Oral contraceptives have been used by women worldwide since they were introduced as birth control pills in 1961. There are two types of oral contraceptives depending on their synthetic hormone components. The first type is the combined pill which is an oral contraceptive that has both oestrogen and progestin. The second type is the progestin-only pill which incorporates one hormone, the progestin or progesterone. The use and safety of oral contraceptives have been eliciting hot debates within and outside medical circles.
The article ‘Oral Contraceptives Use and Mortality During 12 years of Follow-Up: The Nurses’ Health Study’ scientifically proved that oral contraceptives are safe to use by women to prevent unwanted pregnancies (Colditz, 1994). I agree with the author’s assertions that oral contraceptives are not a risk of mortality.
The study was aimed at comparing the risk of mortality between two groups of study participants. The first group was composed of women who had never used oral contraceptives. The second group was composed of women who had used oral contraceptives. It was a prospective cohort study that incorporated 166,755 women.
The ages of the study participants were 30 to 55 years, and the follow-up period was between 1976 and 1988. The study did not find any significant relationship between the 2,879 deaths among the study participants and oral contraceptive use (Colditz, 1994).
The cohort study was designed prospectively, and nurses mailed questionnaires to study participants. The nurses sought to know the risk factors for mortality and cardiovascular disease. The factors were recognized as oral contraceptives, smoking, past use of hormones after reaching menopause, diabetes and cancer, among others (Colditz, 1994). The cohort study could have been biased in accuracy of data that were entered by the respondents. This is because they could have felt that they were not obliged to be accurate.
An epidemiologist would choose to use a cohort study design because it is a powerful design that is used to test the hypothesis of a study. The prospective cohort study was used to show the relationship between the exposure (risk factors) and the outcome (mortality). As demonstrated in the study, cohort design was used to estimate the occurrence of mortality in groups of cohorts used in the study (Colditz, 1994). The calculation was necessary in understanding the risk difference and relative risk.
The disadvantages for cohort studies are the introduction of bias in follow-up time and huge costs. Cohort studies are useful for studying effects of rare exposures over time. The results from such studies can be used to infer to the population because the participants are the representatives of the population.
A study like this has potential public health implications. For example, because this study did not associate mortality with oral contraceptives it could have motivated many women to continue and/or start using oral contraceptives. The findings from this study have implications on standards of care because if to associate the contraceptives with an adverse outcome, then contraception needs of many women could be in jeopardy. This could also imply that many women keep away from using oral contraceptives.
The author’s conclusion is justified because the cohort study did not find any association between the risk (oral contraceptives) and outcome (mortality). The cohort was well designed, and confounding factors were minimized. However, future research needs to be done using both retrospective and prospective cohort designs.
Reference
Colditz, G. A. (1994). Oral contraceptive use and mortality during 12 years of follow-up: the Nurses’ Health Study. Annals of internal medicine, 120(10), 821-826.