Approximately 8,000 regional employees of Northern California Kaiser Permanente for whom the investigators had email addresses were sent an electronic diet and physical activity assessment tool. Those who completed the assessment received instantaneous feedback regarding their current diet and physical activity in relation to national guidelines, details about the study, an informed consent document, and a second baseline questionnaire that was used for tailoring subsequent intervention messages and assessing secondary study outcomes. A total of 797 respondents from 192 different departments provided informed consent. These respondents were randomized by department, after stratification by department size, to either the intervention (ALIVE!) or control group. Ten individuals were excluded from analyses because of a randomization error, leaving a final sample size of 787.
The average age of the participants was 44.2 years. The sample was 74.3% female, 25.7% male, 7.4% African American, 8.5% Asian, 4.1% Latino, 38.0% White, and 42.6% mixed/unknown race/ethnicity.
The following self-report questionnaires were administered at baseline, posttest (4 months after baseline), and follow-up (4 months after the intervention ended):
-- Physical Activity Questionnaire (PAQ), containing 34 activities divided into 6 areas: walking, biking and other transportation, care-giving and household chores, conditioning exercises, dance and sports, and other leisure activities. Respondents indicated days per week and minutes per day they participated in each of the activities in a typical week in the past 4 months. Each activity was assigned a MET value (a measure of energy expenditure where 1 MET is equivalent to the energy required for sitting quietly) according to the Compendium of Physical Activities, multiplied by frequency and duration, and summed over all relevant activities to create summary variables: total activity, moderate physical activity (MPA), vigorous physical activity (VPA), walking, and sedentary behavior.
-- Diet questionnaire, developed for this study using the same data-based approach used in the Block Food Frequency Questionnaire. The survey included 35 items asking about usual intake, including both frequency and portion size. Foods were identified for inclusion based on analyses of the National Health and Nutrition Examination Survey (NHANES), with separate analyses for African Americans, Whites, and Hispanics to ensure inclusion of foods appropriate for those ethnic groups. Fruits and vegetables were measured in cup-equivalents per day, and saturated and trans fats were measured in grams per day.
-- SF-8 Health Survey, a set of quality-of-life measures, consisting of eight questions representing eight domains of physical and mental health. Items were scored on 5-point Likert scale, with the exception of self-assessed health status, which was scored on a 6-point scale.
Primary outcomes of interest included change in physical activity, saturated and trans fats intake, sugar intake, and consumption of fruits and vegetables. Secondary outcomes included change in health-related quality of life, presenteeism (reduced worker productivity resulting from mental and physical conditions, despite being present on the job), self-efficacy, and stage of readiness for change. The study used intent-to-treat analyses that set change in non-responders to the followup questionnaires to zero.