Table 2.

Data collection instruments

INSTRUMENT	CHARACTERISTIC MEASURED	INSTRUMENT INFORMATION
Short Test of Functional Health Literacy Assessment (STOFHLA) Numeracy scale (Nurss, Parker, Williams, & Baker, 2001)	Health literacy	Participant reads a labeled medicine bottle and responds to questions such as, “If you take your first tablet at 7:00 a.m., when should you take the next one?” or reads an appointment card and respond to questions such as “When is your next appointment?” Fourteen questions answered correctly or not totaled 0 - 14, indicating low, marginal, and adequate health numeracy.
Sayles Internalized HIV stigma scale (Sayles et al., 2008)	Internalized HIV stigma	Participants were asked how frequently they felt stigmatized on a 5-point scale ranging from “None of the Time” to “All of the Time.” Sample items include “HIV is different than other diseases like cancer because people with HIV are judged” and “I am concerned that if I go to the HIV clinic someone I know might see me.” Cronbach's α = .86 in this sample.
Social Provision Scale (Cutrona & Russell, 1987)	Social support	Participants were asked about their agreement with 24 items on a 4-point scale ranging from “Strongly Disagree” to “Strongly Agree.” Sample items include “There is no one I can turn to in times of stress” and “No one needs me to take care of them.” Overall Cronbach's α =.66. Individual subscales ranged from α =.55 for Reliable Alliance to α =.74 for Guidance.
Alcohol Use Disorders Identification Test – Current (Adewuya, 2005) and Drug Use Disorders Identification Test – Current (Berman, Bergman, Palmstierna, Schlyter, & Daar, 2005)	Substance use	Sample questions include “How often do you have a drink containing alcohol?” and “Do you use more than one type of drug on the same occasion?” Responses ranged from 0 - 12 for the AUDIT-C and 0 – 16 for the DUDIT-C, with normed cut-off scores for hazardous drinking or drug use.
Patient Health Questionnaire Depression Scale (Spitzer, Kroenke, Williams, & Patient Health Questionnaire Primary Care Study Group, 1999)	Depressive symptoms	Sample symptoms include “Little interest or pleasure in doing things” and Trouble concentrating on things, such as reading the newspaper or watching television.” Scores range from 0 to 36 and were used to compute presence or absence of major depression according to diagnostic criteria.
CASE Adherence rating scale (Mannheimer et al., 2006)	Medication adherence	Rated on a 6-point rating scale
Visual analogue scale of prescribed ARV medicines taken in the previous month (Amico et al., 2006)	Medication adherence	Scores ranged from 0 - 100
LW-IMB-AAQ (Center for Health Intervention and Prevention, 2007)	Information, Motivation, and Behavioral Skills (IMB) deficits for medication adherence	LW-IMB-AAQ used average scores for each domain, measuring agreement with statements on a 5-point scale, ranging from “Strongly Agree” to “Strongly Disagree.” Sample items included “Skipping a few of my HIV medications from time to time would not really hurt my health” and “I am worried that the HIV medications I have been prescribed will hurt my health.” Cronbach's α = .65 for Information, .79 for Motivation, and .87 for Behavioral Skills,
IMB Engagement in Care Questionnaire (unpublished)	Adherence to care	The IMB Engagement In Care measure was developed for this study by the first two authors, using an adaptation of the previously validated LW-IMB-AAQ. It used summed scores in each domain, scoring from 5-15 for Information, 5-50 for Motivation, and 5-50 for Behavioral Skills. Sample items included “I know how important it is to go to my HIV clinic appointment every 3-4 months, even if I feel good” and “I worry about other people seeing me going into the clinic or waiting there for my appointment.” Cronbach's α = .47 for Information, .60 for Motivation, and .82 for Behavioral Skills in this sample.
Electronic Medical Record (EMR)	Visit attendance	Kept visits
EMR	CD4 and HIV RNA viral load
Pharmacy refill	Medication Adherence by refill	Date of refill at pharmacies, excluding automatic shipments