Development and internal validation of a machine learning prediction model for low back pain non-recovery in patients with an acute episode consulting a physiotherapist in primary care

Table 1 Overview of candidate predictors

	Included based on:
	Prognostic evidence	Expert opinion	Adopted from existing questionnaire	Time-points	Change T0-T2
Demographic factors
Age	X [6, 7]		n/a	T0	no
Gender	X [7]		n/a	T0	no
Educational level		X	n/a	T0	No
Other health issues	X [2, 7, 9]		STarT MSK item 7	T0	No
Shoulder and/or neck pain		X	STarT Back item 2	T0	No
Physical activity level		X	n/a	T0, T1, T2	yes
Pain-related factors
Pain severity	X [7, 9]		NRS	T0, T1, T2	Yes
Frequency of previous LBP	X [7]		OMPQ item 11	T0	No
Disability of previous LBP episode		X	n/a	T0	No
Onset of LBP episode (sudden/ gradually)	X [7]		n/a	T0	No
Radiating pain in leg(s)	X [6, 7]		STarT Back item 1	T0	No
Disability	X [2, 7, 9]		STarT Back item 3, 4 and 9	T0, T1, T2	Yes
Occupational factors
Work absenteeism	X [7]		n/a	T0, T3	No
Physically demanding work	X [6, 7]		OMPQ item 8	T0	No
Job satisfaction	X [6]		OMPQ item 17	T0	No
Work ability		X	WAI- Single item	T0	No
Psychological factors
Psychological distress	X [6, 8, 9]		STarT Back item 6	T0, T1, T2	Yes
Depressive mood	X [7,8,9]		STarT Back item 8	T0, T1, T2	Yes
Fear of movement	X [2, 9]		STarT Back item 5	T0, T1, T2	Yes
Catastrophizing thoughts	X [8]		STarT Back item 7	T0, T1, T2	Yes
Pain coping	X [2, 7]		OMPQ item 12	T0, T1, T2	Yes
Recovery expectation	X [7, 9]		n/a	T0, T1, T2	Yes
Resilience		X	Vita-16	T0, T1, T2	Yes

NRS Numeric Rating Scale, OMPQ Orebro Musculoskeletal Pain Questionnaire, STarT MSK Keele STarT MSK Screening Tool, STarT Back Keele STarT Back Screening Tool, WAI Work Ability Index

ISSN: 1471-2474