Table 3.

Trends over time according to SES and tumor thickness: Incidence rate ratio¹ comparing period 2 (1998–2002) to period 1 (1988–1992)

Thickness
SES 2	Women		Men		All
	0–64 yrs	65+ yrs	0–64 yrs	65+ yrs	0–64 yrs	65+ yrs
≤1mm
1	2.24	2.01	2.22	2.70	2.26	2.42
2	1.88	1.97	1.98	2.38	1.93	2.19
3	1.96	1.96	1.89	2.18	1.94	2.13
4	2.08	2.13	1.76	2.13	1.93	2.17
5	1.67	1.84	1.73	1.97	1.69	1.95
1.01–2mm
1	5.25	7.00	4.00	3.97	4.4	4.89
2	3.8	3.89	3.83	8.11	3.5	5.56
3	3.14	3.58	3.09	4.68	3.11	4.24
4	2.36	4.14	2.54	4.06	2.42	4.16
5	2.55	2.44	2.47	3.28	2.5	2.98
2.01–4mm
1	-	12.25	3.33	6.52	5.00	8.3
2	4.00	8.83	5.67	9.75	4.33	9.88
3	2.67	4.45	2.83	4.88	3.00	5.27
4	2.50	2.57	2.25	4.39	2.33	3.48
5	2.25	3.33	2.29	3.05	2.00	3.23
≥4.01mm
1	4.0	4.0	13.0	5.48	8.0	5.38
2	-	4.5	3.33	11.29	4.0	6.71
3	4.0	4.0	3.33	6.69	3.5	5.44
4	2.0	4.13	2.67	5.4	3.0	5.17
5	2.0	4.33	2.67	4.36	2.0	4.31
Unknown3
1	0.45	0.52	0.69	0.85	0.57	0.68
2	0.45	0.58	0.46	0.67	0.45	0.61
3	0.45	0.66	0.42	0.68	0.43	0.64
4	0.40	0.53	0.45	0.68	0.43	0.61
5	0.40	0.53	0.39	0.57	0.39	0.54
All
1	1.68	1.68	1.74	2.07	1.70	1.93
2	1.49	1.71	1.51	1.98	1.50	1.87
3	1.54	1.67	1.43	1.81	1.49	1.81
4	1.50	1.67	1.37	1.88	1.42	1.83
5	1.30	1.55	1.32	1.63	1.31	1.63

- used when unable to calculate ratio since denominator equal to zero

¹Incidence rate ratio was calculated as the number of new cases of melanoma per 100,000 which occurred during period 1 (1998–2002) divided by the number of new cases of melanoma per 100,000 in period 2 (1988–1992)

²Socioeconomic status was divided into 5 quintiles based on an index of neighborhood SES based on characteristics of the census tract of patient residence at the time of diagnosis. SES1 (lowest), SES 5 (highest) (Yost et al., 2001)

³The percentage of cases with missing thickness across SES groups 1 through 5 is: 32%, 28%, 25%, 22% and 21% respectively