What I Did
The California Teachers Study (CTS) has produced a rich body of research about cancer, reproductive health, chronic health conditions, and many other health issues since the study began in 1995. Long-running studies like CTS are one of science’s best tools for learning more about people’s health and finding ways to improve health outcomes. When researchers can look at different combinations of health outcomes, life experiences, and biological samples from 133,477 volunteers over almost three decades, there’s a lot of potential areas to explore.
As California Teachers Study participants get older, there’s an opportunity to learn more about a set of diseases that disproportionately affect people as they age: Alzheimer’s disease and related dementias (ADRD). Death rates from these diseases among women have significantly increased from 2000 to 2020. We can also expect that rate to keep rising because there will be more people at risk of having the disease. From 2020 to 2025, California anticipates that the state’s population over the age of 65 will have grown by 20%.
In this project, I generated age-adjusted mortality rates from ADRD among people in the CTS as a starting point for future researchers to use in their studies. Because participants in the CTS are older on average than people nationally, age-adjustment is a way we can compare the rates in the CTS to the rest of the country. I also calculated rates by race and by people’s socioeconomic status at the study’s start. I used CTS’s mortality data to identify people whose main cause of death was ADRD.
What I Found
Mortality rates from ADRD have grown over time among the people in the CTS, just as they have in California and the entire country. However, rates among CTS participants were consistently lower than the state rate and the national rate. Within the CTS, the mortality rate among nonwhite participants was generally lower than that of white participants, though that gap has narrowed over time. There also did not appear to be a consistent pattern by socioeconomic status within this study, though in recent years participants with a lower socioeconomic status did tend to have higher rates of death from ADRD than participants who were more well off financially.
What Happens Next?
A lot of follow-up questions can be explored from the data presented here. Why is the death rate from ADRD in the CTS lower than the rate in California and the rest of the country? Why is the ADRD mortality rate lower for nonwhite groups when other research has shown that nonwhite groups are more likely to have ADRD? Does it have to do with ADRD not being recorded on death certificates, especially among minorities? Are changes in socioeconomic status across life connected with ADRD mortality?
Because the CTS has so much rich data, there are a lot of other potential risk factors (and protective factors) for ADRD that could be explored. These are heartbreaking diseases at an individual level, and a large and growing issue at a population level. I hope the data provided here sparks ideas for future research.
About the Author
I’m Evan Serge, and I’m a graduate student at the University of Michigan pursuing my Master of Public Health (MPH). I’m transitioning from a career in advertising and marketing to a career in public health. One of the things I’m interested in is the epidemiology of chronic diseases, especially Alzheimer’s and related dementias.
Working with the CTS team on my applied practice experience has allowed me to get real experience exploring that interest, from writing code to interpreting the results and telling the story of what I found. I’m very thankful for the guidance and support of the CTS team throughout the semester.