A Text Message Intervention to Promote Health Behaviors in Cardiac Risk Conditions

Proportion of adaptive TMI messages correctly selected/sent will be included as a measure of feasibility.

Rates of feedback to individual text messages will be included as a measure of feasibility.

0-10 Likert scale score regarding the utility of that day's text message

The positive affect items on the Positive and Negative Affect Schedule (PANAS), a well-validated scale used in other intervention trials and in patients with medical illnesses, will be used to measure positive affect. (Range: 10-50). Higher scores indicate higher levels of positive affect. The measure will be used at baseline, 12 weeks and 24 weeks.

Life Orientation Test-Revised is a well-validated 6-item instrument used to measure dispositional optimism. (Range: 0-24) Higher scores indicate higher levels of optimism. The measure will be used at baseline, 12 weeks and 24 weeks.

The General Self-Efficacy Scale is a self-report measure of self-efficacy. The total score ranges from 10-40, with a higher score indicating more self-efficacy.

The anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A) will be used to measure anxiety. This is a well-validated scale with few somatic symptom items that can confound anxiety assessment in medically-ill patients. (Range: 0-21) Higher scores indicate higher levels of anxiety. The measure will be used at baseline, 12 weeks, and 24 weeks.

The depression subscale of the Hospital Anxiety and Depression Scale (HADS-D) will be used to measure depression. This is a well-validated scale with few somatic symptom items that can confound mood assessment in medically-ill patients.(Range: 0-21). Higher scores indicate worse outcome (i.e. greater levels of depression). The measure will be used at baseline, 12 weeks, and 24 weeks.

This is an 18-item instrument that measures three dimensions of locus of control. It assesses people's beliefs that their health is or is not determined by their own behavior. The survey has three subscales: internality of health locus of control, powerful other locus of control, and chance locus of control. All items are measured on a 6-point Likert scale, and our main subscale of interest will be internal locus of control, which will be a sum of scores from questions 1,6,8,12,13,17 (range: 6-36). Higher scores indicate higher locus of control.

The MSPSS is a 12-item scale designed to measure perceived social support from three sources: Family, Friends, and a Significant Other. It is rated on a 7-point likert scale, ranging from 1 "very strongly disagree" to 7 "very strongly agree." Each subscale score can range from 4 to 28. Items are summed, and a total score is also calculated and ranges from 12 to 84. Higher subscale and total scores indicate high levels of perceived social support.

MEDFICTS is a screening instrument for dietary fat to assess adherence to the Adult Treatment Panel (ATP) III Therapeutic Lifestyle Changes (TLC) diet. The test measures the intake of meats, eggs, dairy, fried foods, fats in baked goods, convenience foods, table fats, and snacks. Higher scores indicate higher fat consumption.

The CDC's BRFSS Fruit and Vegetable Module is a brief questionnaire about frequency of eating different types of fruits and vegetables. It assesses the frequency of consumption of 100% fruit juice, fruit, beans (legumes), dark green vegetables, orange vegetables, and other vegetables over the past month. The outcome measure is the number of fruits or vegetables consumed per day.

Measured by Actigraph accelerometer, in minutes per day.

Measured by Actigraph accelerometer, in number of steps per day.

Measured by Actigraph accelerometer, in minutes per day.

Measured by the self-report International Physical Activity Questionnaire (IPAQ). The measure assess the types of intensity of physical activity that people do as part of their daily lives. All activities are converted to multiples of resting energy expenditure (MET) minutes per week. The measure will be used at baseline, 12 weeks, and 24 weeks.

Measured by the 20-item short form of the Patient-Reported Outcomes Measurement Information System (PROMIS), a well-validated measure of physical function that is highly responsive to changes in a patient's physical function status (Range: 20-100). Higher scores indicate better physical function.

The 6-minute walk test is a test to measure participant's functional capacity, assessing distance walked in meters in 6 minutes.