Table 3 Primary and secondary outcomes

Primary Outcome

t1

t2

t3

t4

Physical functioning

Hannover Functional Ability Questionnaire (FfbH-R)

x

x

x

x

[51]

Secondary Outcomes

Pain

 Pain intensity

Numeric Rating Scale (NRS)

x

x

x

x

[52]

 Pain status

Graded Chronic Pain Status (GCPS)

x

x

x

x

[53]

Physical activity

Freiburg questionnaire on physical activity (FFkA)

x

x

x

[54]

Emotional functioning

 Depression

Patient Health Questionnaire (PHQ-D)

x

x

x

x

[55]

 Anxiety

Generalized anxiety disorder 7-item scale (GAD-7)

x

x

x

x

[56]

Health related quality of life

Short-Form-12 (SF-12)

x

x

x

x

[57]

Stress

Perceived Stress Scale (PSS)

x

x

x

x

[58]

Pain related cognitions, emotions and behavior

 Cognitive and behavioral pain coping strategies

Pain Management Questionnaire (FESV)

x

x

x

x

[59]

 Fear-avoidance and endurance-related responses to pain

Avoidance-Endurance Questionnaire (AEQ)

x

x

x

x

[60]

 Pain related fear

Tampa Scale for Kinesiophobia (TSK)

x

x

x

x

[61, 62]

Motivational and volitional determinants of physical activity

risk perception (3 items), self-efficacy (3 items), outcome expectancies (11items), experiences with physical activity (5 items), self-concordance (12 items), intention (7 items), action (4 items) and coping (4 items) planning, action control (6 items)

x

x

x

x

[63–67]

 Stage of change algorithm for physical activity

two Items (Have you performed moderate physical for 30 minutes or longer on a minimum of 3 days per week? and "Since when are you as regularly active as you are now?"; possible answers: 1. Question: no, and I don’t intend to do so; no, but I am thinking about doing so; no, but I have the strong intention to do so; yes, but it is difficult to me; yes, and it is easy for me; 2. Question: open)

x

x

x

x

[68, 69]

Attitudes towards performing physical activity

modified Version of Short-Questionnaire to measure cognitive and affective attitudes toward sports activities

x

x

x

x

[70]

Treatment satisfactions with exercise therapy

18 items (e.g. “I would recommend the exercise therapy other patients.” measured by using a six-point ordinal scale with 1= “absolutely agree”, 6=“absolutely disagree”; e.g. “The time extent of the exercise therapy, I perceived as…” measured by using a five-point ordinal scale with 1=“far too high“, 5=“far too low“; e.g. “Overall, how do you rate the exercise therapy?” measured by using a six-point ordinal scale with 1= “very satisfied”, 6=not “satisfied at all”)

x

self-designed

Treatment satisfactions with the rehabilitation process

five items (e.g. “Overall, how do you rate the rehabilitation process?”) measured by using a ten-point ordinal scale (1= “very poor”, 10 = „excellent“)

x

self-designed

Others

 Demographic characteristics

sex, age, height, nationality, marital status, education, monthly income, weight, self-reported work status

x

[71]

 Social medical characteristics

a) self-reported low back pain related sick leave, use of health care services, medication use for the last six month and self-reported plan to apply for retirement, severe disabilities

x

[71]

b) diagnosis, work status and physical capability taken from the hospital discharge report

x

 Aftercare

a) aftercare recommendations taken from the hospital discharge report

x

self-designed

b) self-designed; five items (e.g. “Have you participated in the last twelve months in a medically prescribed exercise therapy to rehabilitation aftercare?” with the option to answer yes/no)

x

Job satisfaction

scale on job satisfaction (IRES-3)

x

x

[72]