Table 2

Constructs and measures

Domain	Construct	Measure	Items	Time point*	Completed by
Outcomes
Primary	Disability	RMDQ64	24	T1, T2, T3	Patient
Secondary	Social role disability	Core item69	1	T1, T2, T3	Patient
	Work disability	Core item69	1	T1, T2, T3	Patient
	Pain	Core item69	1	T1, T2, T3	Patient
	Well-being	Core item69	1	T1, T2, T3	Patient
	Satisfaction	Core item69	1	T1, T2, T3	Patient
Non-specific factors
Relationship	Therapeutic alliance	WAI-SF70 71	12	T2	Patient
Healthcare environment	Organisational	ABS-mp24 72	9	T1	Practitioner
Healthcare environment	Appointments, access, facilities	PSQ73	16	T2	Patient
Treatment characteristics	Modalities	Single item	2	T3 per patient	Practitioner
Treatment characteristics	Duration	Single item	1	T3 per patient	Practitioner
Patient's beliefs	Treatment beliefs	LBP treatment beliefs questionnaire74	16	T1	Patient
Practitioner's beliefs	Attitudes to LBP	ABS-mp24 72	12	T1	Practitioner
Practitioner's beliefs	Outcome expectations	Single item	1	T1 per patient	Practitioner
Mediators/prognostic indicators
	Risk complexity for recovery	STarT Back75	9	T1, T2, T3	Patient
	Self-efficacy	Self-efficacy for pain management76	5	T1, T2, T3	Patient
	Adherence to lifestyle advice	Single item	3	T1, T2, T3	Patient
	Illness perceptions	BIPQ77	9	T1, T2, T3	Patient

*T1=baseline (after first treatment for new episode of LBP); T2=during treatment (2 weeks post-baseline); T3=short-term outcome (3 months post-baseline).
ABS-mp, Attitudes to Back Pain Scale—Musculoskeletal Practitioners; BIPQ, Brief Illness Perceptions Questionnaire; LBP, low back pain; PSQ, Patient Satisfaction Questionnaire; RMDQ, Roland-Morris Disability Questionnaire; WAI-SF, Working Alliance Inventory—Short Form.