Results
DSM-5, traumatic stress disorder, Anxiety, DSM-5 PTSD, Trait-State, post-traumatic stress disorder, PTSD, Insomnia, OCD, obsessive-compulsive disorder, trauma
DISORDERS, EVENT, SCID, MINOR, SECONDARY, EVENTS
Participants were recruited between Jan 15, 2018, and March 31, 2020. 348 patients were assessed for eligibility, of whom 242 were eligible and 217 consented to participate. Of those 217 participants, 92 (42%) were randomly assigned to iCT-PTSD, 93 (43%) were randomly assigned to iStress-PTSD, and 32 (15%) were randomly assigned to waiting list with usual care (CONSORT flow diagramiCT-PTSD=internet-delivered cognitive therapy for PTSD. iStress-PTSD=internet-based stress management therapy for PTSD. NHS=National Health Service. PTSD=post-traumatic stress disorder.Of the 217 participants who were randomly assigned, 158 (73%) were female, 57 (26%) were male, and two (1%) had another gender; 170 (78%) were White (British), 20 (9%) were White (other), six were Asian (3%), ten (5%) were Black, eight (4%) had a mixed ethnic background, and three (1%) had another ethnic background (Demographics and trauma characteristicsData are mean (SD) or n (%). AUDIT=Alcohol Use Disorders Identification Test. iCT-PTSD=internet-delivered cognitive therapy for PTSD. iStress-PTSD=internet-based stress management therapy for PTSD. ITQ=international trauma questionnaire. LEC=Life Events Checklist. NHS=National Health Service. OCD=obsessive-compulsive disorder. PTSD=post–traumatic stress disorder. SAPAS=Structured Assessment of Personality Abbreviated Scale. SCID=Structured Clinical Interview for DSM-5. TSDQ=Trait-State Dissociation Questionnaire.Treatment fidelity was excellent, with only two minor deviations identified by the raters across recordings from 207 participants, both of which concerned using specific cognitive therapy techniques in the iStress-PTSD condition. Therapist competence within phone calls and messages was rated as high (on a scale of 0 to 6) for both iCT-PTSD (mean 5·49 [SD 0·49], n=104) and iStress-PTSD (mean 5·49 [SD 0·43], n=103) groups. Participant compliance was high, and ratings of treatment credibilityThe primary intention-to-treat analysis, which included the 185 participants immediately allocated to treatment, showed that iCT-PTSD was superior to iStress-PTSD with an adjusted difference on the PCL-5 of –4·92 (95% CI –8·92 to –0·92; Adjusted mean differences between iCT-PTSD and iCT-Stress for the primary and sensitivity analyses of PTSD symptoms assessed at 13 weeksPTSD symptoms were assessed with the self-reported PCL-5. ITT analysis includes all available data for immediate allocation, controlled for baseline PCL-5, months since the trauma (log), and site. Covariates analysis is the same as ITT but with a variable predicting missing data as an additional covariate (SAPASBoth treatments were superior to the waiting list control on the PCL-5 at 13 weeks; the adjusted difference compared with the waiting list were 20·98 points (95% CI 15·50–26·45) for iCT-PTSD (Across outcomes, iCT-PTSD and iStress-PTSD led to similar improvements across measures up to the 6-week assessment (Comparisons between iCT-PTSD and iStress-PTSD on the primary and secondary outcome measures (intention-to-treat analysis)The table shows the observed unadjusted means for each group. All statistics are based on intent-to-treat analyses using linear mixed-effect models. Within-group effect sizes represent change from baseline in each group. Adjusted mean differences based on linear mixed-effects models adjusted for baseline scores and stratification variables. Standardised effect sizes calculated using the baseline SD of whole sample. CAPS-5=Clinician-Administered PTSD Scale for DSM-5. GAD-7=General Anxiety Disorder-7. iCT-PTSD=internet-delivered cognitive therapy for PTSD. iStress-PTSD=internet-based stress management therapy for PTSD. IES-R=Impact of Event Scale-Revised. ISI=Insomnia Severity Index. PCL-5=PTSD Checklist for DSM-5. PHQ-9=9-question Patient Health Questionnaire. PTSD=post–traumatic stress disorder. Q-LES-Q=Quality of Life Enjoyment and Satisfaction Questionnaire. WHO-5=World Health Organization Five Well-Being Index. WSAS=Work and Social Adjustment Scale.The IAPT Patient Experience QuestionnaireDuring follow-up (39 weeks and 65 weeks), iCT-PTSD remained superior to iStress-PTSD across all outcome measures, and there continued to be no difference in sleep quality (A priori established dichotomous outcome criteria were based on those commonly reported in the literature and national statistics for IAPT services. At 13 weeks, the intention-to-treat rate for clinically significant change on the PCL-5 (ie, a decrease of ≥10 points and post-treatment scores >2 SD below the group baseline score)Dichotomous criteria for improvement and deterioration: outcomes for iCT-PTSD and iStress-PTSD (all allocations)CAPS-5=Clinician-Administered PTSD Scale for DSM-5. IAPT=Improving Access to Psychological Therapies. iCT-PTSD=internet-delivered cognitive therapy for PTSD. iStress-PTSD=internet-based stress management therapy for PTSD. ITT=intention-to-treat. PCL-5=PTSD Checklist for DSM-5. PHQ-9=9-item Patient Health Questionnaire. PTSD=post–traumatic stress disorder.Defined as a reliable change of ≥10 points on the PCL-5 and a score lower than 2 SDs below the mean of treatment sample at baseline.Defined as scoring ≤10 points on the PCL-5 and calculated for participants with available data.Defined as worsening by ≥5 points on the PCL-5 and calculated for participants with available data.Defined as meeting all DSM-5 PTSD criteria with a threshold of 2 points for symptoms and interference ratings on CAPS-5 items, and calculated for participants with available data.Defined as having ≤10 points on CAPS-5 and calculated for participants with available data.Defined as worsening by ≥5 points on the CAPS-5 and calculated for participants with available data.Scoring according to the IAPT manualScoring according to the IAPT manualScoring according to the IAPT manualModeration analyses showed that for participants with high dissociation and those meeting self-reported criteria for complex PTSD,