Overall, the NRW cohort accumulated 344, PY and the Saarland cohort 147, PY. Follow up of the NRW cohort was complete for of the cohort members with a mean follow up time of years. Overall 2,580 () cohort members died. Causes of death were known for of deceased persons. 1,138 () persons were lost to follow-up within the observation period, which means their last date of contact was censored. Individuals were lost follow-up due to different reasons, if they moved abroad or moved to an unknown destination
