Identifying patients with opioid use disorder using International Classification of Diseases (ICD) codes: Challenges and opportunities.
International Classification of Diseases (ICD) diagnosis codes are often used in research to identify patients with opioid use disorder (OUD), but their accuracy for this purpose is not fully evaluated. This study describes application of ICD-10 diagnosis codes for opioid use, dependence and abuse from an electronic health record (EHR) data extraction using data from the clinics’ OUD patient registries and clinician/staff EHR entries.
The study, a secondary analysis of data gathered as part of CTN-0102, a feasibility study about the expansion of medication treatment for OUD in rural communities, used three data sources from each of 4 rural primary care clinics in Washington and Idaho: (1) a limited dataset extracted from the EHR, (2) a clinic-based registry of patients with OUD and (3) the clinician/staff interface of the EHR (e.g. progress notes, problem list). Data source one included records with six commonly applied ICD-10 codes for opioid use, dependence and abuse: F11.10 (opioid abuse, uncomplicated), F11.20 (opioid dependence, uncomplicated), F11.21 (opioid dependence, in remission), F11.23 (opioid dependence with withdrawal), F11.90 (opioid use, unspecified, uncomplicated) and F11.99 (opioid use, unspecified with unspecified opioid-induced disorder). Care coordinators used data sources two and three to categorize each patient identified in data source one: (1) confirmed OUD diagnosis, (2) may have OUD but no confirmed OUD diagnosis, (3) chronic pain with no evidence of OUD and (4) no evidence for OUD or chronic pain.
Analysis found that F11.10, F11.21 and F11.99 were applied most frequently to patients who had clinical diagnoses of OUD (64%, 89% and 79%, respectively). F11.20, F11.23 and F11.90 were applied to patients who had a diagnostic mix of OUD and chronic pain without OUD. The four clinics applied codes inconsistently.
Conclusions: This study found three ICD-10 diagnosis codes (F11.10 [opioid abuse, uncomplicated], F11.21 [opioid dependence, in remission], F11.99 [opioid use, unspecified with unspecified opioid-induced disorder]) that were used more consistently for patients with OUD and others (F11.20 [opioid dependence, uncomplicated], F11.23 [opioid dependence with withdrawal], F11.90 [opioid use, unspecified, uncomplicated]) that were applied to a mix of patients with OUD and patients with chronic pain and no evidence of OUD. Lack of uniform application of ICD diagnosis codes for patients with OUD makes it challenging to use diagnosis code data from the EHR to identify a research population of persons with OUD. Given the richness of the EHR data, it is important to develop new approaches so that researchers can confidently incorporate ICD diagnosis codes in accurately identifying patients with OUD and characterizing their clinical care in their studies.
Related protocols: CTN-0102