Table 3
Univariable and multivariable logistic regression
Variable OR 95% CI P value aOR* 95% CI P value ICMJE journal Yes 1.08 0.55 to 2.16 0.821 – – – No† – – – – – – Risk of bias Low risk 2.36 0.67 to 11.01 0.213 – – – Some concerns 1.14 0.56 to 2.37 0.716 – – – High risk† – – – – – – Impact factor Upper tertile 4.99 2.14 to 12.32 <0.001 5.72 2.23 to 15.85 <0.001 Middle tertile 3.32 1.52 to 7.48 0.003 3.52 1.51 to 8.57 0.004 Lower tertile† – – – – – – Spinal region Cervical 2.80 0.91 to 9.27 0.080 3.04 0.88 to 11.30 0.085 Thoracic 0.96 0.35 to 2.66 0.939 1.09 0.34 to 3.45 0.887 Lumbopelvic† – – – – – – Mixed/unclear 2.83 1.15 to 7.11 0.025 3.18 1.16 to 9.05 0.027 Type of practitioner Chiropractor 6.21 1.71 to 24.85 0.007 4.58 1.14 to 20.24 0.036 Osteopath† – – – – – – Physiotherapist 1.88 0.60 to 6.19 0.282 1.35 0.37 to 5.18 0.648 Medical practitioner 1.20 0.22 to 6.53 0.831 0.81 0.12 to 5.47 0.829 Mixed/other/unclear 2.72 0.78 to 10.17 0.121 2.26 0.57 to 9.64 0.253 Sample size spinal manipulation group‡ Upper tertile 3.64 1.57 to 8.87 0.003 – – - Middle tertile 1.27 0.58 to 2.79 0.544 – – - Lower tertile† – – – – – – *The final model was adjusted for impact factor, spinal region of manipulation, and type of practitioner, while ICMJE journal status, risk of bias and number of participants receiving spinal manipulation were omitted via backward elimination method.
†Reference group.
‡One study with unclear sample size excluded.
aOR, adjusted OR; ICMJE, International Committee of Medical Journal Editors.