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About the CDC-Kaiser ACE Study

	Young woman and young child hug and smileThe CDC-Kaiser Permanente Adverse Childhood Experiences (ACE) Study is one of the largest investigations of childhood abuse and neglect and later-life health and well-being.

The original ACE Study was conducted at Kaiser Permanente from 1995 to 1997 with two waves of data collection. Over 17,000 Health Maintenance Organization members from Southern California receiving physical exams completed confidential surveys regarding their childhood experiences and current health status and behaviors.

The CDC continues ongoing surveillance of ACEs by assessing the medical status of the study participants via periodic updates of morbidity and mortality data.

More detailed information about the study can be found in the links below or in “Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults,” published in the American Journal of Preventive Medicine in 1998, Volume 14, pages 245–258.

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The ACE Pyramid

The ACE Pyramid represents the conceptual framework for the ACE Study. The ACE Study has uncovered how ACEs are strongly related to development of risk factors for disease, and well-being throughout the life course.

	Image shows a six-level pyramid to represent mechanisms by which adverse childhood experiences influence health and well-being throughout the lifespan. An arrow pointing upward is at the left of the pyramid. At bottom of the arrow is the word “conception;” at top is “death.” From the bottom up, the base of pyramid base of pyramid reads “Adverse Childhood Experiences.” Next level up reads “Disrupted Neurodevelopment.” Third level at middle of pyramid reads “Social, Emotional, and Cognitive Impairment.” Level four of the pyramid is Adoption of Health-risk Behaviors. Level five is Disease, Disability, and Social Problems. Level six at the top of the pyramid reads “Early Death.”

Study Questionnaires

The Family Health History and Health Appraisal questionnaires were used to collect information on child abuse and neglect, household challenges, and other socio-behavioral factors in the original CDC-Kaiser ACE Study.*

The questionnaires are not copyrighted, and there are no fees for their use. If you include the ACE Study questionnaires in your research, a copy of the subsequent article(s) is requested (send to dvpinquiries@cdc.gov).

*More detailed information about the ACE Study’s methodology, including survey development, can be found in “Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults,” published in the American Journal of Preventive Medicine in 1998, Volume 14, pages 245–258.

Data and Statistics

Adverse Childhood Experiences (ACEs) are categorized into three groups: abuse, neglect, and family/household challenges. Each category is further divided into multiple subcategories. Participant demographic information is available by gender, race, age, and education. The prevalence of ACEs is organized by category.

ACEs Definitions

All ACE questions refer to the respondent's first 18 years of life.

  • Abuse
    • Emotional abuse: A parent, stepparent, or adult living in your home swore at you, insulted you, put you down, or acted in a way that made you afraid that you might be physically hurt.
    • Physical abuse: A parent, stepparent, or adult living in your home pushed, grabbed, slapped, threw something at you, or hit you so hard that you had marks or were injured.
    • Sexual abuse: An adult, relative, family friend, or stranger who was at least 5 years older than you ever touched or fondled your body in a sexual way, made you touch his/her body in a sexual way, attempted to have any type of sexual intercourse with you.
  • Household Challenges
    • Mother treated violently: Your mother or stepmother was pushed, grabbed, slapped, had something thrown at her, kicked, bitten, hit with a fist, hit with something hard, repeatedly hit for over at least a few minutes, or ever threatened or hurt by a knife or gun by your father (or stepfather) or mother’s boyfriend.
    • Household substance abuse: A household member was a problem drinker or alcoholic or a household member used street drugs.
    • Mental illness in household: A household member was depressed or mentally ill or a household member attempted suicide.
    • Parental separation or divorce: Your parents were ever separated or divorced.
    • Criminal household member: A household member went to prison.
  • Neglect1
    • Emotional neglect: Someone in your family helped you feel important or special, you felt loved, people in your family looked out for each other and felt close to each other, and your family was a source of strength and support.2
    • Physical neglect: There was someone to take care of you, protect you, and take you to the doctor if you needed it2, you didn’t have enough to eat, your parents were too drunk or too high to take care of you, and you had to wear dirty clothes.

1Collected during Wave 2 only.

