Clinical Effectiveness Trial of In-Home Cognitive Processing Therapy for Combat-Related PTSD

The study will use a 3-arm equipoise-stratified randomization design (Lavori et al., 2001; Shalev et al., 2011) to evaluate the clinical effectiveness of CPT-C delivered in three formats: Face-to-Face In-Office (F2F-O), Face-to-Face In -Home (F2F-H), and Telebehavioral Health In -Home (TBH-H). The equipoise stratified design was specifically developed for clinical effectiveness trials involving multiple treatments that may not be appropriate for all research participants. The design will allow for complete randomization of those participants who are interested and eligible for all three treatment arms. It will also allow participants to opt out of one treatment arm if they are not interested or eligible for one of the arms. Without this provision a large proportion of the potential participants would be excluded from the study, seriously compromising external validity. Participants who elect to opt out of one arm will be randomized to one of the two remaining treatment arms. For example, the F2F-O treatment could be eliminated by those who are severely injured, home-bound, or seriously concerned about stigma, and they then would be randomized to receive one of the home-based CPT-C formats. The F2F-H treatment could be eliminated for participants who are uncomfortable with the idea of a mental health provider coming into their home. The telehealth arm could be opted out by veterans who are unable to use a computer, or cannot situate it in a private area.

The equipoise design will be used because a significant confound exists with the use of a completely randomized three-arm research design when all participants cannot be randomized to all arms. With a completely randomized design, participants must be willing to be randomized to all treatment arms or else they must be excluded. All participants willing to be randomized to all arms will occupy a universal donor stratum. The universal donor participants are randomized as in a completely randomized design, and they are able to participate in all statistical analyses. Participants that elect to opt out of one arm will enter a stratum comprising the remaining two arms, and they will be assigned at random to one of the two remaining arms. These participants may participate (along with those in the universal donor stratum) only in statistical analyses that compare arms to which they could have been randomized. By making a choice, each participant assigns himself or herself to a stratum, which consists of all the options that he or she finds equally acceptable. In this design, those who are unable to attend clinic will be randomized to one of the in-home arms. Those who are able to attend clinic will be given the option to reject any one of the three treatments. The randomization plan defines four strata (i.e., those who accept randomization to all three arms and those who reject one of the three treatments). Analyses will be done pairwise using only participants who accepted randomization to two or three treatments, and it will include stratum and the stratum-by-treatment interaction as design effects. Note that this design is the only way to include an in-clinic arm and a sample of participants who are unwilling or unable to be randomized to in-clinic treatment.

Specific Aims. The overall aim of the project is to conduct a 3-group randomized clinical trial to evaluate the clinical effectiveness of CPT-C delivered in three formats: (1) Face-to-Face In-Home CPT-C; (2) Face-to-Face In-Office CPT-C; and (3) Tele-Behavioral Health In-Home CPT-C.

Objective 1: Conduct a randomized clinical trial to evaluate the effectiveness of CPT-C delivered in three formats: (1) Face-to-Face In-Home CPT-C (F2F-H); (2) Face-to-Face In-Office CPT-C (F2F-O); and (3) Tele-Behavioral Health In-Home CPT-C (TBH-H) employing equipoise-stratified randomization.

Hypothesis 1: CPT-C delivered in F2F-H format will be more effective for the treatment of PTSD (symptom reduction below diagnostic threshold on the CAPS-5) than F2F-O \& TBH-H.

Hypothesis 2: CPT-C delivered in F2F-H format will result in greater improvement in secondary outcomes (depression, alcohol consumption, marital and family functioning) than F2F-O \& TBH-H.

Objective 2: Determine if standard F2F-O CPT-C can be enhanced and delivered to special populations (seriously injured, home-based rehab, rural living, severe avoidance) with in-home therapies.

Hypothesis 3: In-home therapies (F2F-H and TBH-H) will result in lower perceived stigma of seeking mental health care and higher treatment adherence (session attendance; out-of-session assignment completion; dose of therapy) compared to mental health clinic-based therapy.

Hypothesis 4: Participants who opt to participate in the in-home therapies (i.e., decline F2F-O) will have higher levels of treatment satisfaction than those in the F2F-O treatment arm.