A risk-predictive model for obstructive sleep apnea in patients with chronic obstructive pulmonary disease

Obstructive sleep apnea syndrome (OSA) is increasingly reported in patients with chronic obstructive pulmonary disease (COPD). Our research aimed to analyze the clinical characteristics of patients with overlap syndrome (OS) and develop a nomogram for predicting OSA in patients with COPD.

We retroactively collected data on 330 patients with COPD treated at Wuhan Union Hospital (Wuhan, China) from March 2017 to March 2022. Multivariate logistic regression was used to select predictors applied to develop a simple nomogram. The area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the value of the model.

A total of 330 consecutive patients with COPD were enrolled in this study, with 96 patients (29.1%) confirmed with OSA. Patients were randomly divided into the training group (70%, n = 230) and the validation group (30%, n = 100). Age [odds ratio (OR): 1.062, 1.003-1.124], type 2 diabetes (OR: 3.166, 1.263-7.939), neck circumference (NC) (OR: 1.370, 1.098-1,709), modified Medical Research Council (mMRC) dyspnea scale (OR: 0.503, 0.325-0.777), Sleep Apnea Clinical Score (SACS) (OR: 1.083, 1.004-1.168), and C-reactive protein (CRP) (OR: 0.977, 0.962-0.993) were identified as valuable predictors used for developing a nomogram. The prediction model performed good discrimination [AUC: 0.928, 95% confidence interval (CI): 0.873-0.984] and calibration in the validation group. The DCA showed excellent clinical practicability.

We established a concise and practical nomogram that will benefit the advanced diagnosis of OSA in patients with COPD.