Collaboration to Transition Members to Preferred Formulary Dipeptidyl-Peptidase-4 Inhibitor

ABSTRACT

Objective: To describe the outcomes of a partnership between a drug plan and pharmacists to switch patients from brand name dipeptidyl-peptidase-4 inhibitors to the generic alogliptin.

Study Design: Single-center, retrospective chart review.

Methods: Clinical pharmacists contacted patients with primary care providers within the health system affiliated with the drug plan to facilitate the switch. Drug plan members with external primary care providers were sent letters communicating the formulary change without contact from the clinical pharmacist. Outcomes included the proportion of patients successfully switched to alogliptin, reasons for not switching, changes in hemoglobin A_1C (HbA_1C), and cost savings.

Results: Initially, more than 50% of patients contacted by pharmacists agreed to switch to alogliptin; however, only 44% were successfully switched to alogliptin per prescription claims data. One patient from the group that received letters without clinical pharmacy intervention switched to alogliptin. Overall, there was no significant difference in the mean HbA_1C level for the patients switched to alogliptin. At the end of the year-long study period, only 12 of the 67 patients successfully switched to alogliptin were still taking alogliptin. Reverting to a branded product and switching to a glucagon-like peptide-1 receptor agonist were the most common reasons that alogliptin was discontinued. Cost savings to the health plan were $220,717, or $0.17 per member per month over 1 year.

Conclusions: The use of pharmacists was beneficial in switching patients to alogliptin and yielded cost savings without compromising patient outcomes.

Am J Manag Care. 2025;31(1):In Press

Takeaway Points

This study investigated a collaboration between a drug plan and clinical pharmacists in facilitating a switch between brand-name dipeptidyl-peptidase-4 inhibitors and a generic.

• Nearly 50% of members were successfully switched to the preferred formulary product.
• There was no significant change in hemoglobin A_1C levels in switched patients.
• Cost savings to the health plan were $220,717, or $0.17 per member per month over 1 year.

In 2003, Kindig and colleagues defined population health as the health outcomes of a group of individuals, including the distribution of the outcomes across subgroups.¹ Population health management includes activities undertaken with the goal of improving the health of a population through disease management and health promotion.² There are various definitions of what activities constitute population health management, but most definitions include 1 or more of the following components: improving health outcomes, improving quality of health care, and reducing health care costs, which correspond to the original Triple Aim of health care.^2,3 In later years, the Quadruple Aim and Quintuple Aim added additional components of provider well-being and health equity.^4,5

Insurers have an interest in encouraging, facilitating, and participating in population health management to improve the health outcomes of their members, which ultimately leads to lower health expenditures. This makes insurers or payers an ideal health care player for pharmacists, pharmacy departments, and pharmacies to partner with. These pharmacy-payer partnerships come in many different forms that have been previously discussed in the literature. Medication therapy management (MTM) services are a common form for this partnership, with platforms such as OutcomesMTM giving pharmacists a method to identify qualifying patients with insurance that will reimburse for these services. This method is often used in the community pharmacy setting, where pharmacists can reach out to patients by phone or integrate MTM services into the pharmacy workflow, such as when patients are at the pharmacy picking up medications.⁶ Primary care clinics also partner with pharmacists in the community and ambulatory care setting to complete comprehensive medication reviews (CMRs) for their patients to improve therapeutic regimens and reduce costs.^6-10 In other cases, payers may partner with pharmacists to help ensure that patients are on guideline-directed therapies for certain disease states. For example, Anderson and colleagues reported on an initiative using ambulatory care pharmacists to help improve the “statin use in patients with diabetes” measure for health plan beneficiaries.¹¹ Another way pharmacists play a role in population health management is through formulary management, helping to ensure that medications on health plan formularies are efficient from a clinical and economic perspective. Various “switch” programs have been described in the literature, for which pharmacists and other health care staff conduct outreach to patients to switch to more affordable, equally efficacious medications.^12-14 These switches yielded neutral or positive clinical outcomes with positive economic outcomes, demonstrating that pharmacists can aid in switching patients to more affordable alternatives without compromising clinical outcomes.^12-14

