Counting the Carbon: Quantifying Financial and Environmental Implications of Wasted Inhaler Doses in the Hospital Setting.

Background: Inhalers contribute to health care-related environmental impacts, particularly through greenhouse gas emissions. They are dispensed in multidose formats, which leads to waste, yet little is known about the environmental impact of inhaler waste in the hospital setting.

Objectives: The primary objective was to quantify wasted inhaler actuations on adult medicine and respiratory wards at a community and a tertiary hospital. Secondary objectives were to quantify the cost and carbon footprint of wasted doses, to determine the rate of duplicate inhaler dispensing, and to quantify the prevalence of dispensed inhalers remaining unused.

Methods: For this multicentre, retrospective chart review, the pharmacy informatics team generated a report of adult inpatients for whom one or more inhalers were dispensed from the pharmacy to the respiratory and general medicine wards at a 500-bed tertiary hospital or to the medicine-surgery ward at a 48-bed community hospital over 3 nonconsecutive months (during fiscal year 2021/22). The number of inhalers dispensed was compared with the number of doses documented on patients' medication administration records.

Results: In this study, 23 031 actuations (211 inhalers) were dispensed for 132 patients. Of these, 81.9% were wasted, at a total cost of $6172.82 over the 3 months of the study. For 22 patients (16.7%), at least one inhaler was dispensed, yet no doses were administered; for 16 (12.1%), a duplicate inhaler was dispensed. The carbon footprint of the wasted doses was 1 226 342 g carbon dioxide equivalent, equivalent to driving 5951 km by car.

Conclusions: This study showed significant inhaler waste in the hospital setting, which contributes to the health care-related carbon footprint without contributing to patient care. These results raise important questions about how to continue providing high-quality patient care while minimizing carbon footprint and health care costs.