Table 1

Description and timing of surveys and health record data collection

Construct	Description of measure	Source	BL	3m	6m	6m EHR
PrEP knowledge	16-item self-report measure of knowledge related to PrEP, including use and effectiveness. Data are collected using a Likert scale.	Team developed	×	×	×
PrEP awareness	One survey question assessing awareness of PrEP. Categorical data are collected.	Team developed	×	×	×
PrEP adherence	Two-item self-report survey assessing ability to take PrEP over the past 7 days and frequency (%) with which PrEP was taken over the past 7 days. Data are collected using a Likert scale.	Team developed	×	×	×
PrEP attitudes	10-item PrEP Stigma and Positive Attitudes Measure assessing personal opinions about PrEP and people who use PrEP; 16 additional items assessing general attitudes and beliefs about PrEP use, provider comfort and medical mistrust related to PrEP use, side effect concerns about PrEP use, disclosure concerns and social norms related to PrEP use and sexual risk concerns about PrEP use. Data are collected using a Likert scale.	Mustanski et al, 201838 ; Pulsipher et al,7 2016	×	×	×
PrEP barriers	Five survey items related to concerns about PrEP use, efficacy and stigma; five additional items assessing potential access barriers to obtaining PrEP, including lack of health insurance coverage, difficulty finding a provider and cost of PrEP. Data are collected using a Likert scale.	Golub et al,8 2012; Pulsipher et al,7 2016	×	×	×
PrEP efficacy beliefs	Two-item measure of beliefs regarding the efficacy of PrEP. Data are collected using a Likert scale.	Pulsipher et al,7 2016	×	×	×
Medication self-efficacy	Four items assessing self-efficacy to adhere to PrEP; adapted for PrEP use from the Self-Efficacy for Appropriate Medication Use Scale. Data are collected using a Likert scale.	Adapted from Risser et al,39 2007	×	×	×
Beliefs about medicines	Items from the Beliefs about Medicines Questionnaire (BMQ), including the BMQ-Specific subscale, a 10-item scale assessing representations of medications, and the BMC-General subscale, an eight-item subscale assessing beliefs about medicines. Data are collected using a Likert scale.	Horne et al40, 1999	×	×	×
Sexual behaviours	Three items measuring over the past 3 months the total number of male anal sex partners, number of partners in which condoms were not used exclusively and the HIV status of partners. Data are collected using numeric text entries.		×	×	×
Mental health	21-item Depression, Anxiety, Stress Scale measuring depression, anxiety and stress over the past week. Data are collected using a Likert scale.	Lovibond and Lovibond,41 1995	×	×	×
Substance use	15 items measuring drug, alcohol and tobacco use over the past month. Data are collected using a Likert scale.	Team developed	×	×	×
Social support	8-item PROMIS Informational and 7-item Emotional Support Scales, respectively, measuring perceived sources of support over the past month. Data are collected using a Likert scale.	Hahn et al42, 2014	×	×	×
Patient satisfaction with PrEP-related services	8-item Client Satisfaction Questionnaire (CSQ-8) measuring of satisfaction with PrEP-related healthcare services received. Data are collected using a Likert scale.	Attkisson and Greenfield,25 2004		×	×
Satisfaction with interpersonal relationship with navigator	For participants randomised to PN intervention only; nine-item measure of satisfaction with care provided by a patient navigator. Data are collected using a Likert scale.	Jean-Pierre et al,26 2012		×	×
PN intervention acceptability	For participants randomised to PN, brief telephone key informant interview assessing acceptability of the PN intervention. Data are qualitative.	Team developed			×
PrEP initiation	Up to 10 survey items assessing whether patient had received a prescription for PrEP, decided to fill a PrEP prescription and taken at least one dose of PrEP since the start of the study. Categorical data are collected.	Team developed	×	×	×
Demographic characteristics	Demographic items (e.g., age, race, gender, sexual orientation, relationship status, country of origin, US citizen status, primary language, education level, employment status, income and health insurance status) have categorical response options. Age data are collected with numeric text entry.		×
Medical characteristics	Comorbid medical conditions, medications prescribed and history of STI testing.					×
PrEP-related healthcare received	Date(s) appointment scheduled for PrEP consultation; date attended appointment for PrEP consultation; date(s) healthcare provider wrote PrEP prescription(s); date the first follow-up PrEP appointment(s) scheduled; date(s) of follow-up medical appointment attended; data recorded in EHR regarding adherence and discontinuation; other data regarding PrEP-related healthcare.	Team developed				×

BL, baseline; EHR, electronic health record; 3m, 3-month follow-up appointment; 6m, 6 month follow-up appointment; PN, patient navigation; PrEP, pre-exposure prophylaxis; STI, sexually transmitted infection.