“Deterioration to Door Time”: An Exploratory Analysis of Delays in Escalation of Care for Hospitalized Patients
J Gen Intern Med
BDeterioration to Door Time^: An Exploratory Analysis of Delays in Escalation of Care for Hospitalized Patients
Christopher B. Sankey 1 2
Gail McAvay 0
Jonathan M. Siner 4
Carol L. Barsky 3
Sarwat I. Chaudhry 1 2
0 Section of Geriatric Medicine, Department of Internal Medicine, Yale University School of Medicine , New Haven, CT , USA
1 Yale-New Haven Hospital , New Haven, CT , USA
2 Section of General Medicine, Department of Internal Medicine, Yale University School of Medicine , New Haven, CT , USA
3 Patient Safety and Quality, Hackensack University Medical Center , Hackensack, NJ , USA
4 Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine , New Haven, CT , USA
BACKGROUND: Timely escalation of care for patients experiencing clinical deterioration in the inpatient setting is challenging. Deterioration on a general floor has been associated with an increased risk of death, and the early period of deterioration may represent a time during which admission to the intensive care unit (ICU) improves survival. Previous studies examining the association between delay from onset of clinical deterioration to ICU transfer and mortality are few in number and were conducted more than 10 years ago. OBJECTIVE: We aimed to evaluate the impact of delays in the escalation of care among clinically deteriorating patients in the current era of inpatient medicine. DESIGN AND PARTICIPANTS: This was a retrospective cohort study that analyzed data from 793 patients transferred from non-intensive care unit (ICU) inpatient floors to the medical intensive care unit (MICU), from 2011 to 2013 at an urban, tertiary, academic medical center. MAIN MEASURES: BDeterioration to door time (DTDT)^ was defined as the time between onset of clinical deterioration (as evidenced by the presence of one or more vital sign indicators including respiratory rate, systolic blood pressure, and heart rate) and arrival in the MICU. KEY RESULTS: In our sample, 64.6 % had delays in care escalation, defined as greater than 4 h based on previous studies. Mortality was significantly increased beginning at a DTDT of 12.1 h after adjusting for age, gender, and severity of illness. CONCLUSIONS: Delays in the escalation of care for clinically deteriorating hospitalized patients remain frequent in the current era of inpatient medicine, and are associated with increased in-hospital mortality. Development of performance measures for the care of clinically deteriorating inpatients remains essential, and timeliness of care escalation deserves further consideration.
inpatient clinical deterioration; delays; care escalation; care transitions; timeliness
Timely escalation of care for patients experiencing
clinical deterioration in the inpatient setting continues to
present significant challenges to clinicians and health
systems. Clinical deterioration that occurs after
admission to a general floor (e.g., non-critical care setting)
has been associated with an increased risk of death.1
The early period of deterioration may represent a time at
which admission to the intensive care unit (ICU) is
associated with improved survival,2 particularly among
patients who experience deterioration after admission to
the hospital.3 The existing studies examining the
relationship between the delay from onset of clinical
deterioration to ICU transfer and mortality were conducted
over a decade ago,4,5 did not examine the role of delays
in care escalation,6 or were restricted to the first 48 h of
hospitalization,7 collectively precluding a contemporary
understanding of the impact of such delays throughout a
To evaluate the current impact of delays in the
escalation of care for clinically deteriorating inpatients, we
examined the time between onset of clinical
deterioration and arrival to a higher level of care in a large,
urban, academic tertiary care hospital. We assessed the
relationship between delays in transfer and in-hospital
mortality, adjusting for demographic and clinical
characteristics. We hypothesized that despite advances in
processes of care for inpatient clinical deterioration, delays
in escalation of care remain associated with increased
mortality. These analyses can provide insight about
whether contemporary management strategies have
translated into timely escalations of care for deteriorating
patients in the hospital setting, and generate hypotheses
as to why delays occur that can be evaluated in future
Setting and Data Source
This retrospective cohort study was performed over a
25month period (1 September 2011 through 30 September
2013) at Yale-New Haven Hospital (YNHH). YNHH is an
academic tertiary medical facility in New Haven, Connecticut
with a 1544 bed capacity and 88,000 discharges annually. The
database utilized to perform this study was developed by
merging a data set containing information about patients’
Rothman Index8 (a severity of illness score utilized for all
inpatients at YNHH) with a data set from the hospital’s bed
management system. Both data sets are continually updated to
reflect the most recently updated information.
