First, ACE stands for Adverse Childhood Experiences. The ACE Study was initiated as a collaboration between the Centers for Disease Control and Prevention (CDC) and Kaiser Permanente’s Health Appraisal Clinic. A decade-long study, its participants numbered more than 17,000 members that underwent a comprehensive physical examination and chose to provide detailed information about their childhood experience of abuse, neglect, and family dysfunction. To date, more than 50 scientific articles have been published and more than 100 conference and workshop presentations have been made. No further participants will be enrolled, but the members are still being tracked for their medical status.

Each study participant completed a confidential survey that contained questions about childhood maltreatment and family dysfunction, as well as items detailing their current health status and behaviors. This information was combined with the results of their physical examination to form the baseline data for the study.

The prospective phase of the ACE Study is currently underway, and will assess the relationship between adverse childhood experiences, health care use, and causes of death.

More detailed scientific information about the study design can be found in “The relationship of adult health status to childhood abuse and household dysfunction,”* published in the American Journal of Preventive Medicine in 1998, Volume 14, pages 245-258.Request ACE Presentation graphic

Click here to learn about the Major Findings of the Study.


The Pyramid

ACE Score


The ACE Pyramid represents the conceptual framework for the study. During the time period of the 1980s and early 1990s information about risk factors for disease had been widely researched and merged into public education and prevention programs. However, it was also clear that risk factors, such as smoking, alcohol abuse, and sexual behaviors for many common diseases were not randomly distributed in the population. In fact, it was known that risk factors for many chronic diseases tended to cluster, that is, persons who had one risk factor tended to have one or more other risk factors too.

Because of this knowledge, the ACE Study was designed to assess what we considered to be “scientific gaps” about the origins of risk factors. These gaps are depicted as the two arrows linking Adverse Childhood Experiences to risk factors that lead to the health and social consequences higher up the pyramid. Specifically, the study was designed to provide data that would help answer the question: “If risk factors for disease, disability, and early mortality are not randomly distributed, what influences precede the adoption or development of them?” By providing information to answer this question, we hoped to provide scientific information that would be useful for developing new and more effective prevention programs.

The ACE Study takes a whole life perspective, as indicated on the orange arrow leading from conception to death. By working within this framework, the ACE Study began to progressively uncover how adverse childhood experiences (ACE) are strongly related to development and prevalence of risk factors for disease and health and social well-being throughout the lifespan.

Click here for the Centers for Disease Control & Prevention ACE Study web pages.


ACE Study Participant Demographics

Based on 17,337 participants:

Demographic Categories

Percent (N = 17,337)









Asian/Pacific Islander






Age (years)








60 and over


Not High School Graduate


High School Graduate


Some College


College Graduate or Higher


Prevalence of Individual Adverse Childhood Experiences

Collected between 1995 and 1997, the prevalence’s (%) presented below are estimated from the entire ACE Study sample (n=17,337). Individual research papers that use only Wave 1 data or Wave 2 data will contain slightly but not significantly different prevalence estimates for individual ACE.

Click here for all of the CDC ACE Study data and statistics.


More Resources and ArticlesRequest ACE Presentation graphic