Pharmacists at University of Michigan Health in Ann Arbor, Michigan, participate in a collaboration with the university benefits office and drug plan, providing various services to the drug plan and the beneficiaries. Most of these services occur within the medication optimization program through an embedded clinical pharmacy team at the institution. This is a group of residency-trained pharmacists with an ambulatory care focus. Some but not all team members carry additional board certifications. This team not only partners with the benefits office but also works with other parties on programs to improve patient and organizational outcomes. These projects include work from clinical pharmacists, pharmacy residents, and pharmacy students. Many of the projects fall under 2 main categories: (1) formulary active switch programs and (2) CMRs. The outcomes for CMRs performed under this model were previously published and included a significant decrease in the number of medications prescribed per patient and a high patient satisfaction rate.⁸ The pharmacists at this institution, similar to those at other institutions, collaborate with the drug plan to help identify patients who qualify to switch to a more cost-effective medication and facilitate this switch with patients and providers. Switches implemented by this team include switching between basal insulin products, switching between oral dosage forms (eg, fluoxetine tablets to capsules), and switching between inhalers in the same class. A recent switch conducted by this team involved switching patients from more costly brand-name dipeptidyl-peptidase-4 (DPP-4) inhibitors to the generic DPP-4 inhibitor alogliptin, if clinically appropriate. The switch involved a clinical pharmacist reviewing patient charts to ensure a DPP-4 inhibitor was appropriate and to determine the appropriate dose, contacting the primary care provider for approval, and contacting the patient to discuss the switch and facilitate sending a new prescription to the preferred pharmacy. At the time of this project, a total of 5.6 pharmacist full-time equivalents (FTEs) were embedded within primary care clinics at University of Michigan Health and were completely funded by the clinics. One FTE had 30% of effort devoted to the medication optimization program and spent roughly 10% of their time per week on the DPP-4 formulary switch described above for a period of 6 months, from fall 2017 through spring 2018. The embedded pharmacists who were not specifically assigned to the formulary switch but were involved in the care of patients identified as eligible for the switch were contacted regarding this initiative but did not dedicate time to this work.

DPP-4 inhibitors (alogliptin [Nesina, Vipidia], linagliptin [Tradjenta], saxagliptin [Onglyza], and sitagliptin [Januvia]) are a commonly used class of oral diabetes medications, particularly in patients who wish to avoid injectable therapy. Currently, only 1 DPP-4 inhibitor, alogliptin, has an available generic, which offers cost savings for patients and health plans. This medication requires renal dosing, as does sitagliptin, the most common DPP-4 inhibitor seen in our baseline patient population. The purpose of this study was to evaluate the clinical and economic outcomes of this DPP-4 inhibitor switch program.

METHODS

This study was a retrospective data analysis of a quality improvement project conducted in collaboration between a university drug plan and clinical pharmacists embedded in primary care clinics at a large academic medical center. In November 2017, all university drug plan members with at least 2 prescription drug plan claims for any DPP-4 inhibitor in the previous 6 months were identified for program eligibility. Patients were excluded if (1) they were no longer taking a DPP-4 inhibitor upon chart review or patient outreach or (2) they were currently on linagliptin, as this agent is often used in patients with reduced renal function when other DPP-4 inhibitors cannot be used. Patients with diabetes being treated by a provider within the health system affiliated with the drug plan were assigned to the active arm of the study. A clinical pharmacist reviewed each patient and, if appropriate, reached out to the provider to facilitate a transition to the generic alogliptin. In the case of patients who already worked with a pharmacist regularly for chronic disease management, this pharmacist conducted the outreach because they already had an established relationship with the patient and provider. After obtaining provider approval, the pharmacist then contacted the patient to discuss the switch and, if approved by the patient, ensured the prescription was sent to the patient’s preferred pharmacy. Patients who were treated by providers outside the health system were placed in the passive switch group, which involved a letter informing them of the formulary change and potential cost savings but relied on the patient to reach out to their provider to initiate the switch. Plan cost savings were calculated as the difference between the sum ingredient costs of all DPP-4 inhibitors received prior to and after the switch throughout the 12-month study period minus program costs.

The primary outcome was the proportion of patients successfully switched from sitagliptin to alogliptin per pharmacy claims data. Secondary workflow outcomes included the number of patients and providers who agreed to the switch and reasons why patients were not switched. Secondary clinical outcomes included the change in hemoglobin A_1C (HbA_1C) level at month 3 post switch and the percentage of patients who retained an HbA_1C level within goal at these time points. The 3-month follow-up for HbA_1C was selected because multiple factors could confound a change in HbA_1C that would make it difficult to correlate changes that occurred at later time points to the change in medication. Checking of the 3-month follow-up HbA_1C occurred only if ordered by the primary care provider or other provider during the course of the study and was not specifically ordered by the pharmacy team. The primary economic outcome was the summative net plan costs or savings to the program. Secondary outcomes included provider approval rates, patient acceptance rates, reasons for not switching, duration of therapy on alogliptin (reported as the proportion of patients continuing at 3, 6, 9, and 12 months), and reasons for discontinuing alogliptin.