Definitions and Outcome Measurements
We defined the Bdeterioration to door time (DTDT)^ as the
time between documented onset of clinical deterioration (in
the electronic medical record) and a patient’s arrival to the
medical intensive care unit (MICU). This measurement has
been termed Bscore to door time^ in a previous study.9 As our
focus in this investigation is the occurrence of clinical
deterioration and the timeliness of care escalation, we selected the
title Bdeterioration to door time^ to indicate the time between
the first occurrence of clinical deterioration and transfer to the
ICU. We did not aim to devise a new score for clinical
deterioration, and while we did examine a particular scoring
algorithm (Rothman Index), this was not used as a Btrigger^
for our assessment of the interval of time between initial
physiologic deterioration and ICU transfer. Clinical
deterioration was defined by the following vital sign abnormalities:
respiratory rate greater than 28 or less than eight breaths per
minute, systolic blood pressure greater than 200 or less than
90 mmHg, and pulse greater than 130 or less than 40 beats per
minute. These vital signs were chosen due to ubiquity of
measurement and the availability of these clinical variables
in our data set. The cut-points selected for each vital sign were
informed by the YNHH rapid response team (RRT) activation
criteria, explicitly chosen to select for Bsicker^ patients
experiencing true clinical deteriorations, and are consistent
with those in other studies.10–13 While the onset of clinical
deterioration required only a single abnormal vital sign (the
earliest), in some cases, multiple abnormal vital signs were
simultaneously present and/or developed during the interval
between initial abnormality and MICU transfer. Other
common types of clinical deterioration (seizure, hemorrhage,
alteration in mental status) were not included in our analysis
because information was not present in our administrative data
Characteristics of patients experiencing clinical
deterioration, including age, sex, race, and discharge diagnosis, were
collected from the electronic medical record. Severity of
illness was collected at the time of initial clinical deterioration
based on the Rothman Index (RI), a measure of illness acuity
that incorporates 26 clinical variables including vital signs,
laboratory results, cardiac rhythms, and nursing assessments
into a single score.8,14–16 An RI value of less than or equal to
30 was used as a marker of severe illness.16 The primary
outcome assessed was 30-day in-hospital mortality, adjusted
We defined an escalation to a higher level of care as any
transfer into the MICU or medical step-down unit at YNHH,
both of which are managed by teams separate from those on
the general medical floors. Together, these units are comprised
of 51 beds, and arrival in a higher level of care for the purposes
of our analysis was identified by change in a patient’s location
to one of these beds. For consistency of terminology in this
study, we have collectively referred to this composite of beds
as Bthe MICU.^ Nursing ratios at our institution differ
markedly between the MICU (ranging from 1:1 to 1:3) and the
general floor (1:5 to 1:6), as does the frequency of vital sign
monitoring (every 1–4 h in the MICU versus every 4–8 h on
the general floor) and continuous cardiac monitoring
(Btelemetry^), which is provided for all MICU patients and
only for select patients on the general floor.
The patient inclusion process is summarized in Fig. 1. All
adult inpatients greater than 18 years old transferred from
nonICU inpatient settings to the MICU were evaluated for
inclusion. Transfers that originated from the emergency room (ER)
or any other intensive care unit were excluded in order to
identify patients experiencing clinical deterioration on a
general floor. Because our goal was to identify timeliness of care
escalation following vital sign abnormalities, patients who did
not have documentation of a specified indicator of clinical
deterioration prior to transfer were not included. To better
understand the clinical circumstances of such transfers, we
examined the medical records of approximately 5 % of
patients transferred without a documented indicator of clinical
deterioration, and confirmed that these transfers primarily
occurred due physiologic derangements (seizure, acute
hemorrhage, change in mental status) that were not identified as
one of our indicators. For patients who had more than one
transfer during the study period, only the first was included.
DTDT times of greater than or equal to 3 days (72 h) were also
excluded from our analysis, as certain patient populations may
have persistent stable derangements in vital signs that could
potentially complicate interpretation of onset of clinical
deterioration (e.g., hypotension in a stable cirrhotic patient and
other Bchronically critically ill^ patients).
