Biomedical subjects
C R Kay
Publications and source records attributed to C R Kay.
Domiciliary thrombolytic treatment.
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Oral contraceptives and malignant melanoma.
Several studies have suggested that prolonged use of oral contraceptives may increase a woman's risk of developing malignant melanoma. In the Royal College of General Practitioners' Oral Contraception Study, 31 cases of malignant melanoma (code 172--International Classification of Diseases, 8th Revision) have been reported among ever-users and 27 cases among never-users. The risk ratio (RR) (indirectly standardised for age, parity, social class and smoking) was 0.92 (95% confidence interval (CI) 0.55-1.54). There was no significant trend with duration of oral contraceptive use, although those women who had used the pill for at least 10 years had an elevated RR of 1.77 (95% CI 0.80-3.90). The Oxford/Family Planning Association Study has recorded 15 cases among ever-users and 17 cases among never-users; the standardised risk ratio was 0.85 (95% CI 0.42-1.70). None of the rates observed in any duration of use category was materially different from those observed in never-users. The results available so far from the two studies suggest that oral contraceptive use is probably not associated with an increased risk of malignant melanoma.
The effect of induced abortion on subsequent pregnancy outcome.
OBJECTIVE: To investigate the effect of induced abortion on the outcome of the next pregnancy. DESIGN: Long-term prospective controlled cohort study. SETTING: Joint Royal College of General Practitioners/Royal College of Obstetricians and Gynaecologists study based in general practice in England, Scotland and Wales. SUBJECTS: 1311 women whose recruitment pregnancy had ended in induced abortion (the abortion group) and 2131 women whose recruitment pregnancy had a natural conclusion (the non-abortion group). MAIN OUTCOME MEASURES: Non-viable outcome (spontaneous or missed miscarriage, ectopic pregnancy or stillbirth), birthweight, length of gestation. RESULTS: Induced abortion was not materially associated with any of the three measures of adverse outcome. Compared with the non-abortion group the relative risk of a non-viable outcome in the abortion group was 1.01 (95% CI 0.81 to 1.27). In the abortion group birthweight was an average 23 g lighter (95% CI -76 g to + 30 g) and length of gestation an average 0.9 days shorter (95% CI -2.2 days to + 0.4 days) than in the non-abortion group. Women who had their abortions in NHS premises had an increased risk of a non-viable outcome (RR 2.55, 95% CI 1.31 to 4.94) and had babies with significantly lower mean birthweight (-119 g, 95% CI -233 g to +5 g) compared with those who obtained their operations in the private sector. Women whose abortion had been carried out by a consultant had the lowest risk of non-viable outcome. Although these differences remained after adjustment for a number of important variables, it is possible that factors not measured in the present study, such as economic status and occupation, played a contributory role. CONCLUSION: Overall, induced abortion was not associated with any important effect on the three measures of adverse outcome in the subsequent pregnancy.
Oral contraceptives and rheumatoid arthritis: new data from the Royal College of General Practitioners' oral contraception study.
From data available at April 1987 it was found that the standardised risk ratio for rheumatoid arthritis between current users of oral contraceptives and never users was 0.82 (95% confidence interval 0.59 to 1.15); the ratio between former users and never users was 0.94 (95% confidence interval 0.72 to 1.22). Important secular trends have occurred within our study population. The incidence of rheumatoid arthritis among former and never users has declined over the past two decades. Current users have not experienced this temporal trend, and the ratio between current and never users has, therefore, approached unity. These secular changes may explain why some studies have found that oral contraceptives have a protective effect, while others have been unable to show such an effect.
Oral contraceptives and diabetes mellitus.
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The contraceptive pill and breast cancer in young women.
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Oral contraception and genital tract malignancy.
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Oral contraception, smoking and inflammatory bowel disease--findings in the Royal College of General Practitioners Oral Contraception Study.
Data from the Royal College of General Practitioners Oral Contraception Study have been examined to determine whether oral contraceptive use was associated with the development of Crohn's disease or ulcerative colitis. Over a 17 year period Crohn's disease developed in 42 women and ulcerative colitis in 78. The incidence of both diseases was greater in oral contraceptive users compared to non-users with the rate ratio for Crohn's disease being 1.7 (95% confidence limits, 0.88, 3.2) and for ulcerative colitis being 1.3 (95% confidence limits 0.82, 2.0). For both diseases incidence was unrelated to parity or social class, but women smoking at recruitment had a greater incidence of Crohn's disease (rate ratio 1.8, 95% confidence limits 0.93, 3.3) and a reduced incidence of ulcerative colitis (rate ratio 0.68, 95% confidence limits 0.41, 1.1). Although these results are based on small numbers and could be chance findings, they are consistent with other studies showing associations between oral contraceptive use, smoking and the development of Crohn's disease and ulcerative colitis.
Oral contraceptives and rheumatoid arthritis: new data from the Royal College of General Practitioners' Oral Contraception Study.
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Oral contraceptives and diabetes mellitus.
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Incidence of thyroid disease associated with oral contraceptives.
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Logistics of study on hormone therapy in the climacteric.
The practical implications of conducting a prospective study into the effects of hormone replacement therapy (HRT) in peri- and post-menopausal women are discussed. The minimum number of woman-years of observation required to yield data of statistical significance is around 50,000, which would involve the participation of 1000 general practitioners.
Recommendations from the findings by the RCGP oral contraception study on the mortality risks of oral contraceptive users.
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Oral contraceptives and benign liver tumours.
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Letter: Oral contraceptives and liver tumours.
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Letter: Oral contraceptives and venous thrombosis.
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