Table 2 Summary of multivariate logistic regression analysis to identify factors that independently predict for the presence of epidermal growth factor receptor (EGFR) mutations in non-Asian and Asian patients

Factors that predict for presence of EGFR mutation^#	Non-Asian patients^¶		Asian patients⁺
	Odds (95% CI) of EGFR mutation	p-value	Odds (95% CI) of EGFR mutation	p-value
Smoking status	6.6 (3.9–11.1) times higher in never-smokers than ever-smokers	<0.0001	2.4 (0.9–5.9) times higher in never-smokers than ever-smokers	0.0702
Histology	3.8 (2.1–6.8) times higher in adenocarcinoma than non-adenocarcinoma	<0.0001	4.7 (1.7–12.8) times higher in adenocarcinoma than non-adenocarcinoma	0.0022
Sex	1.9 (1.2–3.1) times higher in females than males	0.0103	2.2 (0.9–5.5) times higher in females than males	0.1007
WHO PS	1.9 (1.0–3.6) times higher in PS 0–1 than PS 2	0.0594

These data are previously unpublished. ^#: age (<65 years versus ≥65 years) and WHO PS (0–1 versus ≥2; Asians only) were not found to be significant predictors using p<0.2 selection criteria; ^¶: analysis based on INTEREST, INVITE, ISEL, INSTEP, INTACT 1 and 2, and IDEAL 1 and 2 baseline data in non-Asian patients combined (n = 920); overall mutation-positive rate in non-Asian patients was 10%; ⁺: analysis based on INTEREST, V-15-32, INTACT 1 and 2, and IDEAL 1 and 2 baseline data in Asian patients combined (n = 140); overall mutation-positive rate in Asian patients was 39%. WHO: World Health Organization; PS: performance status; INTEREST: IRESSA NSCLC Trial Evaluating Response and Survival versus Taxotere; INVITE: IRESSA in NSCLC versus Vinorelbine Investigation in the Elderly; ISEL: IRESSA Survival Evaluation in Lung cancer; INSTEP: IRESSA NSCLC Trial Evaluating Poor Performance Status Patients; INTACT: IRESSA NSCLC Trial Assessing Combination Treatment; IDEAL: IRESSA Dose Evaluation in Advanced Lung Cancer.