Abstract
The Certified in Disease Intervention (CDI) certification aims to reinforce and expand the expertise of those working at the community level to prevent the spread of infectious disease. To support the recertification process and promote continuing education of CDI competencies, a resource repository of relevant, high-quality materials is being developed. Interdisciplinary subject matter experts at Indiana University’s School of Public Health-Bloomington, a Council on Education for Public Health–accredited and Association of Schools and Programs of Public Health member school, developed a systematic approach to identify and vet training resources. The result was an evidence-informed rubric for assessing multiple attributes of online training materials (including Course Overview and Introduction, Learning Objectives, Learning Assessment and Activities, Instructional Materials, Social Awareness, Scenario-Based Learning, Timeliness of Content, Course Technology, Learner Support, and Accessibility and Usability), a list of resources with evaluation outcomes, and metadata tags for populating a searchable database. The team successfully curated a robust repository of high-quality educational resources. However, the list is not exhaustive, and future work is needed to capture and evaluate more resources and update when new trainings are released for disease intervention professionals in the United States.
Those working to stop the spread of HIV, sexually transmitted infections (STIs), tuberculosis, and other infectious diseases are known widely as disease intervention specialists (DISs). DISs are frontline public health professionals who work to control and stop the spread of infection using methods such as contact tracing, case investigation, and partner services. 1 A systematic review from 2025 found that patients and populations receiving DIS-delivered HIV and STI services showed improved clinical outcomes. 2 During the COVID-19 pandemic, case investigation and contact tracing, 2 primary roles of DISs and other disease intervention (DI) professionals, were associated with a reduction in cases and hospitalization on a population level. 3 Examination of data from the COVID-19 pandemic showed that DI professionals are important community connectors who promote broad access to health services. 4
The Certified in Disease Intervention (CDI) certification aims to reinforce and expand the expertise of those working to prevent the spread of infectious disease at the community level, according to the National Board of Public Health Examiners (NBPHE). 5 To identify competencies for the CDI, the Association of Schools and Programs of Public Health (ASPPH) updated and verified a job task analysis of the DI workforce. 6 The competencies developed from the analysis standardize the knowledge, skills, and abilities needed for the DI workforce and comprise 6 domains: Planning and Case Analysis, Interviewing and Case Management, Field Services and Outreach, Surveillance and Data Collection, Collaboration, and Outbreak Response and Emergency Preparedness.
To promote continued learning and professional competency, the CDI certification requires recertification every 3 years, a standard consistent with other allied health professions. CDI professionals must earn 30 recertification credits focused on DI and prevention competencies. 7
Purpose
To identify high-quality educational resources related to the CDI competencies, a multidisciplinary team developed an evidence-informed rubric and applied it in a standardized approach to repository development.
Methods
The project timeline was February 3 through September 29, 2025. The IU research and online learning teams consisted of a staff member with more than 7 years of DIS experience (B.H.), a faculty member from the Epidemiology Department (C.L., principal investigator), 2 online instructional designers (Z.H. and M.K.), and the director of public health practice (K.S.). In addition, several doctor of philosophy (PhD) and master of public health (MPH) students supported the project. The IU Institutional Review Board (IRB) determined this study was exempt under category 2(ii), which covers adult educational tests, surveys, or interviews when disclosure of identifiable responses would not reasonably harm participants (IRB no. 27054).
Developing the Evaluation Rubric
To identify high-quality resources, the project team developed a rubric to assess multiple attributes, including relevance of content, best practices in test taking, and accessibility. The team developed the rubric through a deliberative process between subject matter experts at IU with final input from ASPPH project managers beginning in March 2025. The IU team, with agreement from the ASPPH project team, finalized the rubric during a meeting on May 30, 2025.
Research and online learning experts each proposed criteria for the draft rubric based on their knowledge area. The research team inventoried the Centers for Disease Control and Prevention’s (CDC’s) Quality eLearning Checklist 8 domains (Analysis, Interactivity, Interface and Navigation, Content Development, Photographs and Graphics, and Learner Assessment) and criteria. Next, the research team used Claude AI (https://claude.ai) to identify additional aspects of online training for evaluation and entered results into the spreadsheet with CDC’s domains to compare, contrast, and merge evaluative domains and criteria from both sources.