Characteristics of the study sample and vital sign indicators of
clinical deterioration were summarized as means and standard
deviations, or as counts and percentages. To explore and
understand the relationship between time to transfer and
outcomes, we examined quintiles of patients with varying times
between onset of clinical deterioration and MICU transfer as
follows: 1 = 0–2.5 h, 2 = 2.6–4.5 h, 3 = 4.6–12 h, 4 = 12.1–
36.5 h and 5 = 36.6–72 h. Quintiles were chosen a priori to
create enough categories to more precisely characterize the
shape of the relationship between DTDT and the outcome.
Additionally, because previous work has suggested a 4-h
cutpoint to distinguish Bfast^ and Bslow^ transfers,5,9 we describe
the percentages of patients meeting these criteria as well.
The association of DTDT and in-hospital mortality was
evaluated using Cox regression models, adjusting for age,
sex, and severity of illness. For this analysis, we set time zero
as the onset time of clinical deterioration and followed patients
for up to 30 days or hospital discharge, whichever came first.
Hazard ratios (HR) and 95 % confidence intervals for
mortality rates in each DTDT quintile were estimated, with the
reference group consisting of DTDT of 2.6–4.5 h (quintile 2)
based on initial bivariate analyses showing lowest mortality
rates in this group. The proportional hazards assumption was
tested by using interaction terms between the time-to-event
outcome and each variable in the multivariable model; the
terms were retained if p < 0.05 after adjusting for the number
The Cox regression models were estimated using SAS
version 9.3 (SAS Institute, Inc., Cary, NC), with a p value < 0.05
(two-sided) denoting statistical significance. A Chi-square tests
was used to test the association between discharge diagnosis
group and mortality. This study was approved by the Yale
University Human Investigation Committee.
Patient characteristics are summarized in Table 1. Nearly half
were less than 65 years of age, approximately half were
female, and nearly 29 % of the sample was of non-white race.
The five most common discharge diagnosis categories were
aIncludes pneumonia/pneumonitis, pulmonary embolism, pleural
effusion, pneumothorax, acute/chronic respiratory failure, asthma/chronic
obstructive pulmonary disease (COPD)
bAny infection with documentation of associated sepsis or septicemia
cIncludes cirrhosis (all types) and associated complications (hepatic
encephalopathy, spontaneous bacterial peritonitis, hepato-renal
syndrome), peptic/duodenal ulcer disease, upper/lower gastrointestinal
bleeding (all types), intestinal obstruction/perforation, obstructive
biliary disease, acute/chronic pancreatitis
dIncludes solid and liquid tumors
eAll infections excluding sepsis and pneumonia
fIncludes myocardial infarction, heart failure/cardiomyopathy (all
types), arrhythmia (including atrial fibrillation)
gIncludes stroke (all types), seizure, substance intoxication/withdrawal,
accidental/intentional overdose, dementia, delirium
hIncludes hematologic (non-malignant), renal/urologic, orthopedic/
rheumatologic, dermatologic, endocrine diagnoses
pulmonary (including pneumonia, pulmonary embolism,
pleural effusion, pneumothorax, respiratory failure, asthma/
COPD), sepsis, gastrointestinal (including cirrhosis and
associated complications, peptic/duodenal ulcer disease,
gastrointestinal bleeding, intestinal obstruction/perforation,
obstructive biliary disease, pancreatitis), malignancy, and infection
(excluding sepsis and pneumonia). Systolic hypotension
(45.8 %), tachypnea (34.3 %), and tachycardia (20.4 %) were
the most common physiologic indicators of clinical
deterioration. Using the Rothman Index, approximately one-third of
our sample was classified as Bseverely ill^ (e.g., RI ≤ 30) at
onset of clinical deterioration. The average length of stay on
the general inpatient floor was 18.9 days (range 1–221), and
the mean length of stay in the ICU was 103 h (range 0.5–977).
In our sample, 64.6 % had DTDTs greater than or equal to 4 h.
