Table 1: Demographic characteristics and results of multiple logistic regression showing the adjusted odds ratio (aOR) and 95% CI (confidence interval) of users from the 1  million random sample of the National Health Insurance Research Database (NHIRD) from 1997 to 2008 in Taiwan.

CharacteristicsHT users who did not use Chinese medicine,
number
HT users coprescribed a Chinese medicine,
number
HT users coprescribed a Chinese medicine/HT users who did not use a Chinese medicine
aOR (95% CI)

Numbers of HT users (breast cancer patients)2,411 (31)3,053 (33)
Incidence of breast cancer11.61.1
Mean (SD) duration of follow-up, person-years8.2 (2.7)9.4 (2.0)
Mean (SD) age at inclusion, years63.4 (6.5)61.0 (5.2)
Age groups at inclusion, years number (%)
 55~59865 (35.9)1,474 (48.3)1.00
 60~64607 (25.2)886 (29.0)0.83 (0.72–0.96)
 65~69438 (18.2)446 (14.6)0.57 (0.48–0.67)
 70~74331 (13.7)193 (6.3)0.34 (0.27–0.42)
 75~79170 (7.0)54 (1.8)0.21 (0.15–0.29)
$NTe/month (Premiums) (%)
 0768 (31.9)878 (28.8)1.00
 1–19,9991,357 (56.3)1,693 (55.4)0.95 (0.83–1.09)
 20,000–39,999207 (8.6)363 (11.9)1.12 (0.90–1.39)
 >=4000079 (3.3)119 (3.9)0.93 (0.67–1.28)
Insured area (%)
 Taipei City533 (22.1)562 (18.4)1.00
 Kaohsiung City162 (6.7)204 (6.7)1.16 (0.90–1.49)
 Northern Taiwan647 (26.9)725 (23.8)1.06 (0.90–1.26)
 Central Taiwan258 (10.7)722 (23.6)2.83 (2.32–3.45)
 Southern Taiwan701 (29.1)718 (23.5)1.04 (0.88–1.24)
 Eastern Taiwan95 (3.9)103 (3.4)1.04 (0.75–1.44)
 Outlying islands15 (0.6)19 (0.6)1.75 (0.80–3.82)
Number of chronic diseases (%)
 0172 (7.1)103 (3.4)1.00
 1360 (14.9)344 (11.3)1.58 (1.17–2.14)
  Cardiovascular disease46 (1.9)38 (1.2)
  Hypertension89 (3.7)47 (1.5)
  Hypercholesterolemia21 (0.9)20 (0.7)
  Diabetes mellitus33 (1.4)24 (0.8)
  Stroke10 (0.4)6 (0.2)
  Osteoporosis161 (6.7)209 (6.9)
 2458 (19.0)528 (17.3)2.04 (1.53–2.74)
 3 or more1,421 (58.9)2,078 (68.1)2.63 (2.01–3.45)
Types and prescription patterns of HT (%)
 Estrogen-alone1,179 (48.9)925 (30.3)1.00
 Progesterone-alone83 (3.4)0 (0.0)
 Estrogen and progesterone combination34 (1.4)33 (1.1)1.17 (0.71–1.95)
 Mixed type1,115 (46.3)2,095 (68.6)2.17 (1.93–2.44)

HT refers to hormonal therapy.
Mixed type refers to the estrogen-alone (E-alone); estrogen together with progesterone (E + P); other preparations, which included progesterone only and vaginal and other local treatments and combinations of the above preparation types.
eNT$ refers to new Taiwan dollars, of which 1 US $ = 30 NT$.
1Incidence rate: number of breast cancer/1,000 person-year.