Using Administrative Mental Health Indicators in Heart Failure Outcomes Research: Comparison of Clinical Records and International Classification of Disease Coding

• Outcomes research uses ICD-9 codes to capture mental health issues.
• This study compared ICD-9 codes with “gold standard” clinician documentation.
• There was substantial agreement with clinical documentation.
• ICD-9 codes can validly identify mental health issues in patients with heart failure.

BackgroundUse of mental indication in health outcomes research is of growing interest to researchers. This study, as part of a larger research program, quantified agreement between administrative International Classification of Disease (ICD-9) coding for, and “gold standard” clinician documentation of, mental health issues (MHIs) in hospitalized heart failure (HF) patients to determine the validity of mental health administrative data for use in HF outcomes research.MethodsA 13% random sample (n = 504) was selected from all unique patients (n = 3,769) hospitalized with a primary HF diagnosis at 4 San Diego County community hospitals during 2009–2012. MHI was defined as ICD-9 discharge diagnostic coding 290–319. Records were audited for clinician documentation of MHI.ResultsA total of 43% (n = 216) had mental health clinician documentation; 33% (n = 164) had ICD-9 coding for MHI. ICD-9 code bundle 290–319 had 0.70 sensitivity, 0.97 specificity, and kappa 0.69 (95% confidence interval 0.61–0.79). More specific ICD-9 MHI code bundles had kappas ranging from 0.44 to 0.82 and sensitivities ranging from 42% to 82%.ConclusionsAgreement between ICD-9 coding and clinician documentation for a broadly defined MHI is substantial, and can validly “rule in” MHI for hospitalized patients with heart failure. More specific MHI code bundles had fair to almost perfect agreement, with a wide range of sensitivities for identifying patients with an MHI.