![](img007.GIF) |
Each study was
assessed for each of these methodological issues eg the study design of prospective cohort
was given preference to that of case-control; selection issues such as participation rates
/ loss of follow-up of subjects in cohorts; histological confirmation of the diagnosis of
prostate cancer; whether smoking status was clearly defined and updated over time in
cohorts; if the five most likely potential confounders were adjusted for (age, race,
family history of prostate cancer, diet, history of vasectomy) - determined from a review
of the literature; statistical issues included provision of confidence intervals or p
values. |