SAPCReN

Study Name: Updating the disease coding system used by physicians across Canada

Investigators: Stephanie Garies¹, Kerry McBrien¹, Hude Quan²

Affiliations:

1. Department of Family Medicine, University of Calgary.
2. Centre for Health Informatics, University of Calgary.

Status: publishing

Abstract

Background: Disease classification systems are essential for generating standardized health data used in research, policy-making, and clinical decision support. In Canada, the International Classification of Diseases, 9th Revision (ICD-9), has been used for outpatient billing since 1979. While hospitals transitioned to ICD-10-CA in the mid-2000s, most physicians across provinces and territories are still required to use ICD-9 for billing. This outdated system no longer reflects the complexity of modern medicine and limits the accuracy of health data. Replacing ICD-9 with a more current classification system could enhance the accuracy of clinical documentation, improve the quality of physician claims databases, and provide governments with a clearer picture of patient care. We have a timely opportunity to consider replacing ICD-9 in primary care with two viable alternatives: ICD-11 (released in 2022 and will be implemented in Canadian hospitals in the near future) and the International Classification of Primary Care version 3 (ICPC-3) (released late 2020).

Objective: to assess the future classification system needs and preferences of Canadian primary care physicians and to evaluate the potential replacement of ICD-9.

Methods: We will conduct two studies using a sequential, embedded mixed methods approach. Project 1 will consist of an analysis of electronic medical record (EMR) data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), which will examine patient encounters and ICD-9 coded billing claims for nearly 2 million patients across the country. The EMR data will also be used for a mapping exercise to examine gaps, overlap and deficiencies of ICD-9, ICD-11 and ICPC-3 in a Canadian primary care context. Project 2 will recruit family physicians from across Canada who will be invited to complete an online coding exercise and electronic survey. Participants will watch an educational video describing ICD-11 and ICPC-3, then directed to code 5 randomly selected patient vignettes using each of ICD-9, ICD-11 and ICPC-3. A total of 30 vignettes will be developed based on common conditions discovered in Project 1. This will allow us to understand and compare the useability of ICD-11 and ICPC-3, as well as measure consistency of coding and ease of use. A survey will follow the coding exercise to ask about preferences between ICD-11 and ICPC-3, satisfaction, acceptability, coding effectiveness, and feasibility of implementation. We will also conduct focus groups with family physicians and interviews with policymakers to discuss in detail the acceptability of ICD-11 and ICPC-3 and potential challenges and benefits of adopting a new system. Our multidisciplinary team consists of family physicians (as ICD-9 users and clinical experts), international leaders in ICD and ICPC development and testing, and nationally recognized primary care researchers.

This work is novel, in that no evaluation of ICD-11 or ICPC-3 has been conducted in Canadian primary care settings to date. We anticipate this work will provide an important family physician perspective about their preferences for a future classification system, as well as assess policymaker readiness for change. Importantly, this knowledge will contribute to the preparation underway at the Canadian Institute for Health Information (CIHI) for ICD-11 adoption in acute care facilities and will be used to support the appeal to provincial/territorial governments to replace ICD-9 concurrently. Lastly, these findings will be useful for other countries who are exploring the adoption of ICD-11 or ICPC-3 in their local contexts.