Medication Extraction from Electronic Clinical Notes in an Integrated Health System: A Study on Aspirin Use in Patients with Nonvalvular Atrial Fibrillation.

PURPOSE: The purpose of this study was to investigate whether aspirin use can be captured from the clinical notes in a nonvalvular atrial fibrillation population. METHODS: A total of 29,507 patients with newly diagnosed nonvalvular atrial fibrillation were identified from January 1, 2006, through December 31, 2011, and were followed up through December 31, 2012. More than 3 million clinical notes were retrieved from electronic medical records. A training data set of 2949 notes was created to develop a computer-based method to automatically extract aspirin use status and dosage information using natural language processing (NLP). A gold standard data set of 5339 notes was created using a blinded manual review. NLP results were validated against the gold standard data set. The aspirin data from the structured medication databases were also compared with the results from NLP. Positive and negative predictive values, along with sensitivity and specificity, were calculated. FINDINGS: NLP achieved 95.5% sensitivity and 98.9% specificity when compared with the gold standard data set. The positive predictive value was 93.0%, and the negative predictive value was 99.3%. NLP identified aspirin use for 83.8% of the study population, and 70% of the low dose aspirin use was identified only by the NLP method. IMPLICATIONS: We developed and validated an NLP method specifically designed to identify low dose aspirin use status from the clinical notes with high accuracy. This method can be a valuable tool to supplement existing structured medication data.

Patient and clinical characteristics associated with gout flares in an integrated healthcare system.

Gout flares have been challenging to identify in retrospective databases due to gout flares not being well documented by diagnosis codes, making it difficult to conduct accurate database studies. Previous studies have used different algorithms, and in this study, we used a computer-based method to identify gout flares. The objectives of this study were to identify gout flares in gout patients newly initiated on urate-lowering therapy and evaluate factors associated with a patient experiencing gout flares after starting drug treatment. This was a retrospective cohort study identifying gout patients newly initiated on a urate-lowering therapy (ULT) during the study time period of January 1, 2007-December 31, 2010. The index date was the first dispensed ULT prescription during the study time period. Patients had to be ≥18 years of age on index date, have no history of prior ULT prescription during 12 months before index date, and were required to have 12 months of continuous membership with drug benefit during pre-/post-index. Electronic chart notes were reviewed to identify gout flares; these reviews helped create a validated computer-based method to further identify patients with gout flares and were categorized into 0 gout flares, 1-2 gout flares, and ≥3 gout flares during the 12 months post-index period. Multivariable logistic regression was used to examine patient and clinical factors associated with gout flares during the 12-month follow-up period. There were 8905 patients identified as the final cohort and 68 % of these patients had one or more gout flares during the 12-month follow-up: 2797 patients (31 %) had 0 gout flares, 4836 (54 %) had 1-2 gout flares, and 1272 patients (14 %) had ≥3 gout flares. Using a multivariate regression analyses, factors independently associated with 1-2 gout flares and ≥3 gout flares versus no gout flares were similar, however, with slight differences, such as younger patients were more likely to have 1-2 gout flares and patients ≥65 years of age had ≥3 gout flares. Factors such as male gender, not attaining sUA goal, having ≥3 comorbidities, diuretics use, no changes in initial ULT dose, and not adhering to ULT all were associated with gout flares versus no gout flares. Using a new method to identify gout flares, we had the opportunity to compare our findings with the previous studies. Our study findings echo other previous studies where older patients, male, diuretics, having a greater number of comorbidities, and non-adherence are more likely to have more gout flares during the first year of newly initiating ULT. There is an unmet need for patients with gout to be educated and managed more closely, especially during the first year.