The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) effectively indicates the risk of mortality in patients with interstitial lung disease, according to data published in Clinical Medicine Insights: Circulatory, Respiratory, and Pulmonary Medicine.
The CAT was developed to measure the health-related quality of life in patients with COPD, and it has recently been introduced to evaluate patients with interstitial lung disease. Fujiko Someya, MD, from the School of Health Sciences at Kanazawa University in Kanazawa, Japan, and colleagues conducted a study to verify the CAT as a predictor of outcome among patients with interstitial lung disease.
The study included 101 consecutive patients with interstitial lung disease who were evaluated by the CAT and then followed for longer than 1 year. CAT scores up to 40 were categorized into 4 groups according to severity—low (CAT ≤ 10), medium (11 ≤ CAT ≤ 20), high (21 ≤ CAT ≤ 30), and very high (CAT > 30).
Overall, patients with higher and more severe CAT scores had lower forced vital capacity and lung diffusion capacity for carbon monoxide. Survival rates were significantly lower among patients with higher scores.
The mortality hazard ratio of high CAT scores compared with low CAT scores was 5.11, the HR for very high scores vs low scores was 19.50, and the HR for medium scores vs low scores was 14.38. The researchers note that age and home oxygen therapy did not influence the hazard ratios.
“This work has demonstrated that it is possible to relate CAT scores to mortality in patients with interstitial lung disease, similar to lung perfusion disturbance,” the study authors concluded. “Considering that the CAT needs no special equipment to evaluate the health status of patients, the CAT may have a potential for use in everyday clinical practice regarding mortality hazard for patients with interstitial lung disease.”
- Someya F, Nakagawa T, Mugli N. The COPD assessment test as a prognostic marker in interstitial lung disease. Clin Med Insights Circ Respir Pulm Med. 2016;10:27-31. doi: 10.4137/CCRPM.S40792.