Table 1.

Characteristics of the NHS, HPFS, CTS, MEC, U/OLCR, and NHEFS cohort members included in this analysis

	NHS10,11	HPFS10,12	CTS13	MEC14,15	U/OLCR16	NHEFS17
Dates of follow-up	1976 to 2002	1986 to 2002	1995–96 to 2002	1993–96 to 2001	2003	1971–75 to 1992
Age at baseline (years)	30–55	40–75	33–79*	45–75	40–79	25–74
Population at risk (N)	121,700 females	51,529 males	108,329 females	82,460 males 101,359 females	438,966 males‡ 447,603 females‡	5,075 males 7,637 females
Incident lung cancer cases (40–79 yrs at diagnosis) (N)	1,817	528	393	1,078 males† 805 females†	273 males 250 females	160 males 75 females
Region	United States	United States	California	California/Hawaii	Uppsala/Örebro, Sweden	United States
Ethnicity	Mostly Caucasian	Mostly Caucasian	Mostly Caucasian	Multiple	Mostly Caucasian	Multiple
Follow-up for lung cancer	Biennial questionnaires and medical records, if possible	Biennial questionnaires and medical records, if possible	Linkage to cancer registry	Linkage to cancer registry	Linkage to cancer registry	Questionnaires every ~5 years and inpatient records or death certificates**
Smoking data	Biennial questionnaires	Biennial questionnaires	Baseline questionnaire	Baseline questionnaire	Questionnaire for at-risk population; medical records or clinical assessment for cases	Baseline and follow-up questionnaire

^*Age range of eligible cohort members was restricted to those potentially aged 40 to 79 years during follow-up.

^†Age range of incident lung cancer cases was 45–79 years at diagnosis.

^‡Population at risk based on 2003 census count of males and females ages 40 to 79 years in Uppsala/Örebro (Statistics Sweden: www.scb.se)⁷⁴; smoking status in population at risk based on a survey of 68,000 randomly selected Uppsala/Örebro residents (64% of whom completed the survey) at the beginning of 2004.

^**The NHEFS lacked information on tumor histology.

Nurses’ Health Study (NHS), Health Professionals Follow-up Study (HPFS), California Teachers Study (CTS), Multiethnic Cohort (MEC) Study, Swedish Uppsala/Örebro Lung Cancer Register (U/OLCR), First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study (NHEFS).