The CBS test: Development, evaluation & cross-validation of a community-based injury severity scoring system in Cameroon

Haley Tupper; Rasheedat Oke; Catherine Juillard; Fanny Dissak-DeLon; Alain Chichom-Mefire; Mbiarikai Agbor Mbianyor; Georges Alain Etoundi-Mballa; Thompson Kinge; Louis Richard Njock; Daniel N Nkusu; Jean-Gustave Tsiagadigui; Melissa Carvalho; Mark Yost; S Ariane Christie

doi:10.1371/journal.pgph.0002110

The CBS test: Development, evaluation & cross-validation of a community-based injury severity scoring system in Cameroon

PLOS Glob Public Health. 2023 Jul 26;3(7):e0002110. doi: 10.1371/journal.pgph.0002110. eCollection 2023.

Authors

Affiliations

¹ Department of Surgery, Program for the Advancement of Surgical Equity (PASE), University of California Los Angeles, Los Angeles, California, United States of America.
² Faculty of Health Sciences, University of Bamenda, Bamenda, Cameroon.
³ Faculty of Health Sciences, University of Buea, Buea, Cameroon.
⁴ Department of Disease Epidemic and Pandemic Control, Ministry of Health, Yaoundé, Cameroon.
⁵ Hospital Administration, The Limbe Regional Hospital, Lime, Cameroon.
⁶ Hospital Administration, The Laquintinie Hospital of Douala, Douala, Cameroon.
⁷ Hospital Administration, The Catholic Hospital of Pouma, Pouma, Cameroon.
⁸ Hospital Administration, The Edea Regional Hospital, Edea, Cameroon.

Abstract

Injury-related deaths overwhelmingly occur in low and middle-income countries (LMICs). Community-based injury surveillance is essential to accurately capture trauma epidemiology in LMICs, where one-third of injured individuals never present to formal care. However, community-based studies are constrained by the lack of a validated surrogate injury severity metric. The primary objective of this bipartite study was to cross-validate a novel community-based injury severity (CBS) scoring system with previously-validated injury severity metrics using multi-center trauma registry data. A set of targeted questions to ascertain injury severity in non-medical settings-the CBS test-was iteratively developed with Cameroonian physicians and laypeople. The CBS test was first evaluated in the community-setting in a large household-based injury surveillance survey in southwest Cameroon. The CBS test was subsequently incorporated into the Cameroon Trauma Registry, a prospective multi-site national hospital-based trauma registry, and cross-validated in the hospital setting using objective injury metrics in patients presenting to four trauma hospitals. Among 8065 surveyed household members with 503 injury events, individuals with CBS indicators (CBS+) were more likely to report ongoing disability after injury compared to CBS- individuals (OR 1.9, p = 0.004), suggesting the CBS test is a promising injury severity proxy. In 9575 injured patients presenting for formal evaluation, the CBS test strongly predicted death in patients after controlling for age, sex, socioeconomic status, and injury type (OR 30.26, p<0.0001). Compared to established injury severity scoring systems, the CBS test comparably predicts mortality (AUC: 0.8029), but is more feasible to calculate in both the community and clinical contexts. The CBS test is a simple, valid surrogate metric of injury severity that can be deployed widely in community-based surveys to improve estimates of injury severity in under-resourced settings.

Copyright: © 2023 Tupper et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Grants and funding

Dr. S. Ariane Christie received salary support from the Association for Academic Surgery Global Surgery Resident Scholarship (2017) ($30,000 to SAC). The Cameroon Trauma Registry was supported by Dr. Catherine Juillard’s departmental research funding from University of California San Francisco from 2017-2019 (CJ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.