Integrating Animal-Assisted Therapy Into Trauma-Focused Cognitive-Behavioral Therapy for Maltreated Youth: A Randomized Feasibility Trial
Phase: NA
Conditions: Child Abuse, Posttraumatic Stress
Sponsor: Milton S. Hershey Medical Center

Cover Page 
 
Official Title: Integrating Animal-Assisted Therapy Into Trauma-Focused Cognitive-Behavioral 
Therapy for Maltreated Youth (TF-CBT+AAT) 
Identifiers: NCT03135119 
Document Date: May 16, 2022 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Integrating Animal-Assisted Therapy Into Trauma-Focused Cognitive-Behavioral Therapy 
for Maltreated Youth (TF-CBT+AAT) Protocol 
1.0 Inclusion and Exclusion Criteria 
 
1.1 
Inclusion Criteria 
 
Minor Patients 
• Age 6-17 years (inclusive) with a participating consenting caregiver with 
legal standing to consent for the minor child (either biological parent or 
adoptive parent).  All youth will be asked to provide assent.  
• Sex:  male or female 
• Fluent in written and spoken English, as the assessment instruments are 
not available in translations and have not been validated for use with non-
English speaking populations.  
• An allegation of abuse or neglect investigated by law enforcement or child 
protective services.  
• A raw score of ≥ 39 on the caregiver-report version of the UCLA PTSD 
Reaction Index completed by the caregiver upon presentation to the TLC 
Clinic or the Pinnacle Health Children’s Resource Center (CRC). 
• A full scale IQ score of ≥ 80 on the Kaufman Brief Intelligence Test (2nd 
ed.; KBIT-2) 
 
Adult Caregiver 
• Biological or adoptive parent of a child meeting inclusion criteria.  Must 
consent to his/her own participation as well as the participation of the 
child. 
• Self-identified as the primary caregiver (responsible for the day-to-day 
care of the child).  
• Age ≥18 years 
• Sex:  male or female 
• Fluent in written and spoken English. See rationale above regarding 
measures. 
 
NOTE: Only youth were enrolled and only data pertaining to youth functioning was collected. 
However, given the importance of caregiver report for assessing these outcomes, inclusion and 
exclusion criteria related to the caregivers was included.  
  
 

1.2 
Exclusion Criteria 
 
Minor Patients 
• Age <6 or >18 years 
• 6-18 years of age and unwilling to give assent 
• A diagnosed cognitive or intellectual deficit, or developmental delay 
• An IQ score < 80 on the KBIT-2 
• A reported fear of dogs, dog allergy, or prior history of aggression toward 
animals.     
 
Adult Caregiver 
• Age < 18 years at the time of enrollment 
• Caregiver inability to participate in treatment or to complete assessment 
measures due to cognitive, psychiatric, or other limitation. 
• Suspected or known to have perpetrated a form of child maltreatment. 
• A reported fear of dogs, dog allergy, or prior history of aggression toward 
animals 
 
2.0 Recruitment Methods 
 
2.1 
Identification of subjects 
 
Participants will be recruited through two mechanisms. First, children presenting 
for services at the Penn State Children’s Hospital’s Stine Foundation 
Transforming the Lives of Children (TLC) Clinic will be eligible for inclusion. 
The TLC Clinic exclusively serves maltreated children and, as a condition of 
admission, an investigated allegation of child maltreatment is required. Children 
meeting inclusion criteria following their initial assessment at the TLC Clinic will 
be offered participation in the trial.  
Second, children presenting to the Pinnacle Health Children’s Resource Center 
(CRC) for forensic interviews following allegations of maltreatment will be 
referred to the HMC research team.  CRC involvement is limited to providing the 
attached recruitment letter to the parent of the child who may be eligible for this 
research. 
NOTE: Only youth were enrolled and only data pertaining to youth functioning was collected. 
However, given the importance of caregiver report for assessing these outcomes, inclusion and 
exclusion criteria related to the caregivers was included. In addition, caregivers provided consent 
for the participation of the youth in the study. 