The online team contributed to the rubric design based on their expertise in using Quality Matters 9 for online course evaluation. However, the framework could not be used in its entirety because of time and resource constraints and a misalignment in objectives. Specifically, the Quality Matters framework provides a comprehensive evaluation for individual courses with up to 9 substandards in each of 8 domains covering topics such as grading policies and learner interaction.
From the compilation of domains and subtopics, the research team began an iterative process to reduce the number and complexity of criteria by targeting goals of the DI repository project and by considering the time and resources needed to conduct evaluations. The research team submitted a draft rubric to the principal investigator on May 6, 2025, for further refinement. The resulting rubric went to the CDI project team at ASPPH for final vetting and approval on May 21, 2025.
The final rubric included 10 criteria: Course Overview and Introduction, Learning Objectives, Learning Assessment and Activities, Instructional Materials, Social Awareness, Scenario-Based Learning, Timeliness of Content, Course Technology, Learner Support, and Accessibility and Usability.
Inclusion criteria for applying rubric
The research team considered resources for evaluation using the rubric if the links were viable and the material could be reasonably assigned continuing education credit hours (based on the project manager’s ≥7 years of frontline DI experience).
Exclusion criteria for applying rubric
The research team excluded resources from evaluation using the rubric if they contained page errors during preliminary screening or were duplicate resources (eg, part of a series of courses, listed under a different name). The research team excluded static written materials, such as books, PDFs, study guides, digital flashcards, and pamphlets, if they could not be reasonably assigned continuing education credit hours. The team also excluded in-person trainings. Although these resources are important for continuing education, the project focused on training available on demand.
Applying the Rubric
In April 2025, the research team hired MPH and PhD students to apply the rubric using a data dictionary that contained each criterion, its definition, and an example as well as the inclusion and exclusion criteria. The research team applied the rubric (Table) and entered the results using REDCap 10 (Research Electronic Data Capture), a secure, web-based software platform designed to support research data capture.
Evidence-informed rubric developed to assess materials for the Certified in Disease Intervention training repository a
All criteria were rated using a 3-point scale, where 1 = good, 2 = okay, and 3 = poor.
An initial list of training resources collated by ASPPH during an initial assessment of the DI training landscape was provided to the IU project team. The project team created a systematic data collection framework to identify additional resources in collaboration with the IU Bloomington Libraries. Recognizing the evolving nature of online training, the research team revisited the resource sites listed on NBPHE’s compilation of CDI study resources from April through July 2025 to capture newly released trainings. Resources were also identified through listening sessions with content developers and frontline DI professionals. Finally, the research team searched links and references from the identified resources to identify other relevant courses and platforms. In August 2025, the research team observed that most search results were yielding duplicate resources and shifted its focus to prioritizing the evaluation of materials.
Starting in May through August 2025, the research team evaluated each training resource against the rubric criteria using a 3-point rubric scale: good (3 points), okay (2 points), or poor (1 point). The research team also had the option to select not applicable (0 points) if a rubric category did not pertain to the resource. For example, prerecorded webinars may lack learning assessments or learner support features. Similarly, a course focused on a specific virus might be highly science oriented—centered on laboratory results and medications—and may not address regional practices or local context. In such cases, scoring the resource on social awareness would not be appropriate. To ensure comparable outcomes, scores were converted into percentages using an automated formula that excluded any not applicable selections, preventing those categories from lowering the overall score.
The research team and the IU project director met weekly during the evaluation process to deliberate unclear findings, clarify data definitions, and refine processes. In addition, the research team prioritized materials for review in response to the project timeline and pace of the review process.
Outcomes
In total, the research team assessed 233 trainings using the rubric, with 187 recommended for the continuing education repository for DI professionals. The recommended resources were selected based on the distribution of scores in a scatterplot (Figure 1). The distribution was concentrated in the upper 75th percentile, and this cut point was selected as the quality benchmark for ensuring quality of the training in the repository. The team lead double-checked materials scoring on or near the 75th percentile to confirm the decision to exclude them.
Scatter plot illustrating results of a quality assessment conducted from May through August 2025. Courses were evaluated by a research team from the Indiana University School of Public Health–Bloomington using an evidence‑informed rubric comprising 10 criteria: Course Overview and Introduction, Learning Objectives, Learning Assessment and Activities, Instructional Materials, Social Awareness, Scenario‑Based Learning, Timeliness of Content, Course Technology, Learner Support, and Accessibility and Usability.
