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Perspectives of Patients on Outpatient Parenteral Antimicrobial Therapy: Experiences and
Yasir Hamad1, Sai Dodda2, Allison Frank3, Joe Beggs4, Christopher Sleckman4, Glen
Kleinschmidt4, Michael A Lane1,5, Yvonne Burnett1,2.
1 Department of Internal Medicine, Washington University in St. Louis School of Medicine, St.
2 St. Louis College of Pharmacy, St. Louis, MO
3 Department of Occupational Therapy, Washington University in St Louis School of Medicine,
St. Louis, MO
4 Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
5 Center for Clinical Excellence, BJC HealthCare, St. Louis, MO
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Corresponding Author & Requests for Reprints:
Yasir Hamad, MD
Campus Box 8051, 4523 Clayton Ave. St. Louis, MO 63110
Division of Infectious Diseases
Washington University School of Medicine
Keywords: OPAT, Adherence, no-show, Compliance, social support
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Introduction: Non-adherence to medication is a burden to the US healthcare system and is
associated with poor clinical outcomes. Data on outpatient parenteral antimicrobial therapy
(OPAT) treatment plan adherence are lacking. The purpose of this study is to determine the
rate of non-adherence and factors associated with it.
Methods: We surveyed patients discharged from a tertiary hospital on OPAT between February
and August 2019 about their baseline characteristics, OPAT regimen, adherence, and
experience with OPAT.
Results: Sixty-five patients responded to the survey. Median age was 62 years, and 56% were
male. The rate of reported non-adherence to intravenous (IV) antibiotics was 10%. Factors
associated with non-adherence to IV antibiotics included younger age, household income of
<$20,000, and lack of time for administering IV antibiotics (30 vs. 64 years, P<0.01; 83% vs. 20%,
P<0.01; and 33% vs. 4%, P=0.04; in non-adherent vs. adherent groups, respectively). While less
frequent administration (once or twice daily) and having friend or family support during IV
antibiotic administration were associated with better adherence (17% vs. 76%, P<0.01; and 17%
vs. 66%, P=0.03; in non-adherent vs. adherent groups, respectively). Most patients attended
their infectious diseases clinic visits (n=44, 71%), and the most commonly cited reasons for
missing an appointment were lacking transportation (n=12, 60%), not feeling well (n=8, 40%),
and being unaware of the appointment (n=6, 30%).
Conclusion: Less frequent antibiotic dosing and better social support were associated with
improved adherence to OPAT. In contrast, younger age, lower income, and lack of time were
associated with non-adherence.
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Outpatient parenteral antimicrobial therapy (OPAT) is an effective modality for treating
patients with serious infectious diseases (ID) outside of a hospital setting [1, 2]. By allowing
patients to receive treatment at home, OPAT avoids expenses associated with prolonged
hospital stays, reduces exposure to nosocomial pathogens, and allows patients to maintain a
normal lifestyle . OPAT is generally considered safe, but requires close monitoring for
therapy-related complications and treatment failure . Past studies have shown readmission
rates for OPAT patients range from 6-26% [5-7]. These readmissions can result from worsening
infection, line complications, or comorbidities [5-7].
Medication non-adherence is a burden to the US healthcare system, leading to higher
healthcare costs and worse patient outcomes. The annual cost of medication non-adherence in
the US is estimated to be $300 billion [8, 9]. Non-adherence to oral antibiotics has been linked
to poor clinical outcomes such as infection relapses, need for new antibiotics, and additional
medical procedures . Factors that are associated with non-adherence to oral antibiotics
include prescription of multiple antibiotics and changing healthcare providers for outpatient
care . In another study, increased dosing frequency negatively impacted oral antibiotic
adherence rates . Antibiotics taken once, twice, or three times daily had adherence rates of
80%, 69%, and 38%, respectively . Reasons for missing scheduled oral doses include being
away from home, asleep, or simply forgetting . However, there is a lack of literature on the
rates and predictors of non-adherence in OPAT.
