How accurate is ICD coding for epilepsy?

Abstract

SUMMARYPurpose: Assess the validity of ICD-9-CM and ICD-10 epilepsy coding from an emergency visit (ER) and a hospital discharge abstract database (DAD). Methods: Two separate sources of patient records were reviewed and validated. (1) Charts of patients admitted to our seizure monitoring unit over 2 years (n = 127, ICD-10 coded records) were reviewed. Sensitivity (Sn), specificity (Sp), and positive and negative predictive values (PPV and NPV) were calculated. (2) Random sample of charts for patients seen in the ER or admitted to hospital under any services, and whose charts were coded with epilepsy or an epilepsy-like condition, were reviewed. Two time-periods were selected to allow validation of both ICD-9-CM (n = 486) and ICD-10 coded (n = 454) records. Only PPV and NPV were calculated for these records. All charts were reviewed by two physicians to confirm the presence/ absence of epilepsy and compare to administrative coding. Results: Sample 1: Sn, Sp, PPV, and NPV of ICD-10 epilepsy coding from the seizure monitoring unit (SMU) chart review were 99%, 70%, 85%, and 97% respectively. Sample 2: The PPV and NPV for ICD-9-CM coding from the ER database were, respectively, 99% and 97% and from the DAD were 98% and 99%. The PPV and NPV for ICD-10 coding from the ER database were, respectively, 100% and 90% and from the DAD were 98% and 99%. The epilepsy subtypes grand mal status and partial epilepsy with complex partial seizures both had PPVs >75% (ICD-9-CM and ICD-10 data). Discussion: Administrative emergency and hospital discharge data have high epilepsy coding validity overall in our health region.

Validating the 8 CPCSSN Case Definitions for Chronic Disease Surveillance in a Primary Care Database of Electronic Health Records

“…18 The CPCSSN case definition for dementia performed better than those constructed from Quebec billing data (sensitivity of 12.9%-39.7%) 19 and Canadian administrative hospital discharge data (sensitivity of 32.3%-66.9%, specificity of 100.0%). 20 The epilepsy results were similar to definitions using administrative databases for various Canadian provinces (PPV of 75.5%-98.9%, NPV of 94.0%-97.4%), 21 and for definitions combining diagnoses and medications to identify epilepsy cases in a US managed care organization data system (PPV of 79.2%-84.1%). 22 Lastly, cases of parkinsonism validated in an American Veteran's Health Administration database showed strong PPV (81%) when using ICD-9 codes alone but had poor sensitivity (18.7%); sensitivity improved when ICD-9 codes and medications were combined (42.5%), but PPV suffered (53.3%).…”

Disparities in surgery among patients with intractable epilepsy in a universal health system

“…Seizures were identified through emergency room and hospitalization records using validated ICD-9 and ICD-10 codes. 21,22 We then excluded records with invalid or inaccurate information and all patients younger than 18 years at the time of the seizure. We further excluded patients with a diagnosis of a brain tumor in the previous 5 years as occasionally patients with brain tumors undergo surgery because of focal neurologic deficits, the tumor's nature (e.g., malignancy), and not because their seizures are refractory to medical treatment.…”

Risk of febrile seizures after first dose of measles–mumps–rubella–varicella vaccine: a population-based cohort study

“…Previous epidemiologic studies [11][12][13][14] have found that these data sources have a high level of completeness and validity. Physicians must submit diagnostic codes (up to 3 per visit) to be reimbursed under the feefor-service insurance plan, and relatively few Alberta physicians (< 7%) are on alternate payment plans, compared with other Canadian provinces.…”