Evaluation of oxygen prescription in relation to hospital admission rate in patients with chronic obstructive pulmonary disease
1 College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2WB, UK
2 Department of Respiratory Medicine & Physiology, Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Bordesley Green, Birmingham B9 5SS, UK
3 Birmingham East and North (BEN) PCT, Fourth Floor, Waterlinks House, Aston, Birmingham B7 4AA, UK
BMC Pulmonary Medicine 2014, 14:127 doi:10.1186/1471-2466-14-127Published: 5 August 2014
Long term oxygen therapy (LTOT) has a strong evidence base in COPD patients with respiratory failure, but prescribing practices are recognized to need reform to ensure appropriate use and minimize costs. In the UK, since February 2006, all Home Oxygen prescription is issued by hospitals, making respiratory specialists totally in charge of home oxygen prescription. It has been widely noted that inappropriate home oxygen, often for intermittent use (“short burst”), is frequently prescribed in patients with COPD and related conditions with the intention to prevent hospital admissions outside of evidence based LTOT guidelines. We participated in a national Lung Improvement Project aimed at making LTOT use more evidence based. We utilised this unique opportunity of studying the effect of removal of oxygen from COPD patients (who did not meet LTOT criteria) on hospital admission rates.
Primary and secondary care data sources were used to identify patients with COPD in a single primary care trust who were admitted to hospital at least once due to COPD between April 2007 and November 2010. Admission rates were compared between LTOT users and non-users, adjusted for age and COPD severity. LTOT users were further studied for predictors of admission in those appropriately or inappropriately given oxygen according to NICE guidance, and for admissions before and after oxygen receipt, adjusting further for co-morbidity. Mortality and economic analyses were also conducted.
Readmission was more likely in LTOT users (3.18 v 1.67 per patient, p < 0.001) after adjustment for FEV1 and age by multiple regression. When stratifying by appropriateness of LTOT prescription, adjusting also for Charlson index and other covariates, FEV1 predicted admission in appropriate users but there were no predictors in inappropriate users. In longitudinal analyses admission rates did not differ either side of oxygen prescription in appropriate or inappropriate LTOT users. Specialist assessment resulted in cost savings due to reduced use of oxygen.
Admission to hospital is more likely in LTOT users, independent of COPD severity. Oxygen use outside NICE guidance does not appear to prevent admissions.