Table 3.

Multivariable logistic regression models of characteristics associated with postoperative hypocalcemia

	Model 1	Model 2	Model 3
Variables	OR (95% CI); p-value	OR (95% CI); p-value	OR (95% CI); p-value
Patient age at surgery	0.99 (0.98–1.01); p = 0.27	0.99 (0.97–1.00); p = 0.17	0.99 (0.97–1.01); p = 0.19
Sex (Male vs. Female)	0.66 (0.34–1.27); p = 0.21	0.62 (0.32–1.22); p = 0.17	0.66 (0.34–1.29); p = 0.23
ASA Score (Ref. ASA I/II)
ASA III/IV	1.49 (0.88–2.52); p = 0.14	1.50 (0.87–2.57); p = 0.14	1.60 (0.92–2.76); p = 0.10
Surgeon volume (high vs. low volume)	1.28 (0.77–2.13); p = 0.34	1.08 (0.64–1.81); p = 0.78	1.14 (0.67–1.93); p = 0.63
Indication (Ref. Goiter)
Malignancy	0.93 (0.36–2.4); p = 0.89	0.76 (0.29–2.04); p = 0.59	0.75 (0.27–2.04); p = 0.57
Hyperthyroidism/Graves' disease	0.90 (0.52–1.57); p = 0.72	0.99 (0.56–1.75); p = 0.97	0.99 (0.55–1.75); p = 0.96
Recurrent Goiter	1.02 (0.3–3.47); p = 0.98	0.82 (0.24–2.79); p = 0.75	0.87 (0.25–3.04); p = 0.82
Thyroiditis	0.19 (0.02–1.57); p = 0.12	0.22 (0.03–1.81); p = 0.16	0.20 (0.02–1.65); p = 0.13
Extent of surgery (Ref. Total thyroidectomy)
TT + lymph node dissection	1.08 (0.37–3.15); p = 0.89	1.48 (0.49–4.46); p = 0.49	1.27 (0.41–3.91); 0.68
iPTH-levels (Ref. > 15 pg/ml)
iPTH 10.0—15.0 pg/ml	2.29 (1.25–4.18); p = 0.01		0.87 (0.44–1.72); p = 0.68
iPTH < 10.0 pg/ml	5.81 (3.59–9.41); p < 0.01		2.01 (1.12–3.59); p = 0.02
Percentage decrease of iPTH (Ref. decrease of 1–50% or no decrease)
iPTH-decrease > 50%		7.08 (4.42–11.33); p < 0.01	5.51 (3.11–9.77); p < 0.01
Statistical model performance, AIC	573.1	544.3	539.7

AIC Akaike information criterion