Development and internal validation of the elderly COPD diagnostic score (ECDS): a multidimensional diagnostic tool...

Accurate diagnosis of chronic obstructive pulmonary disease (COPD) among elderly individuals (≥65 years) presents considerable clinical difficulties. Age-associated physiological alterations, frequent multimorbidity, and atypical symptom manifestations complicate the diagnostic process. The conventional fixed FEV₁/FVC threshold of <0.70 may not be optimally suited for this population. This study aimed to construct and validate a novel multidimensional diagnostic tool that integrates both clinical and functional parameters.

We conducted a single-center retrospective diagnostic accuracy study involving 976 symptomatic elderly patients (mean age 73.0 ± 6.7 years) who underwent comprehensive post-bronchodilator spirometry between February 2023 and March 2025. A blinded multidisciplinary expert panel established final diagnoses (moderate/severe COPD versus non-COPD) based on GOLD 2023 criteria and comprehensive clinical assessment. Using a temporal split approach, patients were allocated to either a Derivation Cohort (n = 650, February-December 2023) or an independent Internal Validation Cohort (n = 326, January 2024-March 2025). Within the Derivation Cohort, we developed the Elderly COPD Diagnostic Score (ECDS) through multivariable logistic regression and established age-specific FEV₁/FVC diagnostic thresholds. The finalized ECDS formula and threshold values were subsequently applied to the Validation Cohort without modification. Diagnostic performance was evaluated using ROC-AUC analysis, sensitivity and specificity calculations, and decision curve analysis (DCA).

The ECDS incorporates five weighted components: (100 - FEV₁/FVC), age >65 years, Charlson Comorbidity Index, mMRC dyspnea scale score, and COPD Assessment Test score. In the Derivation Cohort, the ECDS demonstrated excellent discriminative ability with an AUC of 0.972 (95% CI: 0.962-0.982), significantly outperforming FEV₁/FVC alone (AUC 0.942, p < 0.05). At the optimal cutoff of ≥2.8, sensitivity reached 96.4% with specificity of 93.2%. In the independent Validation Cohort, the ECDS maintained robust performance with an AUC of 0.968, sensitivity of 95.1%, and specificity of 90.8%. DCA confirmed superior net clinical benefit across relevant threshold probabilities compared to alternative diagnostic strategies. Age-stratified FEV₁/FVC cutoffs (e.g., <64.5% for age ≥80) proved more accurate than the fixed <70% threshold. Notably, diagnostic accuracy of standard FEV₁/FVC measurement significantly diminished among patients with high comorbidity burden (CCI ≥ 5).

The Elderly COPD Diagnostic Score (ECDS), which synthesizes spirometric data, clinical parameters, and comorbidity information, demonstrated excellent and validated diagnostic accuracy for moderate-to-severe COPD in elderly patients, surpassing the performance of conventional FEV₁/FVC criteria. Implementation of age-specific spirometric thresholds further refines diagnostic precision. The ECDS represents a practical, superior tool for diagnosing COPD in the complex geriatric patient population. While the ECDS offers a superior diagnostic tool for moderate-to-severe COPD in older adults, its performance in mild disease requires further validation.