TABLE 4.
Effects of Interactions of Socioeconomic Status and Place on Colon Cancer Care and 5-Year Survival: Toronto, ON, and San Francisco, CA, 1996–2006
| Toronto |
San Francisco |
Toronto and San Francisco RR (95% CI) | |||
|---|---|---|---|---|---|
| No.a (Rate) | RRb (95% CI) | No.a (Rate) | RRb (95% CI) | ||
| SES by place on 5-year survival | |||||
| All casesc | |||||
| High income (Ref) | 372 (0.474) | 1.00 | 409 (0.552) | 1.00 | 0.86** (0.75, 0.98) |
| Middle income | 327 (0.558) | 1.18 (1.02, 1.37) | 358 (0.502) | 0.91 (0.80, 1.03) | 1.11 (0.97, 1.26) |
| Low income | 231 (0.440) | 0.93 (0.79, 1.10) | 247 (0.463) | 0.84** (0.72, 0.98) | 0.95 (0.79, 1.15) |
| SES by place and stage on 5-year survival | |||||
| Stage II to IV | |||||
| High income (Ref) | 285 (0.393) | 1.00 | 262 (0.427) | 1.00 | 0.92 (0.75, 1.12) |
| Middle income | 229 (0.425) | 1.08 (0.87, 1.34) | 245 (0.414) | 0.97 (0.82, 1.15) | 1.03 (0.81, 1.30) |
| Low income | 189 (0.399) | 1.02 (0.84, 1.24) | 179 (0.334) | 0.78** (0.61, 1.00) | 1.19 (0.92, 1.53) |
| Stage II and III | |||||
| High income (Ref) | 194 (0.546) | 1.00 | 183 (0.563) | 1.00 | 0.97 (0.80, 1.17) |
| Middle income | 159 (0.586) | 1.07 (0.89, 1.28) | 161 (0.582) | 1.03 (0.89, 1.20) | 1.01 (0.80, 1.26) |
| Low income | 132 (0.559) | 1.02 (0.87, 1.19) | 112 (0.454) | 0.81** (0.65, 1.00) | 1.23* (0.98, 1.54) |
| Stage II | |||||
| High income (Ref) | 77 (0.628) | 1.00 | 96 (0.636) | 1.00 | 0.99 (0.87, 1.12) |
| Middle income | 84 (0.708) | 1.13 (0.93, 1.37) | 84 (0.653) | 1.03 (0.84, 1.26) | 1.08 (0.90, 1.30) |
| Low income | 54 (0.711) | 1.13 (0.87, 1.46) | 49 (0.545) | 0.86 (0.67, 2.10) | 1.30* (0.98, 1.73) |
| SES by place on examination of > 15 regional lymph nodes | |||||
| Stage II and III | |||||
| High income (Ref) | 191 (0.138) | 1.00 | 178 (0.272) | 1.00 | 0.51** (0.34, 0.77) |
| Middle income | 158 (0.099) | 0.72 (0.38, 1.38) | 158 (0.165) | 0.61** (0.40, 0.92) | 0.60* (0.33, 1.10) |
| Low income | 129 (0.190) | 1.38 (0.87, 2.19) | 110 (0.184) | 0.68* (0.44, 1.06) | 1.03 (0.80, 1.32) |
| Examination of > 15 regional lymph nodes by place on 5-year survival | |||||
| < 16 nodes (Ref) | 414 (0.544) | 1.00 | 349 (0.529) | 1.00 | 1.03 (0.88, 1.21) |
| > 15 nodes | 64 (0.688) | 1.26** (1.02, 1.55) | 97 (0.614) | 1.16* (0.97, 1.38) | 1.12 (0.90, 1.39) |
| Only low- and middle-income neighborhoods | |||||
| < 16 nodes (Ref) | 249 (0.555) | 1.00 | 221 (0.534) | 1.00 | 1.04 (0.88, 1.23) |
| > 15 nodes | 38 (0.777) | 1.40** (1.06, 1.85) | 47 (0.534) | 1.00 (0.89, 1.13) | 1.46** (1.08, 1.97) |
Note. CI = confidence interval; NA = not applicable; RR = standardized rate ratio; SES = socioeconomic status. Except as noted, we directly adjusted all rates for age and stage by our sample’s combined Toronto–San Francisco population of cases as the standard (age categories: 25–59, 60–69, 70–79, and 80 years or older; stage categories were: I, II, III, and IV). The interaction pattern was similar for men and women (i.e., SES by place by gender and SES by place by stage by gender interactions were not significant), so rates were not adjusted for gender. Confidence intervals were derived from the Mantel–Haenszel χ2 test.
Number of incident breast cancer cases.
A rate ratio of 1.00 was the within-place baseline.
Not stage adjusted.
P = .10;
P < 0.5.