An expanded scoring system including an index of nutritional status for patients with cystic fibrosis

Evaluation of success or failure of therapy for patients with cystic fibrosis (CF) commonly relies on the results of a single pulmonary function test (PFT). Most PFT measurements reflect different functional aspects of the lung. Although no single parameter can summarize all aspects of lung function, a combination of several may provide an advantage by reflecting the overall abnormality of lung function in one number. Cropp et al. (1982, Am Rev Respir Dis 126:211-216) developed a multiparameter pulmonary function score (PFS) using the results of six separate parameters obtained from a PFT. In CF, there is also the potential for declining nutritional status (NS), leading to malnutrition and skeletal muscle wasting. Our aim was to expand the PFS by including weighted information on NS, and to determine whether the expanded score (nutritional-pulmonary function score, NPFS) was more sensitive in detecting change in outcome variables than the PFS. Individual PFT parameters, percent ideal body weight (%IBW), and an index of anaerobic performance (AP) were measured in 21 patients on admission to the hospital and again at discharge. In the group as a whole, in-hospital therapy resulted in improvement (P < 0.01) in individual PFT parameters, %IBW, PFS, and NPFS, and no change in AP. While the PFS more effectively reflected improvement in lung function than did any single PFT parameter, the NPFS resulted in an even more sensitive index of change. Based on these results, we believe that the NPFS, which includes both lung and nutritional status, provides an effective and sensitive index of disease severity that can be used as a unifying measure to: 1) detect disease progression; 2) guide rehabilitation and training; 3) stratify patients for clinical trials; or 4) evaluate the effects of a therapeutic intervention.