Abstract
Background
Outpatient parenteral antimicrobial therapy (OPAT) is a safe and effective alternative to hospitalization for many patients with infectious disease. The objective of this study was to describe the experience with a newly established formal OPAT program at a Canadian academic centre.
Methods
We conducted a retrospective cohort study including all patients referred to the OPAT clinic between July 2016 and June 2017 and a contemporary cohort of patients who received home parenteral therapy without clinic referral. A quasi-experimental design was used to assess the impact of the clinic on patient outcomes compared with a pre-intervention cohort of patients from 2012 to 2013.
Results
Between July 2016 and June 2017, 334 patients were referred to the OPAT clinic; 33% of the patients visited the emergency department (ED), and 21% required readmission within 60 days. Compared with the clinic patients, urinary tract infection diagnoses were more common among the 39 contemporary patients who were treated with home parenteral antibiotics without OPAT clinic referral (51% versus 4%, respectively; p < 0.001) and treatment durations were shorter (median 10 days versus 42 days; p < 0.001). Compared with a pre-intervention cohort, OPAT clinic implementation was associated with a trend toward decreased ED visits (33% versus 43%; p = 0.07). On multivariable analysis, this translated to an overall adjusted odds ratio of 0.64 (95% CI 0.40 to 1.04, p = 0.07) for readmission and ED visits.
Conclusions
The OPAT clinic served a high volume of patients in its first year of operation and may be helpful in reducing unfavourable patient outcomes.
Keywords: ambulatory care, bacterial infections, OPAT, outpatient parenteral antimicrobial therapy, quality improvement
Abstract
Historique
L’antibiothérapie parentérale ambulatoire (APA) remplace l’hospitalisation de manière sécuritaire et efficace pour bien des patients atteints d’une maladie infectieuse. La présente étude visait à décrire l’expérience d’un nouveau programme officiel d’APA dans un centre universitaire canadien.
Méthodologie
Les auteurs ont procédé à une étude de cohorte rétrospective incluant tous les patients orientés vers une clinique d’APA entre juillet 2016 et juin 2017 et une cohorte de patients qui, pendant la même période, ont reçu un traitement parentéral à domicile sans être orientés en clinique. Ils ont utilisé une méthodologie quasi-expérimentale pour évaluer les répercussions du suivi en clinique sur les patients par rapport à une cohorte de patients avant l’intervention, entre 2012 et 2013.
Résultats
Entre juillet 2016 et juin 2017, 334 patients ont été orientés vers la clinique d’APA; 33 % ont consulté à l’urgence et 21 % ont dû être réhospitalisés dans les 60 jours. Les diagnostics d’infection urinaire étaient plus courants chez les 39 patients recevant une antibiothérapie parentérale à domicile sans être dirigés vers une clinique d’APA que dans la cohorte suivie en clinique (51 % par rapport à 4 %, respectivement; p < 0,001) et la durée du traitement était plus courte (médiane de dix jours par rapport à 42 jours; p < 0,001). Par rapport à la cohorte observée avant l’intervention, le suivi en clinique d’APA était associé à une tendance vers une diminution des consultations à l’urgence (33 % par rapport à 43 %; p = 0,07). À l’analyse multivariable, ces résultats se traduisaient par un rapport de cotes rajusté global de 0,64 (IC à 95 %, 0,40 à 1,04, p = 0,07) pour la réhospitalisation et les consultations à l’urgence.
Conclusions
La clinique d’APA a accueilli un fort volume de patients pendant sa première année de fonctionnement et peut contribuer à réduire les résultats cliniques défavorables chez les patients.
Mots-clés : amélioration de la qualité, antibiothérapie parentérale ambulatoire, APA, infections bactériennes, soins ambulatoires
The practice of providing intravenous (IV) antibiotics in the outpatient setting was first introduced more than 40 years ago (1). Since then, outpatient parenteral antimicrobial therapy (OPAT) has been recognized as a safe and effective alternative to hospitalization, favoured for its cost-effectiveness as well as its patient-centred approach. Recently, several guidelines have been published regarding appropriate patient selection and monitoring (2–4). Although OPAT has become a routine part of clinical practice, there remains significant variation in its delivery. Worldwide, many institutions have established specialized OPAT clinics; however, this is still relatively uncommon in Ontario (5–8). In most locations, there is a lack of formal infrastructure, and OPAT is managed at the discretion of the prescribing physician.
