Noma is a devastating oro-facial gangrene which predominately affects malnourished children across Africa and Southeast Asia; however, the disease can be found anywhere in the world where food insecurity, health inequity, and inadequate sanitation exist. For years, the World Health Organization excluded noma from its list of Neglected Tropical Diseases (NTDs), despite its fitting all the criteria for inclusion. In December 2023, however, noma became an official NTD, sparking tremendous optimism within the noma community internationally. Since then, advocates have questioned what should come next for noma; yet, even validated baseline epidemiological data on the disease is still lacking. To that end, this study sought to evaluate the feasibility of conducting an individual patient data meta-analysis (IPD-MA) on noma in order to assess the risk factors associated with the disease.

To identify relevant analytical studies on noma, a systematic review of the literature was conducted. Potentially-relevant articles published between January 1, 2000 to October 1, 2024 were identified using validated key and Medical Subject Headings (MeSH) terms related to noma in PubMed, Scopus, LILACS, Embase, and the Cochrane Library. Database outputs and the screening process were managed via Covidence. From this search methodology, 7093 articles were initially identified; after removing duplicates, two trained and calibrated reviewers screened 5360 titles and abstracts, with a third trained and calibrated reviewer serving as an arbiter. Full-text screening of 283 retrievable articles resulted in 27 articles being identified as meeting this study’s inclusion criteria. The 19 corresponding authors of these 27 articles were contacted and invited to share their primary, de-identified data.

Of the nineteen corresponding authors identified as possible collaborators in this project, eleven responded. Six authors initially agreed to share their primary data. Three authors shared their primary, de-identified data. Two authors advised that data sharing agreements (DSAs) needed to be signed with Médecins Sans Frontières (MSF) before providing access to their datasets. One author requested help with de-identifying his data and then did not respond to subsequent communications. Three authors cited inadequate or lost access to the original primary data as the main reasons for their not being able to collaborate on this project. Two authors declined to participate in this study. The effective affirmative participant response rate was 32%. The dataset receipt rate was 11%, providing individual patient data for 98 noma patients (3%) out of an upper-end estimated total possible of 3250 cases.

There was no statistically significant association between the likelihood of an identified author’s response as a function of the year in which their analytical study on noma was conducted (Fisher’s Exact, p=1.000; OR: 0.959, 95% CI: 0.791, 1.144, Wald Test: p=0.645), the number of noma cases that author reported (Fisher’s Exact, p=0.294; OR: 0.993, 95% CI: 0.978, 1.001, Wald Test: p=0.360), or the region in which that author’s study was conducted (Fisher’s Exact, p=0.309). There was no statistically significant association between the likelihood of receipt of a dataset from an identified author as a function of the year of publication (Fisher’s Exact, p=0.411; OR: 1.647, CI: 1.046, 5.011, Wald Test: p=0.182), the number of noma cases that author reported (Fisher’s Exact, p=0.627; OR: 0.986, CI: 0.940, 1.000, Wald Test: p=0.341), or the region in which that author’s study was conducted (Fisher’s Exact, p=0.226).

Due to the heterogeneity in the datasets received, the low affirmative participant response rate (32%), and the miniscule percentage of accessible patient data (3%), an IPD-MA is not currently feasible in relation to noma. Future work must now be done to address the dearth of primary, analytical studies available on noma. In order to provide guidance for future noma research, the Noma Operationalized Measures and Analytics for Reporting (NOMA-R) System was developed. This 10-domain, 87-item data collection tool provides researchers with salient data points to include in their case reports or other analytical studies on noma. The systematic collection of data on noma, which can help answer clinical questions, improve patient outcomes and quality of life, must now be done.