Factors associated with misdiagnosis of COPD in primary care

Prim Care Respir J. 2011 Dec;20(4):396-402. doi: 10.4104/pcrj.2011.00039.


Aims: To assess the misclassification of chronic obstructive pulmonary disease (COPD) in Australian primary care.

Methods: A cross-sectional study was performed in 31 (19%) practices in one Australian state. 341 patients with COPD (database diagnosis or current use of tiotropium plus GP confirmation) completed spirometry and questionnaires. Predictors of misclassification were investigated with multi-level mixed-effects logistic regression allowing for clustering by practice.

Results: Spirometric confirmation of COPD (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio <0.7) was not present in 107 (31%) patients; 60 (56%) had normal lung function, seven (7%) had scalloped flow-volume curves and FEV1 <80% predicted, 40 (37%) had restriction (FVC <80% predicted). Among 107 misclassified patients the bronchodilators used were tiotropium in 26% and long-acting β2-agonists in 22%. The likelihood of misclassification increased with overweight/obesity (odds ratio (OR) 2.66; 95% CI 1.50 to 4.70) and self-reported allergic rhinitis/hay fever (OR 1.72; 95% CI 1.13 to 2.64) after adjustment for age, gender, and smoking.

Conclusions: Symptom-based diagnosis of COPD in primary care is unreliable, especially if patients are overweight, so diagnostic spirometry is essential to avoid inappropriate management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchodilator Agents / therapeutic use
  • Cross-Sectional Studies
  • Diagnostic Errors / statistics & numerical data*
  • Forced Expiratory Volume
  • Humans
  • Logistic Models
  • Primary Health Care
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Pulmonary Disease, Chronic Obstructive / drug therapy
  • Pulmonary Disease, Chronic Obstructive / epidemiology*
  • Scopolamine Derivatives / therapeutic use
  • Severity of Illness Index
  • Spirometry / statistics & numerical data
  • Surveys and Questionnaires
  • Tasmania / epidemiology
  • Tiotropium Bromide


  • Bronchodilator Agents
  • Scopolamine Derivatives
  • Tiotropium Bromide