We previously conducted a retrospective study examining outcomes for patients of a single tertiary centre who were discharged on IV antibiotics in the absence of a formal OPAT program. The results of this study, which took place between 2012 and 2013, revealed high rates of emergency department (ED) use and hospital readmission (9). In response, a dedicated OPAT clinic was established at this facility in 2016 as a quality improvement initiative. This clinic—run by infectious diseases (ID) physicians—provides centralized follow-up for patients who are on outpatient parenteral antimicrobials, with the objective of reducing unfavourable outcomes. The purpose of this study was to define the patient population treated at this clinic during its first year of operation and to evaluate its impact on patient outcomes.
Methods
Nature of OPAT clinic intervention
Sunnybrook Health Sciences Centre (SHSC) is a 627-bed academic health sciences centre located in Toronto. Launched in June 2016, the OPAT clinic operates during business hours 5 days per week and is staffed by a rotating roster of ID physicians. The program also employs an administrative assistant and specialist nurse who are shared with other rapid referral clinics (0.25 full-time equivalents dedicated to OPAT clinic). The primary referrals to this clinic are hospitalised patients who were seen by the inpatient ID consult service and determined to be appropriate for OPAT by the ID physician. In addition, the clinic accepts urgent referrals from the ED and other institutionally affiliated outpatient providers. All referrals are vetted by an ID physician. Subsequent follow-up and outpatient monitoring are arranged at the discretion of the ID physician. This program not only provides guaranteed follow-up with an ID physician but also serves as a clear point of contact for OPAT-related issues, with the aim of diverting patients away from unnecessary ED visits. Throughout the study period, administration of outpatient parenteral antimicrobials was coordinated and funded by the Ontario Local Health Integration Networks. Patients received their antibiotics at a community-based infusion clinic (separate from the OPAT clinic), at home by a home care nurse, or through nurse-trained self-administration. This differs from some other Canadian provinces in which an OPAT clinic would need to provide a facility for direct administration of the antibiotics.
Study design and patient selection
We conducted a retrospective cohort study of all SHSC patients (aged 18 years and older) who had received outpatient parenteral antimicrobials during the 1-year period between July 1, 2016, and June 31, 2017. Subjects consisted of patients who were seen at the OPAT clinic (i.e., the clinic cohort) and inpatients who were discharged on IV antibiotics during the same time period but not referred to the clinic (contemporary non-clinic cohort). These subjects were captured by cross-referencing the list of patients who were referred for home care services with the pharmacy database of patients whose parenteral antimicrobials remained active on the day of discharge. This was followed by detailed chart review to exclude patients whose IV antimicrobials had been discontinued before leaving hospital. Outpatients who were discharged directly from the ED with home IV antibiotics but without clinic referral were not captured in this study.
Moreover, to assess the impact of the OPAT clinic on patient outcomes, we conducted a quasi-experimental pre–post study comparing the population during the intervention period (i.e., after the implementation of the OPAT clinic) with the population from the previous 2012–2013 baseline pre-intervention period. For this comparison, a subset of the overall OPAT population from 2016–2017 was generated to match the inclusion and exclusion criteria that had been applied to the 2012–2013 cohort. Specifically, the subset included only patients whose parenteral antimicrobials had been initiated during a hospitalization and who were discharged to a home residence, and we excluded patients who had antimicrobials initiated as an outpatient and those who were transferred from the hospital to another acute-care, long-term care, or rehabilitation facility after discharge.
Data sources and extraction
Patient data were collected from the electronic patient records. The extracted variables included demographics, comorbidities (including any history of infection or colonization with antibiotic-resistant organisms), infectious disease diagnoses, treatment characteristics, and vascular access. Antibiotic-resistant organisms (AROs) were defined as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella (ESBL), and carbapenemase-producing Enterobacteriaceae.