Infectious Diseases Society of America recommends close clinical follow-up for OPAT
patients . Thus, patients’ adherence to office visits is a vital component of OPAT care. A
recent study showed that attendance at follow-up OPAT clinic visits was associated with a
lower readmission rate compared to those who had no follow-up visit . Adherence to OPAT
follow-up appointments has been reported as high, but factors such as transportation, illness,
and work commitments impede some patients from attending their scheduled appointments
This study aims to quantify the rate of non-adherence among OPAT users and
understand the reasons leading to “no-show” appointments. We conducted a survey to gather
detailed information about patient identified factors related to non-adherence.
The survey was developed in collaboration with an ID physician and ID pharmacist. This
survey contained 21 multiple choice or Likert-style items and two free-text items allowing
respondents to provide additional comments. The survey was piloted with a group of content
experts, and questions were modified based on their feedback. The survey recorded the
respondents’ demographic, experience and adherence with OPAT, communication with
healthcare providers, and barriers to receiving optimal OPAT care (Appendix).
Study Population and Distribution
The Infectious Diseases Clinic at Washington University in St. Louis School of Medicine
monitors patients who are discharged from Barnes-Jewish Hospital on OPAT following inpatient
care. The OPAT program follows 1,500 patients annually. About one third of the patients are
discharged to post-acute care facilities while the rest are discharged home with home health
and outpatient infusion centers. The majority of the patients (50%) discharged home on OPAT
are cared for by BJC home care services, while the rest are covered by multiple different home
health care agencies such as Coram and Option Care. Only patients who were discharged home
were asked to participate in the survey. Patients discharged on OPAT are scheduled to follow
up with an infectious diseases provider in 2 weeks. The appointment is usually scheduled prior
to hospital discharge and the instructions are printed and handed to the patient upon hospital
discharge. For the small number of patients who are discharged prior to appointment
scheduling, the clinic staff contact the patient to make the appointment for the visit. Patients
receive an automated call from the clinic to remind them about the appointment 3 days prior
to the visit and a text message 2 days prior to the visit. The most common infection category in
our OPAT program is bone and joint infections (40%), followed by blood stream infections
(21%), intra-abdominal infections (11%), and skin and soft tissue infections (8%). The clinic
distributed our surveys to patients returning for their follow-up appointments between
February and August 2019. Patients then placed the confidential, anonymous surveys in a
locked survey box. The survey was also sent via mail to patients’ home addresses on April 29,
2019 and July 22, 2019 to patients who had completed their course within the last 30 days.
Patients were asked to mail the completed survey back to the investigators in an anonymous,
pre-stamped return envelope. The study was approved by the Washington University School of
Medicine Human Research Protection Office and St. Louis College of Pharmacy’s Institutional
Categorical data was presented using frequencies. To analyze risk factors associated
with non-adherence we used the Fisher Exact test for categorical variables, and Mann-Whitney
U test for continuous variables. For multiple choice questions we analyzed the responses based
on the percentage of patients who answered “Agree” or “Strongly Agree” as opposed to other
answers. Differences were considered statistically significant if P<0.05. All quantitative analyses
were performed using SAS 9.4 software (Cary, NC).
We also analyzed qualitative data. Participants were asked to answer the free-test
responses: “Explain the barriers you encounter to taking your IV antibiotics as prescribed” and
“Please use the space below to share any additional information about your experience taking
IV antibiotics or to elaborate on a question listed above.” Three authors (S.D., C.S., and Y.H.)
systematically read responses and independently categorized them. Disagreements were
resolved by discussion between the team members. Percentages of respondents that answered
each item and illustrative quotes are presented.
A total of 174 surveys were mailed to adult OPAT patients. Twenty-seven (16%)
participants responded and completed the survey. Additionally, 38 participants completed
surveys in the clinic during the study period, resulting in a total of 65 survey responses.
Respondents’ median age was 62 years (IQR 53-69), and 56% were male. Sixteen respondents
(27%) had an annual income below $20,000, and 19 (33%) were unemployed. Almost half of the
respondents had to pay a copayment or coinsurance in order to receive IV antibiotics n=30
(49%). Thirty-five (55%) respondents received only one IV antibiotic, 17 (27%) received two, and
12 (19%) received at least three. Most respondents received intravenous antibiotics either once
or two times per day (24 [38%], or 19 [30%], respectively). Thirty-four respondents (55%) spent
at least an hour administering their antibiotics, including 14 (23%) who spent two hours per day
Most respondents (90%) reported strict adherence to IV antibiotics, while 6 (10%)
reported missing 1-2 doses per week. Thirty-seven respondents (60%) reported having no
reminder system in place, while 28 (45%) reported using an alarm, ‘chart’, or reminder from
someone. Thirty-nine respondents (62%) had a family member or friend help them administer
IV antibiotics, and 18 (29%) reported administering IV antibiotics independently (Table 1).
