How the Data Were Organized
The PTSD-Repository contains over 300 variables. For ease of use, the variables are broken up into separate tables, each with a focus designed to “chunk” related variables together. The organization scheme for tables and coding rules—decisions made about variables and response items—are outlined below. Each of the tables also includes a series of repeated variables described below.
More detail about each of the tables is found on the “primer page” for each dataset—this includes a description, metadata and descriptions of column variables. There is also a table of abbreviations and a data dictionary that is linked to from each primer page.
Creating visualizations—a figure, chart or graph made from data in the PTSD-Repository—is a primary way to use this database. Users can easily create visualizations with variables from a single table. Visualizations can also be made from data in separate tables.
To read more about how to make use of the data, please see How to Work with the Data.
What Tables Are Included in the PTSD-Repository?
Study Characteristics. The Study Characteristics table includes basic information about study design. For example, each randomized controlled trial (RCT) is coded at the study level with respect to its study class. Study class was coded as pharmacotherapy, psychotherapy, complementary and integrative health (CIH), nonpharmacologic biological, nonpharmacologic cognitive, or collaborative care. If a study included more than one type of treatment (either within a single treatment arm or in different treatment arms) the study was coded as either psychotherapy and pharmacotherapy, psychotherapy and CIH or other mixed. Other variables in this table include clinical setting, whether the study looked at PTSD symptom clusters, whether there were any subgroup analyses, and provider credentials. Use this table to better understand the variety of RCT designs employed, compare studies by treatment type or to identify gaps in the literature for potential new RCTs. Visualizations made from this table will be based on the 318 RCTs included in the PTSD-Repository.
Sample Characteristics. The Sample Characteristics table includes information on the participants who are included in the studies. This information is provided at the study level—meaning, data are not broken down into the specific treatment arms such as the intervention or control groups. Use this table if you want to learn more about the number of participants in the study; baseline clinical characteristics such as PTSD severity, trauma type, and comorbidities; and, basic demographic information such as age, gender, or race. Visualizations made from this table will be based on the 318 RCTs included in the PTSD-Repository and answer questions such as Who Has Been Studied.
Study Interventions. The Study Interventions table includes information about each of 706 specific treatment arms that were studied in all 318 RCTs. Within each study, there are arms for each intervention and comparison group. Each intervention arm was coded to indicate whether it included pharmacotherapy (as well subclass such as antidepressant, antianxiety, etc.), psychotherapy (as well as a subclass to identify trauma-focused or non-trauma-focused therapy), complementary and integrative health (CIH), nonpharmacologic biological, nonpharmacologic cognitive, collaborative care, or control. Some helpful tips:
- If an intervention arm included more than one type of treatment, both treatment types were coded. For example, a treatment arm that includes the psychotherapy Cognitive Processing Therapy (CPT) and the CIH intervention, relaxation, was coded as both psychotherapy and CIH.
- Users of the PTSD-Repository are cautioned that if they create a visualization based on a specific treatment type, it could include some other treatments as well.
- If users want to identify treatment arms that only include one specific type of treatment they can limit the studies by first selecting those from the Study Class variable that focuses on the type of treatment of interest (e.g., selecting Psychotherapy as treatment class would ensure that a CPT plus relaxation study would not be included because it would have been coded as “Psychotherapy and CIH”) or by reviewing the treatment arms that are identified by searching psychotherapy and then omitting those that have another type of treatment indicated as well.
- For more on how to drill deeper into the data read Working with the Data.
The Study Intervention table includes information on the format of the treatment (individual, group, couples, mixed); treatment delivery method (in person, by phone, by video, technology alone, technology assisted, written, or mixed); dose or amount of treatment and, treatment completion and adherence. Use this table to learn about number of treatment studies of a particular type.
PTSD Outcomes Within Each Treatment Arm. The PTSD Outcomes Within Each Treatment Arm table includes information on how PTSD was measured at baseline, during treatment and at completion and follow-up. Descriptive information is provided on what measure was used, the statistical approach to measuring change in PTSD, how PTSD was defined and the definition of loss of diagnosis and clinically meaningful change if these variables were included in the study. Results in this table are provided for each treatment arm, and do not include comparisons across the arms. PTSD baseline mean score and standard deviation are provided as well as the within treatment change from baseline. Within group effect size is also included. The percent of participants who achieve loss of PTSD diagnosis and the percent who achieve clinically meaningful response are included for studies that reported these outcomes. Use this table to learn about changes in PTSD resulting from a specific treatment. For example, what is the change in Clinician Administered PTSD Scale score across all trials of a specific treatment type? From the visualization, you can filter by PTSD measure of interest and type of treatment.