Outcomes
The primary outcome of interest was all-cause readmission, ED use, or both; all-cause mortality was examined as a secondary outcome. The rates of these events were measured in the 60 days after initiation of OPAT or discharge from hospital (if parenteral antimicrobials were started as an inpatient).
Statistical analyses
Comparisons between groups were performed using χ2 tests for categorical variables, t-tests for normally distributed continuous variables, and Wilcoxon rank-sum tests for non-normally distributed continuous variables. Logistic regression was performed to assess whether the intervention (i.e., whether the patient was treated after the OPAT clinic was established) was associated with a reduction in the 60-day event rate. Patient age and history of antimicrobial-resistant organisms were a priori selected for inclusion into the model as covariates, based on prior literature (10). Additional variables included in the model were determined through the change-in-estimate approach by assessing potential covariates in bivariate models to look for confounders that changed the coefficient of the intervention by greater than the prespecified 10% cut-off (11). Statistical analyses were performed using IBM SPSS Statistics version 25.0 (IBM Corp., Armonk, NY).
Ethics approval
This study was approved by the Research Ethics Board at SHSC, Toronto.
Results
OPAT clinic population
A total of 373 unique patients received OPAT within the 1-year study period. Of these patients, 334 were seen in the OPAT clinic, and their demographics, clinical characteristics, and outcomes are summarized in Table 1. The majority of patients were male (63%), and the median age was 65 years (interquartile range 52–74 years). Hypertension (51%) was the most common comorbidity, and almost one-third of the patients had diabetes (31%). Only 12% had a history of infection or colonization with antibiotic-resistant organisms.
Table 1:
Characteristics of OPAT clinic patients (N = 334)
| Variables |
OPAT clinic patients no. (%)* |
|---|---|
| Age, y, median (IQR) | 65 (52–74) |
| Male | 210 (63) |
| Prior hospitalization within past 12 mo | 167 (50) |
| History of antibiotic-resistant organisms | 39 (12) |
| Comorbidities | |
| Hypertension | 170 (51) |
| Diabetes | 104 (31) |
| Cancer | 74 (22) |
| Coronary artery disease | 71 (21) |
| Renal disease | 43 (13) |
| Peripheral vascular disease | 37 (11) |
| Syndromes† | |
| Bacteremia | 96 (29) |
| Surgical site infection | 61 (18) |
| Osteomyelitis (extremity) | 61 (18) |
| Prosthetic joint infection | 37 (11) |
| Skin and soft tissue infection | 32 (10) |
| Endocarditis (native and prosthetic) | 16 (5) |
| Urinary tract infection | 14 (4) |
| Antimicrobials† ‡ | |
| Cefazolin | 82 (25) |
| Vancomycin | 63 (19) |
| Ceftriaxone | 61 (18) |
| Piperacillin–tazobactam | 47 (14) |
| Ertapenem | 33 (9) |
| Penicillin | 27 (8) |
| Cloxacillin | 23 (7) |
| Patient outcomes§ | |
| No events | 209 (63) |
| ED visit | 109 (33) |
| Readmission | 71 (21) |
| Mortality (all cause) | 7 (2) |
* Unless otherwise indicated
† Not mutually exclusive
‡ Less commonly used parenteral antimicrobials included meropenem, ceftazidime, ampicillin, penicillin G, and voriconazole
§ Readmission, ED visit, and mortality were measured within 60 days (all cause and not mutually exclusive)
ED = Emergency department; IQR = Interquartile range; OPAT = Outpatient parenteral antimicrobial therapy
The most common infectious syndromes for which patients received OPAT included bacteremia (29%), surgical site infection (18%), and osteomyelitis of the extremities (18%; Table 1; diagnoses were not mutually exclusive). Bone and joint infections featured prominently, affecting 202 patients (60%), of which 49 cases were associated with implanted hardware. In terms of treatment, 18 unique antimicrobials were administered in this study. The three most frequently prescribed antimicrobials were cefazolin (25%), vancomycin (19%), and ceftriaxone (18%; Table 1). Most patients were treated with just one parenteral drug for the duration of OPAT (71%); however, two patients required three IV antimicrobials concurrently. For vascular access, the majority received a peripherally inserted central catheter (95%). The remaining patients were treated using peripheral venous catheters, port-a-caths, or hemodialysis vascular catheters.
