Clinical predictors of time to death or lung transplantation identified on univariate analyses from the entire HP cohort included dyspnea score, crackles on physical examination, need for oxygen therapy, and lung function measures (FVC, total lung capacity, diffusion capacity for carbon monoxide expressed as % predicted, and FEV/FVC ratio). Independent predictors of time to death or lung transplantation included auscultatory crackles on lung examination (hazard ratio [HR], 4.7; P= .02), FVC (HR, 0.7; P= .01), FEV/FVC ratio (HR, 1.58; P < .01), and a history of cigarette smoking (HR, 2.68; P = .01)
For patients with HP who had HRCT scans available for scoring (n = 132), we repeated univariate and multivariate modeling using all prior clinical Zithromax Australia variables and CT scan features of ground-glass opacities, consolidation, mosaic perfusion, reticulation, traction bronchiectasis, honeycombing, and fibrosis score. Interobserver correlation between radiologist scores was good to excellent for reticulation, traction bronchiectasis, honeycombing, and fibrosis score. Radiographic honeycombing, reticulation, traction bronchiectasis, and fibrosis score were statistically significant univariate predictors of time to death or lung transplantation. Using multivariate analyses, fibrosis score was independently associated with mortality and/or transplantation (HR, 1.35; P < .01). When fibrosis score was removed from the model and replaced by its individual components (reticulation and honeycombing), we found that reticulation was the radiographic feature independently associated with time to death or lung transplantation. The vast majority of deaths in the HP radiographic cohort occurred when patients manifested reticulation and/or honeycombing as well as auscultatory crackles (P < .0001).
To visualize how fibrosis score relates to survival in patients with HP, the radiographic cohort was divided into quartiles by their fibrosis score. Patients in the highest quartile for fibrosis score, Q4, had worse transplant-free survival than patients in the two lowest quartiles for fibrosis score (Q1, P < .01; Q2, P < .01). Patients in the third quartile, Q3, had worse survival than Q1 (P < .05). Survival in the third quartile, Q3, and fourth quartile, Q4, were not statistically significantly different (P = .22).