Figure 1.
Pictorial representation of an unstratified case-cohort study design.
Included in the study are a subcohort of individuals randomly sampled from the original cohort, together with all incident cases of the disease of interest. Because the subcohort is a random sample from the whole original cohort, it includes some incident cases. The subcohort sampling fraction is the proportion of individuals in the original cohort who are included in the random subcohort, and is defined at the start of the study.
Figure 2.
Number of individuals in original cohort on which case-cohort study is based, before and after exclusions.
Total length of bar represents number before exclusions, length of black bar represent number after exclusions. Where the bar is all black, the size of the original cohort after exclusions was not reported. Where the bar is all grey, there were no exclusions from the original cohort. Bars are labelled according to the number of the paper in the reference list in Appendix S2.
Figure 3.
Subcohort sampling fractions reported in each of 32 papers included in the review.
Bars are labelled according to the number of the paper in the reference list in Appendix S2.
Table 1.
Approaches to summarizing baseline characteristics in 32 papers identified in the review.
Table 2.
Approaches to analysis reported in 31 papers identified in the review that used Cox regression.
Table 3.
Summary of recommendations for reporting case-cohort studies, to be used alongside existing STROBE guidelines.