Table 34Study characteristics and association between OC use and colorectal cancer mortality

StudyStudy DetailsPoint Estimate (95% CI)aDuration of UsePoint Estimate (95% CI)bCovariatesRegionStudy QualityMeta-Analysis Codec
Hannaford, 201033Royal College of General Practitioner's Oral Contraception study
Exposed: 28,806
Unexposed: 17,306

Mean age at entry: 29 yr (SD 6.6)
Recruitment period: 1968–NR
0.62 (0.46 to 0.83)< 4 yr1.02 (0.52 to 2.0)Age, parity, smoking, social classUKFair1
4–8 yr0.65 (0.30 to 1.43)
≥ 8+ yr0.45 (0.16, 1.28)
Vessey, 2010165Women aged 25–39 yr in Oxford Family Planning Association Contraceptive Study
602,700 person-yr (total for exposed and unexposed)

Recruitment period: 1968–1974
1.2 (0.8 to 2.0)< 48 mo1.2 (0.6 to 2.4)Age, parity, BMI, smoking, social classUKFair1
49–96 mo1.4 (0.7 to 2.5)
≥ 97 mo1.1 (0.6 to 2.0

BMI = body mass index; CI = confidence interval; mo = month/months; NR = not reported; OC = oral contraceptive; OR = odds ratio; UK = United Kingdom; yr = year/years


Point estimate for meta-analysis of ever versus never OC use.


Point estimate for meta-analysis of duration of OC use.


Meta-analysis code: 1=Met inclusion criteria for possible meta-analysis

From: 3, Oral Contraceptives and Other Cancers

Cover of Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer
Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer.
Evidence Reports/Technology Assessments, No. 212.
Havrilesky LJ, Gierisch JM, Moorman PG, et al.

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.