Table 2

Descriptive data of patients with recurrent or persistent low back pain from a randomized clinical trial investigating the outcomes of chiropractic maintenance care

Variable aGroupAll n = 319
(MC, n = 161; Control, n = 158)
Survival analysis, n = 250
(MC, n = 127; Control, n = 123)
Trajectory analysis, n = 254
(MC, n = 145; Control, n = 109)
Age at study start, mean (SD)MC43.4 (11.2)43.0 (11.3)43.5 (11.3)
Control43.1 (13.2)42.4 (13.3)42.6 (13.6)
Female, % (n)MC63.5 (94)64.7 (77)37.9 (50)
Control60.3 (85)57.5 (65)37.0 (37)
Pain intensity, 0–10, mean (SD)1st visitMC5.4 (2.1)5.2 (2.1)5.4 (2.0)
Control5.4 (2.1)5.3 (2.1)5.6 (2.1)
4th visitMC2.4 (1.8)2.3 (1.8)2.6 (1.8)
Control2.3 (1.7)2.2 (1.7)2.3 (1.8)
Study startMC2.1 (1.5)1.8 (1.4)2.1 (1.5)
Control2.2 (1.8)2.0 (1.6)2.2 (1.7)
EQ5D score baseline, mean (SD)MC0.68 (0.23)0.67 (0.24)0.69 (0.21)
Control0.70 (0.20)0.71 (0.20)0.71 (0.19)
MPI Subgroup, % (n)ACMC29.8 (48)31.0 (40)32.0 (46)
Control28.3 (45)32.5 (40)23.9 (26)
IDMC20.5 (33)21.3 (27)20.0 (29)
Control18.2 (29)18.7 (23)22.0 (24)
DYSMC30.4 (49)29.1 (37)32.0 (46)
Control30.2 (48)29.3 (36)34.9 (38)
MissingMC19.3 (31)18.0 (23)24 (17)
Control23.3 (37)19.5 (24)21 (19)
RMDQ Score (study start), mean (SD)MC4.9 (4.0)4.4 (3.9)4.9 (4.1)
Control4.7 (4.1)4.3 (4.1)4.9 (3.8)
a, No imputation has been made for missing data, mean values and percentages are based on true responses for each variable; MC Maintenance Care; SD Standard deviation; n number of participants; MPI West Haven-Yale Multidimensional Pain Inventory; AC Adaptive Coper; ID Interpersonally Distressed; DYS Dysfunctional; RMDQ Roland Morris Disability Questionnaire