Results
Prevalence of MCC by Sex and Age
In 2010, 49.1% of civilian, noninstitutionalized US adults had no chronic conditions, and 24.8% had only 1 chronic condition. One-quarter of US adults had MCC (Table 2); 21.1% had 2 to 3 MCC and 4.9% had 4 or more MCC. For both sexes, older adults had a higher prevalence of MCC than younger adults. Among adults aged 18 to 44 years, men were less likely to have 2 to 3 MCC compared with women (P = .003). For adults aged 18 to 44 years and 45 to 64 years, men were less likely than women to have 4 or more MCC. In contrast, among adults 65 years or older, men were more likely than women to have 4 or more MCC.
Prevalence of MCC by Sex, Age, and Race/Ethnicity
Significant differences in the prevalence of MCC were found when the analysis was further stratified by race/ethnicity (Table 2). For example, among non-Hispanic white adults aged 18 to 44 years, men were less likely than women to have 2 to 3 MCC (P = .005), yet men aged 65 years or older were more likely to have 4 or more MCC than women 65 years or older. Among non-Hispanic black and Hispanic adults aged 45 to 64 years, women were more likely than men to have 4 or more MCC.
Differences in the prevalence of MCC were also found among specific racial/ethnic categories for certain sex/age groups (Table 2). Non-Hispanic American Indian/Alaska Native men aged 45 to 64 years were more likely to have 2 to 3 MCC compared with men 45 to 64 years in all other racial/ethnic groups. Among the same sex and age group (men 45 to 64 years), non-Hispanic white and non-Hispanic black men were more likely to have 4 or more MCC compared with Hispanic men; however, there was no significant difference in the prevalence of 4 or more MCC between non-Hispanic white and non-Hispanic black men. No significant racial/ethnic differences in the prevalence of 4 or more MCC were found among men aged 65 years or older.
For all 3 age groups, non-Hispanic black women had a higher prevalence of 2 to 3 MCC compared with Hispanic women (Table 2). Among those aged 45 to 64 years, non-Hispanic black women had a higher prevalence of 2 to 3 MCC relative to non-Hispanic white women. Non-Hispanic Asian/Pacific Islander women had a lower prevalence of 2 to 3 MCC than non-Hispanic American Indian/Alaska Native, non-Hispanic black, non-Hispanic white, and Hispanic women.
Prevalence of MCC by Sex, Age, Health Insurance, and Race/Ethnicity
Table 3 further stratifies the estimates of MCC by health insurance coverage and shows that differences exist between different coverage statuses. Among men and women aged 18 to 44 years and 45 to 64 years, those with private coverage and those who were uninsured had a lower prevalence of 2 to 3 MCC than those with public coverage. Among women aged 45 to 64 years, the prevalence of 4 or more MCC was higher among those with public coverage than those with other coverage, without coverage, and private coverage. Prevalence of 4 or more MCC was significantly higher among men aged 45 to 64 years with public and other coverage than those with private coverage and without coverage.
Analysis of differences in racial/ethnic groups revealed additional patterns in the prevalence of MCC by health insurance coverage. Non-Hispanic white men aged 45 to 64 years who had public coverage had a higher prevalence of 2 to 3 MCC than those who had private coverage (P < .001) and other coverage (Table 3). The prevalence of 4 or more MCC was higher among non-Hispanic white men aged 45 to 64 years with either public coverage or other coverage than those with private coverage (both P < .001). Among men aged 65 years or older, non-Hispanic black men with public coverage were more likely to have 2 to 3 MCC than non-Hispanic black men with private coverage.
Among non-Hispanic white women aged 45 to 64 years, those with public coverage had a higher prevalence of 2 to 3 MCC (P = .002) and 4 or more MCC (P < .001) than those with private coverage and those who were uninsured (Table 3). These same significant differences in the prevalence of 2 to 3 MCC were also found among non-Hispanic black women aged 45 to 64 years. In addition, non-Hispanic black women aged 45 to 64 years with public coverage also had a higher prevalence of 4 or more MCC than those with private health insurance coverage (P < .001). For Hispanic women aged 45 to 64 years, no significant differences were found in the prevalence of 2 to 3 MCC among health insurance coverage types, but those with public coverage had a much higher prevalence of 4 or more MCC than those with private coverage (P < .001). Among non-Hispanic white women aged 65 years or older, those with public coverage had a higher prevalence of 4 or more MCC than those with private coverage.