PTSD Outcome Comparisons Across Treatment Arms. The PTSD Outcome Comparisons Across Treatment Arms table includes the results of all between-group comparisons on PTSD outcomes. The omnibus test and effect size are provided, followed by pairwise comparisons for any study with more than two treatment arms. Results are provided for PTSD severity, loss of diagnosis and clinically meaningful change for studies that reported these outcomes. Use this table to compare changes in PTSD resulting from two or more treatments.
Other Outcomes. The Other Outcomes table includes information on whether the trial includes measures of depression, anxiety, substance use, sleep, anger, quality of life, and functioning. Results in this table are provided for each treatment arm. The name of the measure is included as well as the between-group effect sizes. Use this table to learn how about the effects of PTSD treatments on other outcomes.
Study Comments. This table includes information from the study abstractors on variables or methodological decisions that may have been reported or handled in a non-standardized way by the study authors. Every study does not have a comment.
What Are Repeated Variables?
Repeated variables include a subset of variables that generally describe the treatment and sample that are included in all of the tables. Having some variables repeated means that it is easier to create visualizations that include these variables. When data are reported at the study level, the variables that repeat are:
- Study ID -- Each RCT has a unique study identification (ID) based on the author name and date (i.e., AuthorXXXX). If an author has two or more studies published in the same year, a lower-case letter is used to distinguish between the two studies (i.e., AuthorXXXXa and AuthorXXXb). For tables that include data at the treatment arm level, each arm is identified with a capital letter separated by an underscore (i.e., AuthorXXXX_A, AuthorXXXX_B). Each assessment time point is indicated with a number separated by an underscore (i.e., AuthorXXXX_A_1 and AuthorXXXX_A_2). Finally, each study is coded with an underscore of “I” to identify if the analyses are intention to treat or “C” to indicate completer analyses (i.e., AuthorXXXX_A_1_I and AuthorXXX_A_1_C).
- Study Class -- Each RCT is coded at the study level as Pharmacotherapy, Psychotherapy, Complementary and Integrated Health (CIH), Nonpharmacologic Biologic, Nonpharmacologic Cognitive, and Collaborative Care, Psychotherapy and Pharmacotherapy, Psychotherapy and Complementary and Integrated Health (CIH), and Other Mixed. For more information, see Study Intervention Table description above.
- Total N Randomized
- Military Status
- Female, Percent
- Male, Percent
- Trauma Type
When data are reported by treatment arm, the variables that repeat are:
- Arm N Randomized
- Treatment Name – The treatment name as reported by the RCT.
- NCPTSD Treatment Name -- To standardize the data, National Center for PTSD staff redefined some of the study treatment names. For example, a treatment called “treatment as usual” was coded as “supportive counseling” because the treatment description made it clear that all participants received supportive counseling in that arm and a treatment called “cognitive restructuring” was coded as “trauma-focused cognitive behavioral therapy” because the treatment description made it clear that there were behavioral components in the therapy as well.
- Psychotherapy subclass – Coded as trauma-focused or non-trauma-focused
- Pharmacotherapy subclass -- Coded as Antidepressant: Selective serotonin reuptake inhibitor (SSRI); Antidepressant: Serotonin-norepinephrine reuptake inhibitor (SNRI; Antidepressant: Tricyclic antidepressant (TCAs); Antidepressant: Monoamine oxidase inhibitors (MAOI); Antiadrenergic; Antianxiety: Benzodiazepine; Antianxiety: nonbenzodiazepine; Phytocannabinoid; Synthetic cannabinoid; Mood stabilizer; Psychostimulants; Steroids; other
- Complementary and Integrated Health
- Nonpharmacologic Biologic
- Nonpharmacologic Cognitive
- Collaborative Care
- Format: group, individual, couples or mixed
- Delivery Method: in person, by phone, by video, technology alone, technology assisted, written, or mixed