Table 2 Effectiveness trial measures

Primary Outcome

Weight

Measured in lbs in light indoor clothing without shoes using a digital scale.

B, 6, 12,18

Secondary Outcomes

Anthropometrics

Waist circumference measured to the nearest 0.1 cm with an anthropometric tape, in a horizontal plane 1 cm above the navel in light indoor clothing. Blood pressure assessed on the right arm of participants after they rest quietly in a seated position for at least 5 minutes, using a validated automated sphygmomanometer. Height measured without shoes with an anthropometric tape to the nearest 0.1 cm at entry into the study. Body mass index: will be calculated from measured height and weight (kg/m²)

B, 6, 12,18

Self-efficacy

The Weight Efficacy Lifestyle (WEL) Questionnaire is a 20-item scale that asks people to rate their confidence to resist eating in certain situations on a 10-point Likert scale ranging from 0 (not confident) to 9 (very confident) [90]. The Multidimensional Health Locus of Control (MHLC) is a 24-item scale that measures the extent to which a participant believes s/he has control over various aspects of their physical health [91]. These scales have established psychometrics

B, 6, 12,18

Physical activity

The International Physical Activity Questionnaire (IPAQ) short form [92] (7 items) asks respondents the number of days per week and the amount of time per day spent in vigorous and moderate activities and walking, during the 7 days prior to the interview. It has established psychometrics, is available in English and Spanish, and is validated for people with SMI [93]. The 6-Minutes Walking Test [94] will be used to measure the distance participants can walk in 6 minutes. This measure has been used in previous health promotion trials with people with SMI [95]. An increase in distance of more than 50 m has been linked to clinically significant reductions in risks for cardiovascular disease [94]

B, 6, 12,18

Dietary behaviors

The Block Fat Screener and Fruit, Vegetable and Fiber Screener Questionnaires are brief food frequency measures that provide valid assessments of the intake of these foods [96]. Three modules from the 2013 CDC Behavioral Risk Factors Surveillance System Questionnaire: fruit and vegetable, drinks with sugar, and salt/sodium. These modules consist of 11 questions that measure eating behaviors in these areas [97]

B, 6, 12,18

Recovery

The Recovery Assessment Scale [98] is a 24-item measure that captures different aspects of recovery and produces a total recovery score and scores on 5 subscales

B, 6, 12,18

Quality of Life

SF-12 [99], a self-report measure available in English and Spanish and validated among adults with SMI that generates two summary scores for physical and mental health-related quality of life [100]

B, 6, 12,18

Moderators

Demographics

Self-reported age, gender, race/ethnicity, education, income, and marital status

B

Psychiatric medications

Self-reported list of psychiatric medications prescribed. Type and dosage will be recorded

B, 6, 12,18

Attitudes toward Peer GLB

Modified version of the Client Satisfaction Questionnaire, an 8-item self-report scale available in English and Spanish to assess participants’ attitudes (e.g., satisfaction, acceptability) toward Peer GLB [101]

6, 12, 18

Mental health

We will use the Revised Behavior and Symptom Identification Scale (BASIS-R) [102], a brief 24-item mental health severity measure designed to assess depression/functioning, difficulty in interpersonal relationships, self-harm, emotional lability, psychotic symptoms, and substance abuse. The BASIS-R is a reliable and valid measure that is sensitive to mental health treatment and has been tested in persons with schizophrenia

B, 6, 12,18

Covariates

Acculturation, barriers to medical care, comorbid medical conditions, service use and alcohol/drug use

Acculturation: nativity, language preference, time in the US, age of migration. The Bidimensional Acculturation Scale [103], a 24-item self-report measure that captures acculturation-related changes in two languages. Barriers to medical care: a list of 11 common factors that may prevent patients from seeking medical care [104, 105]. Comorbid medical conditions: a list of 17 common medical conditions by patient self-report. Service use: we will use established self-reported items from the National Latino and Asian American Study/National Comorbidity Study-Replication to measure participants’ use of mental/physical health services in the previous 6 months. This will help us track use of usual care services in the trial. Substance abuse will be measured using a subset of questions from the Addiction Severity Index (ASI) which assesses frequency of alcohol and drug use [106]

B, 6, 12,18