Cost-benefit Analysis of a Clinical Pharmacist Intervention
Cost-benefit Analysis of a Clinical Pharmacist Intervention
Clinical pharmacy services are vital in the prevention of adverse drug events (ADEs) in
 clinical practice, extending beyond the hospital to chronic disease management in outpatient
 settings. This study sought to evaluate the cost-benefit of a clinical pharmacy intervention
 in resolving treatment-related problems (TRPs) among hospital outpatients with chronic
 diseases. From the hospital system perspective, the cost-benefit analysis was based on a
 randomized clinical trial in the general outpatients of the major hospital in Jordan.
 Eligible patients were randomly assigned to either an intervention or a control group. TRPs
 were identified in both study groups, but interventions were delivered only to the
 intervention group via a home medication management review (HMMR) by a clinical pharmacist. A
 follow-up in both groups took place 3 months after recruitment. The total economic benefit
 was the sum of (i) cost savings due to intervention and (ii) cost avoidance associated with
 preventable ADEs. The primary outcome measures were the net benefit and benefit-to-cost ratio
 with the clinical pharmacist-based HMMR. Based on both of the annual net benefit and
 benefit-to-cost ratio, the study intervention demonstrated to be cost beneficial. Sensitivity
 analyses confirmed the robustness of results. The RCT-based cost-benefit evaluation provided
 evidence-based insight into the economic benefit of a clinical pharmacist-provided HMMR for
 preventing ADEs in the general chronic diseases outpatients. This intervention method against
 the TRPs among outpatients is cost beneficial and offers substantial cost savings to the
 healthcare hospital payer in Jordan.
Economic evaluation The total economic benefit of the intervention was calculated as the sum
 of the cost savings and the cost avoidance associated with the intervention.

 Cost savings Cost savings based on the intervention were the reduced cost of therapy
 associated with treatment changes due to the intervention. Cost savings were therefore
 calculated as (the reduced cost of therapy in the intervention arm) minus (the reduced cost
 of therapy in the control arm).

 Cost avoidance Cost avoidance was the cost avoided by eliminating the occurrence of ADEs as a
 consequence of the pharmacist interventions.

 -  Based on the method of Nesbit et al., utilizing an expert panel of four specialist
 clinical pharmacists, the likelihood of an ADE in the absence of the intervention was
 set. The intervention with the potential to prevent an ADE was assessed for cost
 avoidance.

 -  The cost of an ADE was calculated on the assumption that an ADE in an outpatient will
 lead to a single admission to an internal medicine ward via an emergency department
 visit.

 -  For each intervention with the potential to prevent an ADE, cost avoidance was
 calculated by multiplying the probability of an ADE in the absence of the intervention
 (calculated via the Nesbit method) by the average cost of an ADE. The overall cost
 avoidance was the sum of avoided cost with all interventions for TRPs.

 Cost-benefit analysis The net benefit was calculated as (cost saving) + (cost avoidance). It
 was assumed that no intervention would increase the probability of a preventable ADE.

 -  Calculating monthly cost savings and avoidance was based on a capacity on the part of
 the pharmacist to perform three HMMRs in a day, for an underestimated average of 21
 working days a month, summing to a total of 63 patients per month. The need for a
 monthly outcome cost stems from the fact that outpatient pharmacists are paid monthly in
 Jordan. The assumption of three HMMRs per day is based on the expectation that a single
 home visit will last a maximum of 1 hour, as discussed earlier, and that up to 2 to 3
 hours are needed to identify TRPs, write the physician letter, contact the physician,
 and implement the recommendations.

 -  The cost of the intervention was calculated as (the salary of a regular outpatient
 pharmacist) + (any increased cost of therapy in the intervention arm, measured as -ve
 cost saving). Here, the increased cost of therapy with intervention is referred to as
 '-ve cost saving' in contrast to +ve cost saving, which indicates the reduction in the
 cost of therapy because of treatment changes in the intervention group, as discussed
 above.

 -  The benefit-to-cost ratio was the (sum of cost savings and cost avoidance) divided by
 (cost of the intervention). The net benefit of the intervention was the (sum of cost
 savings and cost avoidance) minus (cost of the intervention).

 Only direct medical costs were considered in calculations, and all costs were adjusted based
 on the Jordanian consumer price index to the financial year 2017/18.
Inclusion Criteria:

 -  ≥18 years old;

 -  with at least one chronic disease, defined as a condition requiring prolonged
 management for a minimum of 3 months;

 -  living in Jordan for the past year;

 -  intention to remain in Jordan for the 3-month study duration;

 -  met at least one of the following criteria:

 -  taking ≥5 medications, taking ≥12 doses a day, discharged from the hospital within the
 past 4 weeks, exposed to significant changes in medication regimens within the past 3
 months, demonstrating symptoms of potential adverse drug reactions, or demonstrating a
 poor therapeutic response to medication therapy. A significant change to medication
 regimen was defined as discontinuing a medication, starting new medications, or
 stepping up because of actual or potential therapy failure or guideline
 recommendations. A poor therapeutic response was defined as persistence of symptoms
 despite treatment.

 Exclusion Criteria:

 -  Patients who don't have a chronic disease

 -  Cognitive or sensory impairment that may prevent conducting the interview

 -  Pregnant patients

 -  Patients who are planning to travel within the next 3 months after the baseline visit
 to the clinic