Accuracy and completeness of ICPC coding for chronic disease in general outpatient clinics

Abstract

Objective: To assess the accuracy and completeness of the International Classification of Primary Care Coding (ICPC) for chronic illnesses in the general outpatient clinics (GOPCs) and to identify common issues in coding for further improvements and implementation. Design: This is a retrospective review of case notes belonging to patients attending eight GOPCs. The data were obtained through the collection of the relevant data in the Hospital Authority's computerized Clinical Management System (CMS). Subjects: A random sample of patients attended from the period: 1st December to 7th December 2008. Main outcome measures: The type and number of chronic illnesses of each case, and the accuracy and completeness of their corresponding ICPC coding. Results: 6095 (38.0% of total attendance) records were reviewed, of which 3274 (53.7%) patients had chronic illness. Overall 6608 chronic illnesses were identified, with a mean of 2.0 chronic illnesses per consultation. 75.4% of chronic illnesses were correctly coded. 19.4% and 5.3% were missed and wrongly coded respectively. The percentage of missing coding was positively correlated to the case complexity while the percentage of correct coding was inversely correlated. Conclusion: 24.7% of ICPC codes for chronic illness were either missed or wrongly coded. The commonly missed or wrongly coded ICPC was identified. Further study, such as focus group discussion or questionnaire for doctors, will be needed to explore the reasons and for further improvements.