Table 4.
Associations between average annual absorbed radiation dose (µGy/year) and endometriosis. [95% CI=95% confidence interval; OR =adjusted odds ratio; Q=quartile]
| N | ORcrude | 95% CI | P-value | ORadja | 95% CI | P-value | |
|---|---|---|---|---|---|---|---|
| Total radiation c | 0.55 b | 0.88 b | |||||
| Q1 (25–466) | 487 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (467–638) | 486 | 1.3 | 0.7–2.4 | 1.3 | 0.7–2.4 | ||
| Q3 (639–828) | 485 | 1.2 | 0.7–2.3 | 1.2 | 0.6–2.2 | ||
| Q4 (829–2094) | 487 | 1.3 | 0.7–2.3 | 1.0 | 0.5–1.9 | ||
| Neutrons | 0.66 b | 0.92 b | |||||
| Q1 (5–101) | 486 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (102–139) | 486 | 1.1 | 0.6–2.0 | 1.1 | 0.6–2.0 | ||
| Q3 (140–175) | 487 | 1.3 | 0.7–2.4 | 1.3 | 0.7–2.3 | ||
| Q4 (175–490) | 486 | 1.2 | 0.7–2.2 | 1.1 | 0.6–2.0 | ||
| Muons | 0.41 b | 0.70 b | |||||
| Q1 (2–49) | 486 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (50–68) | 485 | 1.3 | 0.7–2.4 | 1.3 | 0.7–2.4 | ||
| Q3 (69–82) | 488 | 1.5 | 0.8–2.8 | 1.5 | 0.8–2.9 | ||
| Q4 (83–185) | 486 | 1.3 | 0.7–2.5 | 1.2 | 0.6–2.3 | ||
| Electromagnetic showers |
0.53 b | 0.80 b | |||||
| Q1 (13–254) | 486 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (255–351) | 486 | 1.3 | 0.7–2.5 | 1.4 | 0.7–2.6 | ||
| Q3 (352–467) | 487 | 1.4 | 0.7–2.5 | 1.3 | 0.7–2.4 | ||
| Q4 (468–1147) | 486 | 1.3 | 0.7–2.5 | 1.0 | 0.5–2.0 | ||
| Protons | 0.61 b | 0.88 b | |||||
| Q1 (2–53) | 487 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (54–73) | 486 | 1.1 | 0.6–2.1 | 1.1 | 0.6–2.2 | ||
| Q3 (74–94) | 485 | 1.5 | 0.8–2.8 | 1.5 | 0.8–2.7 | ||
| Q4 (95–257) | 487 | 1.2 | 0.6–2.2 | 1.0 | 0.5–1.9 | ||
| Pions | 0.50 b | 0.93 b | |||||
| Q1 (0.2–3.9) | 489 | 1.0 | Ref | 1.0 | Ref | ||
| Q2 (4.0–5.3) | 484 | 1.2 | 0.7–2.3 | 1.2 | 0.7–2.3 | ||
| Q3 (5.4–6.9) | 486 | 1.2 | 0.7–2.3 | 1.2 | 0.7–2.2 | ||
| Q4 (7.0–16.4) | 486 | 1.3 | 0.7–2.4 | 1.1 | 0.6–2.0 | ||
a
Adjusted for body mass index (continuous variable) and study site.
b
Midpoint of category used to calculate P-value for linear trend.
c
The average yearly effective dose total radiation among flight attendants in this population had a median of 1472 microsieverts (µSv) and a range of 57–5032 µSv using proton weighting factor = 2. Effective dose is commonly used in studies of radiation protection.