Inter-observer reliability in assessment of sensation of skin lesion and enlargement of peripheral nerves in leprosy patients

The accurate diagnosis of leprosy is important to both individuals and to the community. The diagnosis of leprosy is based on clinical examination. However, the reliability of clinical assessment of sensation in skin lesions and thickness of peripheral nerves on palpation has not been well studied, due to the lack of a gold standard. We report an inter-tester reliability study of the clinical assessment of skin lesions and thickness of ulnar and popliteal nerves in leprosy patients by different staff. For sensory testing of skin lesions, the agreement between the leprologist and leprosy control staff, and between one student and leprosy control staff, was poor (kappa values < 0-4). The agreement between the leprologist and the two students, between the two students, and between the other student and local leprosy control staff were fair (kappa values > 0.4, but < 0-6). For the palpation of ulnar and popliteal nerves, the agreement ranged from 0.36 to 0.52 and from 0.02 to 0.29 in different pairs of testers, respectively. The reliability of clinical diagnostic skills based on both sensory testing of skin lesions with the cotton wool method and palpation of superficial peripheral nerves was unsatisfactory.