Table 1

Baseline characteristics of study participants†

Missing, n (%)Total (n=452)GP (n=127)PT (n=130)Chiro (n=195)
Sociodemographic variables
Age, median (IQR)0 (0.0)66 (59–72)67 (60–73)68 (63–74)63 (58–71)
Female, n (%)0 (0.0)235 (52.0)74 (58.3)70 (53.8)89 (46.1)
Marital status19 (4.2)
 Married or living with partner, n (%)347 (76.8)90 (70.1)98 (74.6)158 (81.0)
Employment status5 (1.1)
 Currently in paid work, n (%)212 (45.3)57 (43.3)49 (31.5)106 (55.9)
Educational level, n (%)20 (4.4)
 Low (elementary+high school)253 (56.0)72 (56.7)70 (55.1)110 (56.4)
 High (university level)199 (44.0)55 (43.3)60 (44.9)85 (43.6)
General health variables
Health-related quality of life (SF-36 0–100)41 (9.1)
 Mental sumscore, mean (SD)52.5 (10.0)50.5 (11.5)53.4 (10.0)53.2 (8.8)
 Physical sumscore, mean (SD)41.4 (8.4)40.0 (7.9)40.6 (8.0)42.8 (8.9)
Hazardous alcohol consumption (AUDIT-C*), n (%)59 (13.1)228 (50.4)65 (51.1)65 (50.0)98 (50.2)
Smoking status, n (%)22 (4.9)
 Current smoker63 (13.9)21 (16.5)13 (10.0)28 (14.3)
 Previous203 (44.9)59 (46.4)60 (46.2)84 (43.1)
 Never186 (41.2)47 (37.0)57 (43.8)83 (42.6)
No of comorbidities (SCQ 0–15), median (IQR)18 (4.0)1 (1–2)1 (0–2)2 (1–2)1 (1–5)
BMI, mean (SD)14 (3.1)27.6 (4.7)27.6 (4.5)27.5 (4.7)27.7 (4.8)
Fall last 6 weeks, n (%)24 (5.3)73 (16.1)13 (10.2)24 (18.4)35 (18.2)
Falls self-efficacy (FESI 16–64), mean (SD)48 (10.6)21.8 (6.0)22.4 (6.3)22.2 (6.1)21.1 (5.7)
Widespread pain, n (%)16 (3.5)33 (7.3)5 (4.0)7 (5.3)21 (10.8)
Current back pain and back pain history variables
Previous back pain, n (%)58 (12.8)
 Monthly127 (28.1)42 (33.1)46 (35.4)40 (20.5)
 Every year174 (38.5)45 (35.4)44 (33.8)86 (44.1)
 Every 1–5 years90 (19.9)26 (20.5)19 (14.6)45 (23.1)
 Every 5 years45 (10.0)10 (7.9)16 (12.3)20 (10.3)
 Only once15 (3.3)4 (3.1)6 (4.6)4 (2.1)
Back pain location of current episode, n (%)11 (2.4)
 Thoracic only19 (4.2)4 (3.1)7 (5.4)8 (4.1)
 Lumbar only382 (84.5)106 (83.5)109 (83.8)167 (85.6)
 Both51 (11.3)17 (13.4)14 (10.8)20 (10.3)
Duration of current episode, n (%)76 (16.8)
 0–6 weeks297 (65.7)74 (58.3)67 (51.5)156 (80.0)
 6 weeks to 3 months59 (13.1)22 (17.3)21 (16.2)16 (8.2)
 3 months or over96 (21.2)31 (24.4)42 (32.3)23 (11.8)
Back pain severity (NRS 0–10), mean (SD)31 (6.9)5.4 (2.3)5.7 (2.2)5.1 (2.3)5.4 (2.4)
Back-related disability (RMDQ 0–24), median (IQR)45 (10.0)9 (5–13)10 (6–14)9 (6–13)8 (3–13)
Sleep problems due to back pain, n (%)24 (5.3)
 Weekly189 (41.8)60 (47.2)49 (37.7)80 (41.0)
 Less than weekly263 (58.2)67 (52.8)81 (62.3)115 (59.0)
Morning stiffness, n (%)26 (5.8)
 Significant or extreme178 (39.3)47 (37.0)51 (39.2)81 (41.5)
 Moderate144 (31.9)44 (34.6)48 (36.9)51 (26.2)
 Some or none130 (28.8)36 (28.3)31 (23.9)63 (32.3)
Psychological variables
 Kinesiophobia (FABQ-PA 0–24), median (IQR)18 (4.0)10 (5–14)11 (6–14)10 (5–15)9 (3–13)
 Depression (CES-D 0–60), median (IQR)57 (12.6)8 (4–15)10 (4–17)8.5 (4–15)7 (4–13)
 Pain catastrophising (PCS 0–52), median (IQR)35 (7.7)10 (4–16)11 (5–18)12 (5–18)7 (3–14)
 Back beliefs (BBQ 9–45), mean (SD)57 (12.6)29.8 (7.0)28.0 (6.9)29.3 (7.2)31.3 (6.7)
Expectations for back pain next 3 months, n (%)19 (4.2)
 Fully recovered115 (25.4)19 (15.0)24 (18.5)72 (36.9)
 Much better226 (50.0)66 (52.0)71 (54.6)89 (45.6)
 No change or worse111 (24.6)42 (33.0)35 (26.9)33 (16.9)
Start Back Screening Tool risk profiles, n (%)31 (6.9)
 Low297 (65.7)72 (56.7)92 (70.8)133 (68.2)
 Medium125 (27.7)38 (29.9)32 (24.6)55 (28.2)
 High30 (6.6)16 (12.6)6 (4.6)8 (4.1)
Clinical variables
 Physical performance (BPS 0–18), median (IQR)20 (4.4)5 (2–8)7 (3–9)5 (3–8)4 (1–7)
 Timed-Up-and-Go, mean seconds (SD)7 (1.5)8.0 (2.5)8.2 (3.0)8.3 (2.3)7.8 (2.2)
 Positive diagnostic rule for radiculopathy, n (%)38 (8.4)99 (22.0)37 (29.1)31 (23.8)31 (15.9)
 No of red flags (0–12), median (IQR)50 (11.0)1 (0–2)1 (0–2)1 (0–2)1 (0–1)
 Pain on active range of motion, n (%)9 (2.0)295 (65.3)86 (67.7)88 (67.7)120 (61.5)

*AUDIT-C scores of ≥3/12 for women and ≥4/12 indicates hazardous alcohol consumption.

†The presented characteristics are pooled estimates based on multiple imputation procedures.

AUDIT-C, Alcohol Use Disorder Identification Test-Consumption questions; BBQ, Back Beliefs Questionnaire; BPS, Back Performance Scale; CES-D, Centre for Epidemiological Studies-Depression; Chiro, chiropractor; FABQ-PA, Fear-Avoidance Beliefs Questionnaire-Physical Activity subscale; FES-I, Falls Self-Efficacy Scale-International; GP, general practitioner; NRS, Numeric Rating Scale; PCS, Pain Catastrophising Scale; PT, Physiotherapist; RMDQ, Roland-Morris Disability Questionnaire; SCQ, Self-administered Comorbidity Questionnaire; SF-36, Short Form Health Survey 36 Item.