In the 60 days after initiation of OPAT, 125 (37%) of the patients either visited the ED and/or required readmission. Of these 125 patients, 79 (63%) returned to hospital at least once because of concerns related to their infection or treatment, and the remaining 46 (37%) patients sought care for unrelated issues. Some common reasons for OPAT-related hospital visits included disrupted venous access and adverse drug reactions, as well as infection relapse or treatment failure. All-cause mortality rate at 60 days was 2%. Most of the patients died outside of the hospital (some of whom were palliated), and only one patient died while admitted to an acute care facility.
OPAT clinic population versus contemporary non-clinic cohort
There were notable differences between the clinic patients and their contemporary counterparts who were not referred to the clinic but received OPAT during the same time period (n = 39). The non-clinic patients were more commonly female (56% versus 37%; p = 0.02), treated for urinary tract infections (51% versus 4%; p < 0.001), and had shorter overall treatment duration (median 10 versus 42 days; p < 0.001; Table 2). The non-clinic population also had a higher rate of antibiotic-resistant organisms (49% versus 12%; p < 0.001).
Table 2:
Characteristics and outcomes among OPAT clinic patients and contemporary non-clinic patients
| No. (%)* | |||
|---|---|---|---|
| Variables | Contemporary non-clinic cohort† (n= 39) | OPAT clinic cohort (n = 334) | p value |
| Age, y, median (IQR) | 65 (53–76) | 65 (52–74) | 0.49 |
| Male | 17 (44) | 210 (63) | 0.02 |
| History of antibiotic-resistant organisms | 19 (49) | 39 (12) | <0.001 |
| Syndromes | |||
| Urinary tract infection | 20 (51) | 14 (4) | <0.001 |
| Bacteremia | 7 (18) | 96 (29) | 0.15 |
| Skin and soft tissue infection | 6 (15) | 32 (10) | 0.26 |
| Antimicrobials | |||
| Ertapenem | 20 (51) | 33 (9) | <0.001 |
| Cefazolin | 8 (21) | 82 (25) | 0.58 |
| Ceftriaxone | 6 (15) | 61 (18) | 0.66 |
| Duration of therapy, d, median (IQR) | 10 (7–14) | 42 (28–42) | <0.001 |
| Patient outcomes | |||
| No events | 27 (69) | 209 (63) | 0.41 |
| ED visit | 12 (31) | 109 (33) | 0.81 |
| Readmission | 10 (26) | 71 (21) | 0.53 |
* Unless otherwise indicated
† Contemporary cohort consisted of patients who received home parenteral antimicrobials during the study period but were not referred to the clinic
ED = emergency department; IQR = interquartile range; OPAT = outpatient parenteral antimicrobial therapy
OPAT population versus historical cohort
Of the 373 patients who received OPAT `in the study period, 228 met inclusion and exclusion criteria comparable to those of the historical cohort (discharged from hospital to home on IV antibiotics). Their clinical characteristics relative to the historical cohort are outlined in Table 3. When comparing the crude outcomes of the 228 intervention patients with those of the 2012–2013 pre-intervention cohort, no appreciable differences were found apart from a trend toward decreased return ED visits (p = 0.07). In bivariate analyses, only one variable—bacteremia—met the a priori criterion of a greater than ±10% change-in-estimate of the intervention coefficient. Therefore, the final regression model for assessing the impact of the intervention period consisted of bacteremia plus the two other prespecified covariates: age and history of AROs (Table 4). The intervention period was associated with a 36% reduction in admissions or return ED visits, although this was not statistically significant (adjusted odds ratio 0.64 [95% CI 0.40 to 1.04], p = 0.07).
