Table 2 Distribution of sociodemographic factors and known or suspected risk factors or protective factors for colorectal cancer among 380 cases and 485 controls included in the analysis.

Characteristic	Level			Cases		Controls
				n	%	n	%
Age (years)	30–49			17	4.5	30	6.2
	50–59			55	14.5	87	18.0
	60–69			153	40.3	182	37.5
	70–79			103	27.1	133	27.4
	80+			52	13.7	53	10.9
Sex	Female			170	44.7	214	44.1
	Male			210	55.3	271	55.9
Education	⩽9 years			272	71.6	311	64.1
	10–11 years			61	16.1	89	18.4
	⩾12 years			47	12.4	85	17.5
Participation in general health screening examination	Ever			276	73.4	414	85.5
Family history	First degree relative*			41	10.8	51	10.5
Smoking	Never			177	46.8	239	49.3
	Current			61	16.1	73	15.0
	Former			140	37.0	173	35.7
Body mass index	<20.0 kg/m2			24	6.4	12	2.5
	20.0–24.9 kg/m2			132	35.4	166	34.2
	25.0–29.9 kg/m2			139	37.3	224	46.2
	⩾30.0 kg/m2			78	20.9	83	17.1
NSAID use	Ever regular†			114	30.0	176	36.3
HRT use	Ever regular‡			49	29.5	112	52.3

*History of colorectal cancer in first degree relative.

†Ever regular use of aspirin or NSAID (at least once a month for one year).

‡Ever use of hormonal replacement therapy (women only).

HRT, hormone replacement therapy; NSAID, non‐steroidal anti‐inflammatory drug.