Cohort Study Analysis with a FORTRAN Computer Program

TLDR

The study presents a FORTRAN program for analyzing cohort study data that runs on most computers. The program computes mortality or incidence rate ratios, adjusts for age, sex, and calendar period, tests significance, and allows time‑interval subdivision, exposure subgroup transitions, and censoring. The program produces outputs compatible with GLIM, offers flexible data management, includes documentation and a worked example, and empowers epidemiologists with limited computing experience to perform formal cohort analyses.

Abstract

We describe the analysis of cohort study data with a standard FORTRAN program which should run on most computers. It provides a summary measure of the mortality (or incidence) rate ratio between the study cohort and some standard population, based either on person-years at risk or on proportional mortality, and adjusted for age, sex and calendar period; a test of the statistical significance of the ratio; and a set of observed death rates in the study cohort. Results may also be produced in a form suitable for use with GLIM. The analysis may be subdivided into a range of time intervals since each subject was first exposed to risk. The program provides for movement of subjects between different 'level-of-exposure' subgroups within the cohort, and for various methods of censoring. It allows considerable flexibility in data management, and is available with complete documentation and a worked example. The program should enable epidemiologists with little computing experience to carry out formal analysis of cohort studies.