Development of a severity scale to assess chronic lung disease after extremely preterm birth

Abstract

Objective: Chronic lung disease of prematurity (CLDP) is a frequent complication of prematurity. We aimed to identify what clinicians believe are the most important factors determining the severity of CLDP in extremely preterm infants (<28 weeks gestational age) after discharge from the neonatal intensive care unit (NICU) through 12 months corrected age (CA), and to evaluate how these factors should be weighted for scoring, to develop a CLDP severity scale.

Study design: Clinicians completed a three-round online survey utilizing Delphi methodology. Clinicians rated the importance of various factors used to evaluate the severity of CLDP, from 0 (not at all important) to 10 (very important) for the period between discharge home from the NICU and 12 months CA. Fourteen factors were considered in Round 1; 13 in Rounds 2 and 3. The relative importance of factors was explored via a set of 16 single-profile tasks (i.e., hypothetical patient profiles with varying CLDP severity levels).

Results: Overall, 91 clinicians from 11 countries who were experienced in treating prematurity-related lung diseases completed Round 1; 88 completed Rounds 2 and 3. Based on Round 3, the most important factors in determining CLDP severity were mechanical ventilation (mean absolute importance rating, 8.89), supplemental oxygen ≥2 L/min (8.49), rehospitalizations (7.65), and supplemental oxygen <2 L/min (7.56). Single-profile tasks showed that supplemental oxygen had the greatest impact on profile classification.

Conclusion: The most important factors for clinicians assigning CLDP severity during infancy were mechanical ventilation, supplemental oxygen ≥2 L/min, and respiratory-related rehospitalizations.

Keywords: Delphi panel; bronchopulmonary dysplasia; chronic lung disease; extremely premature; preterm.

Figure 1

Mean absolute importance of factors in evaluating CLDP severity. Each factor was rated individually on a scale of 0 (not at all important) to 10 (very important) and is presented in order of the Round 3 results (most to least important). CLDP, chronic lung disease of prematurity; ED, emergency department [Color figure can be viewed at wileyonlinelibrary.com]

Figure 2

Predicted probability of choosing asymptomatic/minimal versus mild, moderate, or severe lung disease for each attribute level, holding all other attributes at their lowest level. BiPAP, bilevel positive airway pressure; CPAP, continuous positive airway pressure; ED, emergency department; NIPPV, nasal intermittent positive pressure ventilation; suppl, supplemental [Color figure can be viewed at wileyonlinelibrary.com]

Figure 3

Mean overall importance of factors in evaluating CLDP severity. Calculated as the product of absolute importance rating and adjusted relative importance rank (i.e., ranking values adjusted such that “1 = least important”); therefore, higher values indicate greater relative importance; presented in order of the Round 3 results (most to least important). CLDP, chronic lung disease of prematurity; ED, emergency department [Color figure can be viewed at wileyonlinelibrary.com]