Chronic Conditions Among Adults Aged 18─34 Years — United States, 2019

Chronic conditions are common, costly, and major causes of death and disability.* Addressing chronic conditions and their determinants in young adulthood can help slow disease progression and improve well-being across the life course (1); however, recent prevalence estimates examining chronic conditions in young adults overall and by subgroup have not been reported. CDC analyzed data from the Behavioral Risk Factor Surveillance System (BRFSS) to measure prevalence of 11 chronic conditions among adults aged 18–34 years overall and by selected characteristics, and to measure prevalence of health-related risk behaviors by chronic condition status. In 2019, more than one half (53.8%) of adults aged 18–34 years reported having at least one chronic condition, and nearly one quarter (22.3%) reported having more than one chronic condition. The most prevalent conditions were obesity (25.5%), depression (21.3%), and high blood pressure (10.7%). Differences in the prevalence of having a chronic condition were most noticeable between young adults with a disability (75.8%) and without a disability (48.3%) and those who were unemployed (62.3%) and students (45.8%). Adults aged 18–34 years with a chronic condition were more likely than those without one to report binge drinking, smoking, or physical inactivity. Coordinated efforts by public and private sectors might help raise awareness of chronic conditions among young adults and help improve the availability of evidence-based interventions, policies, and programs that are effective in preventing, treating, and managing chronic conditions among young adults (1).

BRFSS is an annual state-based, random-digit–dialed telephone survey of noninstitutionalized U.S. adults aged ≥18 years.^† In 2019, BRFSS included data from 67,104 respondents aged 18–34 years; New Jersey did not collect sufficient data to meet the minimum requirement for inclusion in the public-use data set. The median response rate for the remaining 49 states and the District of Columbia was 49.4% (range = 37.3% for New York to 73.1% for South Dakota).^§ Having a chronic condition was defined as responding “yes” to having ever been told by a doctor or other health professional that the respondent had any of the following: a depressive disorder (depression); arthritis; a heart attack, angina, coronary heart disease, or stroke (heart disease/stroke); chronic obstructive pulmonary disease; skin or other types of cancer (cancer); kidney disease; diabetes; high cholesterol; high blood pressure; or current asthma. The five conditions with the lowest prevalence were combined into a single variable called “other.” Obesity (body mass index ≥30.0 kg/m²) was based on self-reported height and weight. Health-related risk behaviors included self-reported binge drinking, current smoking, and physical inactivity.^¶

Prevalence of any condition and of each specific condition was estimated overall and by selected sociodemographic, location, and health-related characteristics, including self-rated health and access to health care. Prevalence of each health-related risk behavior was estimated by chronic condition status. Paired t-tests were conducted to identify subgroup differences among all pairs except those including other race and ethnicity and other employment status. Although all comparisons reported are statistically significant (Bonferroni-corrected p-value <0.05), only sociodemographic and location comparisons where the prevalence ratio is >1.3 will be discussed. Multiple imputation techniques were used to account for missing data.** SAS (version 9.4; SAS Institute) and SUDAAN (version 11.0; RTI International) were used to account for survey weights and the complex sampling design. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.^††

Overall, 53.8% (39.8 million) of adults aged 18–34 years had at least one of the 11 conditions, and 22.3% had more than one condition (Figure 1). The most frequently reported conditions were obesity (25.5%), depression (21.3%), and high blood pressure (10.7%), and more than one half (ranging from 53.9% among adults with obesity to among 86.0% of adults with diabetes) of those with a specific condition had at least one other condition. For example, although 25.5% of young adults had obesity, 13.7% of young adults had obesity and at least one other condition. Having any chronic condition was significantly associated with all selected characteristics. Differences in the prevalence of having any condition by sociodemographic and location characteristics were most noticeable between young adults with a disability (75.8%) and those without a disability (48.3%) and those who were unemployed (62.3%) and a student (45.8%) (Table).

Consistent with having any condition, the prevalence of having obesity, depression, or high blood pressure was significantly associated with nearly all selected characteristics. Differences in the prevalence for having obesity were most noticeable between young adults aged 25–34 years (29.8%) and 18–24 years (19.4%), non-Hispanic Black persons (33.7%) and non-Hispanic White persons (23.9%), those who were unemployed (29.2%) or employed (26.1%) and a student (15.9%), those with (32.3%) and without (23.8%) a disability, and those living in rural (32.9%) and urban (25.1%) areas. Differences in the prevalence of having depression were most noticeable between females (27.0%) and males (15.8%), non-Hispanic White persons (27.0%) and non-Hispanic Black persons (16.0%) or Hispanic persons (14.6%), adults who were unemployed (30.9%) and employed (19.4%), and those with (48.9%) and without (14.5%) a disability. Differences in the prevalence of high blood pressure were most noticeable between males (13.4%) and females (7.8%), young adults aged 25–34 years (12.7%) and 18–24 years (7.9%), non-Hispanic Black persons (12.5%) and Hispanic persons (9.4%), those who were unemployed (13.5%) or employed (11.0%) and a student (7.1%), those with (17.3%) and without (9.0%) a disability, and those living in rural (13.7%) and urban (10.5%) areas. Prevalence of health-related risk behaviors was higher among those with any condition than among those without one (Figure 2).

Corresponding author: Kathleen B. Watson, iyr4@cdc.gov, 770-488-5489.

