An improved understanding of which groups are more likely to be unaware of their diabetes
may lead to more efficient screening, improved awareness, and overall better treatment
for diabetes. Our objective was to investigate factors associated with being unaware
of having diabetes among adults with diagnosed and undiagnosed diabetes.
The 2011–2014 National Health and Nutrition Examination Survey (NHANES) is a stratified,
multistage probability survey representative of the civilian, noninstitutionalized
U.S. population (1). Data were collected during an in-home interview and a visit to
a mobile examination center. We used data from 1,879 participants with either diagnosed
or undiagnosed diabetes (based on a single measurement of A1C, fasting plasma glucose,
or 2-h plasma glucose).
Using logistic regression, we calculated odds ratios of being unaware of diabetes
associated with age, race/ethnicity, sex, gestational diabetes mellitus (GDM), family
history of diabetes, education, household income, smoking status, BMI, work-time activity,
leisure-time activity, no health insurance, location of routine health care, no health
care in the past year, hospitalization in the past year, hypertension, and hyperlipidemia.
Initial models were unadjusted and subsequent models adjusted for all other variables.
We repeated the analysis stratified by sex. Appropriate sample weights were used so
that the sum added to the total civilian noninstitutionalized U.S. population (2).
Overall, 34.3% were unaware of their diabetes. In unadjusted models, compared with
people aged 20–44 years, participants aged 45–64 years had 34% lower odds of being
unaware of their diabetes (Table 1). Compared with non-Hispanic whites, non-Hispanic
Asians had 75% higher odds and Hispanics of non–Mexican American descent had 69% higher
odds of being unaware. In addition, a family history of diabetes, hospitalization
in the past year, hypertension, health insurance, routine place for health care, and
health care in the past year were associated with awareness. After adjustment, people
with a family history of diabetes had about half the odds of being unaware, people
who did not receive health care in the past year had approximately a sixfold higher
odds of being unaware, and people who were hospitalized in the past year had one-third
lower odds of being unaware.
Table 1
Odds ratios (95% CI) of being unaware of having diabetes among people with diabetes,
U.S., 2011–2014
Unadjusted
Adjusted†
Overall
Overall
Men
Women
Age
20–44 years
Reference
Reference
Reference
Reference
45–64 years
0.66 (0.45–0.97)
0.76 (0.51–1.13)
1.02 (0.55–1.89)
0.53 (0.27–1.05)
≥65 years
0.70 (0.48–1.01)
0.99 (0.68–1.44)
0.92 (0.51–1.67)
1.17 (0.63–2.18)
Race/ethnicity
Non-Hispanic white
Reference
Reference
Reference
Reference
Non-Hispanic black
0.86 (0.56–1.32)
1.11 (0.75–1.64)
0.93 (0.51–1.70)
1.46 (0.85–2.49)
Non-Hispanic Asian
1.74 (1.18–2.58)
1.44 (0.82–2.54)
1.52 (0.66–3.49)
1.72 (0.68–4.39)
Mexican American
1.23 (0.86–1.76)
1.06 (0.73–1.53)
0.62 (0.34–1.11)
1.91 (1.09–3.34)
Other Hispanic
1.69 (1.08–2.62)
1.30 (0.78–2.14)
0.96 (0.40–2.30)
2.21 (1.12–4.34)
Sex and GDM status
Women without GDM
Reference
Reference
—
Reference
Women with GDM
1.02 (0.68–1.51)
1.06 (0.68–1.65)
—
1.04 (0.65–1.65)
Men
1.23 (0.84–1.79)
1.07 (0.71–1.61)
—
—
Family history of diabetes
0.53 (0.39–0.72)
0.48 (0.33–0.70)
0.43 (0.25–0.76)
0.53 (0.32–0.88)
Education
