Table 2.
Incidence of systemic sclerosis 1994–2013 (per million person-years)
| Cases | Person-years | Crude incidence rate (95% CI) | Crude rate ratios (95% CI) | Adjusted rate ratios (95% CI) | P valuea | |
|---|---|---|---|---|---|---|
| Overall | 1327 | 68,529,194 | 19.4 (18.3–20.4) | |||
| Sex | ||||||
| Male | 223 | 34,069,626 | 6.5 (5.7–7.5) | 1 | 1 | < 0.0001 |
| Female | 1104 | 34,459,569 | 32.0 (30.2–34.0) | 4.9 (4.2–5.7) | 4.7 (4.1–5.4) | |
| Age group (years) | ||||||
| Age 0–15 | 35 | 11,955,198 | 2.9 (2.1–4.1) | 0.5 (0.3–0.7) | 0.5 (0.3–0.7) | Ptrend < 0.0001 |
| Age 16–39 | 132 | 20,729,227 | 6.4 (5.4–7.6) | 1 | 1 | |
| Age 40–54 | 338 | 15,329,346 | 22.0 (19.8–24.5) | 3.5 (2.8–4.2) | 3.4 (2.8–4.2) | |
| Age 55–69 | 513 | 11,887,368 | 43.2 (39.6–47.1) | 6.7 (5.6–8.2) | 6.7 (5.5–8.1) | |
| Age 70–84 | 283 | 7,100,416 | 39.9 (35.3–44.8) | 6.3 (5.1–7.7) | 5.7 (4.6–7.0) | |
| Age 85+ | 26 | 1,528,196 | 17.0 (11.6–25.0) | 2.7 (1.8–4.1) | 2.1 (1.4–3.1) | |
| Each additional calendar year | 1.0 (1.0–1.0) | Ptrend 0.24 | ||||
| IMD 2010 | ||||||
| Quintile 1—most deprived | 196 | 9,911,807 | 19.8 (17.2–22.7) | 1 | 1 | Ptrend = 0.63 |
| Quintile 2 | 187 | 9,728,120 | 19.2 (16.7–22.2) | 1.0 (0.8–1.2) | 0.9 (0.8–1.2) | |
| Quintile 3 | 157 | 8,356,976 | 18.8 (16.1–22.0) | 1.0 (0.8–1.2) | 1.0 (0.8–1.2) | |
| Quintile 4 | 152 | 7,802,398 | 19.5 (16.6–22.8) | 1.0 (0.8–1.2) | 1.1 (0.9–1.3) | |
| Quintile 5—least deprived | 120 | 6,304,656 | 19.0 (15.9–22.7) | 1.0 (0.8–1.2) | 1.1 (0.9–1.4) | |
| IMD not known | 515 | 26,425,793 | 19.5 (17.9–21.2) | 1.0 (0.8–1.2) | 1.0 (0.9–1.2) | |
Crude incidence rate is calculated using univariable Poisson regression, and the adjusted rate ratio is calculated using multi-variable Poisson regression including sex, age-group, year of diagnosis and IMD-quintile as a priori confounders
aFrom multi-variable (adjusted) analysis using the likelihood ratio test