Table 1.
Study measures across time points.
| Construct | Description, example, scale | Baseline | Follow-ups (months after baseline) | ||||
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3 | 6 | 12 | 15 |
| Primary outcome |
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|
|
Hemoglobin A1c | Result from lab-drawn clinic test or mail-in test kit | X | X | X | X | Xa |
| Secondary outcomes |
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|
|
|
Medication adherence |
Adherence to Refills and Medications Scale for Diabetes [45]; Summary of Diabetes Self-Care Activities medications subscale (SDSCA-MS) [46] | X | X | X | X | X |
|
|
Diet adherence | Personal Diabetes Questionnaire subscales for Problem Eating Behavior and Use of Information for Diet Decision Making [47] | X | X | X | X | X |
|
|
Exercise adherence | International Physical Activity Questionnaire–short form [48,49] | X | X | X | X | X |
|
|
Self-monitoring of blood glucose (SMBG) adherence | SDSCA–SMBG subscale [46] | X | X | X | X | X |
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|
Diabetes self-efficacy | Perceived Diabetes Self-Management Scale [50] | X | X | X | X |
|
| Mediators |
|
|
|
|
|
|
|
|
|
Barriers to diabetes medication adherence |
Information, motivation, and behavioral skills-based barriers to medication adherence [36] | X | X | X | X |
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|
|
Family behaviors | Frequency of family or friends’ helpful and harmful behaviors over the past month | X | X | X | X |
|
| Moderators |
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|
|
Race and ethnicity |
White, African American, Asian, American Indian or Alaskan Native, Native Hawaiian or Pacific Islander, and/or other race; Hispanic or Latino or not Hispanic or Latino | X |
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|
Education | Years of school completed | X |
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|
|
Income | Total household income in 1 year | X |
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X |
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|
Insurance status | Uninsured, private, or public | X |
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|
| Other measures |
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Other sociodemographics |
Gender, age, marital status, living situation | X |
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Diabetes characteristics | Insulin status, number of prescribed diabetes medications | X | X | X | X | X |
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|
Mobile phone use | Use of smartphones and health apps, frequency of text messaging, and frequency of not being able to text and/or call because of reaching monthly limits | X |
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|
X |
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|
Depression | Patient Health Questionnaire–8 [51] | X | X | X | X |
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|
Health literacy | Brief Health Literacy Screen [52] | X |
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|
Numeracy | Subjective Numeracy Scale [53] | X |
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|
|
|
Sociological stressors | Tool for Assessing Patients’ Stressors [54] | X |
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X |
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|
|
Trait self-control | Brief Self-Control Scale (8-item subset) [55] | X |
|
X |
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|
|
Diabetes duration | Length of time diagnosed with type 2 diabetes | X |
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|
|
Emergency room (ER) visits and Hospitalizations | Number of times in ER and hospitalizations in the last year | X |
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X |
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|
|
Smoking status | Behavioral Risk Factor Surveillance System items on tobacco use [56] | X | X | X | X |
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|
Alcohol consumption | Frequency of having a drink containing alcohol | X | X | X | X |
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aWe will also review medical charts at 9 months to collect HbA1c values for those participants who have this data available since there is no planned follow-up assessment at this time point.