Respondents contacted a variety of healthcare resources when they had questions about their
IV antibiotic therapy including home health service (n=47, 75%), pharmacist (n=22, 35%) or
primary physician (n=21, 33%). Most respondents (n=44, 71%) were compliant with ID doctor
appointments. Reasons for missed clinic appointments were mostly due to lack of
transportation in 12 (60%), not feeling well in 8 (40%), and being unaware of the appointment
in 6 (30%) responses. In the subset of respondents who answered the survey by mail, 18 (62%)
reported adherence to clinic visits. Among the 11 mail-in respondents who reported missing a
clinic visit, the most common reasons were not feeling well in 7 (63%) and lack of
transportation in 4 (36%) responses.
Seventeen respondents (27%) felt they spent too much time administering antibiotics.
Only 4 (6%) said they did not have enough time to administer the prescribed antibiotics.
Twenty-one respondents (34%) reported not knowing the side effects of their medication, while
6 respondents (10%) reported having a serious side effect from the antibiotics (Tables 1-2).
Factors that were associated with medication non-adherence included younger age,
household income of <$20,000, and not having enough time for IV antibiotics administration
(30 vs. 64 years, P<0.01; 83% vs. 20%, P<0.01; and 33% vs. 4%, P=0.04, in non-adherent vs.
adherent groups, respectively). While less frequent administration and having friend or family
support during IV antibiotics administration were associated with lower risk of non-adherence
(17% vs. 76%, P<0.01 and 17% vs. 66%, P=0.03, in non-adherent vs. adherent groups,
respectively). Lack of knowledge about side effects and medication reminders were not found
to be associated with non-adherence (Table 3).
A total of 24 patients provided free text responses about barriers to receipt of IV
antibiotics (Table 4). Common barriers included difficulties in the administration of antibiotics
by the patient (n=5, 20.8%), central line related issues (n=5, 20.8%), extensive time needed to
administer IV antibiotics (n=4, 16.7%), challenges with going to doctor’s appointments while on
IV antibiotics (n=3, 12.5%), medication side effects (n=2, 8.3%), and limitations in social
activities (n=1, 4.2%).
Furthermore, 24 respondents provided additional free text responses about their overall
experience on OPAT. The most common themes included were about experiencing side effects
(n=7, 29.2%) and having a great experience with OPAT (n=5, 20.8%), whereas 2 patients (8.3%)
commented about the financial cost of OPAT. As one respondent explained, “Out of pocket
costs [were] too high. [I am] Still paying on the $4,000 bill.” One respondent discussed being
frustrated about not receiving the results of the weekly lab draws. Despite the reported
challenges with OPAT, 20.8% of participants providing free text responses felt the use of OPAT
was easy and satisfying. As one respondent stated, “Very easy. Anyone can do it.” (Table 5).
This study examines patient-reported rates of non-adherence with OPAT and identified
factors associated with non-adherence. Overall, patients self-reported relatively high rates of
adherence to therapy with 90% of respondents reporting no missed doses in an average week.
OPAT medication non-adherence was found to be disproportionately associated among people
who are young, low-income, self-reportedly busy, and without social support. Non-adherence
to clinical follow-ups was more common as 29% reported missing an ID appointment. The most
common reason leading to “no-show” appointments at the ID clinic was lack of transportation.
