In 2007, nine of the 26 family developments managed by the Boston Housing Authority (BHA) had an active RHA. Four housing developments were selected for this study on the basis of the following criteria: presence or absence of an RHA, community health center within 1 mile, and availability of an adequate parking space for the van. Two intervention sites were selected and pair-matched with a control site that had a similar number of adults aged 18 years or older, proximity to a community health center, location, and previous mobile health screening visits (Table 1). In 2008, the 2 sites that did not have RHAs serving as controls in 2007 received the intervention.

The Boston University institutional review board approved the research design, all data collection instruments, and consent forms. For the first study outcome, van use and screening results, informed consent was not required because mobile health screening was considered a standard community service, particularly among residents of public housing. For the second outcome, verification of an appointment, we sought screening participants' consent and personal information to follow up with health centers to verify whether appointments were kept.

The PHH-PRC has trained RHAs every year since 2002 to improve the health status of BHA residents. RHAs are recruited to the training program through an application process. Twelve applicants are chosen each year for a 14-week training program (6 hours per week). The BHA then hires RHAs to work 6 hours per week at their developments, where they educate their fellow residents and become a health information resource for their communities. Each RHA identifies another resident (designated a "peer leader") to assist in distributing flyers and recruiting housing residents on mobile health screening days.

The primary task of the RHAs in our study was to use various outreach strategies to motivate residents aged 18 years or older to attend mobile health screenings. Before the arrival of the screening van in 2007, RHAs and peer leaders, via one-to-one conversations, encouraged residents at the 2 intervention sites to use the mobile health screening service to address concerns regarding screening. One-to-one conversations took place in various settings (eg, in the management office, at the tenant task force meetings, in the hallways, in parking lots). More than 3,000 flyers in English and Spanish were distributed door-to-door to notify the 1,715 residents of screening dates and times for June through August 2007 and to provide specific health information. Residents of control sites received the same flyer, which tenant management staff distributed in accordance with earlier BPHC protocols.

In 2008, we first conducted a door-to-door survey to determine optimal venues for distribution of flyers and appropriate messages for the flyers. Survey responses led us to create a new, more visually appealing and easier-to-read flyer. Recruitment flyers were also distributed in new locations such as laundry rooms, mail stops, and rooms where bingo games were held.

The BPHC's mobile public health van, "The Health Connection," is a medical mobile unit that has provided residents of Boston's neighborhoods with free on-site health education and health promotion screening services since 2000. During the summer of 2007, the mobile health screening service came 3 times to each of the 4 sites, for a total of 9 hours per site. Rotating morning, afternoon, and evening schedules were held constant at intervention and control sites. At intervention sites, 5 to 8 RHAs and peer leaders including at least 1 bilingual RHA helped residents to the van, informed them of the pilot study, and processed referral information for those who agreed to participate in the pilot study. We reviewed screening data from 2007 and found that most people visited the mobile unit during afternoon and evening sessions. Consequently, in 2008, the mobile unit conducted afternoon and evening visits only. During the summers of 2007 and 2008, dental examiners worked in the van during 3 of the 6 visits at both intervention and control sites. In 2008, they were present for 4 of the 6 intervention visits.

All participants were asked to complete an intake form before receiving screening services. The intake form asked for demographic information, health and health care access information, how they heard about the van, whether they had been screened before, and timing of the last visit to a doctor. We defined "untreated positive screen" as a screen-positive result in a participant who was not previously aware of his or her condition or who had not been taking a prescribed medication for the condition or both.

Activities described in this section apply equally to participants at both intervention and control sites as part of the standard care offered by the public health mobile unit. Participants were screened for hypertension, high cholesterol, glucose, diabetes risk, and dental disease. Blood pressure and cholesterol cutoffs were those endorsed by the US Preventive Services Task Force (Box) (17). To assess diabetes risk, we used a standard 8-question self-administered tool that asked about diet, exercise, age, and diabetes in the family. Scores could range between 0 and 2 (very low risk), 3 and 9 (low to medium risk), and 10 or more (high risk) (18). High-risk participants were offered a blood glucose screening test. Results were categorized as either normal (mean plasma glucose level ≤140 mg/dL) or high (>140 mg/dL). Dental screening consisted of a visual and tactile inspection of the gums, teeth, and tongue and other soft tissues for irregularities or sensitivity (19). A dental examiner from Boston University Goldman School of Dental Medicine joined the mobile unit health staff to provide dental screenings for presence of root tips and untreated caries, number of missing teeth, denture stability and retention, and other soft tissue abnormalities. Any inspection that resulted in a referral for follow-up care was considered a positive screen.

In 2007, residents with screen-positive results were offered help in making an appointment at the health center of their choice at both intervention and control sites. At both intervention and control sites, RHAs made appointments either on-site or at a later time, in which case the person being referred was called with the appointment information.

