Table 1

Age specific incidence rates and SIR with 95% CI for multiple sclerosis in Swedish female nurse anaesthetists in 1980–99

Swedish nurse anaesthetistsIncidence rates of
Age group, yearsNumber of casesPerson-yearsGothenburg womenDanish women
References are incidence data for women in the Gothenburg region in 1950–64 and in Denmark 1950–89. The incidence rates are expressed as cases per 105 person-years. For calculations, see Hernberg.4
20–2903170 9.9 11.35
30–39017860 12.26 11.77
40–49812260 6.33 7.62
50–5924440 3.57 2.50
20–591037730SIR = 2.9 (95% CI 1.3 to 5.3)SIR = 2.8 (95% CI 1.3 to 5.2)