Table 3.

GLM-MANOVA test of the overall effect of the sociodemographic and clinical variables on the EORTC QLQ-C30 and H&N35 scales

	QLQ-C30				QLQ-H&N35
	One-factor model*		Multifactor model**		One-factor model*		Multifactor model**
Variable	Wilk's λ	p	Wilk's λ	p	Wilk's λ	p	Wilk's λ	p
Sociodemographic variables
Age: <40 v 40~60 v ≥ 60 years	0.922	0.016	0.942	NS	0.926	0.013	0.939	NS
Gender: female v male	0.890	<0.01	0.877	<0.01	0.919	0.018	0.963	NS
Education years: ≤ 6 v 6~12 v >12	0.914	0.011	0.928	NS	0.920	0.033	0.941	NS
Marital status: with v without spouse	0.958	0.042	0.951	NS	0.975	NS	0.968	NS
Annual family income: < 0.6 v 0.6~1.2 v ≥ 1.2 (million NTD)	0.845	<0.01	0.896	0.032	0.866	<0.01	0.910	NS
Clinical variables
CCI score: 0 v ≥ 1	0.937	0.001	0.910	NS	0.965	NS	0.935	NS
Tumor site: Oral cavity v Oropharynx v Hypopharynx/Larynx v Nasopharynx	0.805	<0.01	0.828	<0.01	0.618	<0.01	0.824	<0.01
AJCC stage: stage I-II v III-IV	0.870	<0.01	0.863	<0.01	0.880	<0.01	0.869	NS
Treatment methods: S + RT v S + RT+ C/T v RT±C/T	0.865	<0.01	0.845	<0.01	0.832	<0.01	0.906	NS
RT technique: 2DRT v 3DCRT v IMRT	0.888	<0.01	0.876	<0.01	0.869	<0.01	0.829	<0.01
Follow-up years: 2~3 v 3~5 v > 5	0.937	NS	0.928	NS	0.933	NS	0.938	NS

*: The one factor model: only one independent variable was entered into the model. **: The multifactor model: all mentioned variables were entered as independent variables in the model. Abbreviations: GLM-MANOVA: general linear model multivariate of variance; EORTC QLQ-C30: European Organization for Research and Treatment of Cancer Quality of Life Core questionnaire; H&N35: Head and Neck Module; NTD: New Taiwan Dollar (1 USD = 33 NTD); CCI: Charlson comorbidity index; AJCC: American Joint of Cancer Committee published in 2002; S: surgery; RT: radiotherapy; C/T: chemotherapy; 2DRT: two dimensional RT; 3DCRT: three dimensional conformal RT; IMRT: intensity modulated RT; NS: not significant.