Problems related to disease classification grouping schemes in the cost-of-illness tabulation and introduction of Clinical Classification Software

Cost-of-illness tabulations are commonly used information in health service researches and administration decision-making. In order to tabulate the disease-specific cost of an illness, a scheme of grouping disease categories is needed in order to cluster related 4-digit or 5-digit categories into a meaningful and manageable number for the purposes of analysis and discussion. The aim of this study was to discuss the problems of currently used grouping scheme and to find out the modified grouping schemes that intended to resolve these problems. The problems in using the 'chapter' as a grouping schemes include: (1) the titles of the groups are too general and nonspecific; (2) the number of categories within each group varies greatly; (3) diseases classified within the same ICD chapter are too heterogeneous. The problems in using the 'basic tabulation list' as a grouping scheme include: (1) categories and number of disease in other residual groups are too large, and (2) diseases with similar etiology are scattered into different bodily organ system chapters. The Clinical Classification Software (CCS) grouping scheme was developed by the Agency for Healthcare Research and Quality (AHRQ) to solve the above problems. The CCS could efficiently reduce the number of Other...' residual groups and of Chapter XVI 'signs, symptoms, and ill-defined conditions' and generally provides more specific information. Nevertheless, we should not overlook the problems of accuracy of diagnosis and multiple diagnoses in claims data.