Table 1.

Summary of ages and methods of collection of data used in analyses

	1946 cohort		1958 cohort
	Age/s (years) at collection	Method of collection	Age(s) (years) at collection	Method of collection
Outcome measures
Body mass index (kg/m2)	43 and 53	Height and weight measured by nurses during home visit	44–45	Height and weight measured by nurses during home visit
Waist circumference (cm)	43 and 53	Measured by nurses during home visit	44–45	Measured by nurses during home visit
Main explanatory variable
Hysterectomy status	43 and 53	Home visit questionnaire	44–45	Home visit questionnaire
	47 to 54 and 57	Annual postal questionnaires
Covariates
Pre-hysterectomy body mass index	26 and 36	Height and weight self-reported at age 26, measured by nurses at age 36	23 and 33	Height and weight self-reported at age 23, measured by interviewers at age 33
Parity	Up to 53	Self-reported in questionnaires	Up to 44–45	Self-reported in questionnaires
Age at menarche	14–15	Medical interview	16	Parental questionnaires
Father's occupational class	11	Parental questionnaires	11	Parental questionnaires
Own occupational class	43	Self-reported in questionnaire	42	Self-reported in questionnaire
Educational level	26	Self-reported in questionnaire	33	Self-reported in questionnaire
Exercise levels	36, 43 and 53	Self-reported in questionnaire [30]	33 and 42	Self-reported in questionnaire [31]
Hormone replacement therapy use	Up to 53	Self-reported in questionnaire	44–45	Self-reported in questionnaire