Table III.

Number of patients at risk in each follow-up year, prior to matching.

		Surgical groups		Non-surgical groups
Year	Total cohort	Lob	Sub	Rad	Obs
0	27,239	18,154	4,759	2,618	1,585
1	21,000	14,794	3,700	1,715	791
2	16,536	12,236	2,874	1,003	423
3	12,826	9,856	2,190	543	237
4	9,858	7,768	1,654	311	125
5	7,333	5,933	1,170	153	77
6	5,262	4,343	795	71	51
7	3,648	3,069	500	41	31
8	2,349	2,010	305	28	11

lob, lobectomy; sub, sublobar resection; rad, radiation; obs, observation.