Greater than high school education
Reference
Reference
Reference
Reference
High school education
0.99 (0.66–1.48)
1.07 (0.65–1.78)
0.85 (0.40–1.82)
1.17 (0.63–2.18)
Less than high school education
1.02 (0.67–1.57)
0.98 (0.56–1.70)
1.23 (0.59–2.57)
0.65 (0.34–1.26)
Household income <$20,000
0.84 (0.62–1.14)
0.88 (0.65–1.21)
1.05 (0.67–1.65)
0.85 (0.50–1.45)
Smoking status
Never smokers
Reference
Reference
Reference
Reference
Former smokers
0.97 (0.71–1.31)
0.96 (0.63–1.46)
1.06 (0.60–1.87)
0.82 (0.39–1.71)
Current smokers
0.84 (0.60–1.17)
0.75 (0.51–1.12)
0.63 (0.37–1.08)
1.09 (0.49–2.44)
BMI
<25 kg/m2
Reference
Reference
Reference
Reference
25–29.9 kg/m2
1.15 (0.79–1.67)
1.17 (0.66–2.07)
2.56 (1.23–5.30)
0.53 (0.24–1.21)
30–34.9 kg/m2
0.90 (0.52–1.56)
0.95 (0.45–1.99)
2.04 (0.69–6.03)
0.49 (0.18–1.31)
≥35 kg/m2
0.70 (0.43–1.15)
0.77 (0.39–1.53)
1.52 (0.53–4.35)
0.47 (0.21–1.05)
Low work-time activity levels
0.86 (0.59–1.23)
0.74 (0.48–1.12)
0.66 (0.39–1.14)
0.77 (0.44–1.34)
Low leisure-time activity levels
1.03 (0.74–1.43)
1.13 (0.78–1.64)
0.99 (0.58–1.68)
1.43 (0.85–2.40)
No health insurance
1.79 (1.29–2.48)
1.25 (0.74–2.11)
1.21 (0.64–2.27)
1.32 (0.61–2.83)
Routine health care location
Health care at doctor’s office or HMO
Reference
Reference
Reference
Reference
Other place for health care
0.90 (0.61–1.34)
0.68 (0.41–1.11)
0.82 (0.48–1.40)
0.51 (0.30–0.90)
No routine place for health care
2.61 (1.68–4.05)
0.79 (0.43–1.47)
1.00 (0.52–1.89)
0.89 (0.29–2.73)
No health care in the past year
5.88 (3.47–9.99)
5.85 (2.39–14.34)
5.12 (1.54–17.06)
7.03 (2.67–18.51)
Hospitalized in the past year
0.54 (0.41–0.73)
0.66 (0.44–0.99)
0.57 (0.26–1.27)
0.67 (0.38–1.17)
Hypertension
0.68 (0.51–0.91)
0.74 (0.53–1.02)
0.66 (0.39–1.12)
0.78 (0.46–1.30)
Hyperlipidemia
0.81 (0.57–1.14)
0.80 (0.51–1.24)
0.96 (0.57–1.63)
0.65 (0.34–1.24)
HMO, health maintenance organization.
†
Adjusted for all other variables listed in the table. Odds ratios in boldface type
are statistically significant at P < 0.05.
Among men, having a family history of diabetes, having a BMI 25.0–29.9 kg/m2, and
receiving no health care in the past year were associated with being unaware after
adjustment. Among women, being of Mexican American or other Hispanic descent, having
a family history of diabetes, receiving routine health care other than at a doctor’s
office, and receiving no health care in the past year were associated with being unaware
after adjustment.
Overall, approximately one-third of people with diabetes were undiagnosed/unaware
of it. Non-Hispanic Asians and Hispanics of non–Mexican American descent were more
likely to be unaware in unadjusted models but not after adjustment. In adjusted models,
those with a family history of diabetes and those who had been hospitalized in the
past year were less likely to be unaware, while those who received no health care
in the past year were more likely to be unaware. Results were generally consistent
when stratified by sex except that Mexican American and other Hispanic women were
more likely to be unaware of their diabetes.
Some participants may have been misclassified, as a repeat measurement is recommended
by the American Diabetes Association after a single positive test based on A1C, fasting
plasma glucose, or 2-h plasma glucose; however, the NHANES only includes one study
visit. Also, since participants self-reported many of the variables in our analysis,
there may be inaccuracies.