Cohort of Swedish Men - COSM

The Cohort of Swedish Men (COSM) is a multidisciplinary longitudinal project on the association of lifestyle and genetic factors with morbidity and mortality in middle-aged and elderly men.

The Cohort of Swedish Men 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, 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 members of the Cohort of Swedish Men who were still alive, 37,861. The 2008 Health 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. The response rate were 78% and there are 29,503 valid answers.

An additional third questionnaire was sent in 2009 to those cohort members who completed the 2008 Health questionnaire,  and a 90% response rate. The 2009 Life style questionnaire collected information on diet and alcohol intake, dietary supplements, smoking, physical activity, and sun habits. After removing invalid answers there were 26,156 participants left.

A third follow up of the Cohort of Swedish Men was performed in 2019 using the same questionnaires as in 2008/2009. The Health questionnaire was sent in January 2019 to all living participants in the cohort, 26,392 men, of which 72% responded.The number of valid answers were 18,901. The Lifestyle questionnaire was sent in September 2019 to all men responding to the Health questionnaire and alive, 18,746 resulting in a response rate of 86% and 16,166 valid answers.

In addition, researchers at Örebro University are since five years collecting blood samples (whole blood, plasma and serum) from members of the Cohort of Swedish Men with incident urological cancer (prostate, kidney, bladder and penile cancer). Urine is additionally collected from prostate cancer patients. Hitherto, samples from approximately 2,000 incident cancer cases have been collected.

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 Cohort of Swedish Men will be extended with information on polymorphisms in low risk genes during 2020. Numbers are pending but approximately 30,000 participants are included. This will facilitate studies of genetic susceptibility and of interplay/interactions between lifestyle factors and genes in the development of chronic diseases. For more information you are welcome to contact the SIMPLER office.