 
 
 
2.2 
Recruitment process 
 
Potential participants will be referred to study coordinators who will conduct a 
phone screen for eligibility related to the inclusion of the dogs, explain the study 
procedures and review inclusion/exclusion criteria. Pending meeting 
inclusion/exclusion criteria, those interested in participating will be scheduled an 
assessment session. 
 
2.3 
Recruitment materials 
 
The attached recruitment letter will be distributed to potential participants at the 
time they are identified as meeting initial eligibility at presentation to either the 
TLC Clinic or CRC. 
 
2.4 
Eligibility/screening of subjects 
 
Once participants are contacted by study coordinators, a brief screening 
questionnaire will be administered over the phone (see attached). Participants who 
agree to participate will be scheduled for the pre-treatment assessment session 
where the KBIT-2 and other study measures will be implemented. Final eligibility 
will be determined after this session. 
 
3.0 Consent Process and Documentation  
 
3.1 
Consent Process  
  
3.1.1 Obtaining Informed Consent 
 
3.1.1.1 Timing and Location of Consent 
 
Child will attend study assessment and treatment appointments 
at the TLC Clinic (2626 N. 3rd St., Harrisburg). The research 
assistant will obtain informed consent in a private setting/room 

within the clinic when they attend the pre-treatment 
assessment session. 
3.1.1.2 Coercion or Undue Influence during Consent 
 
Study procedures will be fully explained, voluntariness will be 
emphasized as well as the fact that declining participation will in 
no way impact the relationship of the participant with the TLC 
Clinic, Department of Pediatrics, or PSHMC. 
3.1.2 Waiver or alteration of the informed consent requirement 
 
Waiver;  recruitment of children. 
 
A waiver of consent is requested to review medical record information to 
determine preliminary eligibility to participate in the research. 
3.2 
Consent Documentation 
 
3.2.1 Written Documentation of Consent 
 
The consent process will be documented in writing with the long form of 
consent documentation.  The research assistant will assist in the explanation 
and obtaining of the written consent.  A copy of the signed consent will be given 
to the participant and another copy will be saved in filing cabinets located at the 
TLC Clinic. 
 
3.2.2 Waiver of Documentation of Consent (Implied consent, Verbal consent, etc.) 
 
A waiver of documentation of consent is requested for recruitment purposes 
because patients interested in the study will be calling the research assistant for 
a phone screening in response to seeing the recruitment letter or talking to staff 
at the CRC or TLC Clinic. 
 
Verbal consent will be obtained from study therapists and dog handlers.  A 
summary explanation of the research procedures will be provided to therapists 
and handlers about their role in completing the study.  Verbal consent is used in 
this case as no PHI is collected from therapists or handlers. 
 

3.3 
Consent – Other Considerations  
 
3.3.1 Non-English Speaking Subjects 
 
N/A:  Excluded since the assessment materials used in the current study are only 
available in English, and have not been validated in other languages. 
 
3.3.2 Cognitively Impaired Adults 
 
3.3.2.1 Capability of Providing Consent 
 
Caregivers with obvious cognitive, psychiatric, or other impairment 
that are incapable of understanding the purpose of the measures 
or participate in treatment will not be allowed to consent for 
themselves or their child.   
3.3.2.2 Adults Unable To Consent 
 
Adults unable to provide consent, and their children, will not be 
enrolled in this study. There would be concerns regarding their 
ability to provide informed consent and participate in treatment. 
3.3.2.3 Assent of Adults Unable to Consent 
N/A 
 
3.3.3 Subjects who are not yet adults (infants, children, teenagers)  
 
3.3.3.1 Parental Permission 
 
 
All children in the study will be between the ages of 6 and 17 
 
(inclusive). Each child will require the consent of a legal caregiver.       
 
This will be obtained when they attend the scheduled pre-
treatment assessment session at the TLC Clinic. 
 
3.3.3.2 Assent of subjects who are not yet adults 
 
Assent will be obtained from all youth participants and 
documented for all minors 7 years of age or older. 