RESULTS

Overall, 201 patients were identified via prescription claims data, as shown in the Figure. All these patients were taking sitagliptin or a sitagliptin-metformin combination tablet (Janumet). None of the patients were taking saxagliptin. Of the 201 patients initially identified, 154 patients met inclusion criteria, with most of the excluded patients no longer taking DPP-4 inhibitors at the time of chart review or patient outreach. Additionally, 7 patients were no longer treated by a provider located within the health system, and 4 patients were prescribed linagliptin.

In total, more than half (84 of 154; 54.5%) of patients meeting inclusion criteria received both patient and provider approval to switch to alogliptin. Overall, provider approval rates were high, with only 1 provider refusing to switch the patient to alogliptin and 11 providers not responding to the pharmacist’s outreach. The most common reason patients were not switched was patient refusal (24 of 70; 34.3%). Patient refusal was due to a variety of reasons, with patients wishing to consult with their provider as the most common reason given, despite pharmacists explaining that they had already received provider approval. Other reasons for not switching included inability to reach the patient, no response from the provider, and provider refusal, as outlined in Table 1. Although 84 patients agreed to switch to alogliptin when speaking with the pharmacist, only 67 patients had subsequent prescription claims for alogliptin to confirm a successful switch.

The mean (SD) change in HbA_1C level from baseline to month 3 was negligible (–0.15% [0.90%]), with only roughly half (32 of 67; 47.8%) of patients having their HbA_1C level checked within the first 3 months of switching to alogliptin (Table 2). Retention of patients on alogliptin was low, with less than a quarter of patients (15 of 67; 22.4%) having claims for alogliptin supporting continuation of therapy beyond 12 months. Regarding safety and patient preference, the most common reasons for discontinuing alogliptin were switching to a glucagon-like peptide-1 (GLP-1) receptor agonist and reverting to sitagliptin (Table 3). Only 2 patients experienced adverse effects that may have been attributed to alogliptin (hypoglycemia and chest pain). Three patients experienced worsened glycemic control, although from chart review it is difficult to determine whether this was due to the medication switch or other factors.

Regarding economic outcomes, the 12-month operational cost of the program was $10,425, including program design and pharmacist time. The program had an annualized net savings of $0.17 per member per month, which added up to a cumulative savings of $220,717 for this specific plan.

DISCUSSION

This study demonstrated the utility of clinical pharmacists in facilitating an active formulary switch initiative for a prescription drug plan. Clinical pharmacists were able to collaborate with patients and providers to switch more than half of eligible patients from a more costly brand medication to the more affordable generic DPP-4 inhibitor alogliptin. Patient refusal was the most common reason for not switching to alogliptin. Upon further review, many of these patients wanted to discuss the switch further with their provider. Although the language used by the pharmacists cited approval from the provider as a necessary component of the switch, some patients still preferred to discuss this with their regular provider rather than one of the clinical pharmacists. This is one problem that could be ameliorated with closer ties to the providers’ offices. For example, an embedded pharmacist in the clinic may have greater accessibility to the patients and providers in that clinic vs a centralized pharmacist and may have a better opportunity to follow up with patients who were not able to be reached via phone or portal messaging. Another complicating factor that led patients to prefer to remain on the brand-name sitagliptin or revert to this product was the availability of a discount card that reduced the co-pay to $5, which is less than patients would pay for the generic alogliptin through their prescription drug plan. The next most common reason for patients to stay on sitagliptin was because pharmacists were unable to contact the patient. Pharmacists utilized both telephone and electronic health record portal messaging to perform patient outreach but were unable to reach all patients.

This study focused on the population of drug plan patients who had a provider within the affiliated health system. This was the active switch arm of the larger initiative, in which health system pharmacists actively reached out to patients who were eligible for the switch. A large number of eligible patients had primary care providers outside this health system; these patients were part of the passive switch arm of this study. A letter was sent to these patients informing them of the formulary change and potential for cost savings but relied on the patients themselves to reach out to their providers to initiate the switch. Of the 229 eligible patients in the passive switch arm, only 1 patient was successfully switched to alogliptin, with confirming evidence from claims data. This illustrates how pharmacists were able to increase the number of patients switched to alogliptin via outreach, with 43.5% of eligible patients in the active switch arm having at least 1 claim for alogliptin following the intervention compared with 0.4% in the passive switch arm.