Table 3:
Patient characteristics and outcomes in intervention (OPAT clinic) period versus pre-intervention period
| No. (%)* | |||
|---|---|---|---|
| Variables | Pre-intervention (n = 104) | OPAT clinic intervention (n = 228†) | |
| Age, y, median (IQR) | 63 (43–74) | 65 (52–74) | |
| Male | 65 (63) | 138 (61) | |
| Prior hospitalization within past 12 mo | 59 (57) | 113 (50) | |
| Comorbidities | |||
| Hypertension | 46 (44) | 115 (50) | |
| Diabetes | 29 (28) | 74 (32) | |
| Cancer | 27 (26) | 66 (29) | |
| Coronary artery disease | 23 (22) | 50 (22) | |
| Syndromes | |||
| Surgical site infection | 34 (33) | 37 (16) | |
| Bacteremia | 22 (21) | 71 (31) | |
| Skin and soft tissue infection | 18 (17) | 29 (13) | |
| Urinary tract infection | 16 (15) | 29 (13) | |
| Osteomyelitis (extremity) | 15 (14) | 36 (16) | |
| Antimicrobials | |||
| Ceftriaxone | 22 (21) | 49 (21) | |
| Cefazolin | 21 (20) | 57 (25) | |
| Piperacillin–tazobactam | 15 (14) | 26 (11) | |
| Vancomycin | 14 (13) | 27 (12) | |
| Ertapenem | 13 (13) | 33 (14) | |
| Patient outcomes | |||
| ED visit | 45 (43) | 75 (33) | |
| Readmission | 27 (26) | 55 (24) | |
| ED visit, readmission, or both | 48 (46) | 84 (37) | |
*Unless otherwise indicated
† This analysis only includes the subset of OPAT patients who met the same inclusion and exclusion criteria applied to the historical cohort
ED = Emergency department; OPAT = Outpatient parenteral antimicrobial therapy
Table 4:
Multivariable logistic regression model to evaluate association of OPAT clinic intervention with composite outcome of ED visits, hospital readmission, or both
| Variables | Adjusted OR (95% CI) |
|---|---|
| Intervention period* | 0.64 (0.40 to 1.04) |
| Bacteremia | 2.14 (1.29 to 3.57) |
| History of AROs | 1.48 (0.83 to 2.65) |
| Age | 1.00 (0.98 to 1.01) |
* This analysis was performed using the historical cohort (i.e., pre-intervention; n = 104) and the subset of OPAT patients (i.e., intervention; n = 228) with matching inclusion and exclusion criteria
AROs = Antimicrobial-resistant organisms; ED = Emergency department; OPAT = Outpatient parenteral antimicrobial therapy; OR = Odds ratio
Discussion
In this study, we analyzed the usage and impact of a newly established OPAT program at a single tertiary centre within a 1-year period. We found key differences between the patients who were referred to the OPAT clinic and those who were not. There also appeared to be a trend toward decreased readmission and ED visits after the implementation of the OPAT program compared with a pre-intervention cohort.
Similar to other studies in the literature, our clinic population was predominantly treated for bacteremia or osteoarticular infections, or both (10,12–14). However, there were differences in antimicrobial selection, namely less frequent use of vancomycin and carbapenems, in our study compared with others, which is likely related to variability in local resistance patterns (6,12,15). With respect to outcomes, the 60-day all-cause readmission rate of 21% is comparable to the results of other OPAT publications (10,13,14).
When comparing the clinic population with the contemporary cohort who received OPAT without clinic referral, we noted several key differences. The proportion of women was higher among non-clinic patients, and ertapenem was the most frequently prescribed antimicrobial. This was likely driven by the high prevalence of ESBL organisms in this population. The lack of clinic referral in this group of patients is not unexpected, given that the most common clinical syndrome was urinary tract infection (arguably a less complex syndrome) and the average duration of parenteral antibiotic therapy was less than 2 weeks. In fact, there is selection bias inherent in the design of the clinic because the aim was to capture all complex patients requiring prolonged IV treatment, not necessarily “simple” cases that required short durations of treatment. In the context of this selection bias, we found no crude differences in clinical outcomes between the clinic population and the contemporary cohort.