 
4.0 Study Design and Procedures 
 
4.1 
Study Design 
 
Randomized clinical trial with two active conditions and no placebo or waitlist 
conditions.   
 
4.2 
Study Procedures 
 
Children enrolled in the study will already demonstrate a sufficient elevation on the 
UCLA prior to completing the pre-treatment assessment, either at the TLC Clinic or the 
CRC. Additional measures (see below) will be completed at a pre-treatment session 
administered by the research assistant. Children will be randomly assigned to either the 
TF-CBT or TF-CBT+AAT condition using a blocked randomization procedure to balance 
the two groups on gender and age, thereby reducing bias and confounding that may be 
attributable to these factors (Efird, 2011). This randomization will be performed using a 
computer algorithm in SAS v. 9.4 with randomly selected block sizes of 4, 6, and 8. In 
addition, each child will be randomly assigned to one of two clinicians participating in 
the RCT using a random number generator. The randomization sequence will be defined 
prior to beginning the trial and will be developed and maintained by Dr. Ming Wang 
(PSU Public Health Sciences). Children will be scheduled to complete a post-treatment 
assessment within 2 weeks of completing the 12th (final) session of the treatment 
protocol. The research assistant will administer the posttreatment assessment 
(measures described below) and all data collected will be entered into a database 
developed for this project using the Penn State College of Medicine’s Research 
Electronic Data Capture (REDCap) system. Data monitoring and management, and 
statistical consultation, will be provided by Dr. Wang. The study will be single-blinded as 
all staff handling data will be blinded to a child’s treatment condition (i.e., research 
assistants, Dr. Wang, Dr. Shenk). The study coordinator/research assistant will be 
responsible for reviewing study procedures with potential participants, liaising with the 
CRC, scheduling and verifying appointment times, conducting assessments, and 
contacting participants to re-schedule in the event that assessment sessions are missed. 
 
The same two clinicians will implement the treatment in both conditions, thereby 
eliminating the impact of clinician-related factors on outcome. Both clinicians involved 
in the current project have completed requisite training and supervision requirements 
set forth by the TF-CBT developers and are certified TF-CBT clinicians. Clinicians will be 
required to complete and maintain a fidelity checklist (adapted from Deblinger et al., 
2014; see attached) and the clinicians themselves will enter this data into REDCap to 

ensure the research assistant remains blinded to participant condition. Dr. Allen will 
facilitate bi-weekly group TF-CBT supervision with the clinicians and be responsible for 
supervising research assistants.  
 
The clinicians will be responsible for scheduling treatment sessions, which will occur 
once per week. This project will employ the standard TF-CBT treatment protocol, which 
includes twelve 90-minute sessions. TF-CBT is typically described as including 3 phases, 
each focusing on a common goal and encompassing a third of treatment (4 sessions). 
The first phase focuses on skills-building and includes psychoeducation, parenting skills 
training, relaxation skills training, affect modulation skills training, and cognitive coping 
skills training. The second phase involves focused gradual exposure activities, including 
construction of a narrative account of the child’s maltreatment experiences and 
cognitive processing of maladaptive thoughts. The third phase emphasizes the child’s 
mastery over environmental reminders of the maltreatment and includes sharing the 
trauma narrative with the caregiver, in vivo exposure to physical stimuli, and enhancing 
future development. 
 
Susquehanna Service Dogs (SSD), a fully accredited member of Assistance Dogs 
International (ADI), will partner in the completion of this project (see letter of support 
from Pamela Foreman). SSD facility dogs are fully trained/certified according to ADI 
standards and serve in canine-assisted interventions in local mental health settings. 
These dogs are skilled in basic obedience, maintain a calm manner and good social 
behavior in a variety of environments, and are trained for public access 
(http://www.assistancedogsinternational.org/standards/assistance-dogs/standards-for-
dogs/training-standards-for-facility-dogs/). Three pre-determined facility dog/handler 
teams will participate in this project. Each team will schedule 4-hour blocks of time 
either in the morning or afternoon on various days of the week. Children assigned to the 
TF-CBT+AAT condition will be scheduled in one of these time blocks. The dog will then 
be considered an extension of the clinician; if the dog cannot attend an appointment 
then the appointment will be re-scheduled. This will assure that the child remains with 
the same dog each session for the duration of the protocol. Dogs will only be scheduled 
to participate with one child per day. If the child needs to change the regular 
appointment time, the dog’s handler will be consulted and attempts will be made to re-
schedule without changing the dog involved.  
 
