scale

	n	%	Mean (SD)	Range
Total sample	27
Age, in years	27		39.5 (11.3)	21–59
Male	16	59.3
Female	11	40.7
Height (cm)	27	100	174 (10.1)	160–197
Weight (kg)	27	100	79.8 (16.2)	58–112
Education
Elementary school	1	3.7
High school	6	22.2
Vocational school	18	66.6
College or university	2	7.4
Duration of symptoms
0 to 3 months	13	48.1
3 to 6 months	1	3.7
More than 6 months	13	48.1
Adherence rate*	27	100	67.4 (27.2)	16–100
EXAS score	27	100	57.1 (25.9)	12.8–100

n: number of participants in sample; SD: Standard Deviation; cm: centimeters; kg: kilograms; *: Adherence rate is calculated as the percentage of patient-reported adherence to therapist home-based exercises recommendations; EXAS: Exercise Adherence Scale

Table 3. Patient characteristics of the reliability study of the exercise adherence scale quality of performance score

	n	%	Mean (SD)	Range
Total sample	50
Age, in years	50	100	25.6 (7.37)	18–55
Male	31	62
Female	19	38
Height (cm)	50	100	177.1 (11.3)	151–200
Weight (kg)	50	100	73.3 (11.6)	50.4–106.1
Education
Vocational school	1	2
College or university	49	98
EXAS Quality of performance	200*		4^†	1–5

n: number of participants in sample; SD: Standard Deviation;

cm: centimeters; kg: kilograms; EXAS: Exercise Adherence Scale; *: quality of performance scores from the first assessment only; ^†: Mode reported instead of mean

Table 4. Associations between the exercise adherence scale and lack of time to exercise, lack of motivation to exercise, pain, and the Quebec back pain disability scale

	Lack of time to exercise	Lack of motivation to exercise	Pain	QBPDS
n	27	27	27	26
EXAS	0.47*	0.48**	0.24	0.005

QBPDS: Quebec Back Pain Disability Scale; n: number of participants in sample; EXAS: Exercise Adherence Scale; *: p < 0,05; **: p < 0,001; Spearman’s rho was used for all associations