To evaluate the clinical impact of the OPAT program, we also compared the outcomes of the OPAT clinic intervention population with those of a pre-intervention cohort with equivalent inclusion characteristics. This comparison was necessary because the contemporary non-clinic cohort was too different to allow for a meaningful assessment of the clinic’s influence on patient outcomes. Although both studies were conducted during a 1-year period, the current cohort accrued more than double the sample size compared with the pre-intervention study, which reflects an increased usage of OPAT services over time. We were most interested in determining whether implementation of the ID physician-led OPAT clinic led to appreciable differences in health outcomes. ID supervision of OPAT is routinely recommended by published guidelines, and several recent studies have demonstrated the importance of ID involvement in reducing readmissions and health care costs (2,3,16,17). In our study, although we found no significant change in 60-day readmission rate, there was a trend toward reduced ED use and readmissions. This result is encouraging, considering that the clinic is relatively new and—with further refinement over time—has the potential to yield a further reduction in return visits. For instance, disrupted venous access is a common reason for ED use, and this highlights an opportunity for patient education initiatives.
Apart from the selection bias mentioned previously, other limitations of this study include the retrospective study design and potentially incomplete follow-up data. Because SHSC is a tertiary referral centre, some patients may have sought care at their local hospital, leading to an underestimation of health care utilization and adverse outcomes. In addition, temporal confounding could play a role in the pre–post study design, if other aspects of SHSC patients or management changed between the study periods. Our results may not be generalizable to other jurisdictions in which OPAT clinics are charged with the actual provision of all antimicrobial doses; our study in Ontario could be viewed as evaluating a model of care involving centralized ID oversight of OPAT care.
In conclusion, this newly established OPAT clinic served a high volume of patients with complex infectious diseases syndromes during its first year of operation. The program has been able to centralize the care of patients receiving OPAT and shows promise in its ability to reduce unfavourable outcomes. Ongoing quality improvement initiatives and evaluation are required to streamline the program and maximize its clinical impact.
Acknowledgments:
The authors thank Marion Elligsen, who assisted with data collection, and Robin Atherley and Charlotte Karunanithy, who oversee the day-to-day operations of the clinic.
Competing Interests:
The authors have nothing to disclose.
Ethics Approval:
This study was approved by the Research Ethics Board at Sunnybrook Health Sciences Centre,Toronto, Ontario, Canada.
Informed Consent:
N/A
Registry and the Registration No. of the Study/Trial:
N/A
Animal Studies:
N/A
Funding:
There was no funding for this study.
Peer Review:
This article has been peer reviewed.
References
- 1.Rucker RW, Harrison GM. Outpatient intravenous medications in the management of cystic fibrosis. Pediatrics. 1974;54(3):358–60. [PubMed] [Google Scholar]
- 2.Norris AH, Shrestha NK, Allison GM, et al. 2018 Infectious Diseases Society of America clinical practice guideline for the management of outpatient parenteral antimicrobial therapy. Clin Infect Dis. 2019;68(1):e1–35. 10.1093/cid/ciy745. [DOI] [PubMed] [Google Scholar]
- 3.Chapman ALN, Seaton RA, Cooper MA, et al. Good practice recommendations for outpatient parenteral antimicrobial therapy (OPAT) in adults in the UK: a consensus statement. J Antimicrob Chemother. 2012;67(5):1053–62. 10.1093/jac/dks003. Medline: [DOI] [PubMed] [Google Scholar]
