Browsing by Author "Schnyder, Ulrich"

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    Application of data pooling to longitudinal studies of early post-traumatic stress disorder (PTSD) : the International Consortium to Predict PTSD (ICPP) project
    (Taylor & Francis Open, 2018) Qi, Wei; Ratanatharathorn, Andrew; Gevonden, Martin; Bryant, Richard; Delahanty, Douglas; Matsuoka, Yutaka; Olff, Miranda; DeRoon-Cassini, Terri; Schnyder, Ulrich; Seedat, Soraya; Laska, Eugene; Kessler, Ronald C.; Koenen, Karestan; Shalev, Arieh
    Background: Understanding the development of post-traumatic stress disorder (PTSD) is a precondition for efficient risk assessment and prevention planning. Studies to date have been site and sample specific. Towards developing generalizable models of PTSD development and prediction, the International Consortium to Predict PTSD (ICPP) compiled data from 13 longitudinal, acute-care based PTSD studies performed in six different countries. Objective: The objectives of this study were to describe the ICPP’s approach to data pooling and harmonization, and present cross-study descriptive results informing the longitudinal course of PTSD after acute trauma. Methods: Item-level data from 13 longitudinal studies of adult civilian trauma survivors were collected. Constructs (e.g. PTSD, depression), measures (questions or scales), and time variables (days from trauma) were identified and harmonized, and those with inconsistent coding (e.g. education, lifetime trauma exposure) were recoded. Administered in 11 studies, the Clinician Administered PTSD Scale (CAPS) emerged as the main measure of PTSD diagnosis and severity. Results: The pooled data set included 6254 subjects (39.9% female). Studies’ average retention rate was 87.0% (range 49.1–93.5%). Participants’ baseline assessments took place within 2 months of trauma exposure. Follow-up durations ranged from 188 to 1110 days. Reflecting studies’ inclusion criteria, the prevalence of baseline PTSD differed significantly between studies (range 3.1–61.6%), and similar differences were observed in subsequent assessments (4.3–38.2% and 3.8–27.0% for second and third assessments, respectively). Conclusion: Pooling data from independently collected studies requires careful curation of individual data sets for extracting and optimizing informative commonalities. However, it is an important step towards developing robust and generalizable prediction models for PTSD and can exceed findings of single studies. The large differences in prevalence of PTSD longitudinally cautions against using any individual study to infer trauma outcome. The multiplicity of instruments used in individual studies emphasizes the need for common data elements in future studies.
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    Correction to: Evaluating a screener to quantify PTSD risk using emergency care information : a proof of concept study
    (BMC (part of Springer Nature), 2020-06-29) Van Der Mei, Willem F.; Barbano, Anna C.; Ratanatharathorn, Andrew; Bryant, Richard A.; Delahanty, Douglas L.; deRoon-Cassini, Terri A.; Lai, Betty S.; Lowe, Sarah R.; Matsuoka, Yutaka J.; Olff, Miranda; Qi, Wei; Schnyder, Ulrich; Seedat, Soraya; Kessler, Ronald C.; Koenen, Karestan C.; Shalev, Arieh Y.
    An amendment to this paper has been published and can be accessed via the original article.
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    Evaluating a screener to quantify PTSD risk using emergency care information : a proof of concept study
    (BMC (part of Springer Nature), 2020-03-02) Van der Mei, Willem F.; Barbano, Anna C.; Ratanatharathorn, Andrew; Bryant, Richard A.; Delahanty, Douglas L.; DeRoon-Cassini, Terri A.; Lai, Betty S.; Lowe, Sarah R.; Matsuoka, Yutaka J.; Olff, Miranda; Qi, Wei; Schnyder, Ulrich; Seedat, Soraya; Kessler, Ronald C.; Koenen, Karestan C.; Shalev, Arieh Y.
    Background: Previous work has indicated that post-traumatic stress disorder (PTSD) symptoms, measured by the Clinician-Administered PTSD Scale (CAPS) within 60 days of trauma exposure, can reliably produce likelihood estimates of chronic PTSD among trauma survivors admitted to acute care centers. Administering the CAPS is burdensome, requires skilled professionals, and relies on symptoms that are not fully expressed upon acute care admission. Predicting chronic PTSD from peritraumatic responses, which are obtainable upon acute care admission, has yielded conflicting results, hence the rationale for a stepwise screening-and-prediction practice. This work explores the ability of peritraumatic responses to produce risk likelihood estimates of early CAPS-based PTSD symptoms indicative of chronic PTSD risk. It specifically evaluates the Peritraumatic Dissociative Experiences Questionnaire (PDEQ) as a risk-likelihood estimator. Methods: We used individual participant data (IPD) from five acute care studies that used both the PDEQ and the CAPS (n = 647). Logistic regression calculated the probability of having CAPS scores ≥ 40 between 30 and 60 days after trauma exposure across the range of initial PDEQ scores, and evaluated the added contribution of age, sex, trauma type, and prior trauma exposure. Brier scores, area under the receiver-operating characteristic curve (AUC), and the mean slope of the calibration line evaluated the accuracy and precision of the predicted probabilities. Results: Twenty percent of the sample had CAPS ≥ 40. PDEQ severity significantly predicted having CAPS ≥ 40 symptoms (p < 0.001). Incremental PDEQ scores produced a reliable estimator of CAPS ≥ 40 likelihood. An individual risk estimation tool incorporating PDEQ and other significant risk indicators is provided. Conclusion: Peritraumatic reactions, measured here by the PDEQ, can reliably quantify the likelihood of acute PTSD symptoms predictive of chronic PTSD and requiring clinical attention. Using them as a screener in a stepwise chronic PTSD prediction strategy may reduce the burden of later CAPS-based assessments. Other peritraumatic metrics may perform similarly and their use requires similar validation.
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    Screening for consequences of trauma – an update on the global collaboration on traumatic stress
    (Taylor & Francis, 2020) Olff, Miranda; Bakker, Anne; Frewen, Paul; Aakvaag, Helene; Ajdukovic, Dean; Brewer, Douglas; Elmore Borbon, Diane L.; Cloitre, Marylene; Hyland, Philip; Kassam-Adams, Nancy; Knefel, Matthias; Lanza, Juliana A.; Lueger- Schuster, Brigitte; Nickerson, Angela; Oe, Misari; Pfaltz, Monique C.; Salgado, Carolina; Seedat, Soraya, 1966-; Wagner, Anne; Schnyder, Ulrich
    This letter provides an update on the activities of “The Global Collaboration on Traumatic Stress” (GC-TS) as first described by Schnyder et al. in 2017. It presents in further detail the projects of the first theme, in particular the development of and initial data on the Global Psychotrauma Screen (GPS), a brief instrument designed to screen for the wide range of potential outcomes of trauma. English language data and ongoing studies in several languages provide a first indication that the GPS is a feasible, reliable and valid tool, a tool that may be very useful in the current pandemic of the coronavirus disease 2019 (COVID-19). Further multi-language and cross-cultural validation is needed. Since the start of the GC-TS, new themes have been introduced to focus on in the coming years: a) Forcibly displaced persons, b) Global prevalence of stress and trauma related disorders, c) Socio-emotional development across cultures, and d) Collaborating to make traumatic stress research data “FAIR”. The most recent theme added is that of Global crises, currently focusing on COVID-19-related projects.