The updated, ongoing review will encompass evidence from any English language peer-reviewed report of research conducted on or about the health of WTC populations, including case reports, observational studies, controlled trials, and systematic or narrative reviews. The research may be funded by the Program or by other sponsors and may be published between November 1, 2020, and December 31, 2022. Our approach to completing the record search, eligibility screening, data abstraction, analysis, and evidence map of WTC clinical and translational research is described below. In our previous work [1], we validated the search and screening approach by comparing results to lists of pertinent studies identified by topic experts and the “Summary of World Trade Center Health Program Research: NIOSH Research Compendium” [7] completed in 2019 by program staff.

Record search

We will use a systematic and validated search strategy to find records of WTC-related health research from databases of peer reviewed publications. An information specialist (Larkin) was involved in developing and validating the strategy. We will group search terms into four hierarchical statements, shown below. A full list of search terms is presented in Additional file 1.

1.

Terms related to the terrorist attacks on September 11, 2001

2.

Terms related to the numerical date (i.e., 9/11) and the type of disaster

3.

Terms related to the New York City and New Jersey locations and the type of disaster

4.

Terms related to the Shanksville, Pennsylvania, and Pentagon locations and the type of disaster

To find records of peer-reviewed publications, we will search six databases using terms relevant to the September 11 attacks. Using the four statements described above and in Additional file 1, we will search titles, abstracts, and keywords in OVID MEDLINE, PsycINFO, Scopus, Web of Science, CINAHL, and Embase for records of peer-reviewed articles, books, book chapters, conference abstracts, and dissertations.

Validation results, such as recall rates, will be reported in the manuscript. Automated exclusions for non-health research (such as construction engineering studies) will be applied. Included records will be limited to articles published over a 2-year period, from November 1, 2020, through December 31, 2022.

Eligibility screening

We (Concannon, Faherty, Chari) will apply five exclusion filters of increasing specificity. The filters are as follows: (1) not in English; (2) not peer reviewed research; (3) not about 9/11 attacks; (4) not about 9/11 populations; (5) not about health conditions, care, or outcomes. Titles and abstracts collected during the record search will be screened first. Records that pass sequentially through all five screens will be included in the data abstraction process described below. Those that do not will be excluded and reported as such in a Preferred Items for Reporting on Systematic Reviews and Meta Analyses (PRISMA) flowchart [8]. The first reason for exclusion will be recorded in Supplementary material. Records that are deemed uncertain will proceed to full text screen. In this stage, full text articles will be obtained, and the screening process will be repeated until every record is determined to be eligible or ineligible for inclusion. Final results of the screening process will be reported in the PRISMA flowchart.

Data abstraction

A standardized query form, shown in Additional file 2, was developed in collaboration with NIOSH to guide data abstraction. Included query term items will be coded into DistillerSR [9] as a survey tool with drop down, numeric text, and free text fields response options. Experienced reviewers (Concannon, Faherty, Chari) will abstract data from included articles. The first 10% of included articles will be double reviewed and adjudicated by the whole team. Single reviews will commence on subsequent rounds of 10% of included articles if 85% agreement is achieved on priority items in the survey tool on at least one of the rounds.

Inventory of research (RQ1)

An inventory of research (RQ1) will be captured by categorizing research publications according to elements of the PICOTSS and PECOTSS frameworks (population, interventions or exposures, comparators, outcomes, timing, setting, and study design). PECOTSS is the environmental equivalent of the Agency for Healthcare Research and Quality’s PICOTS expansion of the PICO framework, which was developed for evaluations that focus on clinical interventions rather than exposures [10].

Evidence of research impacts (RQs 2 and 3)

An assessment of translational impacts (RQs 2 and 3) will be captured by mapping research to recognized translational research frameworks (the National Institute of Environmental Health Sciences Translational Research Framework for Environmental Health Sciences [4], the Tufts Clinical and Translational Science Institute Six Types of Evidence Framework [5], and the NIOSH Research to Care (RTC) model [6], a logic diagram designed to help in program planning. The National Institute of Environmental Health Sciences (NIEHS) framework is especially well suited to evaluating the translation of research in an environmental disaster. This framework includes a tool for visualizing how ideas and knowledge move from the earliest stages of fundamental questioning to the later stages of impact (Fig. 1). The visualization depicts a series of concentric rings moving from research that addresses Fundamental Questions (purple ring, rectangles) to research that addresses Application and Synthesis (light blue ring, ovals). Other research includes Implementation and Adjustment (green ring, hexagons), Practice (dark blue ring, circles), and Impact (black ring, triangles). On each ring are nodes that identify approaches, methods, and activities that are typically used within each type of research.

Fig. 1

The National Institute of Environmental Health Sciences translational research framework (Reproduced from Environmental Health Perspectives with permission from the authors)

Reporting and visualization of results

The inventory of research (RQ1) will be reported in tables and accompanying narrative. We will present information in sequence for each item in the PICOTSS and PECOTTS frameworks. Items pertaining to the translational aspects of research (RQs 2 and 3) will be presented in tables and, where possible, we will use figures to depict concentrations of research publications along specific parts of the translational frameworks (see Fig. 1 for an example). All data collected and all data prepared for visualization and reporting will be made available with the publication of a peer reviewed and publicly available RAND Report. All RAND Reports are made avialable online and are indexed and searchable through major scientific public databases.

As this is a scoping review designed to provide data on existing research across a vast range of populations, conditions, and outcomes, we do not plan to conduct risk of bias or strength of evidence analyses at the effect level or study level. However, we will collect information (see Additional file 2) that can be used to assess risks of bias and strength of evidence in future systematic reviews on specific populations, conditions and outcomes.