Efficacy of Internet-delivered Cognitive-behavior Therapy for PTSD

The CAPS-5 is structured interview that assesses the Diagnostic and Statistical Manual of Mental Disorders version 5 (DSM-5) criteria for PTSD (Weathers et al., 2013). Each item is rated on a severity scale ranging from 0 (Absent) to 4 (Extreme/incapacitating) and combines information about frequency and intensity for each of the 20 symptoms. Total Score (Range 0-80 with higher scores representing more PTSD symptoms.

The PCL-5 is a 20-item self-report measure based upon the Diagnostic and Statistical Manual (DSM-5) criteria for PTSD. Total Score (Range 0-80 with higher scores representing more PTSD symptoms.

The ITQ includes six items measuring each PTSD symptom cluster and these items measure how bothersome each symptom has been in the past month. The ITQ also includes six items measuring each 'Disturbance in Self-Organization' (DSO) symptom in complex PTSD. These items measure how a respondent typically feels, thinks about oneself, and relates to others. The PTSD and DSO symptoms are accompanied by three items measuring associated functional impairments in the domains of social, occupation, and other important areas of life. All items are answered on a 5-point Likert scale ranging from 0 (Not at all) to 4 (Extremely). Thus, PTSD and DSO symptom scores range from 0 to 24 and CPTSD symptom scores range from 0 to 48. Higher scores represents more PTSD and complex PTSD symptoms.

The PHQ-9 is a widely used and well-validated instrument for measuring the severity of depressive symptoms. Scores are calculated based on how frequently a person experiences 9 symptoms of depression ranging from "not at all" response is scored as 0; "several days" response is 1; "more than half the days" response is 2; and "nearly every day" response is 3. Higher scores represents more depressive symptoms.

Change in overall health from baseline to post treatment and follow up . EQ-5D is a standardized self-report measure of overall health status measured in terms of five dimensions; mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Mobility dimension asks about the person's walking ability. Self-care dimension asks about the ability to wash or dress by oneself, and usual activities dimension measures performance in "work, study, housework, family or leisure activities". In pain/discomfort dimension, it asks how much pain or discomfort they have, and in anxiety/depression dimension, it asks how anxious or depressed they are. The respondents self-rate their level of severity for each dimension using a three-level scale: 1 having no problems, 2 having some problems and 3 having extreme problems. A higher score indicate worse severity.

Used to assess cost-effectiveness. 20 questions that assess different aspects of quality of life. The AQoL provides a utility score that ranges from 1.00 (full health) to 0.00 (death-equivalent health states) to -0.04 (health states worse than death.

Self-rated questionnaire on healthcare utilization and productivity losses in patients with a psychiatric disorder. The TIC-P questionnaire measures costs in two dimensions: use of health resources and loss of productivity. Lower cost is better.

Self-rated questionnaire on negative effects. It contains 32 items that are scored on a five point Likert-scale (0-4) and differentiates between negative effects that are attributed to treatment and those possibly caused by other circumstances. The total score of the NEQ ranges from 0 to 80 points, a higher score reflects more negative effects.

The CSQ-8 yields a single score measuring a single dimension of overall satisfaction. An "overall score" is calculated by summing the score on each of the eight scale item. Scores range from 8 to 32, with higher values indicating higher satisfaction.

Data will be gathered on total number of completed modules during the 10 week treatment.

Data will be gathered on total number of messages sent and received back and forth between the participant and the therapist during the 10 week treatment.

Measures treatment expectancy and rationale credibility. The CEQ is a 5-item measure of the treatment's credibility and the patients' expectations. The patients assess each domain on a 11-point likert scale (scored 0-10), with a total score ranging between 0-50 where higher score indicates higher credibility and higher expectations.

Measures the therapeutic alliance in therapy. The WAI-SR is a 12-item measure of the patient's experience of their working alliance with the therapist. The patients assess each item on a 7-point likert scale (scored 0-6), with a total score ranging between 0-72 where higher score indicates higher better working alliance according to the patient.