The Jerusalem seventy-year-old longitudinal study.  I: Description of the initial cross-sectional survey. 
The main objectives of our first cross-section of a longitudinal study of a cohort of 70 year olds in Jerusalem, are to survey the social and medical conditions of the heterogeneous elderly population and to contribute to the knowledge of aging processes for specific age-groups.  Whereas, most previous surveys were conducted on homogeneous and stable population groups, the elderly of Jerusalem provide the basis for ethnographic comparisons and for assessing the impact of profound historical and personal changes.  From a representative systematic sample (from a geographically sorted electoral register) of 759 persons, 605 persons replied to our home-visit questionnaire gathering data on migration history, dwelling conditions, health status, health service utilization, employment status, activities of daily living, social support, use of drugs and war experience.  Later on, 463 persons attended our geriatric research institute where we gathered information from in-depth anamnesis and physical examination, as well as cognitive and psychological tests.  In addition, a battery of biochemical and hematological blood tests were performed as well as urine analysis and culture, ECG and pulmonary function tests.  The heterogeneity of our cohort population is demonstrated by the finding that 84% were born in 40 different countries outside of Israel.  In contrast, in the seventy-year old population studied in Gothenburg, Sweden, only 3% were not native born.  In the years 1996, 2001 and 2006, our initial study cohort will be re-examined and compared to control groups representing states of no-survey intervention until ages 75, 80 and 85 years old.  This background paper describes the study design, protocols and procedures.  The responders were found to be representative of the 70 year old Jewish population in Jerusalem as a whole, in terms of mortality and hospital utilization rates.  The results of the study to be reported in subsequent papers will allow conclusions regarding all 70 year old Jews in Jerusalem to be made.