Table 2.

Univariate regression analysis of outcome parameters with and without drainage

Outcome parameter	Total	+Drain	−Drain	Logistic regression
	n (%) or mean ± SD			OR	95% CI	p value
Periorbital edema (early; moderate or severe)	9 (10.0%)	6 (16.2%)	3 (5.7%)	0.310	0.072–1.330	ns
Subgaleal swelling (early)	55 (36.7%)	25 (39.7%)	30 (34.5%)	0.800	0.409–1.565	ns
Subgaleal swelling (late)	3 (2.3%)	2 (3.6%)	1 (1.3%)	0.349	0.031–3.945	ns
Impaired wound healing	5 (3.3%)	2 (3.2%)	3 (3.4%)	1.089	0.177–6.718	ns
Pain, VAS 5–10 (early)	8 (9.6%)	4 (11.8%)	4 (8.2%)	0.667	0.155–2.873	ns
Pain, VAS 5–10 (late)	3 (2.5%)	2 (4.0%)	1 (1.4%)	0.343	0.030–3.888	ns
Need for operative revision	10 (6.7%)	4 (6.3%)	6 (6.9%)	1.093	0.295–4.045	ns
Infection	11 (7.3%)	4 (6.3%)	7 (8.0%)	1.291	0.361–4.613	ns

The effect of drainage on recorded outcome parameters was analyzed using the binary logistic regression model. Outcome parameter at the time of discharge was decelerated as early follow-up; after 6 weeks, as late follow-up. The incidence of periorbital edema (moderate or severe), subgaleal swelling (moderate and severe, early and late), impaired wound healing (until late follow-up), non-adequate pain control (early and late f/u), need for operative revision, and infection was not affected by the presence of subgaleal drains. Infection was defined as any of the following: evidence of a purulent wound, meningitis (verified by lumbar puncture), intracerebral abscess, or wound healing disorder in conjunction with increased inflammatory parameters (early or late follow-up).

CI, confidence interval; +drain, patient with subgaleal drainage; −drain, patient without subgaleal drainage; ns, not significant; OR, odds ratio; SD, standard deviation; VAS, visual analog scale