Exacerbation Risk Assessment System Proves Successful for Patients With COPD, Comorbidities

Investigators of a 3-year observational study identified independent risk factors for exacerbations related to chronic obstructive pulmonary disease (COPD) and successfully developed a novel risk score for COPD exacerbations.

Investigators developed an exacerbation risk assessment system for patients with chronic obstructive pulmonary disease (COPD) with comorbidities, which performed well and identified key exacerbation predictors in a recent study.

The prospective cohort study, published in Journal of Inflammation Research, was one of the first attempting to clarify the impact that comorbidities have on acute exacerbations of COPD and the role they play in leading to a poor prognosis.

“The results in our study described part of comorbidities and emphasized the importance of cardiovascular events in COPD patients,” said the investigators.

Having comorbidities can alter the body’s internal microenvironment and homeostasis in patients with COPD. Comorbidities can develop prior to COPD onset, and patients with COPD have a significantly higher prevalence of comorbidities than the general population. However, the underlying pathological pathway of this effect has not been fully explored. Little research has been done on the relationship between comorbidities and exacerbations in patients with COPD, although early recognition of high exacerbation risk is critical to preventing them. Additionally, prior research in this area has mainly focused on all-cause mortality of COPD rather than exacerbation events.

The investigators conducted the Shanghai COPD Investigation on Comorbidity Program, a 3-year observational cohort study, analyzing some of the patients aged 40 or older who had a primary diagnosis of COPD. Among the 742 patients enrolled in the study, 415 were eligible for the analysis.

The frequency of comorbidities ranged from 0.40% to 30.84%. Nearly 65% of patients with COPD had at least 1 comorbidity and almost 35% had 2 or more comorbidities. Hypertension was the most common comorbidity, and the coexistence of anxiety and hypertension was high.

The patients were split into 3 clusters based on the type and severity of their comorbidities:

  • Cluster 1: nonsevere cases with respiratory, metabolic, immune, and psychologic diseases (n = 99)
  • Cluster 2: severe cases with cardiovascular and neoplastic diseases (n = 16)
  • Cluster 3: less comorbidity (n = 300)

Cluster 1 had the highest prevalence of asthma, allergic rhinitis, osteoporosis, and connective tissue disease. Cluster 2 had a higher prevalence of myocardial infarction, arrhythmia, and neoplastic diseases, including gastrointestinal tumors. Cluster 3 suffered the least from diseases than the other clusters and had the lowest number of comorbidities; however, these patients did have worse pulmonary function and a greater degree of airflow limitation.

The crude regression model found that anxiety was the most significant factor influencing exacerbation risk (odds ratio [OR], 7.42; P < .001). After adjusting for confounding factors, hypertension (OR, 3.14; P = .001), angina (OR, 10.16; P = .03), and anxiety (OR, 5.94; P = .001) were identified as independent risk factors of COPD exacerbations.

However, there was a low number of patients with angina in the cohort, meaning that this data should be applied with caution. Patients with allergic rhinitis had less exacerbation events than those who did not.

The investigators used the comorbidity profiles and conventional comprehensive indices found in the study to develop a new exacerbation risk score, incorporating 4 comorbidities and the BODE index (BODEx; body mass index, obstruction [FEV1], dyspnea), which is used to predict all-cause mortality and mortality from respiratory causes in patients with COPD.

The score showed superiority in detecting patients with worse symptoms. In the internal validation sample of 152 patients, the score behaved well (area under the curve [AUC], 0.72). Additionally, the novel BODEx scoring system was more appropriate for predicting mild exacerbations in patients with angina, hypertension, anxiety, and allergic rhinitis (AUC, 0.74).

Some of the limitations of the study included the lower number of patients in Cluster 2 and the lack of data collection surrounding exacerbation dates, which limited the investigators’ ability to estimate the rate of 30-day exacerbation or hospitalization. Future studies should examine further validation of large-sample populations to validate the stability of the risk score system.

“To some extent, we hope our results may provide some assistance for assessing the risk of acute exacerbation of COPD,” wrote the investigators.

References

Ge H, Liu X, Gu W, et al. Distribution of COPD comorbidities and creation of acute exacerbation risk score: Results from SCICP. J Inflamm Res. 2021;14:3335-3348. doi:10.2147/JIR.S315600