Table 1 Timing of body size assessments and numbers of participants, cases, and person-years included in each analysis, by study population

From: Body size in early life and risk of epithelial ovarian cancer: results from the Nurses' Health Studies

Body size measure

Cohort a

Year assessed b

No. of participants

No. of cases

No. of person-years

Body fatness at ages 5 and 10 years

NHS

1988

64 876

372

888 845

 

NHSII

1989

110 274

131

1 614 085

Body mass index at the age of 18 years

NHS

1980

84 643

581

1 680 079

 

NHSII

1989

112 119

136

1 640 636

Height

NHS

1976

110 311

735

2 528 901

 

NHSII

1989

113 059

137

1 654 409

Birthweight

NHS

1992

49 321

226

521 364

 

NHSII

1991

77 952

88

1 016 804

  1. aThe Nurses' Health Study (NHS) began in 1976 and had 121 700 participants at enrolment, 30–55 years of age. The Nurses' Health Study II (NHSII) began in 1989 and had 116 609 participants at enrolment, 25–42 years of age.
  2. bThe year when each body size measure was assessed defined the baseline for that analysis; follow-up was through 31 May 2004 for NHS and 31 May 2005 for NHSII.