Prevalence of MCC Dyads and Triads
To meet an additional objective of the HHS MCC framework — determination of the most common MCC dyads and triads — we assessed the 5 most prevalent MCC dyad and triad combinations by sex and age group (Table 4). We list the individual chronic conditions within each dyad and triad alphabetically. For US men and women with at least 2 chronic conditions, for each age group, the MCC dyad with the highest prevalence was ever having had arthritis and ever having had hypertension. This MCC dyad was more prevalent among women aged 65 years or older compared with men 65 years or older (P < .001). The second most prevalent dyad for men in each age group was ever having had diabetes and ever having had hypertension. This dyad was also the second most prevalent for women aged 45 to 64 years and 65 years or older, where women 45 to 64 years were less likely to have diabetes/hypertension compared with men aged 45 to 64 years (P < .001). For women aged 18 to 44 years the second most prevalent dyad was ever having had arthritis and currently having asthma.
Among US adults with at least 2 chronic conditions, the MCC dyad of ever having had arthritis and ever having had diabetes appeared across each of the various sex and age groups as 1 of the 5 most prevalent MCC dyads, with the exception of women aged 18 to 44 years (Table 4). Ever having had cancer and ever having had hypertension was 1 of the 5 most prevalent dyads among men aged 45 to 64 years and 65 years or older and women aged 65 years or older. Ever having had coronary heart disease and ever having had hypertension was 1 of the 5 most prevalent dyads among men aged 45 to 64 years and 65 years or older; however, this was not the case for women, regardless of age group.
As for the most prevalent MCC triads among US adults who had at least 3 chronic conditions (Table 5), for both men and women in most age groups the most prevalent triad was ever having had arthritis, ever having had diabetes, and ever having had hypertension. The one exception was for women 18 to 44 years, where the most common triad was ever having had arthritis, currently having asthma, and ever having had COPD. However, the arthritis/diabetes/hypertension triad was still one of the most prevalent among women aged 18 to 44 years with MCC.
Another common MCC triad was ever having had arthritis, currently having asthma, and ever having had hypertension, which was 1 of the 5 most prevalent triads for each sex and age group with the exception of men aged 65 years or older (Table 5). Ever having had arthritis, ever having had cancer, and ever having had hypertension was prevalent among both men and women aged 45 to 64 years and 65 years or older; this prevalence was higher for women aged 45 to 64 years than for men aged 45 to 64 years.
Trends in MCC
From 2001 through 2010, there was a slight (albeit significant) increasing trend among US adults for the prevalence of 2 to 3 MCC (P < .001) and 4 or more MCC (P < .001) (Figure 1). The same trend — slightly increasing and statistically significant — was also found when examining 2 to 3 MCC and 4 or more MCC separately for men and women.
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Figure 1.
Prevalence of multiple chronic conditions among the total US adult population and separately, among US men and women, National Health Interview Survey for 2001 through 2010. [A tabular version of this figure is also available.]
Examination of the 2001–2010 NHIS data for MCC by age showed no significant increase in the prevalence of 2 to 3 MCC or 4 or more MCC for adults aged 18 to 44 years (Figure 2). For adults 65 years or older, there were slight significant increases from 2001 to 2010 in the prevalence of both 2 to 3 MCC (P = .005) and 4 or more MCC (P < .001). For adults aged 45 to 64 years with 2 to 3 MCC, the increasing trend was significant (P = .005) during 2007 through 2010. A significant increase in the prevalence of 4 or more MCC from 2001 through 2010 was found among adults aged 45 to 64 years.
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Figure 2.
Prevalence of multiple chronic conditions among US adults aged 18 to 44 years, 45 to 64 years, and 65 years or older, National Health Interview Survey for 2001 through 2010. [A tabular version of this figure is also available.]
For the prevalence of MCC from 2001 through 2010 by race/ethnicity (Figure 3), a slight increase in 2 to 3 MCC was found among non-Hispanic white adults (P < .001). However, for non-Hispanic black adults (P = .04) and Hispanic adults (P = .03), the increasing trend was significant only during 2007 through 2010. Among non-Hispanic white and non-Hispanic black adults there was a slight, significant increase in the prevalence of 4 or more MCC over time. This trend in the prevalence of 4 or more MCC was not significant for Hispanic adults.
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Figure 3.
Prevalence of multiple chronic conditions among non-Hispanic white, non-Hispanic black, and Hispanic adults in the United States, National Health Interview Survey for 2001 through 2010. [A tabular version of this figure is also available.]