Table 2.
Instruments for Outcome Measures
| Concept measured | Details | No. of Items | Validity and reliability |
|---|---|---|---|
| Demographic data (researcher- developed instrument) | Age, gender, race/ethnicity, educational level, marital status, living arrangements, smoking, alcohol use, history of being overweight, family history of heart disease (siblings, parents, grandparents, aunts, and uncles). | Used in other studies regarding chronic disease risk (T2D) with participants from the preliminary studies leading to this protocol. | |
| Dietary intake: NCI Multifactor Screener | Assesses frequency of intake of various foods over the last month (by d, wk, mo). The screener asks respondents to report how frequently they consume foods in 16 categories. | 16 | Multifactor screener has demonstrated correlations of 0.5-0.8 with estimated true intake.78 |
| Physical activity: Stanford Brief Activity Survey | Assesses two categories of physical activity—work and leisure. Five options for degree of activity to choose from in each of the two areas of activity. | 2 | Test-retest reliability demonstrated (r = 0.62) and construct validity shown through significant inverse correlations with stress, anxiety, and depression and positive correlations with mental and physical well-being.79,80 Has been correlated inversely with CHD risk.79,80 |
| Coronary and diabetes risk perception | Assesses level of personal perceived risk, fear, anger, worry regarding T2D and CHD risk. | 52 | Used in two prior studies by investigative team. |
| Perceived control over T2D | Personal control subscale of the Brief IPQ (adapted for type 2 diabetes and CHD).81 Sample item: “Whether or not I get diabetes depends on me.” Response scale 1 (strongly disagree) to 5 (strongly agree). | 6 | Demonstrated good test–retest reliability and concurrent validity with relevant measures. The discriminant validity of the Brief IPQ was supported by its ability to distinguish between different illnesses.81 |
| Patient activation | Assesses the following 4 stages of patient activation: (1) believing the patient role is important, (2) having the confidence and knowledge necessary to take action, (3) actually taking action to maintain and improve one's health, and (4) staying the course even under stress.82 | 13 | Cronbach's ? of 0.87 as well as established criterion and construct validity. |
| Readiness for change | Assesses stage of change based upon the Transtheoretical Model75 for 5 health behavior domains (dietary intake, exercise, weight loss, smoking cessation, and medication adherence). Individual items are validated,83 aggregated by co-PI, and used in prior studies. | 5 | Used in prior studies involving health coaching.12,13 |
Abbreviations: CHD, coronary heart disease; IPQ, illness perception questionnaire; NCI, National Cancer Institute; PI, principal investigator; T2D, type 2 diabetes.