On the basis of our experience with referrals in 2007, we pilot-tested a process in 2008 that involved several steps to improve appointment-making and to ensure that appointments were kept. First, we reduced to 2 pages the consent form requesting participants' permission for research staff to seek follow-up information. The revised medical intake form also included 2 new boxes to record whether the participant needed a referral and if the appointment was urgent. Van visits were scheduled for the time of day when health centers were more accessible for appointment-making (usually midday). RHAs also accompanied people to their appointments, translated as needed, and offered information on services for the uninsured.

We entered data on demographics, access to health care, health information, and screening results from the mobile health unit intake forms and referral forms into an Excel 2003 spreadsheet (Microsoft Corporation, Redmond, Washington) and conducted statistical analysis with SAS  version 9.1 (SAS Institute, Inc, Cary, North Carolina). The primary analysis compared use of the mobile health screening service in the intervention with control conditions. The 2 control housing developments in 2007 constituted the control condition; the intervention condition included the experience at the intervention sites in 2007 in addition to the 2008 experience at the housing developments that had been control sites in 2007. The use of the mobile health screening service was measured as the proportion of the total adult population (aged ≥18) who received screening services. From BHA records, we obtained the number of adult residents by sex, age, race/ethnicity, and primary language spoken at home.

We calculated relative risk (RR) for participants' attendance with 95% confidence intervals (CIs) to compare the proportion of intervention and control condition residents who attended screenings. We calculated P values by using χ² or t tests as appropriate. Because there were no morning screenings in 2008 and, therefore, more afternoon and evening visits in the intervention condition, we calculated a standardized RR, weighted by the total number of morning (n = 4), afternoon (n = 8), and evening (n = 6) sessions in 2007 and 2008. We also compared the distribution of participants at intervention and control sites in 2007 by sex, age, race/ethnicity, time of screening (morning, afternoon, or evening), primary language spoken at home, education, medical and dental insurance status, and most recent primary care visit.

To assess the role of RHAs in facilitating follow-up medical care after a positive screening, we compared the proportion of consent forms completed (to gauge the success of the enrollment process) and the proportions of appointments made and kept in the summer of 2007 with those in the summer of 2008. We combined intervention and control sites in 2007 because there were no differences in the nature or intensity of efforts to increase follow-up at either set of sites.

In 2007, 6% (n = 100) of adult residents at the 2 intervention sites were screened, compared with 3% (n = 47) of residents from control sites (RR, 1.74; 95% CI, 1.24-2.44). Use at the intervention sites, adjusted for time of day of mobile health screening visits, was also higher than at control sites for both years combined (RR, 1.55; 95% CI, 1.12-2.15).

For both intervention and control sites combined in 2007, mobile health screening participants were primarily female, Hispanic, had a mean age of 44, and had completed high school (Table 2). Hispanic (57% of mobile health screening participants compared with 41% of adult residents, P < .001) and male residents (39% of mobile health screening participants compared with 27% of adult residents, P = .001) used the van at rates disproportionate to their numbers in the developments.

Of the 224 participants from intervention and control sites across both years, 146 (65%) had at least 1 positive screening diagnosis for hypertension, high cholesterol, diabetes risk, or dental disease. Of the 217 participants screened for hypertension, 64 had either stage 1 (n = 36) or stage 2 (n = 28) hypertension. Twenty of the 64 participants with stage 1 or stage 2 hypertension had not seen a doctor in the past 12 months, and 39 were considered an untreated positive screen (Table 3).

Although 25% of participants had a screening diagnosis of hypertension and 24% had high cholesterol, findings of diabetes risk and dental disease were more common. Two-thirds of those screened (n = 114) had a high diabetes risk score based on the 8-question self-administered tool, and 9 of the 114 had a positive blood glucose test (Table 3). A total of 127 people attended the mobile health screening service on days when screening for dental disease was provided, 49 of whom chose not to use dental services. Of the 78 who were screened, 41 (53%) were referred to a dentist for follow-up. Referrals were based on a 0-3 scoring system used by the dental staff (Box). Urgent care was recommended for 3 participants who reported significant pain or had obvious infection.

In 2007, among the 91 participants who screened positive for any condition, 44 (48%) provided consent for follow-up. Of these, appointments were made for 27 participants (61%) within 3 months after the date of the screen-positive finding. Appointments were not made for 17 participants for 2 major reasons: disconnected telephone lines or inability to contact the resident after several telephone calls (n = 8) and system barriers (n = 9). Fourteen (52%) of the 27 participants with appointments kept them. In 2008, among the 44 participants who screened positive, 33 (75%) provided consent for follow-up. Of those who consented, appointments were made for all 33 participants within 1 month after the date of the screen-positive finding. Of the 33 participants with appointments, 24 (73%) had kept an appointment within 2 months after the initial screening. Overall, the proportion of all screen-positive participants who completed a follow-up medical appointment through the mobile health screening mechanism increased from 15% (14 of 91) in 2007 to 55% (24 of 44) in 2008.