Capturing anaphylaxis through medical records: Are ICD and CPT codes sufficient?

Abstract

Objective: The identification of anaphylaxis cases is imperative for optimal clinicalprovider knowledge deficiencies in diagnosis and treatment and the efficacy of reimbursement codes, such as International Classification of Diseases (ICD) and current procedural terminology (CPT) codes, in detecting anaphylaxis.

Data sources: Pubmed.

Study selections: Recent and clinically relevant literature on anaphylaxis and provider knowledge, ICD, CPT, Healthcare Common Procedural Coding System (HCPCS), and E-codes were selected and reviewed.

Results: Reimbursement codes are used to detect anaphylaxis in administrative claims databases. Inaccurate recognition of the diagnosis by providers, underreporting, and cause identification are challenges faced by health researchers using reimbursement codes for anaphylaxis case identification. Anaphylactic shock-specific ICD codes were noted to have a positive predictive value (PPV) of 52% to 53% of anaphylaxis events compared with physician chart review, which was improved to 63% to 67.3% when used in conjunction with anaphylaxis symptom-specific ICD, CPT, HCPCS, and E-codes 31, 34, and 35.

Conclusion: Education of providers to properly diagnose and treat anaphylaxis requires systematic and educational investments. The ICD codes specific to anaphylactic shock have suboptimal PPV to identify anaphylaxis in administrative claims databases. Use of algorithms incorporating other reimbursement codes improve the PPV, but they are limited by inaccurate diagnoses and underreporting of anaphylaxis. Future ICD-11 reclassification may improve anaphylaxis detection by reimbursement codes.