This study supports a strong positive correlation between medication adherence and
age. The median ages of non-adherent and adherent groups were 30 and 64, respectively. This
may be surprising since the geriatric population is more prone to chronic and recurrent illness
which may require chronic medication with multiple drugs. However, others have also found
that younger adults are more likely to be non-adherent to therapy in various other populations
[15-18]. Therefore, other risk factors such as knowledge of the drug’s purpose, complexity of
the drug regimen, and type of prescriber should be considered when planning OPAT treatment
Multiple socio-economic factors have been found to affect adherence. Higher rates of
medication non-adherence have been reported in a study assessing low-income, uninsured
patients . Individuals with lower income tend to be younger, which is a known risk factor for
non-adherence . Social support networks also have an impact on adherence to OPAT. This
study showed that having a friend or family member assist with IV antibiotic administration was
associated with better rates of OPAT adherence. This is consistent with prior studies that have
shown the association between medication adherence and practical social support, which can
be defined as having a family member who helps with medications or transportation .
Previous studies have found mixed results for using reminders as an aid to assist with
medication adherence [23, 24]. In our study we did not find an association between reminders
and adherence. This adds to a mixed collection of results in the literature on the efficacy of
reminders across multiple modalities to improve medication adherence. Vervloet et al. found
that text message reminders improve medication adherence to oral medication in Type 2
Diabetes patients who are electronically monitored in real-time . Liu et al. showed that
reminders from medication monitors improved adherence in tuberculosis patients, but text
message reminders did not. In general, many types of interventions have attempted to improve
adherence in diverse treatment regimens, but most have failed. .
Our study showed that simpler regimens with once or twice daily dosing were
associated with improved adherence to IV antibiotics. This is consistent with literature that
reports lower rates of adherence with multiple administrations per day . Unlike oral
antibiotics, IV antibiotics require significantly more time to administer. In this survey, 55% of
patients reported spending more than an hour per day to administer the antibiotics, with nearly
a quarter of all patients spending at least two hours per day. Clinicians should keep this in mind
when recommending an OPAT regimen and use simpler regimens when feasible.
The strengths of this study includes novelty in examining adherence in the OPAT
population, of which data is scarce. The participants spanned different ages and socio-economic
backgrounds allowing us to examine the effects of these factors on adherence. This study
identified OPAT-specific factors that are associated with non-adherence so that clinicians can
identify those at high-risk and address preventable factors to improve adherence.
Despite a small sample size, this is the largest study addressing non-adherence in OPAT.
Response rate to the mail survey was low; however, this could in part be due to the lack of
reminders. Since the responses were anonymized we were not able to compare the
respondents to the non-respondents to see if the two groups were different. However, the fact
that responses came from patients across different age groups and socioeconomic backgrounds
improves the generalizability of the survey results. Additionally, like other studies, the main
limitation of the results presented here is a dependency on subjective self-reporting. These
descriptions may be unreliable for three different reasons: (1) subjects may have forgotten
when and how they took their medication, (2) they may not have been truthful out of the
perceived fear that their answers would affect their continued treatment, or (3) patients who
were unconcerned with their care may not have answered survey questions, whereas patients
concerned about their health did respond (non-responder bias). We addressed each of these
concerns as follows. First, to decrease the likelihood of forgetfulness, surveys were
administered to current patients in the clinic or mailed to patients who recently completed
their OPAT treatment. Second, patients were notified that surveys were anonymous, and
identifying information was removed. Third, while the non-responder bias might have resulted
in a lower response rate from non-adherent patients, we collected enough responses from
patients who reported non-adherence and were able to identify some risk factors associated
with medication adherence. The outcomes of this study can lead to a more efficient workflow
that improves patient care, medication adherence, and clinic attendance.
While younger age, lower income, and lack of time for IV antibiotic administration were
factors associated with non-adherence, less frequent dosing regimens and having friend or
family support during IV antibiotic administration were protective. Lack of transportation was
also the main risk factor for missing follow-up infectious diseases clinic visits. With information
collected in this survey, we garnered a better understanding of this patient population that will
lead to targeted efforts to improve care for OPAT patients.
S.D., A.F., J.B., C.S., and G.K. are cofounders of HIVE Medical, a student-run start-up that is
trying to improve medication adherence for OPAT. Y.H., M.A.L, and Y.B. have nothing to
This work was supported by a grant from the Sling Health Incubator program, St. Louis MO.
