# The Significance of Density Measurement and the Modified Bhalla and Reiff Scores in Predicting Exacerbations and Hospital Admissions in Cystic Fibrosis Patients

## TL;DR

This study shows that measuring lung tissue density and using specific CT-based scores can predict how often cystic fibrosis patients experience flare-ups and need hospital care.

## Contribution

The study introduces PLND as a new predictive measure alongside modified Bhalla and Reiff scores for cystic fibrosis outcomes.

## Key findings

- The modified Bhalla score was most strongly linked to exacerbations and hospitalizations.
- PLND and Reiff scores also showed significant predictive value for future hospital admissions.
- Cut-off values for each score were identified to optimize prediction accuracy.

## Abstract

Background and Objective: This study’s objective was to determine the impact of the percentage of lung tissue within the normal density range (PLND) on exacerbations and hospitalizations compared with the modified Bhalla and Reiff scores. We also investigated the effects of these measures on pulmonary function tests (PFTs). Materials and Methods: This retrospective analysis involved adult cystic fibrosis (CF) patients who had thoracic computed tomography (CT) while in a stable clinical condition. A dedicated radiologist analyzed CT images and conducted modified Bhalla, Reiff, and PLND assessments. We analyzed the exacerbations and hospitalizations in the year after the CT scan. We also examined PFTs at the time of the CT scan and one year later. Results: This study’s population consisted of 63 subjects (33 men), with a median age of 23.2 years. The median modified Bhalla score was 9.0 (IQR: 7.0–12.0), the median Reiff score was 11.0 (IQR: 8.0–15.0), and the median PLND was 79.4% (IQR: 74.5–82.0). The Bhalla score had the strongest relationship with both the number of exacerbations (p < 0.001, r: −0.559) and hospitalizations the following year (p < 0.001, r: −0.636), followed by the PLND score and the Reiff score. Youden’s index shows that the optimum cut-off values for hospitalization at ≤2 and >2 are 6.5 for the modified Bhalla score, 13.5 for the Reiff score, and 76.5% for the PLND. Conclusions: The measurement of PLND may serve as a predictor for exacerbation and hospitalization rates, aligning with the modified Bhalla and Reiff scores, and shows potential for application in follow-up assessments.