For this community-based study, the HCV Task Force of the Health Care for the Homeless Clinicians’ Network (HCHCN, a membership group of the National Health Care for the Homeless Council), which included HCH clinicians and researchers, worked collaboratively to design and oversee this study from its inception, including development of the fieldwork protocol and data collection instruments. Lead clinicians from the HCH Hepatitis C Task Force volunteered their clinics as study sites and agreed to lead their clinic’s onsite data collection. Additional clinics were recruited to balance geographic distribution. A $500 incentive was provided to each participating clinic to partially offset staff time used for data collection.
Eight clinics were chosen from geographically diverse urban settings. Although the clinics were not randomly selected, they were selected from diverse regions of the US including Los Angeles, CA; Phoenix, AZ; Denver, CO; Albuquerque, NM; Des Moines, IA; Milwaukee, WI; Birmingham, AL and Providence, RI.
Study protocols were piloted at three sites. Researchers and HCH project staff worked with clinical teams at each clinic to tailor the standard research protocol to each site. Then each clinical team, which would be collecting all data for the study at their respective sites, also piloted data collection and fieldwork protocols at their own sites. During the data collection period, the HCH Project Director and the researchers were available on-call throughout the data collection process to address emerging issues and concerns. Training in laboratory procedures was similarly carried out between the Project Director, individual site staffs, and the independent laboratory coordinator. The lab coordinator met with individual sites to discuss the lab protocol including blood testing, storage and mailing procedures. All blood was tested at a centralized laboratory.
Sampling, screening, and recruitment
The recruitment goal was fifty homeless adult clients randomly sampled from each of the eight study clinics for a total sample size of 400. Clients were sampled systematically with a random start. Lead clinicians continued recruitment over a number of days until a sample size of 50 clients was completed for each clinic.
At the beginning of the clinic day, an intake staff person systematically sampled potential subjects from the appointment list or intake roster, for example, by sampling every fifth client after a random start. In turn, each of these clients was screened for eligibility for the study based on two criteria: age (18 and older) and meeting the federal definition of literal homelessness. “Literal homelessness” was based on one question about the place where the client had spent the previous night. Eligible clients were invited to complete an interview and blood draw to test for HCV and hepatitis B (HBV) infections. The clinician then obtained written informed consent to participate in the study. A separate consent form authorized subsequent access to each client’s medical records to determine whether they returned for their respective test results.
Each client completed a 20-minute face-to-face interview with the lead clinician followed by tailored pre-test counseling for HBV and HCV and a blood draw. Each client received an incentive of $10 cash or a $10-cash equivalent for completion of all three. Clients were then scheduled for an appointment in the same clinic about two weeks later to obtain the results of their blood tests.
Blood specimens were sent to and tested by an independent central laboratory. Only HCV antibody results were analyzed here. To assess for HCV, blood specimens were analyzed for the HCV antibody and alanine aminotransferase (ALT). Based on the CDC suggested protocol, confirmation of HCV antibody positivity was conducted using the recombinant immunoblot assay (RIBA) test for cases in which the signal-to-cutoff ratio was less than 3.8 on the initial anti-HCV antibody EIA test.24
Individual lab results were faxed back to respective clinics and affixed to each client’s medical chart by clinic staff. Depending on their HCV test results, returning clients received tailored post-test counseling and usual treatment according to local clinic protocols. The HCH Task Force provided written pre- and post-test counseling guidelines as a resource for the clinics.
The structured interview included questions about sociodemographic characteristics and background; homelessness history; detailed medical, psychiatric, and prison history; HCV-specific knowledge and prior testing; and recent alcohol use. Questions also included potential risk behaviors for HCV transmission including lifetime drug use [e.g., drugs used, modes of use (i.e., injection, intranasal, or smoked), and sharing of injection and other drug-use equipment]; tattoos; transfusions before 1990; and sexual risk behaviors (that included number of lifetime sex partners, trading sex for cash or drugs, and lifetime anal sex). The instrument was adapted from a prior study of homeless and other indigent adults. Additional items were developed by the HCHCN HCV Task Force to address specific concerns of clinical staff.
The completion rates varied by site from 92% to 100%. Overall, 396 clients completed interviews, and among these, 387 had blood draws for an overall completion rate of 97.7%. In six clinics, lead clinicians reviewed medical records for 300 participants to determine whether each one returned for results. Among these, records indicated that 186 (62%) participants returned to the clinic during their respective 30-day follow-up periods.
The University of California Los Angeles (UCLA) Institutional Review Board (IRB) served as the multiple project assurance agency that approved the study. The study was also approved by the Federal Office of Management and Budget and individual clinic IRBs. Prior to onset of data collection, all research and clinic personnel involved in the study completed an online UCLA IRB course in the protection of human subjects.
Data from the eight clinics were merged into an aggregated dataset. Data analysis was performed using SAS 9.0. Categorical variables were created for age (45 < and 45+), number of lifetime sexual partners (15< or 15+), chronic homelessness (one year or more accumulated since age 18 versus less than one year), tattoos, and years of injection drug use. Differences between sites were analyzed using Chi Square tests. At the bivariate level, associations between categorical variables and HCV infection were examined with odds ratios (OR) and 95% confidence intervals (CI).
Three logistic regression models were developed to identify variables independently associated with HCV infection for the total sample and for two mutually exclusive groups: i.e., those who reported injection of any illicit drugs in their lifetimes, and those who reported none. Each model initially included all variables that were at least marginally associated with HCV status in the bivariate analysis (p≤0.10). Each model also controlled for age as a continuous variable, biological sex and race. Variables were entered into stepwise backward logistic regression models to create a core model, and then they were confirmed using stepwise forward analysis. Variables in each core model were examined and corrected for multicollinearity, defined as correlations greater than 0.5 and a variance inflation factor greater than or equal to four. Model fit was judged by the comparison of the −2 log-likelihood of model improvement and Wald statistics of the beta coefficients.