The CALIPER-Revised Version of the Composite Physiologic Index is a Better Predictor of Survival in IPF than the Original Version

CALIPER is a computer-based quantitative algorithm to accurately characterize and quantify pulmonary fibrosis, and a revised version of composite physiologic index (CPI) has been developed against this new algorithm. The prognostic capabilities of the original and CALIPER-revised versions of CPI were compared in a cohort of 185 patients with IPF prospectively followed in 2 centers. CALIPER-revised CPI was a significant risk factor towards lung transplant (LTx)-free survival, with enhanced hazard ratio (5.68) compared to the original CPI (5.36). Accuracy of LTx-free survival was substantially improved with CALIPER-revised CPI (area under the curve [AUC] 0.75 vs. 0.66), with much better specificity (83% vs. 55%). Six-month changes of CALIPER-revised CPI predicted survival significantly (AUC 0.65). CALIPER-revised CPI is a better predictor of LTx-free survival in patients with IPF. Since CALIPER technology is not available to all centers, this simple and easy to obtain tool may be used to guide management decisions in IPF.