The Impact an Accurate COPD Diagnosis May Have on 30-Day Hospital Readmissions

Abstract

Background: In fiscal year 2015, CMS began reducing payments for patients readmitted within 30 days of hospital discharge with a diagnosis of acute exacerbation of COPD. GOLD guidelines suggest that while COPD should be considered in symptomatic patients, spirometry (PFT) is required to make the diagnosis. As part of a COPD hospital discharge review, we noticed there were instances where the patient’s diagnosis may not have been supported by available PFT data and thus may have had an impact on hospital readmissions. Methods: Institutional IRB approval was obtained. Patients coded with a COPD hospital discharge in 2018 at Cleveland Clinic Main Campus were reviewed. PFT data (if available) was recorded to include kg/m² and FVC. The kg/m² /FVC ratio was calculated and compared with the predicted Lower Limits of Normal (LLN) values. Hospital discharge diagnosis and 30-day hospital readmission data was also available. One-tailed two-proportions z-test with continuity correction was used in R version 3.3.2 and all analysis were performed at a significance level of 0.05. Results: In 2018, there were 523 hospital admissions with a COPD diagnosis at Cleveland Clinic Main Campus. 109 of these patients (20.8%) had a 30-day hospital readmission. 99 of these patients had PFT data available at the time of this analysis. Of the 99 patients with data, 34 (34.3%) had a kg/m² /FVC ratio that was greater than their predicted LLN on PFT. Of the 414 patients that were not readmitted within 30 days, 318 had PFT data available and 85 (26.7%) had a ratio greater than LLN. If the 34 readmitted patients had not been coded with COPD, the 30-day readmission rate would have decreased significantly from 20.8 to 15.3% (109/523 vs. 75/489, P = .014). Even if all of the 119 patients that had PFT data greater than LLN had not been counted, the readmission rate would still have decreased from 20.8 to 18.6% but not significantly (109/523 to 75/404, P = .22). Those that were coded with a principal diagnosis of COPD exacerbation and had PFT data were significantly less in the group that did not support the diagnosis than in those that did (36/119 vs. 172/298, P < .001). Conclusions: When available, providers should take into account PFT results to possibly prevent a COPD misdiagnosis. An accurate diagnosis may decrease the amount of COPD hospitalizations and readmissions. Limitations of this study include incomplete PFT data. Further studies are encouraged to examine this impact.