- 4.Seaton RA, Barr DA. Outpatient parenteral antibiotic therapy: principles and practice. Eur J Intern Med. 2013;24(7):617–23. 10.1016/j.ejim.2013.03.014. Medline: [DOI] [PubMed] [Google Scholar]
- 5.Wai AO, Frighetto L, Marra CA, Chan E, Jewesson PJ. Cost analysis of an adult outpatient parenteral antibiotic therapy (OPAT) programme. A Canadian teaching hospital and Ministry of Health perspective. PharmacoEconomics. 2000;18(5):451–7. 10.2165/00019053-200018050-00004. Medline: [DOI] [PubMed] [Google Scholar]
- 6.Gardiol C, Voumard R, Cochet C, de Vallière S. Setting up an outpatient parenteral antimicrobial therapy (OPAT) unit in Switzerland: review of the first 18 months of activity. Eur J Clin Microbiol Infect Dis. 2016;35(5):839–45. 10.1007/s10096-016-2606-z. Medline: [DOI] [PubMed] [Google Scholar]
- 6.Barr DA, Semple L, Seaton RA. Outpatient parenteral antimicrobial therapy (OPAT) in a teaching hospital-based practice: a retrospective cohort study describing experience and evolution over 10 years. Int J Antimicrob Agents. 2012;39(5):407–13. 10.1016/j.ijantimicag.2012.01.016. Medline: [DOI] [PubMed] [Google Scholar]
- 8.Mansour O, Heslin J, Townsend JL. Impact of the implementation of a nurse-managed outpatient parenteral antibiotic therapy (OPAT) system in Baltimore: a case study demonstrating cost savings and reduction in re-admission rates. J Antimicrob Chemother. 2018;73(11):3181–8. 10.1093/jac/dky294. Medline: [DOI] [PubMed] [Google Scholar]
- 9.Yan M, Elligsen M, Simor AE, Daneman N. Patient characteristics and outcomes of outpatient parenteral antimicrobial therapy: a retrospective study. Can J Infect Dis Med Microbiol. 2016;2016:8435257. 10.1155/2016/8435257. Medline: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Allison GM, Muldoon EG, Kent DM, et al. Prediction model for 30-day hospital readmissions among patients discharged receiving outpatient parenteral antibiotic therapy. Clin Infect Dis. 2014;58(6):812–9. 10.1093/cid/cit920. Medline: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Greenland S, Daniel R, Pearce N. Outcome modelling strategies in epidemiology: traditional methods and basic alternatives. Int J Epidemiol. 2016;45(2): 565–75. 10.1093/ije/dyw040. Medline: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Williams DN, Baker CA, Kind AC, Sannes MR. The history and evolution of outpatient parenteral antibiotic therapy (OPAT). Int J Antimicrob Agents. 2015;46(3):307–12. 10.1016/j.ijantimicag.2015.07.001. Medline: [DOI] [PubMed] [Google Scholar]
- 13.Schmidt M, Hearn B, Gabriel M, Spencer MD, McCurdy L. Predictors of unplanned hospitalization in patients receiving outpatient parenteral antimicrobial therapy across a large integrated healthcare network. Open Forum Infect Dis. 2017;4(2):ofx086. 10.1093/ofid/ofx086. Medline: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Means L, Bleasdale S, Sikka M, Gross AE. Predictors of hospital readmission in patients receiving outpatient parenteral antimicrobial therapy. Pharmacotherapy. 2016;36(8):934–9. 10.1002/phar.1799. Medline: [DOI] [PubMed] [Google Scholar]
- 15.Huck D, Ginsberg JP, Gordon SM, Nowacki AS, Rehm SJ, Shrestha NK. Association of laboratory test result availability and rehospitalizations in an outpatient parenteral antimicrobial therapy programme. J Antimicrob Chemother. 2014;69(1):228–33. 10.1093/jac/dkt303. Medline: [DOI] [PubMed] [Google Scholar]
- 16.Saini E, Ali M, Du P, Crook T, Zurlo J. Early ID outpatient follow-up of OPAT patients reduces 30-day readmission. Clin Infect Dis. 2019;69(5):856–8. [DOI] [PubMed] [Google Scholar]
- 17.Conant MM, Erdman SM, Osterholzer D. Mandatory infectious diseases approval of outpatient parenteral antimicrobial therapy (OPAT): clinical and economic outcomes of averted cases. J Antimicrob Chemother. 2014;69(6):1695–700. 10.1093/jac/dku015. Medline: [DOI] [PubMed] [Google Scholar]