Choose Wisely: Metered Dose Inhalers Versus Nebulized Inhaled Solutions in The Inpatient Setting

In 2018, Kaiser Permanente regional pharmacy team explored an initiative targeting Metered-Dose Inhalers (MDIs) due to their high potential for incurring medication waste. MDIs are bulk items that provide an average of a 30-day supply of medication. While this lengthy day supply is convenient from an outpatient standpoint, it creates a substantial amount of medication waste for the inpatient setting. The average hospitalization length of stay is far less than the medication day supply provided by MDIs. To correct this, many drug manufacturers offer institutional size MDIs with reduced medication day supply for inpatient use only. Unfortunately, not all MDIs are available in institutional size packaging. Studies have shown that less than 15% of MDIs are used during hospitalization and the rest is wasted.⁽⁵⁾

To combat this cycle of medication waste, our inpatient pharmacy evaluated workflow and found clear opportunities to mitigate MDI waste. Historic dispensing records showed that the costly ipratropium MDI was the highest utilized MDI at our medical center, specifically in the CCU and SDU. Therefore, a therapeutic substitution protocol was drafted and presented to the Baldwin Park Pharmacy & Therapeutics Committee (P&T) in October of 2018. The protocol called for converting all ipratropium MDI orders to ipratropium nebulized solution, hospital wide. Unlike MDIs, nebulized solutions are available in a unit-dose package which makes them cost friendly and less wasteful.

The protocol was revised to be limited to the CCU and SDU for implementation due to lack of additional resources outside of these two units from the respiratory therapy department. RCPs presented challenges in absorbing the increased workload that this conversion may create. The decision to convert MDIs to nebulized solutions was previously supported by the American College of Chest Physicians and the American College of Asthma, Allergy and Immunology, who endorsed the use of nebulized solutions as a delivery method of respiratory medications as non-inferior to MDIs.^(2,3)

This IRB approved, retrospective data-only MUE assessed the overall drug cost impact of converting patients from the ipratropium MDI to ipratropium nebulized solution. The study period consisted of two phases: the pre-implementation phase from 11/01/2017 to 09/30/2018 and the post-implementation phase from 11/01/2018 to 09/30/2019. The same time was used to account for seasonal variation in inhaler use.

The study population consisted of patients hospitalized in the CCU or SDU during the study period. Patients were eligible for inclusion if they had an active order for ipratropium MDI or ipratropium nebulized solution during their stay. Patients who were under the age of 18 years old were excluded. To obtain the study population, medication administration records were utilized to gather reports using the pre-specified inclusion criteria during each phase of the study. A total of 216 patients were included during the pre-implementation phase, while 267 patients were included during the post-implementation phase (Table 1).

The primary outcome of this MUE was to analyze the drug cost savings of prescribing nebulized solutions over MDIs in the inpatient setting. The electronic health record was utilized to access medication administration data during the pre and post implementation phases of this evaluation to estimate total drug costs. For patients with an active order for ipratropium MDI, we accounted for one inhaler dispense per hospital stay. For patients started on or converted to ipratropium nebulized solutions, each nebulized solution administration was collected to calculate the total drug cost of nebulized solution use during both pre-implementation and post-implementation.

The secondary outcome was to assess the overall compliance with the conversion protocol since implementation. Patients who were ordered an ipratropium MDI during the post-implementation phase of the study were evaluated for lack of conversion reasons by conducting detailed chart reviews.

Discrete variables were expressed as counts (percentages) and continuous variables as means. The total costs of each medication administered was added for each phase of the study. The overall drug costs were calculated and then extrapolated to a one year period. Descriptive analysis was utilized to compare the overall drug costs of the two phases in this study.

The primary outcome focused on analyzing the cost savings attained by converting patients from MDIs to nebulized solutions in the inpatient setting. To do so, we calculated the total number of administrations of ipratropium MDI and ipratropium nebulized solution during each phase of the study and compared them.

During the pre-implementation phase, a total of 3751 inhalations of the ipratropium MDI were administered in the CCU and SDU. Administrations declined to a total of 336 inhalations during the post-implementation period (Figure 1A), resulting in a 91% decrease in ipratropium MDI administrations.

The number of ipratropium nebulized solution administrations increased from 380 inhalations during the pre-implementation phase to 3092 inhalations during the post-implementation phase (Figure 1B). This accounts for a 714% increase in utilization of the nebulized solution.

The total number of administrations of each medication was utilized to estimate total drug costs. The 2018 average wholesaler price (AWP) of each medication was utilized for cost calculations. Costs were extrapolated to a one-year period to give a better picture of annual drug cost savings. The estimated drug cost savings that occurred by substituting MDIs to nebulized solutions during post-implementation was approximately $68,700 (Table 2).

A sub-analysis of ipratropium MDI utilization hospital wide, outside of the CCU and SDU was conducted. There is a potential for an additional $17,300 in drug cost savings if the conversion protocol was carried out hospital wide (Table 3).

The secondary outcome was to assess the overall compliance with the conversion protocol in the CCU and SDU since implementation. A total of 34 patients were not converted to ipratropium nebulized solution during the post-implementation phase. A report of average ipratropium MDI administrations per day over a three-month period pre-implementation (12/1/2017 through 2/28/2018) was obtained and compared to the same time period post-implementation (12/1/2019 through 2/29/2020). Average MDI administrations declined from 18/day to 1.2/day during post-implementation.

Our conversion focused on the ipratropium MDI due to its high utilization rate for COPD patients admitted to the CCU and SDU at our medical center. This costly MDI does not have an institutional size package and its use results in an estimated 85% medication waste at point of discharge.^(3,5)

This conversion protocol led to a 91% decrease in ipratropium MDI administrations during post-implementation. Only 34 patients were not converted post-implementation to ipratropium nebulized solution due to unclear reasons and lack of documentation.

Despite having some challenges, through interdisciplinary collaboration, our conversion protocol was successful at obtaining an estimated $68,700 in drug cost savings over a one-year period. Since the conversion protocol was limited to the CCU and SDU, a sub-analysis of ipratropium MDI utilization hospital wide was conducted. Utilization of the ipratropium MDI outside of the CCU and SDU was minimal, with 70% of ipratropium MDI administrations occurring in these two units. An estimated additional drug cost savings of $17,300 could occur if this conversion protocol was carried out hospital wide.

Healthcare costs such as RCP labor costs and costs of respiratory therapy equipment’s were not evaluated in this study. Future direction includes evaluating these costs and presenting the sub-analysis findings to the respiratory therapy department in order to drive agreement for implementing a hospital wide therapeutic substitution.

A complete chart review of each patient included in our evaluation was not feasible due to time constraints, therefore, an accurate count of MDI dispenses was lacking and an estimation of one MDI per patient, per admission was assumed. Additionally, drug costs are pure estimates based on the 2018 AWP price of each medication.

This interdisciplinary RCP and physician led conversion protocol was successful at reducing MDI waste and attaining an estimated $68,700 in drug cost savings over a period of one year since implementation. Sub-analysis of MDI utilization outside of the CCU and SDU highlighted an opportunity for an additional $17,300 in drug cost savings if the conversion was carried out to other hospital units. Our study showed that effective interprofessional collaboration can lead to organizational cost savings in the inpatient setting.