Resource Format
Most of the trainings to be included in the repository were online courses (n = 120; 64.2%). Approximately one-third were prerecorded webinars or videos (n = 64; 34.2%). Only 3 (1.6%) were resource materials (eg, factsheets, infographics, toolkits) that the research team included in the analysis because they had continuing education credits assigned to them.
Mapping to CDI Examination Domains
Using the DIS Certification Job Task Analysis Validation Survey developed by NBPHE and currently pending final approval, the educational resources were mapped to the CDI examination domains when applicable (Figure 2). Distribution across domains was relatively even, with Interviewing and Case Management slightly higher (n = 59; 31.6%), followed by Planning and Case Analysis (n = 43; 23.0%), Field Services and Outreach Activities (n = 44; 23.5%), Surveillance and Data Collection (n = 42; 22.5%), Collaboration (n = 39; 20.9%), and Outbreak Response and Emergency Preparedness (n = 40; 21.4%). A total of 49 trainings (26.2%) did not fall into any CDI examination category.
Number of educational resources (N = 233) mapped across Certified in Disease Intervention (CDI) examination domains during assessment using an evidence‑informed rubric. Resources were evaluated from May through August 2025 by a research team at the Indiana University School of Public Health–Bloomington using a standardized approach to evaluate material for a CDI training repository. Counts across domains are not mutually exclusive and may exceed the total number of resources assessed.
Topic Area
While the CDI examination categories were based on skills, the project team also wanted to capture topic areas, because workforce members may be looking for trainings in specific diseases or topics that are not explicitly in the CDI examination. These were topics such as effective communication, public health policy and advocacy, basics of epidemiology, motivational interviewing, leadership skills, infectious diseases such as COVID-19 and mpox, and enteric disease investigations. HIV and STI trainings were the most common topic areas (HIV: n = 40 [21.4%]; STI: n = 49 [26.2%]), while tuberculosis (n = 20; 10.7%), hepatitis (n = 24; 12.8%), infectious outbreak investigation (n = 26; 13.9%), and emergency preparedness and response (n = 24; 12.8%) accounted for the rest of the topic areas.
Level of Difficulty
Most of the educational resources reviewed were introductory-level trainings: Introductory (n = 124; 66.3%), Intermediate (n = 20; 10.7%), Advanced (n = 3; 1.6%), and All Levels (n = 40; 21.4%).
Lessons Learned
To support continued professional growth for those with CDI certification, it will be important to support efforts at sustaining the quality and relevance of the training repository. Continued use of the rubric, which was developed for its efficiency and focus on CDI competencies, will be a cost-effective way to audit and maintain the repository.
In addition, the use of the rubric points to the strengths and weaknesses in the training landscape and will help inform priority areas for development of new training resources. For example, many of the training materials were at the introductory level, indicating a gap in online options for advanced topics.
One of the primary challenges of this project was the short project period and the inconsistent availability of federal training resources. The project required us to quickly identify relevant trainings, develop an evaluation rubric, and conduct reviews of a substantial number of educational resources—all within a condensed period. The length of many training courses posed an additional obstacle, with some individual courses exceeding 4 hours. While some courses or webinars offered features such as downloadable transcripts or adjustable playback speeds, many did not, making the review process particularly time intensive. In addition, this project was conducted when commonly used resources hosted by CDC TRAIN (https://www.train.org/cdctrain) were temporarily removed from public websites and later reinstated. It was difficult to assess which resources were not available because the content was no longer current and which were not deemed to be aligned with the federal administration’s policy agenda.
Despite these challenges, the team successfully curated a robust repository of high-quality educational resources. However, the list is not exhaustive, and future work is needed to capture and evaluate more resources and update when new trainings are released for DI professionals in the United States.
Footnotes
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This publication was supported by the Centers for Disease Control and Prevention of the US Department of Health and Human Services (HHS) through Notice of Funding Opportunity (NOFO) no. CK20-2003 titled Improving Clinical and Public Health Outcomes through National Partnerships to Prevent and Control Emerging and Re-Emerging Infectious Disease Threats. The contents are those of the authors and do not necessarily represent the official views of, nor an endorsement by, CDC/HHS or the US government.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.