PT - JOURNAL ARTICLE AU - Daniel B Hier AU - Joshua Pearson TI - Two algorithms for the reorganisation of the problem list by organ system AID - 10.1136/bmjhci-2019-100024 DP - 2019 Dec 01 TA - BMJ Health & Care Informatics PG - e100024 VI - 26 IP - 1 4099 - http://informatics.bmj.com/content/26/1/e100024.short 4100 - http://informatics.bmj.com/content/26/1/e100024.full SO - BMJ Health Care Inform2019 Dec 01; 26 AB - Objective Long problem lists can be challenging to use. Reorganisation of the problem list by organ system is a strategy for making long problem lists more manageable.Methods In a small-town primary care setting, we examined 4950 unique problem lists over 5 years (24 033 total problems and 2170 unique problems) from our electronic health record. All problems were mapped to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) and SNOMED CT codes. We developed two different algorithms for reorganising the problem list by organ system based on either the ICD-10-CM or the SNOMED CT code.Results The mean problem list length was 4.9±4.6 problems. The two reorganisation algorithms allocated problems to one of 15 different categories (12 aligning with organ systems). 26.2% of problems were assigned to a more general category of ‘signs and symptoms’ that did not correspond to a single organ system. The two algorithms were concordant in allocation by organ system for 90% of the unique problems. Since ICD-10-CM is a monohierarchic classification system, problems coded by ICD-10-CM were assigned to a single category. Since SNOMED CT is a polyhierarchical ontology, 19.4% of problems coded by SNOMED CT were assigned to multiple categories.Conclusion Reorganisation of the problem list by organ system is feasible using algorithms based on either ICD-10-CM or SNOMED CT codes, and the two algorithms are highly concordant.