How are the data organized?

The PTSD Repository contains over 300 variables extracted from randomized controlled trials (RCTs) of PTSD treatments published through February 2023. It continues to be updated annually.
For ease of use, the variables are broken up into separate tables (called datasets), each with a focus designed to “chunk” related variables together.
Each dataset is organized at either the study level or the arm level.  Study-level datasets correspond to the overall study, whereas arm-level datasets correspond to each specific treatment condition in the study. For example, an RCT might be classified at the study-level as a psychotherapy study and at the arm level as having a Prolonged Exposure (PE) arm, a Cognitive Processing Therapy (CPT) arm, and a treatment as usual arm. Users are cautioned to pay attention to whether tables are organized at the study or arm level. To help, we include information on the primer page for each dataset that identifies if each row is a "study" or an arm (listed as "intervention group in a study". See below for examples.
The organization scheme for tables and coding rules—decisions made about variables and response items—are outlined below. Each of the datasets also includes a series of repeated variables—the variables included in every dataset (also described below).

Understanding Study ID

Each dataset in the PTSD Repository starts with a unique Study ID that helps the user understand key aspects of the study they are viewing. The Study ID always begins with the first author's name and year that the study was published (i.e., AuthorXXXX). If an author has 2 or more studies published in the same year, a lower-case letter is used to distinguish between the studies (i.e., AuthorXXXXa and AuthorXXXXb). 
In datasets that include arm-level data, Study ID may also include additional specifiers such as: measure name, intervention arm (or intervention arms being compared), assessment timepoint, and the analysis type. Specifically:
  • Measure name: In the outcome datasets, an abbreviation of the measure name is included to differentiate outcomes associated with different measures (i.e., AuthorXXXX_CAPS and AuthorXXXX_PCL). A list of measure abbreviations can be found in the Abbreviations dataset. 
  • Intervention arm: Each treatment arm is identified with a capital letter separated by an underscore (i.e., AuthorXXXX_A, AuthorXXXX_B). For datasets that include between-groups data analysis in which the conditions are compared, this could also look like AuthorXXXX_CAPS_AvB (i.e., condition A versus B).
  • Assessment timepoint: Each assessment time point is indicated with a number separated by an underscore. Timepoints are either coded as “baseline” or represent the number of weeks post-treatment where “0” represents immediate posttreatment (i.e., AuthorXXXX_A_Baseline, AuthorXXXX_A_0, and AuthorXXXX_A_4).  
  • Analysis type: Each study is coded with an underscore of “ITT” to identify if the analyses are intention to treat (i.e., include all participants who were randomized) or “Comp” to indicate completer analyses in which only people who completed the treatment are included (i.e., AuthorXXXX_A_1_ITT and AuthorXXXX_A_1_Comp).
Important Note: Datasets organized at the arm level have multiple rows per study based on the study characteristics above. For example, a study that compares PE to CPT would have at least 2 rows corresponding to the 2 treatment arms.  If there were 2 different measures (e.g., an interview and a self-report) administered to participants within 2 treatment arms, there would be 2 rows for each measure for each arm—equating to 4 total rows. If participants were measured at 2 different timepoints, that would add 2 more rows, etc. When creating visualizations, users are cautioned to be aware of occurrences in which individual studies may be contributing more than one data point (i.e. multiple arms of the same study included).

