Table 1

Adjusted monthly diabetes-related OOPE rates for the associations with demographic and treatment variables among participants with type 1 diabetes, using interval-censored regression models

Variable (%)Model 1Model 2Model 3
Monthly OOPE rate (95% CI)PMonthly OOPE rate (95% CI)PMonthly OOPE rate (95% CI)P
Age (in years)0.99 (0.97, 1.01)0.501.0 (0.98, 1.03)0.931.00 (0.75, 1.33)0.79
Diabetes duration (in years)1.00 (0.96, 1.05)0.991.0 (0.95, 1.05)0.931.01 (0.99, 1.01)0.51
Race/ethnicity
 Non-Hispanic black (11)0.66 (0.51, 0.85)0.0060.76 (0.57, 1)0.121.00 (0.75, 1.33)0.60
 Hispanic (12)0.77 (0.6, 0.99)0.79 (0.6, 1.04)0.85 (0.65, 1.11)
 Other (2.5)0.82 (0.51, 1.33)1.07 (0.63, 1.84)0.82 (0.48, 1.4)
 Non-Hispanic white (74.5)ReferenceReferenceReference
Sex
 Female (50.1)0.92 (0.78, 1.07)0.280.88 (0.75, 1.04)0.140.88 (0.75, 1.04)0.14
 Male (49.9)ReferenceReferenceReference
Level of parental education
 Bachelor’s degree or more (51.6)1.45 (1.1, 1.91)0.00011.3 (0.97, 1.74)0.0021.05 (0.82, 1.33)0.01
 Some college (33.3)1.11 (0.85, 1.46)1.06 (0.8, 1.41)0.9(0.68, 1.19)
 Less than high school (3.8)0.59 (0.37, 0.93)0.53 (0.33, 0.87)0.53 (0.33, 0.85)
 High school graduate (11.25)ReferenceReferenceReference
Median household income
 $75,000+ (38)1.27 (1.01, 1.61)<0.00011.22(0.96, 1.56)<0.00011.04(0.82, 1.32)0.004
 $50,000–74,000 (16.1)ReferenceReferenceReference
 $25,000–49,000 (16.9)0.71 (0.54, 0.93)0.73 (0.55, 0.97)0.82 (0.62, 1.08)
 <$25,000 (16)0.37 (0.28, 0.49)0.39 (0.29, 0.52)0.61 (0.45, 0.82)
 Did not know/refused (13.1)0.89 (0.66, 1.2)0.88 (0.64, 1.2)0.89 (0.65, 1.21)
Type of diabetes provider
 Adult endocrinologist (16.9)1.51 (1.17, 1.94)0.031.62 (1.24, 2.12)0.0051.44 (1.11, 1.87)0.003
 Family practice doctor (3.7)1.32 (0.85, 2.05)1.72 (1.07, 2.77)1.98 (1.21, 3.22)
 None/no source of medical care (1.2)1.01 (0.49, 2.08)1.08 (0.48, 2.41)0.59 (0.24, 1.49)
 Other (19.3)1.10 (0.89, 1.35)1.12 (0.9, 1.4)1.05 (0.85, 1.31)
 Pediatric endocrinologist (58.9)ReferenceReferenceReference
HbA1c, age-specific
 Intermediate (40.7)1.05 (0.8, 1.38)0.720.96 (0.73, 1.27)0.54
 Poor (47.1)1.11 (0.84, 1.46)1.07 (0.8, 1.42)
 Good (12.3)ReferenceReference
BMI
 <85th percentile (66.6)Reference0.26Reference0.32
 85th–95th percentile (20.8)0.93 (0.76, 1.13)0.95 (0.78, 1.16)
 >95th percentile (12.6)0.82 (0.64, 1.05)0.85 (0.66, 1.08)
Insulin regimen
 Insulin injections including long acting (35.6)0.84 (0.7, 1.01)0.010.78 (0.65, 0.94)0.004
 Insulin injections excluding long acting (8.3)0.63 (0.45, 0.87)0.63 (0.45, 0.86)
 Pump therapy (56.1)ReferenceReference
Frequency of SMBG
 Did not use a glucometer (2.2)1.06 (0.59, 1.89)0.371.06 (0.59, 1.89)0.45
 Less than once a day, only when sick (12.6)1.09 (0.84, 1.42)1.09 (0.84, 1.42)
 1–2 times a day (10.4)0.99 (0.75, 1.32)0.99 (0.75, 1.32)
 3 times a day (13.6)1.13 (0.87, 1.45)1.13 (0.87, 1.45)
 4–6 times a day (50.4)ReferenceReference
 ≥7 times a day (10.8)1.38 (1.03, 1.85)1.26 (0.94, 1.69)
CGM use
 Yes (17.4)1.29 (1.03, 1.62)0.031.35 (1.08, 1.68)0.01
 No (78.3)ReferenceReference
Health insurance
 None (3.3)0.83 (0.5, 1.38)<0.0001
 Other/Medicaid/Medicare (25.7)§0.22 (0.18, 0.27)
 Private (71)Reference
  • Model 1 examines OOPE with adjustment for nonmodifiable characteristics including age, diabetes duration, race/ethnicity, sex, highest level of parental education, household income, type of diabetes provider, and SEARCH site. Model 2 builds on model 1 with addition of modifiable clinical variables including HbA1c, BMI, insulin regimen, and frequency of SMBG and CGM use. Model 3 builds upon model 2, controlling for health insurance.

  • SMBG, self-monitoring of blood glucose.

  • We defined glycemic control based on the following HbA1c level cutoffs. For participants <18 years old, glycemic control is good with HbA1c <7.5%, intermediate with HbA1c 7.5% to <9%, and poor with HbA1c >9.0%. For participants ≥18 years old, glycemic control is good with HbA1c <7%, intermediate with HbA1c 7% to <9%, and poor with HbA1c >9.0%.

  • § Other insurance categories include school-based insurance and Tribe/Indian Health Service.

  • P value of the omnibus test for comparing the different subgroups with the reference.