Table 3.

Factors influencing whether patients with SPN undergo at least one invasive test (Odds ratio [OR] and 95% confidence interval [CI]).

Factor	n	Unadjusted OR of receiving invasive test (CI)*	Adjusted OR of receiving invasive test (CI)+	P$
Patient characteristics
Age
35–65	52	0.8 (0.3–1.7)	1.5 (0.5–4.3)	0.38
> 65	60	1	1
Sex
Male	82	2.9 (1.2–7.2)	0.5 (0.1–3.8)	0.57
Female	30	1	1
Referral pattern
Specialist	94	4.1 (1.2–13.5)	6.6 (1.4–30.3)	0.01
GP	18	1	1
History of smoking
Current or past smoker	79	19.2 (5.3–68.8)	32.9 (4.3–247.7)	<0.01
Never smoked	33	1	1
Nodule characteristics
Calcification within the nodule
Yes	12	0.1 (0.1–0.8)	0.5 (0.1–4.2)	0.54
No	100	1	1
Spiculated nodule
Yes	32	4.7 (1.8–11.8)	5.7 (1.6–19.5)	<0.01
No	80	1	1
Mediastinal involvement
Yes	31	1.9 (0.8–4.6)	1.4 (0.4–4.3)	0.49
No	81	1	1

GP = general practitioner

*In univariate logistic regression models

+In multivariate logistic regression model

^$p values for the factors are the Wald statistics for the estimates in the model