Jacob Choi (Cleveland Clinic), Suha Abushamma (Cleveland Clinic), Jessica Donato (Cleveland Clinic)
Hypophosphatemia is an electrolyte abnormality commonly found on the general hospital wards. Despite its frequent occurrence, there are limited number of studies investigating the appropriate prescribing practices resulting in the overuse of intravenous (IV) phosphate products, which is 4- to 11- times the cost of oral phosphate products.
We developed a simplified protocol for phosphate repletion. Our specific aim was to increase the percentage of oral phosphate therapy in asymptomatic patients with mild or moderate hypophosphatemia who can take oral medications by 10% on the internal medicine teaching services over a 4 week implementation period.
Adult inpatient medical profiles were screened during an 8-week period in November/December of 2017 for serum phosphorus level of 2.6 mg/dL or less. Patients on general hospital wards admitted to an internal medicine teaching service were included if at least one oral or IV dose of phosphate replacement product was given during the study time period. Eligibility for oral therapy was defined by the presence of other administered oral medications on the day of phosphate repletion. A protocol was then designed classifying different degrees of hypophosphatemia and outlining the appropriate route and dosing for repletion (Figure 1). After protocol implementation, appropriateness of prescribing (based on adherence to the protocol for repletion) was reviewed over a 4-week period in March of 2018.
Overall, 31 orders for phosphorus were evaluated prior to intervention. IV phosphate agents were used in 40% of cases. 70% of those cases were either mild or moderate hypophosphatemia and 100% of these patients were eligible for oral phosphate repletion. Post-intervention analysis showed that IV phosphate products were prescribed in approximately 46% (13/28) cases. 92% of the cases were mild or moderate hypophosphatemia and approximately 85% of the patient were eligible for oral therapy.
IV phosphate formulations are commonly prescribed for mild and moderate cases of hypophosphatemia despite nearly all patients meeting eligibility for oral therapy. Establishment of a phosphate repletion protocol and prescriber education did not increase the use of oral therapy in patients with mild or moderate hypophosphatemia who were candidates for oral therapy.
Implications for the Patient
Taken collectively, our data suggests that current overuse of IV phosphate products can cost additional $150-500 per 100 patients per 30-inpatient hospital days. Implementation of a computerized prescribing and clinical decision support system may improve adherence to guidelines for phosphate repletion, ultimately decreasing the cost without affecting therapeutic efficacy.