A REVIEW AND ECONOMIC-EVALUATION OF BRONCHODILATOR DELIVERY METHODS IN HOSPITALIZED-PATIENTS

Background: Bronchodilator delivery by metered dose inhaler (MDI) to t reat airflow obstruction is considered to be less expensive and as eff ective as nebulized therapy. Objectives: To document the utilization o f bronchodilator delivery methods in a tertiary care Canadian universi ty teaching hospital and to perform an economic evaluation. Methods: A prospective 6-week audit of 4 preselected hospital wards (respiratory , thoracic surgery, general surgery, and a general internal medicine c linical teaching unit) and a cost-minimization economic evaluation wer e performed. Bronchodilator (salbutamol and ipratropium bromide) doses , frequency, and delivery methods, either MDI or wet nebulizer (WN), w ere recorded for 95 patients treated with aerosolized bronchodilators, Direct costs for medications and hourly wages including benefits and equipment were obtained. Time and motion studies identified time alloc ated to MDI and WN delivery. We used sensitivity analyses to test assu mptions that could significantly affect treatment costs, especially as sumptions about medications, labor, and spacer devices. Costs are expr essed in Canadian dollars (Can$1 = US$0.75). Results: Sixty-seven pati ents (70.5%) were treated with WN, 6 (6.3%) with MDI, and 22 (23.2%) w ith both WN and MDI. Self-administration of salbutamol by MDI was the least expensive: $1.27 for 200-mu g doses and $1.73 for 400-mu g doses compared with $2.62 for a 2.5-mg dose delivered by WN. The difference in cost between equivalent treatments (400-mu g MDI vs 2.5-mg WN) is only $0.89, Sensitivity analyses showed that MDI was the least expensi ve therapy when self-administration was possible and for all levels of supervision if more than 4 minutes was needed to administer a WN trea tment. Conclusions: Bronchodilator delivery by WN is commonly prescrib ed for hospitalized patients despite evidence for equivalency of effec t using MDI and in the absence of substitution protocols. Previous stu dies have estimated a far greater cost differential based on unrealist ic labor estimates. We found that supervision of patients using MDIs m inimized the differential cost between WN and MDI therapy and that cos t savings are maximal in patients who can self-administer MDI therapy, Methodologically sound economic evaluations can better identify true cost savings and variables that need further study.