Overall this study demonstrated discharging self-pay patients with a diagnosis of ABSSSI to receive dalbavancin and patient assistance through vial replacement to be an effective cost-saving strategy. From 2005 to 2014 skin and subcutaneous tissues infections in adults aged 18–44 years have been documented in the top five reasons for hospital admission . With interventions in hospitals being focused on patient outcomes that are clinically safe, effective, and cost conscientious, understanding the financial impact of treatment options is important in this common inpatient diagnosis . This study found dalbavancin to have no difference in clinical outcomes or safety profile based on no significant increase in LOS, 30-day readmission rates, or adverse events while in the hospital. In addition to dalbavancin being shown as a clinically effective agent for ABSSSI in self-pay patients, this study also highlights the cost-savings aspect of choosing this therapy which is discussed in more detail in paragraphs below.
This study found that patients with ABSSSI were consistent with patient characteristics in previous studies analyzing the use of dalbavancin regarding age, gender, race, and infectious diagnosis [13,14,15,16,17,18]. Streifel et al.  found that patients treated with dalbavancin in their academic center had a mean age of 48.6 years with 22% of the infections being skin and soft-tissue infections, only second behind osteomyelitis. Morrisette et al.  found similar patients in their analysis of long-acting lipoglycopeptides for ABSSSI. The majority of the ABSSSI cases were cellulitis. This was consistent with previous data showing cellulitis and/or abscess making up 80% of the cases while 20% had wound infections (e.g., post-traumatic or postoperatively) . There was no difference found in antibiotic allergy status. This is important to note as certain allergies (e.g., penicillin) have been linked to increased rates on antibiotic resistance, Clostridioides difficile, and increased use of broad-spectrum antibiotics which could have influenced the primary and secondary outcomes [24, 25]. A numerically higher amount of IVDU in the dalbavancin group were found (25% vs 13.7%, p = 0.387). This was similar to the finding in the study by Morrisette et al.  that also discovered the high percentage of patients who are IVDUs with methicillin-susceptible and methicillin-resistant S. aureus infections are eligible for dalbavancin. Outpatient parenteral antimicrobial therapy (OPAT), specifically long-acting lipoglycopeptides, pose as a useful solution in this patient population. There are many advantages to this treatment option, especially with dalbavancin. These include a reduced need for long-term central lines which reduces infection risk and substance abuse concerns, increased compliance for patients with poor adherence or difficult life situations (e.g., homelessness, incarceration, rural location) with a one-time dose, and discharge assistance when oral antibiotics may not be adequate treatment .
Interestingly, there were a high amount of infectious diseases (ID) consults in this population, with a higher percentage in the SOC group (37% vs 48%). This could be attributed to the underlying difficult transitions of care decisions with a self-pay patient population . All of the patients discharged to receive dalbavancin in this study were empirically started on vancomycin at admission. This could be explained as vancomycin is one of the targeted antimicrobial therapies reviewed by the ID PharmD on a daily basis and the difficulties in identifying possible dalbavancin candidates in a reasonable timeframe. The increased risk of side effects and lack of alternate treatment options lend to the ID PharmD being able to determine potential dalbavancin candidates and assist with transitions of care . The impact of the ID PharmD has been shown in the previous study, as they are able to assist with clinical knowledge skills to aid in selecting, counseling, and effectively treating this patient population with dalbavancin .
Results showed discharging to receive dalbavancin for ABSSSI to be a cost-saving option of $1252 per patient. Previous studies have shown both cost and LOS reduction benefits with dalbavancin. Streifel et al.  found that analyzing 27 patients who received dalbavancin found an avoidance of 617 hospital days which resulted in a mean cost savings per patient of $40,414; however, that study did include non-ABSSSI cases. An additional study in Germany demonstrated the cost-savings effect of dalbavancin in MRSA ABSSSI by reducing LOS by 6.45 days with a cost savings of $3099.69 (2865 €) . The previous study at our institution was associated with decreased cost and length of stay . The impact of vial replacement was shown to mirror previous data of dalbavancin as a cost-effective option in the self-pay population. To our knowledge, there are no current data to compare the financial results to self-pay patients. For those with third-party payers, dalbavancin has been shown to save $1442 to $4803 per complicated skin and soft-tissue infection (cSSTI) case with a safe adverse event profile .
In an economic evaluation of dalbavancin in three European countries, dalbavancin was found to reduce length of stay for patients with ABSSSI by 3.3 days per patient with no additional cost towards the health system . Additionally, McCarthy et al.  found a reduction in length of stay (3.2 days vs 4.8 days, p = 0.003) which was attributed to an increase in productivity for the staff. While this study did not result in a significant decrease in length of stay, there were two confounding factors that could have contributed to this. One patient in the dalbavancin group had a LOS of 11 days. There was an attempt to adjust for this by presenting the data as median days. Additionally, for ABSSSI there was a high percentage in the standard of care group of ID consults (47.9%), which could have contributed to a shorter length of stay. The adverse event profile was similar in this study between the two groups. This was important since previous literature has shown MRSA ABSSSI treated with vancomycin has an increased risk for acute kidney injury (AKI) in patients with no medical insurance (OR 3.451, 95% CI 1.131–9.090) . The rates of AKI in both treatment groups were similar despite 50% of MRSA infections in both groups.
Several limitations are present within this study. First, the low number of patients enrolled in the dalbavancin arm (n = 12) makes it difficult to determine definitive conclusions on safety and efficacy. Similarly, the retrospective nature of this design limited the ability to control factors, such as patient assistance and vial replacement receipt. The 15 patients that did not have vial replacement performed identify a performance improvement for our institution but a limitation of this study. Additionally, these patients were not randomized. This led to certain comorbidity and infection etiology discrepancies that could have influenced clinical parameters outside of costs. During the screening process for patients, it was found that some patients had a documented abscess infection without a matching ICD-10 code. This potential human error could have resulted in fewer patients being included in the two groups and lower numbers in the abscess groups. Some patients who met inclusion criteria might not have been candidates for dalbavancin therapy. This is because only primary diagnosis codes for inclusion or exclusion criteria were used. Secondary codes could have influenced LOS or prohibited use of dalbavancin therapy. Access to the financial data was limited because some accounts were frozen for financial reimbursement investigation or deemed charity. Indirect costs were limited to data on current inpatient stay and do not reflect any outpatient costs (i.e., outpatient antibiotic prescriptions) associated with care beyond dalbavancin patients receiving infusion.