The Northern Sweden MONICA Study
The Northern Sweden MONICA Study:
The Northern Sweden MONICA study covered the two northernmost counties of Sweden, i.e. Norrbotten and Västerbotten with altogether 510,000 inhabitants. Population surveys were performed in 1986, 1990, 1994, 1999, 2004 and 2009, with altogether 10,517 unique participants (20). On the first two occasions, 2,000 persons aged 25 to 64 years were randomly selected, and in the last three surveys, the upper age limit was extended to 74 years and 2,500 individuals were invited. A stratified randomized selection procedure by age and sex (250 persons in each sex/10-year age stratum) has been used. The participation rate was 69-81%. Detailed analyses of non-participants have been performed. In 1999, all people invited to any of the three previous population surveys were re-invited for repeated measurements to be collected. Incident cardiovascular events (myocardial infarction and stroke) occurring in the region between 1985 and 2010 and below the age of 75 were collected and validated according to MONICA criteria by two event registers whose accuracy and validity have been tested against national registers (21). Follow-up is available for all cohorts until December 2011 for mortality and non- fatal coronary, stroke, chronic heart failure, atrial fibrillation, cancer and diabetes events. Coronary and stroke events below the age of 75 validated applying the MONICA diagnostic criteria, and diabetes according to careful case review (22).