Having the dog’s handler in the treatment room for the TF-CBT+AAT condition creates a 
significant confound as a second individual will not be present in the TF-CBT condition. 
Therefore, SSD handlers will deliver a 3-hour training to the clinicians in the 
management of the service dog and provide a further 7 hours of consultation to the 
clinicians throughout the project. When the session is ready to begin, the handler will 
transfer the handling duties to the clinician. Handlers will observe sessions through a 

one-way mirror and/or closed circuit television system with a focus on monitoring the 
well-being of the dog. Handlers will be free to interrupt sessions if they believe it is 
warranted given the dog’s behavior. Handlers will not be able to hear what is being 
discussed from the observation room, although various emotional responses will be 
visible and they may become aware of some details of the child’s maltreatment. The 
clinicians will provide a 3-hour training to the handlers on secondary trauma and self-
care, and provide continuing support to the handlers as needed. 
 
Treatment sessions will be structured as follows: (1) A research assistant will facilitate 
the application of 
electrodes to the child for purposes of recording psychophysiological data (see below). 
Research assistants will be trained to affix these electrodes by Dr. Shenk. The dog’s 
handler will affix a heart rate monitor to the dog as well as collect a saliva sample for 
cortisol analysis (see below; IACUC approval pending). Dr. Dreschel will train handlers in 
these procedures. Note data collection related to the dog is being performed by the 
handler in order to maintain the blinded status of the research assistant. (2) The child 
will be given 10 minutes of unstructured time prior to the implementation of treatment 
techniques to engage in relaxing, pleasurable activities while in the treatment room. 
Children in the TF-CBT group may select toys, games, books, or other activities, and 
children will be allowed to determine whether the clinician is involved in these activities. 
Children in the TF-CBT+AAT group will be given the same options; however, the dog will 
be in the room during these 10 minutes and the child may interact with the dog during 
that time. (3) The clinician will implement the child-focused TF-CBT components 
indicated for the given session (approximately 45 minutes). For the TF-CBT+AAT 
sessions, the dog will be instructed to sit or lay near the seated child during this time 
and the child will be allowed to pet or otherwise interact with the dog during the 
session. Children assigned to the TF-CBT group will be given the option of taking a 
stuffed animal or other tactile sensory stimulus (e.g., Koosh ball) into session. (4) The 
dog will be reunited with the handler, and the handler will remove the heart rate 
monitor from the dog and collect a saliva sample. Children in the TF-CBT+AAT group will 
be allowed to say good-bye to the dog. A research assistant then will facilitate the 
removal of electrodes from the child. (5) The clinician will implement the caregiver-
focused TF-CBT components assigned for the given session (approximately 45 minutes) 
and a research assistant will implement indicated data collection procedures with the 
child (see below). The conditions specified in point (3) will apply during conjoint sessions 
where both the child and caregiver are present. 
 
