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Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder
Thesis (PhD)--Stellenbosch University, 2025.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614124952780800 |
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| access_status_str | Open Access |
| author | Wright, Simonne Lesley |
| author2 | Seedat, Soraya |
| author_browse | Seedat, Soraya Wright, Simonne Lesley |
| author_facet | Seedat, Soraya Wright, Simonne Lesley |
| author_sort | Wright, Simonne Lesley |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/134418 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:47:03.084Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/134418 Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder Wright, Simonne Lesley Seedat, Soraya Sijbrandij, Marit Karyotaki, Eirini Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Psychiatry. Thesis (PhD)--Stellenbosch University, 2025. Wright, S. L. 2025. Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder. Unpublished doctoral thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/f2a7640b-6fcc-4e4d-ac69-721576b826c8 Posttraumatic stress disorder (PTSD) is a pervasive and debilitating mental health condition arising from exposure to traumatic events. Despite advancements in treatment, challenges persist in identifying which therapeutic approaches are most effective for specific patient subgroups and in understanding factors that contribute to treatment dropout. This dissertation addresses these issues through a series of systematic reviews and individual participant data (IPD) meta-analyses of psychological and pharmacological treatments for PTSD. This research was a collaborative effort between Stellenbosch University and Vrije Universiteit to develop a comprehensive database of randomized control trials (RCTs) on PTSD treatments. The primary objectives were to identify demographic, clinical, and psychological predictors and moderators of treatment outcomes, and to explore adverse effects, particularly study dropout. In the first study, I conducted a detailed examination of the efficacy of eye movement desensitization and reprocessing (EMDR) and cognitive-behavioral therapy with a trauma focus (CBT-TF) using IPD meta-analyses across eight studies (n = 346). Findings revealed no significant differences in PTSD symptom severity (β = −0.24), treatment response (β = 0.86), remission rates (β = 1.05), and study dropout (β = −0.25) between EMDR and other psychological treatments. Moderator analyses found unemployed participants had higher PTSD symptom severity post-treatment than employed (β = 0.80), and males were more likely to drop out than females (β = 0.23) receiving EMDR. In the second study, I conducted a systematic review and IPD meta-analyses to evaluate the efficacy of 12 studies comparing CBT-TF to inactive treatments (n = 625), as well as 11 studies comparing CBT-TF to active treatments (n =706). The analysis focused on identifying participant-level factors that might moderate the effectiveness of CBT-TF against both inactive and active comparison groups independently. Results indicated participants receiving CBT-TF had significantly lower PTSD symptom severity (β = −0.78) and higher PTSD remission (OR = 2.34) post-intervention than inactive comparison groups such as waiting list control, treatment-as-usual, and CBT for substance use disorder. When comparing CBT-TF to inactive treatments, moderator analysis found that divorced participants who received CBT-TF had greater PTSD symptoms post-intervention than participants who were single, cohabitating, or married and received CBT-TF (β = 0.93). Furthermore, no significant difference in PTSD symptom severity (β = 0.02) and PTSD remission (OR = 0.53) was found between participants receiving CBT-TF and the active comparison groups post-intervention. In the active treatment comparison, moderator analysis found that participants taking psychotropic medication had lower PTSD symptoms than those not taking psychotropic medication following CBT-TF (β = −0.39). In the third study, I investigated predictors of study dropout in CBT-TF in 28 CBT-TF intervention groups from 25 studies (n = 823). Results indicated that overall, 221 (27%) of the 823 dropped out. Of 581 civilians, 133 (23%) dropped out, as did 75 (42%) of 178 military personnel/veterans. Bivariate and multivariate analyses indicated that military personnel/ veterans (RR 2.37) had a significantly greater risk of dropout than civilians. Furthermore, the chance of dropping out significantly decreased with advancing age (continuous; RR 0.98). In the last study, I first examined dropout rates between drug and placebo groups through a conventional meta-analysis of 43 RCTs (n = 4,829). Results indicated that although the dropout rate in the drug group was marginally less than in the placebo group, the difference was not statistically significant (RR = 0.92). Subgroup analyses and meta-regression indicated that dropout rates were not associated with drug class, dosing regimen, population characteristics, study duration, or gender composition. Additionally, I explored participant-level predictors of dropout across drug, placebo, and combined groups, using data pooled from three RCTs (n = 246). Results indicated no significant difference in dropout rates between the drug and placebo groups (p = .617). Gender emerged as a significant predictor of study dropout in the drug group analyses only, with males showing higher dropout rates (p = .046). However, when baseline PTSD symptom severity was controlled for, gender was no longer a statistically significant (p = .051). In summary, this doctoral study utilized IPD meta-analyses to assess PTSD treatment outcomes across various demographic and clinical subgroups, offering nuanced insights into the efficacy of EMDR and CBT-TF, and identifying key factors that influence treatment retention. The findings have important implications for optimizing PTSD treatment strategies and highlight the necessity of personalized treatment approaches. Moreover, this research contributes to the growing body of evidence needed to enhance global PTSD treatment practices, with a specific focus on addressing high-risk subgroups and improving patient outcomes. Doctoral 2025-11-20T12:08:33Z 2025-11-20T12:08:33Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/134418 en Stellenbosch University 338 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Wright, Simonne Lesley Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title | Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title_full | Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title_fullStr | Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title_full_unstemmed | Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title_short | Individual Patient Data Meta-Analysis for Posttraumatic Stress Disorder |
| title_sort | individual patient data meta analysis for posttraumatic stress disorder |
| url | https://scholar.sun.ac.za/handle/10019.1/134418 |
| work_keys_str_mv | AT wrightsimonnelesley individualpatientdatametaanalysisforposttraumaticstressdisorder |