With regard to clinical outcomes, HbA_1C control varied, with an overall neutral pattern post switch showing no worsening of clinical outcomes with the change to more a cost-effective medication (Table 2). A lower proportion of patients were at goal at the 3-month end point compared with baseline, but without a comparator group, it is difficult to conclude whether this was due to switching to alogliptin or other factors. Additionally, only approximately half these patients had their HbA_1C checked, further limiting the conclusions that can be drawn from these data. Overall, the minimal changes in HbA_1C level from baseline suggest that the medication switch did not compromise therapeutic efficacy.

Of the patients who switched to alogliptin, 78% (52 of 67) discontinued therapy within 12 months. This was due to a variety of reasons, with most patients switching to a GLP-1 receptor agonist or returning to sitagliptin. It appears from provider notes that some patients did not understand the switch and continued to take sitagliptin rather than switching to alogliptin, despite new prescriptions being sent to their pharmacies. Future projects should include follow-up with patients who agreed to switch to ensure they understood that this new agent will be continued in place of sitagliptin. Another future step would involve contacting the patient’s preferred pharmacy to ensure discontinuation of sitagliptin. Two patients encountered difficulty obtaining alogliptin from the pharmacy due to back order and returned to sitagliptin due to better availability. The patients who reverted to sitagliptin highlight the importance of clearly explaining the reason for and potential benefits of a formulary switch. Additional pharmacist follow-up with patients around the time of the first prescription refill could also have identified some of these missed opportunities. Overall, alogliptin was well tolerated, with few patients discontinuing due to adverse effects.

The cost of the pharmacist’s time was less than $11,000 and was outweighed by the financial benefit of switching members to a cost-effective medication, with more than $220,000 in savings. This study illustrated a cost-effective way to leverage pharmacists for patient outreach to facilitate an active formulary switch program for a prescription drug plan that led to significant cost savings for the plan. Later iterations of this project have likely been even more cost-effective because the pharmacist now supervises training pharmacy students and residents to do this work, which lowers the cost.

This study had several strengths, some of which were unique to the partnership between clinical pharmacists and the prescription drug plan. One of the strengths of this initiative was access to the electronic health record and providers; pharmacists were health system employees rather than drug plan employees, who do not always have access beyond claims data and other demographic information collected from beneficiaries. Additionally, pharmacists had access to clinical data including laboratory results and provider notes, which could have helped inform their decisions (eg, renal dosing for alogliptin). Lastly, this study paired chart review and prescription drug plan data to assess both clinical and economic outcomes.

Limitations

As a retrospective chart review, this study has a few limitations. Some patients never switched medications even though alogliptin was prescribed, which may have been due to patient confusion. In some cases, it was unclear why patients were not switched to alogliptin, particularly for patients treated by embedded clinical pharmacists, because they sometimes did not have documented follow-up or rationale for not switching in the chart and were not contacted by the centralized clinical pharmacists who completed most of the outreach for the switch program. Finally, the HbA_1C laboratory results collected at 1 to 3 months may not reflect treatment with alogliptin because patients may have been completing a previous supply of sitagliptin. HbA_1C was checked for only approximately half the patients switched to alogliptin, which further limited ability to infer conclusions. This could represent another possible intervention for clinical pharmacists to ensure proper laboratory monitoring is occurring.

CONCLUSIONS

This study’s findings demonstrate how a partnership between a prescription drug plan and clinical pharmacists at a large academic institution and health system can be used to facilitate an active formulary switch to a more cost-effective agent. Although the pharmacists were not able to reach all the patients, nearly 50% were switched to the cost-effective alternative, alogliptin, which led to an overall cost savings for the prescription drug plan without compromising therapeutic efficacy. 

Author Affiliations: University of Michigan Health (KE, ANT, HMC, LG), Ann Arbor, MI; University of Michigan College of Pharmacy (KE, ANT, HMC, SL, LG), Ann Arbor, MI; now with Ascension Borgess Hospital (KE), Plainwell, MI; University of Michigan Prescription Drug Plan (AB, SL), Ann Arbor, MI.

Source of Funding: None.

Author Disclosures: The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (ANT, HMC, SL, LG); acquisition of data (KE, SL, LG); analysis and interpretation of data (KE, AB, LG); drafting of the manuscript (KE, AB, HMC); critical revision of the manuscript for important intellectual content (ANT, AB, SL, LG); obtaining funding (HMC); administrative, technical, or logistic support (HMC); and supervision (ANT).

Address Correspondence to: Kelsey Ernst, PharmD, Ascension Borgess Hospital, 345 Naomi St, Plainwell, MI 49080. Email: kelsey.ernst@ascension.org.

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