S30 Predicting hospital length of stay for acute admissions in patients with COPD

p=0.01) and lean mass (b=2.45,p=0.002). PA was lower in males (b=-49.84,p=0.001), on weekends (b=-5.49, p=0.01) and in those who died within 1-year (b=-41.24,p=0.04), and was associated with total sleep time (TST) (b=0.01,p=0.003), EXACT score (b=-0.97,p=0.002), COPD assessment test (b=1.63,p=0.02), FEV1 (b=46.38,p<0.001), inspiratory capacity (b=44.17,p<0.001), PImax (b=2.14,p<0.001) and neural respiratory drive, measured using parasternal EMG (b=-2.12, p=0.01). Patients readmitted within 28-days exhibited poorer sleep quality than non-readmitted patients (TST: b=-110, p=0.004, latency: b=34,p=0.03). Conclusions This study provides a novel insight into the improvement in daytime activity occurring in the 28 days following hospital discharge after severe COPD exacerbation. Physical activity related inversely to age, symptom burden, health status and neural respiratory drive, and positively to lean mass, respiratory muscle strength, expiratory airflow and inspiratory capacity. Total sleep time fell following hospital discharge, and sleep quality was lower in readmitted patients. Future research is needed to evaluate the impact of targeted interventions that enhance physical activity and sleep quality on hospital readmission in this high-risk population.