Table 3.

Reliability parameters of the WHOQOL-OLD facets

	Classical test theory				IRT
Item no./WHOQOL-OLD facet	Item-test correlation	Corrected item-test correlation	Inter-item correlation	Cronbach’s alpha if item deleted/alpha	Q-Index	INFIT
Old 01	0.8882	0.7849	0.6350	0.8369	−0.1828	0.687
Old 02	0.9137	0.8337	0.6035	0.8167	−0.5315	0.509
Old 10	0.8206	0.6755	0.7097	0.8793	0.6041	1.031
Old 20	0.8255	0.7114	0.6842	0.8669	0.1172	0.780
Sensory abilities			0.6581	0.8842	Andrich reliability
					0.798
Old 03	0.7790	0.6062	0.4057	0.6696	−0.5757	0.662
Old 04	0.7595	0.5148	0.4694	0.7218	0.5710	0.847
Old 05	0.7472	0.5558	0.4371	0.6949	−0.0180	0.747
Old 11	0.7594	0.5409	0.4519	0.7017	0.1018	0.797
Autonomy			0.4015	0.7537	Andrich reliability
					0.703
Old 12	0.8197	0.6062	0.4228	0.6851	−0.1279	0.694
Old 13	0.7849	0.5811	0.4377	0.6945	−0.0293	0.737
Old 15	0.7141	0.5254	0.4750	0.7263	0.2049	0.804
Old 19	0.7402	0.5551	0.4608	0.7112	−0.0690	0.771
Past, present and future activities			0.4491	0.7619	Andrich reliability
					0.751
Old 14	0.7514	0.5667	0.6817	0.8596	1.3272	1.071
Old 16	0.8309	0.7167	0.5781	0.8042	−0.4557	0.694
Old 17	0.8897	0.7891	0.5318	0.7656	−0.9818	0.540
Old 18	0.8600	0.7146	0.5804	0.8019	0.0255	0.718
Social participation			0.5930	0.8502	Andrich reliability
					0.801
Old 06	0.8443	0.7211	0.5859	0.8095	−0.5266	0.737
Old 07	0.8806	0.7666	0.5559	0.7884	−1.2724	0.610
Old 08	0.8163	0.6747	0.6163	0.8280	0.4899	0.849
Old 09	0.8044	0.6432	0.6403	0.8415	1.1852	0.946
Death and dying			0.5996	0.8567	Andrich reliability
					0.829
Old 21	0.8675	0.7667	0.7625	0.9051	0.5563	0.901
Old 22	0.9230	0.8517	0.7022	0.8767	−0.5745	0.578
Old 23	0.8958	0.8153	0.7278	0.8891	−0.1093	0.706
Old 24	0.8897	0.8018	0.7369	0.8934	0.1258	0.765
Intimacy			0.7324	0.9162	Andrich reliability
					0.888