Participants who enroll into HCWABT II will be randomized into one of two study arms: MPI or MPC. In order to randomly choose which arm participants will be enrolled into, the RA will select an envelope prior to the 12-Month visit that will tell them which arm to consent the participant into. A total of 68 envelopes will read MPI and 68 envelopes will read MPC. If a participant declines the maintenance phase, that envelope will be recycled for a future drawing.
All data will be stored in a password-protected database on Sinai's secure server. Data will be de-identified, except for one data collection tool, the Personal Data Sheet, which will contain the participant's personal information along with their study ID. This information will be kept in a separate password protected database. All data will be archived. Paper files will be saved for a minimum of seven years in a secure locked facility. Electronic data will be saved indefinitely, but will always remain password protected and stored on a secure server hosted by Sinai's Information Systems Department. De-identified data will be available to researchers who wish to use it through a data agreement approved by both institutions. Findings will be widely disseminated. The dissemination plan is discussed in Rating Factor 5.
Baseline characteristics will be compared between participants who complete the entire intervention and follow-up period, and those who are either lost to follow-up or dropout, to assess the effect of selection bias. Dropout and completion rates will be reported. Screening-to-enrollment ratios will be calculated from screening data. Frequencies, means and medians, as appropriate, will be calculated for each outcome variable at baseline and over the follow-up period associated with that outcome. The effect of the 12-month AI will be evaluated using pre-posttest methods with each participant serving as his/her own historical control. Participants enrolled in Maintenance RCT will be both evaluated against their own historical data as well as the data of the other arm of the study. A cost effectiveness analysis will also be conducted using process measures, including staff time, materials, referrals and time spent on various intervention activities in order to calculate program-specific costs. Non-parametric tests will be used to assess whether changes between baseline and follow-up are statistically significant. In cases where the degree of difference is important, such as when comparing differences in outcomes between the two study arms, the Wilcoxon Signed-Rank test will be used. Frequencies across time will be assessed via the McNemar Test for Proportions. All statistical tests will be two-sided, with a significance level of 0.05.
Goals and milestones will be rigorously evaluated each quarter and adjustments made if/when we are behind our target. As one example, we expect to enroll 25 new participants, or 25% of our total goal, into the AI every quarter of the first year. If, for some reason, we are only able to recruit 10% of the total participants after the first quarter, we will adjust our methods of recruitment, send out an additional mailing to Housing Choice Voucher residents and pursue real-time monitoring of eligible patients in our health system to ensure that we are reaching all adults who need our program. If after those efforts we've only met 30% of our recruitment goal after the second quarter, we may propose a limited expansion in our targeted area, but we do not foresee this being an issue.
