Analysis of colorectal cancer stage among HMO members targeted for screening

Background: This study is a retrospective analysis of data collected from patient medical records, a fecal occult blood test (FOBT) screening program, and computerized health maintenance organization (HMO) claims and encounters records. Objective: To identify factors associated with a diagnosis of early (Dukes A and B) colorectal cancer among older adults targeted for annual FOBT screening. Methods: Study subjects were insured by the former US Healthcare Inc (Blue Bell, Pa), an independent practice association-type HMO. The HMO was recently integrated into Aetna-US Healthcare. Before diagnosis, subjects were eligible for free annual FOBT screening through the HMO's colorectal cancer screening program. The study subjects included men and women (N=222) who were aged 50 years or older and had a diagnosis of colorectal cancer between 1987 and 1990. Variables considered were patient age, gender, socioeconomic status, medical history, screening history, length of enrollment in the HMO, and stage of disease at diagnosis. Results: Univariate analyses indicate that colorectal cancer diagnosis due to FOBT screening (P=.03), frequency of FOBT screening (P=.09), and length of HMO membership (P=.10) were positively related to being diagnosed as having early stage colorectal cancer. Multivariable analysis shows that having a screen-detected colorectal cancer was significantly and positively related (P=.03) to being diagnosed as having early stage disease. Conclusions: Findings support annual FOBT screening among older adults. Results illustrate the value of applying standard methods to the collection and analysis of patient data in a managed care context. The study also highlights a need for research on patient adherence to screening and physician follow-up of abnormal screening test results.