Measures 
 

(1) Posttraumatic stress (PTS) will be assessed primarily through caregiver-report on the 
UCLA PTSD Reaction Index. In addition to the pre-treatment/referral and post-treatment 
assessments discussed above, the caregiver will complete the UCLA when presenting for 
the 5th treatment session (score after the first phase of treatment [sessions 1-4]) and 
the 9th treatment session (score after the second phase of treatment [sessions 5-8]). 
Thus, PTS will be assessed at four separate points in the treatment process, which will 
allow for a comparison of the rate of progress across the two conditions. Children will 
also complete the self-report version of the UCLA at each of the four assessment points. 
(2) Emotional and behavioral concerns will be assessed by caregiver-report using the 
Strengths and Difficulties 
Questionnaire (SDQ; Goodman, 1997). As with the UCLA, the caregiver will complete the 
SDQ at pretreatment, during sessions 5 and 9, and at post-treatment. Children will self-
report their anxiety concerns on the Screen for Child Anxiety Related Disorders 
(SCARED; Birmaher et al., 1999) and their depression concerns on the Mood and 
Feelings Questionnaire (MFQ; Angold et al., 1995) at each of the four assessment points. 
A research assistant will be responsible for administering measures at each assessment. 
(3) Emotion regulation will be assessed in three ways. First, caregivers will complete the 
Emotion Regulation Checklist (ERC; Shields & Cicchetti, 1997) during the pre- and post-
treatment assessments. Similarly, children will complete the self-report Emotion 
Regulation Index for Children and Adolescents (ERICA; MacDermott et al., 2010) during 
the pre- and post-assessments. Last, children’s resting and stress reactivity respiratory 
sinus arrhythmia (RSA) will be assessed both pre- and post-treatment. RSA is assessed 
via an electrocardiogram (ECG) and is a well-established psychophysiological marker of 
emotion regulation (Beauchaine, 2015). RSA will be assessed with a UFI 3991/4 EIRS 
BioLog ambulatory physiological data recorder using disposable Ag/AgCl electrodes. 
Electrodes will be placed on the chest and abdomen to acquire inter-beat intervals. 
Placement of the electrodes will be facilitated by the research assistant conducting the 
assessment and the child’s caregiver will be present during the application and later 
removal of the electrodes. The caregiver will not be present during the administration of 
the assessment procedures. To assess resting RSA, children will watch pre-selected 
television programs that are not emotionally-laden for 15 minutes. Stress reactivity will 
then be assessed using the Trier Social Stress Test (TSST; Buske-Kirschbaum et al.,1997; 
Kirschbaum et al., 1993). In addition, children will be shown a $15 gift card to a toy or 
electronics store prior to beginning the TSST and told that they must achieve a 
satisfactory performance across the TSST tasks to earn the gift card. The gift card will be 
provided to all participants at the completion of the TSST. In both the resting and 
stressor paradigms, RSA will be sampled in 30 second epochs. Dr. Shenk, who will be 
blind to participant condition, will be responsible for editing the ECG files to remove 
artifacts and scoring the files using CardioEdit and CardioBatch software (Brain-Body 
Center, University of Illinois at Chicago, 2007). Dr. Shenk is trained and certified by the 
developers in the use of this software. (4) Youth perception of the caregiver will be 
assessed at both the pre-treatment and post-treatment assessment sessions using the 
Security Scale, to determine whether participation in TF-CBT improved the youth’s 
perception of their caregiver as a source of support. To examine potential caregiver-

related interpersonal factors on this outcome, the caregiver will complete the 
Experiences in Close Relationship-Revised (ECR-R) and the Caregiving Systems Scale 
(CSS). 
 