2 Items were reverse-scored to reflect the framing of the question.

Participant Demographics

Demographic information is from the entire ACE Study sample (n=17,337).

Demographic Information for CDC-Kaiser ACE Study Participants, Waves 1 and 2.

Demographic Information Percent (N = 17,337)
Gender
Female 54.0%
Male 46.0%
Race/Ethnicity
White 74.8%
Hispanic/Latino 11.2%
Asian/Pacific Islander 7.2%
African-American 4.5%
Other 2.3%
Age (years)
19-29 5.3%
30-39 9.8%
40-49 18.6%
50-59 19.9%
60 and over 46.4%
Education
Not High School Graduate 7.2%
High School Graduate 17.6%
Some College 35.9%
College Graduate or Higher 39.3%

Note: Research papers that use Wave 1 and/or Wave 2 data may contain slightly different reports of participants’ demographic information.

ACEs Prevalence

The prevalence estimates reported below are from the entire ACE Study sample (n=17,337).

Prevalence of ACEs by Category for CDC-Kaiser ACE Study Participants by Sex, Waves 1 and 2.

ACE Category Women Men Total
Percent (N = 9,367) Percent (N = 7,970) Percent (N = 17,337)
ABUSE
Emotional Abuse 13.1% 7.6% 10.6%
Physical Abuse 27% 29.9% 28.3%
Sexual Abuse 24.7% 16% 20.7%
HOUSEHOLD CHALLENGES
Mother Treated Violently 13.7% 11.5% 12.7%
Household Substance Abuse 29.5% 23.8% 26.9%
Household Mental Illness 23.3% 14.8% 19.4%
Parental Separation or Divorce 24.5% 21.8% 23.3%
Incarcerated Household Member 5.2% 4.1% 4.7%
NEGLECT
Emotional Neglect3 16.7% 12.4% 14.8%
Physical Neglect3 9.2% 10.7% 9.9%

Note: 3Collected during Wave 2 only (N=8,629). Research papers that use Wave 1 and/or Wave 2 data may contain slightly different prevalence estimates.

ACE Score Prevalence for CDC-Kaiser ACE Study Participants by Sex, Waves 1 and 2.

Number of Adverse Childhood Experiences (ACE Score) Women
Percent(N = 9,367)
Men
Percent (N = 7,970)
Total
Percent (N = 17,337)
0 34.5% 38.0% 36.1%
1 24.5% 27.9% 26.0%
2 15.5% 16.4% 15.9%
3 10.3% 8.5% 9.5%
4 or more 15.2% 9.2% 12.5%

Note: Research papers that use Wave 1 and/or Wave 2 data may contain slightly different prevalence estimates.

Source: Centers for Disease Control and Prevention, Kaiser Permanente. The ACE Study Survey Data [Unpublished Data]. Atlanta, Georgia: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention; 2016.

Major Findings

		Five stick figures, one red and four blue, represent the statistic one in five.Adverse Childhood Experiences (ACEs) are common. Almost two-thirds of study participants reported at least one ACE, and more than one in five reported three or more ACEs.

The ACE score, a total sum of the different categories of ACEs reported by participants, is used to assess cumulative childhood stress. Study findings repeatedly reveal a graded dose-response relationship between ACEs and negative health and well-being outcomes across the life course.

As the number of ACEs increases so does the risk for the following*:

Dose-response describes the change in an outcome (e.g., alcoholism) associated with differing levels of exposure (or doses) to a stressor (e.g. ACEs). A graded dose-response means that as the dose of the stressor increases the intensity of the outcome also increases.

  • Alcoholism and alcohol abuse
  • Chronic obstructive pulmonary disease
  • Depression
  • Fetal death
  • Health-related quality of life
  • Illicit drug use
  • Ischemic heart disease
  • Liver disease
  • Poor work performance
  • Financial stress
  • Risk for intimate partner violence
  • Multiple sexual partners
  • Sexually transmitted diseases
  • Smoking
  • Suicide attempts
  • Unintended pregnancies
  • Early initiation of smoking
  • Early initiation of sexual activity
  • Adolescent pregnancy
  • Risk for sexual violence
  • Poor academic achievement

*This list is not exhaustive. For more outcomes see selected journal publications.


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