COSM - a cohort of 50,000 Swedish men

The COSM is a population-based prospective cohort study established in Central Sweden (Västmanland and Örebro Counties) in the fall of 1997. All men, born between 1918 and 1952 (n=100,303), received an invitation to participate in the study. The invitation included the same self-administered questionnaires used for the women in the Swedish Mammography Cohort (SMC) in 1997. It included information about modifiable lifestyle factors such as diet, physical activity, smoking, weight, use of dietary supplements, some prescribed drugs, alcohol intake in addition to some genderspecific questions. A total of 48,850 (49% response rate) men returned a completed questionnaire and after exclusions, 45,906 men remained in the cohort.

In 2008, a second questionnaire was sent to all COSM members (n=37,861) who were still alive. The 2008 questionnaire collected information on general health status, disease diagnoses, current weight, height, waist and hip circumferences, dental health, medication use, sleep habits, urine and bowel habits, family history of selected diseases, stress, and social support (78% response rate). See Health questionnaire below.

In 2009 a third questionnaire was sent to those cohort members who completed the 2008 questionnaire (90% response rate). The 2009 questionnaire collected information on diet and alcohol intake (132-item FFQ), dietary supplements, smoking, physical activity, and sun habits.See Lifestyle questionnaire below.

With the information from the cohort, we are able to investigate major chronic diseases such as cancer (prostate, colon, bladder, kidney etc), cardiovascular disease, osteoporosis, cataracts, lower urinary tract symptoms (LUTS) and obesity. Follow-up of the cohort is accomplished through matching with national and regional registers with high completeness of diagnoses and population register at the Statistic Sweden. The COSM will be extended with information about polymorphisms in low risk genes (ongoing collection of buccal cells). This will facilitate studies of genetic susceptibility and of interplay/interactions between lifestyle factors and genes in the development of chronic diseases.