Assessing ICD-9-CM and ICPC-2 Use in Primary Care. An Italian Case Study

Abstract

Controlled vocabularies and standardized coding systems play a fundamental role in the healthcare domain. The International Classification of Diseases (ICD) is one of the most widely used classification systems for clinical problems and procedures. In Italy the 9 th revision of the standard is used and recommended in primary care for encoding prescription documents. This paper describes a statistical and terminological study to assess ICD-9-CM use in primary care and its comparison to the International Classification of Primary Care (ICPC), specifically designed for primary care. The study has been conducted by analyzing the clinical records of about 199,000 patients provided by a set of 166 General Practitioners (GPs) in different Italian areas. The analysis has been based on several techniques for detecting coding practice and errors, like natural language processing and text-similarity comparison. Results showed that the selected GPs do not fully exploit the diseases and procedures descriptive capabilities of ICD-9-CM due to its complexity. Furthermore, compared to ICPC-2, it resulted less feasible in the primary care setting, particularly for the high granularity of the structure and for the lack of reasons for encounters.

Fitness for purpose of routinely recorded health data to identify patients with complex diseases: The case of Sjögren's syndrome

“…However, as there are only about 700 separate entries, the level of granularity of ICPC coded primary care records is lower than that of the ICD coded records in secondary care. 15 Due to the low granularity of the ICPC coding system, there is no separate ICPC code for pSS. pSS is recorded under "Musculoskeletal disease other (L99)," as are for example Systemic Lupus Erythematosus and Systemic Sclerosis, which are autoimmune disorders that can occur in association with Sjögren's syndrome.…”

“…In contrast with for example the International Classification of Diseases (ICD 14 ) coding system used in secondary care, ICPC has separate entries for symptoms (such as belly ache) and for diagnoses (such as urinary tract infection). However, as there are only about 700 separate entries, the level of granularity of ICPC coded primary care records is lower than that of the ICD coded records in secondary care 15 …”

Assessing primary care data quality

“…Our study also showed that clinical coding had higher error rates than pharmaceutical coding. Clinical coding for patients could be highly complex and inconsistent depending on context (Cardillo et al , 2015). Pharmaceutical compounds coding is more intuitive and straightforward since drug preparations can be easily linked to their specific chemical names (Liaw et al , 2011).…”

Healthcare Terminology Management and Integration in Italy: Where we are and What we need for Semantic Interoperability

“…In recent years, different studies [2,12] try to get an outline of the Italian situation related to the effective use of standardized terminologies among physicians, especially focusing on GPs, or to evaluate how different classification systems would adapt to the use in GPs' daily practice and how to support them in the coding process. They generally agree in depicting either an inappropriate use or a not sufficiently deep knowledge of the recommended classification system, i.e.…”

“…in research, health care policy, and health care finance), generating ambiguities in the registered information, coding errors, concept generalization, dissatisfaction about the coding practice, etc. [2].…”