(5) Participant attrition, cancelled appointments, and missed appointments without 
prior notice will be recorded to determine if the conditions differ on consistency of 
attending and completing treatment. (6) Treatment satisfaction will be assessed by 
caregiver and child report during the posttreatment assessment using the Youth Client 
Satisfaction Questionnaire (YCSQ; Shapiro et al., 1997). (7) Ability to implement TF-CBT 
techniques will be assessed in multiple ways. First, the number of sessions that are 
cancelled because of reasons attributable to the availability of the dog will be recorded 
(e.g., dog/handler illness). Second, the clinician will complete a fidelity checklist after 
each session to report whether the assigned techniques for the session were 
successfully completed (see attached). Completing such checklists will allow for a 
comparison between the two conditions to determine whether the presence of the dogs 
facilitated a greater rate of completion of assigned techniques or hindered completion 
of assigned techniques. Third, clinicians will report whether a treatment disrupting 
event attributable to the dog occurred during session (e.g., emotional distress requiring 
handler intervention). (8) Stress response in dogs will be evaluated using physiological 
and behavioral measures. To measure hypothalamic-pituitary-adrenal (HPA) response, 
three saliva samples for cortisol assessment (pre-session/prior to meeting child, post-
session/immediately after separation from child, and 20 minutes post-session) will be 
taken from each dog at treatment sessions 1, 6, and 12 (beginning of treatment 
protocol, predicted child peak emotional level during protocol, end of treatment 
protocol). Each of these samples will be obtained by the handler. Representative control 
day samples (at the same time on non-therapy days) will be taken by the handler at 
home for each dog. Dr. Dreschel will train handlers in the collection, transportation, and 
storage of samples. For autonomic nervous system response, canine heart rate will be 
measured at each session using a Polar H7 monitor with bluetooth connection to a 
tablet computer. Using conversion software, RSA (R-R intervals) will be determined for 
each session. Sessions will be videotaped and Dr. Dreschel will code behavioral stress 
signals in the dogs as well as children’s behavior toward the dogs (Dreschel & Granger, 
2005). In addition, handlers will be trained by Dr. Dreschel to assess their dogs’ behavior 
before, during, and after treatment sessions using the Behavioral Instrument for the 
Assessment of Dog Well-Being Before/During/After Therapy Sessions (Fine, et al., 2013; 
Ng et al., 2015). 
 
(9) Stress experienced in session will be assessed via ECG. Children will be connected to 
a UFI 3991/4 EIRS BioLog ambulatory physiological data recorder using disposable 
Ag/AgCl electrodes prior to the start of treatment sessions 1, 4, 6, 8, and 12. Placement 
of electrodes will be performed by a research assistant using the procedures specified 
previously. Event marks will be recorded at the point of transition from the 10-minute 

relaxation/pleasurable activities time to the start of the implementation of techniques. 
RSA will be sampled in 30 second epochs and calculated for each of these two time 
periods (10 minute phase prior to technique implementation, 45 minute phase of 
technique implementation). This methodology will allow for assessment of within-
participant RSA trajectories over the course of treatment, and between-group 
comparisons on physiological stress response both prior to and during technique 
implementation. (10) Quality of therapeutic rapport will be assessed via child and 
caregiver-report using the appropriate versions of the Therapeutic Alliance Scale for 
Children-Revised (TASC-R; Accurso et al., 2013; Creed & Kendall, 2005; Shirk & Saiz, 
1992). AAT is believed to facilitate the development of rapport and, therefore, assessing 
rapport at multiple points in the first phase of treatment is appropriate. As such, rapport 
will be assessed at the 2nd and 4th treatment sessions as well as at post-treatment. A 
research assistant will administer the TASC-R with caregivers and children during these 
sessions and will explicitly state that the clinician will not be made aware of the answers 
provided. (11) Attitudes toward pets will be assessed for the youth at the pre-
treatment assessment only using the Pet Attitude Scale to determine whether pre-
existing attitudes toward pets is related to outcome in the TF-CBT+AAT group. (12) The 
demographics form will be completed at the pre-treatment assessment only. 
 
Note on the Recording of sessions: The TLC Clinic currently has video recording 
capabilities and uses them on a regular basis. These recording are done by equipment 
installed in the TLC Clinic by the PSHMC IT department and stored digitally on PSHMC 
servers behind the firewall. A back-up system uses a camcorder within the clinic and the 
files are stored on a memory card. The files are then transferred to the TLC Clinic shared 
drive that is only accessible to TLC Clinic staff with permission to access the drive. The 
video recorded files are then deleted from the memory card.   
 
