Development and testing of a de novo clinical staging system for podoconiosis (endemic non-filarial elephantiasis)

Objective To develop and test a robust clinical staging system for podoconiosis, a geochemical disease in individuals exposed to red clay soil. Methods We adapted the Dreyer system for staging filarial lymphoedema and tested it in four re‐iterative field tests conducted in an area of high‐podoconiosis prevalence in Southern Ethiopia. The system has five stages according to proximal spread of disease and presence of dermal nodules, ridges and bands. We measured the 1‐week repeatability and the inter‐observer agreement of the final staging system. Results The five‐stage system is readily understood by community workers with little health training. Kappa for 1‐week repeatability was 0.88 (95% CI 0.80–0.96), for agreement between health professionals was 0.71 (95% CI 0.60–0.82), while that between health professionals and community podoconiosis agents without formal health training averaged 0.64 (95% CI 0.52–0.78). Conclusions This simple staging system with good inter‐observer agreement and repeatability can assist in the management and further study of podoconiosis.