Understanding Treatment Codes

The RCTs in the PTSD Repository are organized in several ways to allow users to identify and sort those studies that interest them most. 
Data are organized at the study level by Treatment focus (i.e., PTSD or PTSD plus substance use disorder [SUD]) and Study class that indicates the type of treatment studied. Then, treatments are coded at the arm level by Treatment focus, Study class subcode and Treatment name. See below for more detail. 
Treatment Focus (study level)
Each RCT in the PTSD Repository is coded as being a study that is focused on PTSD or on both PTSD and SUD (PTSD+SUD). PTSD+SUD studies are treatment studies that are designed to target both PTSD symptoms and SUD symptoms. Studies that are coded as PTSD+SUD also have a subclass code for each arm to indicate whether the treatments are integrated or not integrated. Users can choose to access all studies in dataset or limit results to PTSD studies or PTSD+SUD studies by using a filter. 
Treatment Focus (Arm level)
Each arm in the PTSD Repository is coded as being focused on PTSD, SUD, both PTSD and SUD (PTSD+SUD), active control, or inactive control.
  • PTSD+SUD arms include interventions that target both PTSD and SUD within a single arm.
  • Active control arms are those where a treatment is offered that is designed to have some positive effect but not as strong as the intervention it is being compared to.
  • Inactive control arms offer no treatment (e.g., waitlist) or only a treatment that is not designed to help mental health symptoms (e.g., an educational intervention).
Study Class (study level)
Each RCT is coded with regard to 8 study classes:
  • Pharmacotherapy
  • Psychotherapy
  • Complementary and Integrative Health (CIH)
  • Nonpharmacologic Biological
  • Nonpharmacologic Cognitive
  • Collaborative Care
  • Other Study Class
  • Control
There are 3 additional study classes. If a study included more than one type of active treatment (either within a single treatment arm or in different treatment arms), the study was coded as:
  • Psychotherapy & pharmacotherapy
  • Psychotherapy & CIH
  • Other Mixed
Study Class Subcodes (arm level)
To help users view data by different types of treatments, the specific treatment arms are further classified into subtypes. See our Reference Guide: Treatments Found in the PTSD Repository for more information about the organization of treatments.
  • 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 (TCA); Antidepressant: Monoamine oxidase inhibitors (MAOI); Antidepressant: Other; Antiadrenergic; Antipsychotic; Antianxiety: benzodiazepines; Antianxiety: nonbenzodiazepines; Phytocannabinoid; Mood stabilizer; Psychostimulant; Steroids; Other pharmacotherapy; Mixed
  • Complementary and Integrative Health (CIH) subclass: Coded as Acupuncture; Clinical hypnosis; Meditation; Massage therapy; Tai chi/qi gong; Yoga; Energy therapies; Natural products; Creative therapies; Relaxation; Spirituality; Other CIH
If a treatment arm included more than one type of treatment, both treatment types were coded in separate variables. These dichotomous variables are labeled according to the same study class categories noted above. For example, a treatment arm that includes the psychotherapy CPT and the CIH intervention, relaxation, was coded as both psychotherapy (Psychotherapy = yes) and CIH (CIH = yes).
  • Because of this nuance, PTSD Repository users are cautioned that if they create a visualization based on a specific treatment type using the individual treatment type variables like Psychotherapy or Pharmacotherapy, in a few cases 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 filtering 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.
Treatment Name (arm level)
Treatments are assigned 2 types of names: the name used by the investigators in the research (Treatment Name) and the standardized National Center for PTSD (Standardized Treatment Name), which applies more consistent names across treatments to allow for easier identification and comparison of treatments. Most users of the PTSD Repository will likely find the Standardized Treatment Name to be the one they want to use.

What datasets are included in the PTSD Repository?

