Noninvasive Ventilation Usage in Children and Adults with Duchenne Muscular Dystrophy: A Multi-center Analysis

Background: Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to chronic respiratory insufficiency often necessitating noninvasive ventilation (NIV). However, factors promoting optimal NIV usage and determinants of adherence in the DMD population are unclear. The aims of the current study are to (1) evaluate NIV use across a pediatric and adult cohort of individuals with DMD; and (2) identify clinical and socioeconomic determinants of NIV usage.

Methods: We performed a multicenter retrospective review of all DMD patients that were prescribed home NIV between Feb/01/2016 to Oct/01/2020. Patients were followed at Rady Children’s Hospital San Diego (RCHSD), The Hospital for Sick Children, Toronto (SickKids) or University of California San Diego Health (UCSD). NIV use was determined objectively from device downloads. A priori, we defined adherence as ≥4 hours NIV use per night, quantified as the percentage of nights above this threshold across a 90-day period. We defined usage as average hourly use and percentage of nights used over a 90-day period. Predictors examined included demographics, social determinants, Deflazacort prescription and pulmonary function. R version 4.0.3 was used for statistical analysis. All institutions obtained IRB approval.

Results: We identified 59 patients with genetically confirmed DMD utilizing home NIV with 13 (22%) from RCHSD, 26(44%) from SickKids and 20(34%) from UCSD. 39(66%) represented pediatric patients evaluated at a children’s hospital. Mean age was 20.1±6.7 years (range 7-39 years), BMI was 23.8±8.8 kg/m2 and 33(56%) were prescribed Deflazacort. Mean seated forced vital capacity (FVC) was 41.6%±31.1% with pediatric patients having greater average FVC compared to adults (66.0%±27.3% SickKids vs. 32.9%±19.5% RCHSD vs. 15.1%±9.1% UCSD; p=0.001). Children had significantly lower NIV usage compared to adults (5.3±3.7 vs. 9.5±4.7 hours; p=0.002). Average nightly NIV usage increased with declining percent predicted FVC (r=-0.33, p=0.014) and increasing age (r=0.32, p=0.014) (Figure 1). Average NIV usage was lower in patients prescribed deflazacort compared to those who were not (6.0±3.3 vs. 8.8±4.6 hours; p=0.02).

Conclusion: Using a multi-center cohort of adult and pediatric DMD patients, most patients met the minimum threshold for NIV adherence with adults having significantly higher NIV usage compared to children. Decreasing FVC and older age were correlated with increased NIV usage. Future investigations will evaluate the specific impact of socioeconomic and clinical outcomes on NIV usage across the spectrum of disease.