The overall in-hospital mortality for our study was 19.8 %,
while the observed mortality in patients without vital sign
indicators of clinical deterioration prior to ICU transfer was
only 8 %. The relationship between DTDT and in-hospital
mortality is summarized in Table 2. Mortality was
32 (19.8 %)
21 (13.4 %)
24 (15.3 %)
36 (22.8 %)
44 (27.7 %)
aCox regression model, controlling for age, sex, and severity of illness
significantly increased beginning at a DTDT of 12.1 h after
adjusting for age, gender, and severity of illness. The increased
mortality seen for DTDTs of 0–2.5 h and 4.6–12 h did not
reach statistical significance and may be due to chance.
Mortality ranged from 75 to 84 % by discharge diagnosis group
(pulmonary, cardiac, infectious, malignancy, gastrointestinal),
but differences in mortality between groups were not
statistically significant. The relationship between severity of illness
and DTDT category is depicted in Fig. 2, demonstrating that
the proportion of patients with higher illness acuity declined as
the time to transfer increased. This relationship between illness
severity and DTDT was statistically significant, with
p = 0.006.
Our study demonstrates that delays in the escalation of care for
clinically deteriorating patients on general medical floors are
frequent, and are associated with in-hospital mortality. Our
findings confirm and update those of previous investigations
suggesting delays are common after the inpatient onset of
clinical deterioration,4,9 and that delays in the time from
Figure 2 Severity of illness and deterioration to door time (DTDT)
Categories. Rothman Index (RI) is severity of illness tool, with RI
value inversely related to illness severity, and a value of 30 or less
used as the cut-point for severe illness.
abnormal vital signs to ICU admission are associated with
increased mortality.5 The overall rate of mortality of 19.8 %
in our study is consistent with that published in a previous
study examining unplanned intra-hospital ICU admission.6 In
addition, the higher mortality rate observed in the 12–24 h
group was not attributable to higher illness acuity, since the
percentage of high acuity illness actually decreased in this late
This investigation provides a contemporary examination of
the timeliness of care escalation among clinically deteriorating
inpatients and its impact on clinical outcomes. Four previous
studies have collectively addressed the issues of inpatient care
escalation and mortality: two4,5 utilized data from the 1990s
and included fewer than 100 patients transferred from general
medical floors to an ICU, one6 investigated the association
between in-hospital transfers to a higher level of care and
mortality, but did not examine the role of delays in care
escalation, and one7 was a triage study which evaluated
clinical deterioration occurring immediately following admission
from the emergency department. Compared with these
previous studies, our investigation provides a contemporary update,
as the standard process of care for inpatient clinical
deterioration has evolved substantially in the last 15 years. Our study
also examines a larger cohort of transfers, and investigates the
role of delays as they relate to escalation of care and mortality
for patients at any point during hospitalization.
Two prior investigations used a cut-point of 4 h as a
distinction between Bfast^ and Bslow^ transfers; using this
convention, our rate of Bslow^ transfers (64.6 %) was comparable
to the rates of 61%5 and 71%9 reported previously. We did not
use a single cut-point in order to examine the shape of the
association between time and mortality, including the BU^
shaped relationship between DTDT and mortality (that is,
higher mortality with very short and longer DTDTs) and the
graded, step-wise relationship between DTDT and mortality.
