The classification of subjects with joint complaints on incomplete biochemical and haematological datasets

We performed a retrospective study on 163 subjects suffering from rheumatic fever (16), rheumatoid arthritis (36), lupus erythematosus (17), gout (21), arthrosis (50) and osteomyelitis (23). The number of variables evaluated was 39. These were all of a general biochemical and haematological nature. A feature reduction resulted in sixteen variables that matched well with those known from the literature. Linear discriminant analysis yielded poor results in classifying the six disease categories (with 18 variables 61.8%). A reduction to three disease categories improved the classification results remarkably. This, and the excellent discriminating power between patients and the reference group, shows that the selected variables are illustrative only for general clinical pictures, such as infection, and not for the desired differential diagnosis.