Table 1

Characteristics of study population of Swedish women with RA 2006–2016, and matched population referents

RAPopulation referents
Persons (N)15 92179 441
Birth year (Q1–Q4)1952 (1940–1963)1952 (1940–1963)
Mean age at entry (SD)59 (16)59 (16)
Education (%)
 9 years or less2725
 10–12 years5655
 More than 12 years1519
RA in a first-degree relative (%)104
Breast or ovarian cancer in a first-degree relative (%)1010
Invasive cancer prior to entry (%)56
Country of birth (%)
 Rest of Europe1111
 Rest of the world56
ACPA and RF negative28NA
ACPA or RF positive68NA
Mean age at first live birth (SD)25 (5.0)25 (5.0)
Children at index date (SD)2 (1.4)2 (1.4)
Combined oestrogen and progestin HRT (%)55
Unopposed oestrogen HRT (%)66
Combined oestrogen and progestin contraceptive (%)99
Progestin only contraceptive (%)77
  • ACPA, Anti-citrullinated protein antibodies; HRT, hormone replacement therapy; RA, rheumatoid arthritis; RF, Rheumatoid factor.