Sex-specific model coefficients for differentiated thyroid cancer rates by incidentally detected status, 1998–2017*
| Covariate | Female patients; rate ratio (95% CI) n = 28 735 | Male patients; rate ratio (95% CI) n = 7796 | ||
|---|---|---|---|---|
| Nonincidentally detected† n = 26 055 | Incidentally detected n = 2680 | Nonincidentally detected n = 6482 | Incidentally detected n = 1314 | |
| Age group, yr | ||||
| 15–19 | 0.23 (0.04–1.22) | 0.09 (0.06–0.14) | 0.11 (0.09–0.14) | 0.06 (0.03–0.12) |
| 20–24 | 0.44 (0.10–1.83) | 0.17 (0.13–0.23) | 0.22 (0.19–0.26) | 0.13 (0.08–0.21) |
| 25–29 | 0.68 (0.21–2.25) | 0.31 (0.25–0.39) | 0.38 (0.34–0.44) | 0.26 (0.19–0.37) |
| 30–34 | 0.90 (0.35–2.33) | 0.51 (0.42–0.61) | 0.53 (0.47–0.59) | 0.38 (0.28–0.52) |
| 35–39 | 1.01 (0.49–2.07) | 0.64 (0.54–0.76) | 0.77 (0.70–0.86) | 0.55 (0.43–0.71) |
| 40–44 | 1.02 (0.63–1.65) | 0.77 (0.65–0.90) | 0.87 (0.79–0.96) | 0.69 (0.54–0.87) |
| 45–49 | 1.03 (0.80–1.31) | 0.89 (0.76–1.03) | 0.91 (0.82–1.00) | 0.83 (0.66–1.04) |
| 50–54 | Referent | Referent | Referent | Referent |
| 55–59 | 0.87 (0.68–1.11) | 1.01 (0.86–1.18) | 1.06 (0.96–1.17) | 1.06 (0.85–1.32) |
| 60–64 | 0.75 (0.46–1.21) | 1.13 (0.96–1.32) | 1.12 (1.01–1.23) | 1.23 (0.99–1.54) |
| 65–69 | 0.62 (0.30–1.27) | 1.14 (0.97–1.35) | 0.90 (0.81–1.01) | 1.61 (1.29–2.00) |
| 70–74 | 0.54 (0.21–1.41) | 0.97 (0.81–1.17) | 0.86 (0.76–0.98) | 1.45 (1.14–1.85) |
| 75–79 | 0.36 (0.11–1.18) | 1.00 (0.82–1.22) | 0.56 (0.47–0.66) | 1.23 (0.93–1.62) |
| 80–84 | 0.19 (0.05–0.80) | 0.82 (0.65–1.03) | 0.37 (0.29–0.46) | 1.04 (0.74–1.47) |
| Diagnosis period | ||||
| 1998–2002 | Referent | Referent | Referent | Referent |
| 2003–2007 | 1.60 (1.26–2.04) | 1.80 (1.55–2.10) | 1.39 (1.27–1.52) | 1.62 (1.30–2.01) |
| 2008–2012 | 2.35 (1.46–3.77) | 2.88 (2.50–3.32) | 2.03 (1.87–2.20) | 2.62 (2.14–3.19) |
| 2013–2017 | 2.49 (1.22–5.08) | 3.45 (3.00–3.96) | 2.38 (2.20–2.58) | 3.21 (2.65–3.90) |
Note: CI = confidence interval.
↵* Estimates are for the 3-month look-back period; Appendix 3 (Supplementary Tables 1–4; available at www.cmajopen.ca/content/8/4/E695/suppl/DC1) provides estimates for each look-back period.
↵† Female nonincidentally detected statistical model includes birth cohort parameter estimates, which are nonsignificant owing to the constraint imposed (birth cohort parameter 1918–1927 = 1923–1932). Complete coefficients are provided in Appendix 3 (Supplementary Table 1).