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morbidities associated with dysvascular amputation
are associated with increased medical complications.
Unfortunately, dysvascular patients who undergo lower
extremity amputation often rehabilitate at subacute
rehabilitation facilities and skilled nursing facilities,
where the level of medical supervision is significantly
lower (9). Despite this, there is strong evidence that
dysvascular amputees benefit greatly from inpatient
rehabilitation in terms of functional gains and, poten-
tially, survival (10, 11).
Across all rehabilitation diagnoses, infection is the
most common complication, and dysvascular patients
are at risk of this due to poor blood flow and the pre-
sence of a wound (12). The presence of peripheral
vascular disease, the most common cause of amputa-
tion (13), is associated with a higher risk of interrup-
tion to rehabilitation, with Meikle et al. finding that
18% of dysvascular amputees were discharged from
inpatient rehabilitation due to wound healing issues
(6) The study also found that time from amputation to
starting inpatient rehabilitation was a significant risk
factor for complications.
Medical comorbidities may also contribute to fewer
functional gains during inpatient rehabilitation. For
example, lower extremity amputees receiving haemo-
dialysis make less functional gains and have longer
lengths of stay than those without end-stage renal di-
sease (ESRD) (14). Furthermore, patients who undergo
amputation due to a sarcoma, and therefore may not
have significant chronic comorbidities, perform bet-
ter on inpatient rehabilitation units and have shorter
lengths of stay than dysvascular amputees (12). Finally,
cognitive impairment, which is commonly observed in
patients with severe vascular disease, has been shown
to have a negative impact on inpatient rehabilitation
performance of dysvascular amputees (15).
Unfortunately, while the previously-mentioned
studies evaluate dysvascular amputees within the
framework of 1 or a few comorbidities, these patients
often have multiple significant comorbidities and
many have not been evaluated in this population.
While prior research by Dillingham et al. has demon-
strated the impact of medical and social factors on
determining the post-acute care discharge destination
following dysvascular lower limb amputations, there
has been limited research into how specific medical
comorbidities affect the rate of unplanned transfers
from inpatient rehabilitation for this patient popula-
tion (16). Furthermore, Sauter et al. found that patients
who undergo dysvascular lower limb amputations have
significantly improved functional outcomes from recei-
ving rehabilitation at an inpatient rehabilitation facility
compared with a skilled nursing facility, probably due
to their high medical complexity and increased risk
www.medicaljournals.se/jrm
of medical complications, which necessitate closer
medical monitoring (17).
The primary objective of this study was to examine
whether certain indicators of medical comorbidities,
available at the time of admission to inpatient rehabi-
litation, were associated with an increased risk of un-
planned transfers from inpatient rehabilitation among
patients with amputation due to vascular disease.
Specifically, the study focused on factors associated
with infection, poor wound healing, organ failure, and/
or previous amputations that were commonly available
at the time of admission to inpatient rehabilitation. No
previous study has evaluated indicators of infection
risk, such as the presence of wound vacuums, ESRD,
or diagnoses that confound vascular disease, such
as diabetes, as they relate to the risk of unplanned
transfers from inpatient rehabilitation in dysvascular
amputee patients. The secondary objective was to
examine whether the aforementioned factors were
associated with decreased functional gains during in-
patient rehabilitation. A greater understanding of these
risk factors can help identify patients at greater risk of
severe medical complication, which could allow for the
reduction in unplanned discharges by identifying spe-
cific comorbidities that might require more proactive
management, or situations that may warrant a delay in
admission to rehabilitation in order for medical stabi-
lity to be firmly established prior to transfer.
METHODS
Study design
Using a cross-sectional, retrospective design, data were col-
lected from electronic medical records of patients who received
inpatient rehabilitation in an academic tertiary rehabilitation
centre. Ethics approval for a waiver of informed consent was
obtained before initiation of the study from the University of
Michigan, Medical School Institutional Review Board. Data
were collected from consecutive patients over the age of 18
years who were admitted to the acute inpatient rehabilitation unit
from January 2011 to April 2015 following new transfemoral
or transtibial amputation(s) due to sequelae of chronic vascular
disease. Patients with previous amputations were included in the
sample if they were undergoing a new, contralateral amputation.
Patients were excluded from the sample if they had missing or
incomplete data, were admitted for partial foot or toe ampu-
tations, or if their rehabilitation stay followed hospitalization
for a reason other than amputation. In total, 49 patients were
excluded, primarily because their admission to inpatient rehabi-
litation was not due to a new amputation. Only 3 patients were
excluded due to having had foot or toe amputations, compared
with above/below knee amputations (Fig. 1).
Study variables
The primary outcome of this study was the incidence of transfer
from inpatient rehabilitation to an acute care medical service due
to a medical complication. The secondary outcome was func