The increased mortality in the 0–2 h DTDT group likely
reflects high clinical acuity in the most clearly clinically
decompensating (Bcrashing^) patients who experienced
immediate escalation and experienced poor outcomes on basis of
their clinical severity. Our work extends findings from a
previous study, that delays in the time from abnormal vital
signs to ICU admission are associated with increased
mortality5; however, the data in that prior study were collected nearly
20 years ago and had a small sample size (< 100). We have
updated these results in the current era of increased attention to
the clinically deteriorating patient. In addition, a more recent
investigation examining the duration from detectable
physiologic abnormality to ICU arrival (Bscore to door time^) did not
examine patient outcomes.9
The reasons for which delays remain numerous and
correlate with increased mortality are complex, and the reason for
which exploratory (Bhypothesis-generating^) studies such as
this are necessary.17 We postulate that there are likely
systemrelated and patient-related factors that influence this
relationship and contribute to what has come to be known as Bfailure
to rescue.^18,19 System-related factors may include general
inpatient floor staffing models and provider–patient ratios,20
temporal issues including the time of day and day of the week
at which deterioration occurs,21 adherence to vital sign
monitoring protocols,22 and ICU bed availability.7,23,24 There are
also cultural barriers preventing staff from calling for
assistance,25–28 and nurse/physician providers often do not
accurately self-assess the quality of their care for clinically
deteriorating patients.28 Patient factors, such as severity of illness,
age,29 medical comorbidities, and the number and type of
specific criteria heralding deterioration12,13,30 may all play a
role as well. Further investigation into the factors leading to
delays in detection of clinical deterioration and escalation of
care and the relative impact each may have on outcome is
No consensus or standards currently exist by which the care
of clinically deteriorating patients can be evaluated; hence, our
use of approximate quintiles of DTDT. Timeliness has been
recognized by the Agency for Healthcare Research and
Quality, the Institute of Medicine, and the Joint Commission as an
essential component of quality medical care.31–33
BDoor-toballoon time^34 and Bdoor-in to door-out time^35 for acute
myocardial infarction and Bdoor-to-needle time^36 for acute
ischemic stroke are widely familiar national benchmarks for
quality medical care that punctuate the value of timeliness.
Despite such measures becoming canon in medical culture,
targets for the timely detection of clinical deterioration and
escalation of care for inpatients remain comparatively
undeveloped. Given our results, we suggest further efforts be made
to establish a validated patient-centered safety metric with
respect to timeliness in recognition and escalation for clinical
deterioration in inpatient settings.
Our study has important limitations. This study was
conducted at a single urban hospital and may not be generalizable
to other settings. We do not have information regarding
interventions (e.g., volume resuscitation for hypotension or diuretic
therapy for acute pulmonary edema) performed on the general
floor in response to clinical deterioration, and allowed patients
to remain on the general floor and avoid MICU transfer. As
outlined in our methods, limitations were also present
regarding availability of certain clinical variables in the data set,
including patient comorbidities, other types of clinical
deterioration (hemorrhage, hypoxia, change in mental status), and
rapid response team (RRT) activation. We acknowledge that
potential confounders/covariates may have influenced patient
outcomes, including RRT involvement, antibiotic
administration, respiratory therapy involvement, and others that were not
available. Additionally, investigation into the relative
proportions of delay attributable to the floor of origin (e.g., Bfailure to
rescue^) versus the MICU (e.g., bed availability and patient
acceptance) would be informative. Our study also carries
potential for Bover-correcting,^ given that we adjusted for
the RI, which also contains vital signs. However, we re-ran
the data analysis without controlling for the RI and found
Our results indicate that delays of care for clinically
deteriorating hospitalized patients remain common in the current era
of inpatient medical practice and are associated with increases
in in-hospital mortality. Delays in care escalation from the
onset of specified vital sign abnormalities to arrival in the
MICU of greater than 12 h are associated with a significant
increase in in-hospital mortality. These findings occur despite
the evolution in the process of care for inpatient clinical
deterioration, including early warning systems and rapid
response teams, which do not appear sufficient to fully mitigate
the harm associated with delays. If hospitals and health
systems are to address the frequency and potential harms of such
delays, investigation into sources of delay will be necessary.
Development of performance measures for the care of
clinically deteriorating inpatients remains essential and deserves
Acknowledgements: The authors would like to thank Dr. Frank
Davidoff for his thoughtful commentary and assistance with critical
revision of this manuscript.
Corresponding Author: Christopher B. Sankey, MD; Section of
General Medicine, Department of Internal MedicineYale University
School of Medicine, Harkness Hall A, Room 306, 367 Cedar St., New
Haven, CT 06510, USA (e-mail: ).
Compliance with Ethical Standards:
Conflict of Interest: None of the authors of this manuscript have any
conflicts of interest or relationships with industry. Dr. Chaudhry
receives salary support from the Yale Center for Healthcare Innovation,
Redesign and Learning (CHIRAL). CHIRAL is funded by a P30 grant
(#1P30HS023554-01) from the Agency for Healthcare Research and
Quality (AHRQ) and receives support from Yale New Haven Hospital
(YNHH) and the Claude D. Pepper Older Americans Independence
Center at Yale University School of Medicine (#P30AG021342 NIH/
NIA). All other authors declare that they do not have a conflict of
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