Evaluation of the Sensitivity and Specificity of the New Clinical Diagnostic and Classification Criteria for Kashin-Beck Disease, an Endemic Osteoarthritis, in China.

This study aimed to evaluate the sensitivity and specificity of the new clinical diagnostic and classification criteria for Kashin-Beck disease (KBD) using six clinical markers: flexion of the distal part of fingers, deformed fingers, enlarged finger joints, shortened fingers, squat down, and dwarfism. One-third of the total population in Linyou County was sampled by stratified random sampling. The survey included baseline characteristics and clinical diagnoses, and the sensitivity and specificity of the new criteria was evaluated. We identified 3,459 KBD patients, of which 69 had early stage KBD, 1,952 had stage I, 1,132 had stage II, and 306 had stage III. A screening test classified enlarged finger joints as stage I KBD, with a sensitivity and specificity of 0.978 and 0.045, respectively. Shortened fingers were classified as stage II KBD, with a sensitivity and specificity of 0.969 and 0.844, respectively, and dwarfism was classified as stage III KBD with a sensitivity and specificity of 0.951 and 0.992, respectively. Serial screening test revealed that the new clinical classification of KBD classified stages I, II, and III KBD with sensitivities of 0.949, 0.945, and 0.925 and specificities of 0.967, 0.970, and 0.993, respectively. The screening tests revealed that enlarged finger joints, shortened fingers, and dwarfism were appropriate markers for the clinical diagnosis and classification of KBD with high sensitivity and specificity.

[Logistic regression of the environmental risk factors in areas with Kashin-Beck disease].

OBJECTIVE: In order to find the factors influencing the prevalence of KBD, the possible nosogenetic factors of the family in Kashin-Beck disease (KBD) areas were analyzed. METHODS: The possible nosogenetic factors in mild, middle, high prevalence KBD areas were analyzed by logistic regression. The differences of the factors between three kinds of KBD areas were compared. RESULTS: Univariate analysis found sanitary conditions and meat-egg-mild were associated with KBD prevalence in all kinds KBD areas. Binary logistic analysis of multivariate suggested the possible nosogenetic factors were different in the different kind of KBD areas. It was wheat in mild prevalence area, sanitary conditions and meat-egg-mild in middle prevalence area, and sanitary conditions, rice and meat-egg-mild in high prevalence area. CONCLUSION: The risk factors are associated with the kind of KBD areas. The different preventive methods should be taken according to the kind of KBD areas, which will improve the effect of prevention.

[Epidemiological characters of Kashin-Beck disease in nuclear families].

OBJECTIVE: To understand the epidemiological characters of Kashin-Beck disease (KBD) in nuclear families, and to probe the pathogenetic mechanism and its etiology. METHODS: Clinical diagnosis was used to identify nuclear families in KBD areas. Based on the clinical manifestation of parents in the nuclear families, 4938 nuclear families were divided into four types. According to the seriousness in KBD areas, prevalence of offspring and family aggregation in low, middle and high prevalence areas were formed and data was analyzed. RESULTS: (1) Type of nuclear family was associated to the degree of disease seriousness in the areas. (2) There was an aggregation of disease among the offsprings in the nuclear families of medium and high prevalence diseased areas. (3) There was an aggregation of offspring in the nuclear family of both parents or father alone who were suffered from KBD. (4) The prevalence of offspring in nuclear family of both parents with KBD was obviously higher than that in the nuclear family with single parent or neither having KBD. CONCLUSION: The degree of diseased areas seemed to influence the seriousness of KBD in individuals. The prevalence of parents in nuclear families might play a role in the pathogenesis of KBD.