Table 1. Characteristics of published cohort and case-control studies on night work shift and risk of colorectal cancer.

First Author	Published year	No. of cases/No. of subjects	Study design	Quality score	Region	Type of Cancer	gender	Range of night work shift	Variables of adjustment	Expossure assessment
Papantonion	2014	1658/5046	case-control	5	Spain	colorectal cancer	both	never vs. >30 years	Lifetime occupational history on daily time schedule of each job, day/night/rotating shifts, light at night exposure, and duration of different job	interview
Tsai	2013	1412/2176	case-control	8	US	colorectal cancer	female	daytime vs. regular night shift	obesity, smoking status, alcohol consumption, race, income, education, health insurance coverage, and marital status	interview
Parent	2012	439/951	case-control	9	Canada	colon cancer	male	never vs. ever	Smoking, BMI, alcohol, β-carotene, occupational, physical activity	interview
Parent	2012	236/748	case-control	9	Canada	rectal cancer	male	never vs. ever	Smoking, beer, BMI	interview
Schwartzbaum	2007	449/2102126	cohort	8	Sweden	colon cancer	male	never vs. ever	age, socioeconomic status, occupational position, and county of residence.	interview
Schwartzbaum	2007	326/2102126	cohort	8	Sweden	rectal cancer	male	never vs. ever	age, socioeconomic status, occupational position, and county of residence.	interview
Schwartzbaum	2007	16/1148661	cohort	8	Sweden	colon cancer	female	never vs. ever	age, socioeconomic status, occupational position, and county of residence.	interview
Schwartzbaum	2007	4/1148661	cohort	8	Sweden	rectal cancer	female	never vs. ever	age, socioeconomic status, occupational position, and county of residence.	interview
Schernhammer	2003	347/78586	cohort	8	US	colon cancer	female	never vs. >15 years	age in years, pack-years of smoking before age 30 in quintiles, body mass index in five categories, physical activity in quintiles, regular aspirin use, screening endoscopy during the study period, consumption of beef, pork, or lamb as a main dish, alcohol consumption status, total caloric intake in quintiles, use of postmenopausal hormones, menopausal status, and height in seven categories	questionnaire
Schernhammer	2003	103/78586	cohort	8	US	rectal cancer	female	never vs. >15 years	age in years, pack-years of smoking before age 30 in quintiles, body mass index in five categories, physical activity in quintiles, regular aspirin use, screening endoscopy during the study period, consumption of beef, pork, or lamb as a main dish, alcohol consumption status, total age in years, pack-years of smoking before age 30 in quintiles, body mass index in five categories, physical activity in quintiles, regular aspirin use, screening endoscopy during the study period, consumption of beef, pork, or lamb as a main dish, alcohol consumption status, total caloric intake in quintiles, use of postmenopausal hormones, menopausal status, and height in seven categories	questionnaire
Schernhammer	2003	602/78586	cohort	8	US	colorectal cancer	female	never vs. >15 years	age in years, pack-years of smoking before age 30 in quintiles, body mass index in five categories, physical activity in quintiles, regular aspirin use, screening endoscopy during the study period, consumption of beef, pork, or lamb as a main dish, alcohol consumption status, total caloric intake in quintiles, use of postmenopausal hormones, menopausal status, and height in seven categories	questionnaire
Tynes	1996	9/2619	cohort	6	Norway	colon cancer	female	never vs. ever	shift work and duration of employment	database
Tynes	1996	6/2619	cohort	6	Norway	rectal cancer	female	never vs. ever	shift work and duration of employment	database