4.3 
Duration of Participation 
 
Each child is expected to participate in the pre-treatment assessment, 12 sessions of 
treatment, and a post-treatment assessment. 
Statistical Plan 
 
5.1        Number of Subjects 
 
60 participant youth 
 
5.2         Sample size determination 
 

Although a primary objective of this study is to derive effect size estimates that can 
inform the design of a larger clinical trial, a preliminary power analysis was conducted. 
Results indicated that the proposed sample of 60 participants (equal sample sizes across 
the two conditions) can achieve 80% power to detect an approximately 5 point 
difference of pre-post change between the groups on the PTS measure (i.e., UCLA) when 
the standard deviation of each group is assumed to be 6.5 and the significance level is 
set at .05. Ethnic and gender composition will likely reflect those of the larger Harrisburg 
area (45% White, 45% African-American, 10% other ethnicities; 50% female, 50% male). 
 
5.2        Statistical methods 
 
Intent-to-treat analyses will be used for all statistical analyses (i.e., all of the available 
data from randomized participants are utilized for analyses). Descriptive statistics (e.g., 
means, ranges, standard deviations) will be computed for continuous variables; 
frequencies will be calculated for 
categorical variables. Measurements of PTS, emotional and behavioral concerns, and 
emotion regulation are continuous variables and will be examined over time with 
individual-level graphical checks. Transformation methods may be needed based on 
normality checks (i.e., Shapiro-Wilks test). To adjust for potential confounding variables 
that may be identified (e.g., gender, age, number of trauma types endorsed on the 
UCLA), multilevel models with partial nesting (i.e., youth in the TF-CBT+AAT group 
nested by dog, youth in the TF-CBT group not nested) will be employed to investigate 
the temporal trend and compare the trajectories of outcomes between the two groups 
using SAS PROC NLMIXED v. 9.4. Note that parameter estimates will be obtained using 
maximum likelihood estimation, and that p-values can be computed based on Chi-
square tests (Liang & Zeger, 1986). If missing data or dropouts occur, the mechanism 
(i.e., missing completely at random, missing at random) will be explored and adjusted 
for valid statistical inference. 
 
Analyses of categorical data (i.e., participant attrition, cancelled appointments, missed 
appointments without prior notice, and ability to implement TF-CBT techniques) will 
likely utilize descriptive and non-parametric methods (e.g., Fisher’s exact tests). 
Differences between the conditions for treatment satisfaction will be examined with 
parametric (e.g., between groups t-tests) or non-parametric 
analyses (Wilcoxon rank-sum tests). Given the small sample sizes and primary interest in 
a covariate effect, generalized estimating equations (GEE) can be used for the analysis of 
repeated cortisol assessments (Wang & Long, 2011). The GEE model with autoregressive 
(AR) working correlation structure can be fitted to investigate the difference of within 
session samples and between the treatment and control day samples. Three variables of 
interest are included: day of sample (0 = control; 1 = treatment), the session status (0 = 
presession; 1 = post-session; 2 = 20 minutes post-session), and their interaction. 

Modified variance estimators are calculated to reduce bias when sample sizes are small 
and t-tests are used for valid inference. The analysis will be conducted using the 
function of “geesmv” in R (Wang et al. 2016). Similar methods can be used for the 
analysis of canine heart rate variability and behavior. 
 
With regards to the ECG data, interrupted time series analyses can be used to analyze 
RSA from two time periods. The covariates of interest include time (in minutes) since 
the start of RSA assessment, the treatment group (0 = TF-CBT; 1 = TF-CBT+AAT), the 
time period (0 = phase prior to 
technique implementation; 1 = technique implementation), time (in minutes) since 
technique implementation, and the interactions of the last variables with the treatment 
group. The correlation among time series observations is represented in the error term. 
Residual plots can be used to detect the autocorrelation, where the Durbin–Watson 
statistic can be used. This model can be fitted by SAS PROC AUTOREG v. 9.4. Regression-
based mediational analyses can be conducted at each of the four assessment sessions to 
examine if therapeutic rapport mediates the relationship between the presence of the 
dogs and PTS outcomes. Bootstrap or Monte Carlo methods can be applied to testing 
significance of the indirect effect (Tofighi &MacKinnon, 2015). This model can be fitted 
using the PROCESS macro for SAS v. 9.4 (Hayes, 2013).