Table 3.

Results

Risk factors	Univariate analysis: chi2 tests and OR			Multivariate analysis: binary logistic regression
	OR	95% CI	p	OR	95% CI	p
General risk factors
Smoking	3.71	1.6–8.45	0.0014	4.14	1.56–11	0.0046
Open fractures	2.52	1.09–5.84	0.0285	2.76	0.85–8.9	0.08
Diabetes	1.16	0.32–4.24	0.8	1.93	0.44–8.42	0.3
Multiple trauma	1.95	0.88–4.34	0.09	1.94	0.58–6.46	0.2
No head injury	1.42	0.51–3.98	0.5	2.2	0.6–8.25	0.2
Treatments
External fixation	0.45	0.2–1	0.04	0.4	0.04–5	0.5
Nailing	−	−	−	0.9	0.08–10	0.9
Flexible nail	−	−	0.01	−	−	0.9
Plate fixation	2.66	0.76–9.3	0.1	2.5	0.2–31	0.4
Non-operative treatment	4.17	0.37–47	0.2	8	0.3–244	0.2

OR odds ratio, 95% CI 95% confidence interval