Table 1. Baseline characteristics of the study population.

	Year of diagnosis
	2001	2002	2003	2004	2005	2006	2007	2008	2009	2010	P-value
N	439	418	432	474	529	481	483	499	471	454
Age
Mean (±s.d.)	57.78±12.78	61.00±13.12	59.00±13.34	59.51±13.31	59.53±12.75	59.20±13.53	59.51±12.91	59.22±13.87	59.55±13.96	59.72±13.96	0.146
Charlson index
Mean (±s.d.)	0.33±0.48	0.29±0.47	0.32±0.49	0.29±0.48	0.32±0.48	0.38±0.52	0.37±0.52	0.39±0.54	0.41±0.55	0.48±0.58	<0.0001
Location, n(%)
Urban	353 (90.1%)	346 (88.3%)	350 (86.8%)	383 (88.0%)	727 (88.4%)	382 (86.8%)	407 (91.5%)	413 (90.8%)	381 (90.3%)	350 (86.8%)
Semirural	33 (8.4%)	44 (11.2%)	50 (12.4%)	51 (11.7%)	49 (10.1%)	55 (12.5%)	35 (7.9%)	37 (8.1%)	35 (8.3%)	50 (12.4%)
Rural	6 (1.5%)	2 (0.5%)	3 (0.7%)	1 (0.2%)	7 (1.4%)	3 (0.7%)	3 (0.7%)	5 (1.1%)	6 (1.4%)	3 (0.7%)