Table 1.
List of variables used in the study (for both BRCA1 and BRCA2 populations), data types, and variable inclusion in Cox proportional hazards models (i) to (vi)
| Variable | Data type | Model (i) | Model (ii) | Model (iii) | Model (iv) | Model (v) | Model (vi) |
|---|---|---|---|---|---|---|---|
| Genetic predisposition score (GPS) | Numeric | ✓ | ✓ | ✓ | |||
| Year of birth | Numeric | ✓ | ✓ | ✓ | ✓ | ||
| Manchester score | Numeric (inverse hyperbolic sine scale) | ✓ | ✓ | ✓ | ✓ | ||
| Body mass index (BMI) | Numeric | ✓ | ✓ | ✓ | ✓ | ||
| Parity | Quartiles (q1 … q4) + missing category | ✓ | ✓ | ✓ | ✓ | ||
| Age of menarche | Quartiles (q1 … q4) + missing category | ✓ | ✓ | ✓ | ✓ | ||
| Age of menopause | Quartiles (q1 … q4) + missing category + ovulating stratum | ✓ | ✓ | ✓ | ✓ | ||
| Age of first full-term pregnancy | Quartiles (q1 … q4) + missing category + never had full term pregnancy | ✓ | ✓ | ✓ | ✓ | ||
| Oral contraception usage | Quartiles (q1 … q4) | ✓ | ✓ | ✓ | ✓ | ||
| Oophorectomy | Binary (yes vs. no) | ✓ | ✓ | ✓ | ✓ | ||
| Mastectomy | Binary (yes vs. no) | ✓ | ✓ | ✓ | ✓ | ||
| Individual single nucleotide polymorphisms (SNPs, rs614367, rs704010, rs713588, rs889312, rs909116, rs1011970, rs1156287, rs1562430, rs2981579, rs3757318, rs3803662, rs4973768, rs8009944, rs9790879, rs10995190, rs11249433, rs13387042, rs10931936) | Binary (yes vs. no) | ✓ | ✓ | ✓ |