Table 1: Characteristics and responses of 65 patients who responded to the survey
Age Median (IQR)
Sex (Female) (58 responses)
Annual Household Income: (59 responses)
Employment: (57 responses)
Does insurance cover antibiotics cost (61 responses)
All of the cost
Part of the cost
How many IV antibiotics prescribed (64 responses)
4 or more
How often do you take IV antibiotics (63 responses)
Three times daily
How much time do you spend per day taking IV antibiotics (62 responses)
How many other medications do you take (63 responses) Median (IQR)
Who do you ask if you have questions about IV antibiotics (63 responses)
Home health service
I wait until next doctor visit
If I miss my doctor’s appointment, it is because: (62 responses)
I have never missed an appointment
Reasons for missed clinic appointment (20 of 61 responses) responder can
choose more than one choice
I don’t have a ride
I don’t feel well
I was unaware of the appointment
I don’t have time off work
I was hospitalized
How do you remember to take your IV antibiotics (62 responses)
responder can choose more than one choice
I just remember
I have an alarm set up
Someone reminds me
How many doses of IV antibiotics have you missed per week (62 responses)
Who administers your IV antibiotics (63 responses)
A family member/ Friend
Abbreviations: IQR: inter-quartile range, IV: Intravenous.
*Respondents were able to select all responses that applied; numbers add to more than 100%
Table 2: Responses of survey participants to the multiple choice questions
Likert scale questions responses
I don’t have enough time to administer my
I don’t know the side effects of my medications
I spend too much time administering antibiotics
I do NOT have a consistent way to get my IV
I would like to be able to take my IV antibiotics
I would be interested in a device that makes it
easier to move around during IV antibiotic
I would be interested in a device that monitors
how I take my IV antibiotics and shares this
information with my doctor
I experience serious side effects from my IV
Abbreviations: IV: Intravenous.
Table 3: Factors associated with non-adherence with IV antibiotics
(N=56) N(%) or
patients (N=6) N(%)or
Low income (<$20,000)
Less frequent administration
(Daily or Twice Daily) for IV
Family support in administration
of IV antibiotics
I spend too much time
I don’t have enough time to
administer my antibiotics
I would like to be able to take my
IV antibiotics outside home
I don’t know the side effects of
Patient having a reminder set up
I missed an Infectious Diseases
Abbreviations: IV: Intravenous; IQR: Interquartile range
Table 4: Concerns raised about barriers in OPAT
(Percentage of 24
who Responded to
Difficulty in administering
IV antibiotics by the
“[I had difficulty in] Making sure everything stays sterile while
using the medicine”
“Cannot push plunger slow enough - too difficult to push in all
the ml's over such a long time doing it manually”
“[I had difficulty] learning how to switch bags. making sure
every 8 hours to take the oral antibiotic”
“My girlfriend had to go in the hospital for 2 days and it was
hard to do but I did them. She called to remind me”
central catheter (PICC)
“PICC line isn't waterproof”
“[I had a] clog in my IV port”
“[Had difficulty] changing clothing [while having PICC line in
Time needed to
administer IV antibiotics
“That it was three times a day and 1.5 hrs each time. Very easily
“It takes too long”
Challenges with doctor’s
“Making appointments around the IV meds”
“The only time I may have an issue is the time of day. I normally
take antibiotic around lunch time everyday unless I'm at Dr.
Appointment which may delay the time of day its administered”
Medications side effects
“I had severe side effects to all the medications I was
Limitation in social
“Not being able to go and socialize while taking them”
Abbreviations: OPAT: Outpatient parenteral antimicrobial therapy; IV: Intravenous
Table 5: summary of additional comments provided by patients about their experience
(Percentage of 24
who Responded to
Experienced side effects
“Had allergic reaction and had to stop treatment”
“The antibiotic I was taking caused constipation and lowered my
white blood cell count”
“The side effects were terrible! Especially after 2 weeks! I was
happy when it was over. Thanks.”
Did have a good
“I was happy with the ability to us[e] the device provided and I
didn't need an IV pole like in the hospital”
“I like taking at home instead of an outpatient location.
Especially since its daily. Very convenient”
“Very easy. Anyone can do it”
“Out of pocket costs [was] too high. [I am] Still paying on the
“I called billing 3x with no return call. I have supplies left that I
did not need. Would like to get credit for those supplies! I did
Abbreviations: IV: Intravenous
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