Development and Validation of a Healthcare Utilization-Based Algorithm to Identify Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Abstract

Introduction: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are important events that may precipitate other adverse outcomes. Accurate AECOPD event identification in electronic administrative data is essential for improving population health surveillance and practice management. Objective: Develop codified algorithms to identify moderate and severe AECOPD in two US healthcare systems using administrative data and electronic medical records, and validate their performance by calculating positive predictive value (PPV) and negative predictive value (NPV). Methods: Data from two large regional integrated health systems were used. Eligible patients were identified using International Classification of Diseases (Ninth Edition) COPD diagnosis codes. Two algorithms were developed: one to identify potential moderate AECOPD by selecting outpatient/emergency visits associated with AECOPD-related codes and antibiotic/systemic steroid prescriptions; the other to identify potential severe AECOPD by selecting inpatient visits associated with corresponding codes. Algorithms were validated via patient chart review, adjudicated by a pulmonologist. To estimate PPV, 300 potential moderate AECOPD and 250 potential severe AECOPD events underwent review. To estimate NPV, 200 patients without any AECOPD identified by the algorithms (100 patients each without moderate or severe AECOPD) during the two years following the index date underwent review to identify AECOPD missed by the algorithm (false negatives). Results: The PPVs (95% confidence interval [CI]) for both moderate and severe AECOPD were high: 293/298 (98.3% [96.1-99.5]) and 216/225 (96.0% [92.5-98.2]), respectively. NPV was lower for moderate ) than for severe AECOPD (95. 0% [88.7-98.4]). Results were consistent across both healthcare systems. Conclusion:This study developed healthcare utilization-based algorithms to identify moderate and severe AECOPD in two separate healthcare systems. PPV for both algorithms was high; NPV was lower for the moderate algorithm. Replication and consistency of results across two healthcare systems support the external validity of these findings.

Reduced Cost Sharing and Medication Management Services for COPD

“…We examined 3 prespecified secondary outcomes (eMethods 2 in Supplement 2): annualized count of acute moderate-to-severe COPD exacerbations, count of short-acting inhaler fills, and total spending. Following a previously validated algorithm based on the definition of an exacerbation from the Global Initiative for Chronic Obstructive Lung Disease (GOLD), moderate exacerbations were measured from the claims data as an office visit or emergency department visit with a primary diagnosis related to COPD and a prescription for a respiratory antibiotic or systemic steroid; severe exacerbations were measured as an inpatient hospitalization with a primary diagnosis related to COPD . Short-acting inhaler fills were measured from prescription drug claims for any short-acting β-agonist or short-acting antimuscarinic antagonist.…”

“…Moreover, to the extent that actively filling a prescription is an indicator of prior and future use, we found a significant increase in the proportion of beneficiaries with initial fills, second fills, and third fills. PDC has been validated in other contexts, and our claims-based measure of COPD exacerbations has been validated against a detailed and multisite review of medical records . Second, our use of administrative data did not allow for an assessment of other clinical outcomes that may be affected by a change in adherence, such as forced expiratory volume in 1 second or respiratory quality of life.…”

Health trajectories before initiation of non-invasive ventilation for chronic obstructive pulmonary disease: a French nationwide database analysis

“…In that context, previous data suggest that moderate AECOPD may not be accurately identified by healthcare utilization-based algorithms. 30 Furthermore, severe exacerbations are particularly important in COPD because these are a major driver of direct costs. 31 …”