An easy way to locate a dataset is to select the “Data Catalog” button in the top navigation (menu icon on the left). If you are not signed in, look for the “Browse” button on the top left. Then, in the Data Catalog, use the left navigation or filter, select "View Types" and choose “Datasets.”
Below is a short description of all datasets included in the PTSD Repository. Click the dataset name to go to the primer page which provides information about the dataset, a full list and description of variable columns, and metadata (keywords or phrases used to describe, tag or organize the data).  Included in the description is information about whether the data are organized at the study or arm level.
Study Characteristics (study level).  The Study Characteristics dataset includes basic information about study design. In addition to study class (defined above), the dataset includes clinical setting, whether the study looked at PTSD symptom clusters, whether there were any subgroup analyses, type of diagnostic measure used (e.g., diagnostic interview, self-report), and provider credentials. Use this dataset to better understand the variety of RCT designs employed, compare studies by study class or to identify gaps in the literature for potential new RCTs. Visualizations made from this dataset will be based on the 496 RCTs included in the PTSD Repository.
Sample Characteristics (study level). The Sample Characteristics dataset 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 dataset if you want to learn more about the number of participants in the study; inclusion and exclusion criteria related to substance use and suicidality; baseline clinical characteristics such as PTSD severity, trauma type, military status, and comorbidities; and basic demographic information such as age, gender or race for the sample as a whole. Visualizations made from this table will be based on the 496 RCTs included in the PTSD Repository and answer questions such as  Who Has Been Studied.
Study Interventions (arm level). The Study Interventions dataset includes information about each of 1094 specific treatment arms that were studied in all 496 RCTs. Each study arm was coded to indicate the type of intervention or comparison condition. Download our Reference Guide: Treatments Found in the PTSD Repository. This dataset includes the study-level Study Class as well as individual variables for each category of treatment, coded as Yes or No for each arm. Study arm treatment category variables are as follows:
  • Pharmacotherapy (as well as a 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; as well as a subclass such as relaxation or meditation)
  • Nonpharmacologic Biological
  • Nonpharmacologic Cognitive
  • Collaborative Care
  • Other Study Class
  • Control
The Study Intervention dataset also 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 dataset to learn about treatment studies of a particular type, including our story, Which PTSD treatments have been studied?
Datasets related to PTSD outcomes (arm level). There are 4 PTSD outcome datasets. Data is reported separately for continuous and dichotomous outcome measures.  Datasets are further categorized as to whether the comparisons are made within or between arms. 
  • PTSD Continuous Outcomes Within Arms. This dataset provides within-arm results for continuous measures. Included is information on score means and variance, and pre-post comparisons (pre-post score difference, statistical test p-value, and study-reported effect sizes). Where possible, the within-arm standardized effect size (analog of Cohen’s d) was calculated. For the calculated effect size, negative values indicate a lower score at follow-up compared to baseline, while positive values indicate a higher score at follow-up. Each treatment arm is presented on its own row. There are also separate rows for studies with more than one measure, time point and analysis type.
  • PTSD Dichotomous Outcomes Within Arms.  This dataset provides within-arm results for dichotomous outcomes: loss of diagnosis and clinically meaningful response. Included is information on how loss of diagnosis and clinically meaningful response were defined as well as the percent of participants who achieved loss of PTSD diagnosis/clinically meaningful response Each treatment arm is presented on its own row. There are also separate rows for studies with more than one measure, time point and analysis type or when there is more than one definition of diagnostic change or clinically meaningful change.
  • PTSD Continuous Outcomes Between Arms. This dataset provides results for between-arm comparisons of continuous measures. Included is information on score differences, p-value for statistical test, and study-reported effect sizes. Where possible, the between-arm standardized effect size was calculated, using Hedges’ g. We calculated Hedges’ g based on the following (in order of preference): 1) adjusted mean difference; 2) follow-up scores; 3) unadjusted mean difference; 4) change scores. For the calculated effect size, information on the basis for calculation is included along with measures of variance. Negative values for Hedges’ g indicate a larger decrease (or lower follow-up score) in the first arm than in the second arm, while positive values indicate the reverse. Each comparison is on a separate row, and pairwise as well as omnibus (multi-arm) comparisons are included. There are also separate rows for each measure, time point and analysis type.
  • PTSD Dichotomous Outcomes Between Arms. This dataset provides between-arm results for dichotomous outcomes: loss of diagnosis and clinically meaningful response. Included is information on how loss of diagnosis and clinically meaningful response were defined, p-value for statistical test, and study-reported effect sizes. Each comparison is on a separate row, and pairwise as well as omnibus (multi-arm) comparisons are included. There are also separate rows for studies with more than one measure, time point and analysis type or when there is with more than one definition of diagnostic change or clinically meaningful change.  
Other Outcomes (arm level). The Other Outcomes dataset includes information on whether the trial includes measures of depression, anxiety, substance use, sleep, anger, quality of life and functioning. Results in this dataset are provided for each treatment arm. The name of the measure is included as well as the between-group effect sizes. Use this dataset to learn how about the effects of PTSD treatments on other outcomes.
Risk of Bias (study level). Each study in the PTSD Repository was coded for risk of bias (ROB) in five specific domains as well as an overall risk of bias for the study using Cochrane’s Risk of Bias 2 rating system. Each domain and the overall rating were coded as high risk, low risk or some concerns.
For more information about ROB, see our story, Risk of Bias Assessment in the PTSD Repository
Harms (arm level). The Harms dataset includes information on serious adverse events and participant withdrawals from the studies due to adverse events. Adverse events are reported as the percent of participants within a treatment group that experienced an adverse event or who withdrew from the study.  Detail on the specific adverse event or reason for withdrawal is provided when available. This dataset also reports on the percentage of patients who attempted or completed suicide (when available).
Other non-data datasets. There are 3 other datasets that are purely informational and do not contain specific data elements:
  • References and Study IdentifiersIdentifying information about each study, including citation, PubMed ID, PTSDpubs ID, ID, location and funding source.
  • Secondary Studies. A list of secondary studies included with primary studies reported in the PTSD Repository. These secondary, referenced studies may or may not have contributed data to the abstraction of the listed primary study.
  • AbbreviationsDefinitions of abbreviations found throughout the PTSD Repository.

Key Variables Repeated in Each Dataset

Repeated variables include a subset of variables that generally describe the treatment and sample; these are included in all datasets described above.  Having some variables repeated in every dataset means that it is easier to create visualizations that include these variables.
In a few cases there are study-level variables included in datasets organized by arm. In these cases, the variable name will include “(Study level)” to remind the user that the data applies to the full RCT, not any particular arm of the study. For example, the “Percent Female (Study level)” variable is coded at the study level, so the values correspond to the overall study, not the specific treatment arm and will thus be identical for each arm (row) of a study. 

Next Steps

Now that you understand how the data are organized, read our How do I get started working with the PTSD Repository? story to learn tips on using the platform to create your own visualizations, download data and more.