¹Division of Population Health, National Center for Chronic Disease Prevention and Health Promotion, CDC; ²Division of Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC.

References

1. Committee on Improving the Health, Safety, and Well-Being of Young Adults; Board on Children, Youth, and Families; Institute of Medicine; National Research Council. Investing in the health and well-being of young adults. Bonnie RJ, Stroud C, Breiner H, eds. Washington, DC: National Academies Press; 2015. https://www.ncbi.nlm.nih.gov/books/NBK284787/#!po=16.6667
2. US Department of Health and Human Services. Healthy people 2020. Washington, DC: US Department of Health and Human Services; 2021. https://www.healthypeople.gov/2020/data-search/Search-the-Data?nid=4968
3. Villarroel MA, Blackwell DL, Jen A. 2018 National Health Interview Survey. Tables of summary health statistics for US adults. Atlanta, GA: US Department of Health and Human Services, CDC; 2019. https://www.cdc.gov/nchs/nhis/SHS/tables.htm
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FIGURE 1. Percentage* of chronic conditions^† among adults aged 18–34 years — Behavioral Risk Factor Surveillance System, United States, 2019

Abbreviation: COPD = chronic obstructive pulmonary disease.

* 95% CIs indicated by error bars.

^† Behavioral Risk Factor Surveillance System respondents were classified as having a chronic condition if they had a body mass index >30.0 kg/m² or if they had ever been told by a doctor, nurse, or other health professional they had any of the following conditions: depression, arthritis, heart disease/stroke, COPD, cancer, kidney disease, diabetes, high cholesterol, high blood pressure, or currently have asthma. https://www.cdc.gov/brfss/annual_data/2019/pdf/codebook19_llcp-v2-508.HTML

Abbreviations: FPL = federal poverty level; HBP = high blood pressure; NH = non-Hispanic.
* Behavioral Risk Factor Surveillance System respondents were classified as having an underlying chronic condition if they answered “yes” to having any of the following conditions (question number): depression (C06.09); HBP (C04.01); high cholesterol (C05.01); asthma (C06.04 and C06.05); arthritis (C07.01); other (C06.01, C06.02, C06.03, C06.06, C06.07, C06.08, C06.10, and C06.11). The questionnaire can be found at https://www.cdc.gov/brfss/questionnaires/pdf-ques/2019-BRFSS-Questionnaire-508.pdf. Obesity was defined as having a body mass index ≥30.0 kg/m² based on self-reported height and weight.
^† Having any chronic condition was significantly (p<0.05) associated with all characteristics, except health care coverage.
^§ Having obesity, depression, HBP, current asthma, arthritis, or other chronic conditions was significantly (p<0.05) associated with sex, age, race and ethnicity, poverty level, employment status, disability status, region, and all self-rated health characteristics; obesity, HBP, and arthritis were significantly (p<0.05) associated with urban-rural status; and obesity, HBP, and other conditions were significantly associated with education level. Obesity, depression, current asthma, arthritis, and other chronic conditions were significantly associated with health care coverage.
^¶ Having high cholesterol was significantly (p<0.05) associated with age, employment status, disability status, region, and self-rated general, physical, and mental health.
** Poverty level is the ratio of total family income to FPL per family size (% FPL).
^†† Sample size <67,104 because of missing data; multiple imputation has been used for all other characteristics and conditions.
^§§ Adults were considered to have a disability if they reported having one or more of the following six disability types: hearing, vision, cognition, mobility, self-care, or independent living.
^¶¶ https://www2.census.gov/geo/pdfs/maps-data/maps/reference/us_regdiv.pdf
*** Urban-rural status was categorized using the National Center for Health Statistics 2013 Urban-Rural Classification Scheme for Counties. https://www.cdc.gov/nchs/data/series/sr_02/sr02_166.pdf
^††† Fair or poor general health was defined based on responses to the question, “Would you say in general that your health is—excellent, very good, good, fair, or poor?”
^§§§ Frequent physical distress was defined as responding ≥14 days to the question, “Now thinking about your physical health, which includes physical illness and injury, for how many days during the past 30 days was your physical health not good?”
^¶¶¶ Frequent mental distress was defined as responding ≥14 days to the question, “Now thinking about your mental health, which includes stress, depression, and problems with emotions, for how many days during the past 30 days was your mental health not good?”

FIGURE 2. Percentage* of engaging in health-related risk behaviors,^† by adults aged 18–34 years with and without reported chronic conditions^§ — Behavioral Risk Factor Surveillance System, United States, 2019

* 95% CIs indicated by error bars; prevalence of physical inactivity is significantly different (p<0.05) between those with and without the following conditions: any condition, obesity, high blood pressure, and other; prevalence of binge drinking is significantly different (p<0.05) between those with and without the following conditions: any condition, obesity, high blood pressure, and depression; prevalence of current smoking is significantly different (p<0.05) between those with and without each condition.

^† Health-related risk behaviors were defined as follows: physical inactivity (other than regular job, not engaging in any physical activities or exercises such as running, calisthenics, golf, gardening, or walking for exercise during the past month); binge drinking (males having five or more drinks on one occasion, females having four or more drinks on one occasion); current smoking (smoking ≥100 cigarettes in one’s lifetime and still smoking on at least some days).

^§ Other includes the following conditions: chronic obstructive pulmonary disease, cancer, diabetes, heart disease/stroke, and kidney disease.