Table 1. Quality control index of laryngeal cancer in China, 2011.

Areas	Sex	MV%	DOC%	M/I	UB%
All	Both	77.98	2.62	0.55	0.3
	Male	79.5	2.41	0.53	0.23
	Female	65.54	4.31	0.73	0.92
Urban	Both	82.72	1.93	0.51	0.31
	Male	83.91	1.9	0.49	0.17
	Female	71.02	2.27	0.71	1.7
Rural	Both	69.43	3.86	0.63	0.28
	Male	71.12	3.39	0.61	0.33
	Female	59.06	6.71	0.75	0

MV%, the percentage of cases morphologically verified; DCO%, the percentage of death certificate-only cases; M/I, mortality to incidence ratio; UB%, the proportion of diagnosis of unknown basis.