Health and Vital Status Follow-Up

Annual follow-up of the RBS cohort for health status and vital status began in 1977 and has continued through July 2019. Each year, forms were sent to ascertain vital status and current address for members of the cohort not known to be dead. Health status data were collected at clinic research visits and via annual mailers. During this 42-year period, a total of 32 annual mailers were sent to all surviving RBS participants with response rates ranging from 65% to 93%. Health status information was also collected at each of 10 research clinic visits that occurred during this time period.

Health Status
A standardized questionnaire was included approximately every two years with annual mailings to gather updated data on current health and physician-diagnosed diseases and conditions, as well as events such as myocardial infarction, surgeries and fractures.  Many of the standard health status questions for each clinic research visit were also included in the yearly mailers. This allowed assessment of changes between visits as well as continued detailed follow-up of those who did not attend every visit. For a summary of health status assessments by visit and mailer, see the overview for the Health Status data group.

Vital Status
Each year, forms were sent to ascertain vital status and current address for members of the cohort not known to be dead.  When participants did not respond to a mailer or to a clinic visit invitation, every attempt was made to locate the participant. If the participant could not be contacted, a relative or friend was contacted (updated contact information for a friend or relative was obtained at every visit and mailer in case contact with the participant was lost). When informed of a participant’s death, a death certificate was requested and primary and underlying causes of death were ICD-9 coded by a certified nosologist.

As of July 2019, overall mortality for the entire RBS cohort of 6726 participants is 71% (N=4781). Death certificates have been obtained and cause of death coded for 91% of decedents with verification of date of death for 99% of decedents (by death certificate, family report, or the Social Security Death Index).  To date, the average age at death for all RBS decedents is 82.7 yrs; 84.1 yrs for women and 81.2 yrs for men.  The most common underlying causes of death in order of prevalence are cardiovascular disease (47%), cancer (22%), respiratory diseases (11%).

The figure below shows age at death by decade for the entire RBS cohort; 3207 decedents lived to age 80 or older, 1216 to age 90 or older, 75 were centenarians.

Vital Status for Subset Age 60+ at Entry 
Among the 51% (N=3426) of RBS participants who were age 60 years or older at entry into the cohort, the mortality rate as of July, 2019 is 97%; age at death has been verified for all decedents, underlying cause of death is available on 94% of decedents. The average age at death for those age 60+ at entry is 85.7 yrs; 87.0 yrs for women and 84.1 yrs for men. More than 2500 members of this subset lived to age 80 or older, 1058 lived to age 90 or older, 72 were centenarians.