Table 2 'Death in Low-Mortality DRGs'

PSI 2: Death in Low-Mortality DRGs
Origin: Review of an AHRQ PSI (3)
Dimension Description
Description of Specific
Aspects of Patient Safety
Death in patients admitted to hospital for an extremely low-mortality
condition or procedure might happen due to adverse events. Thus this
theme is suitable as a measure of patient safety.
Aim of the PSI This PSI is intended to flag cases of in-hospital deaths in patients
unlikely to die during hospitalisation.
Level of Determination of
Patient Safety
Safety is assessed at the aggregated patient level.
Source(s) This indicator was originally proposed by Hannan et al. as a criterion
for targeting “cases that would have a higher percentage of quality of
care problems than cases without the criterion as judged by medical
record review” (3).
Extent of Clinically
Testing
The AHRQ project team developing this PSI conducted empirical
analyses on this PSI. The team concluded: “Deaths in low-mortality
DRGs generally performs well on several different dimensions
including reliability, bias, relatedness of indicators and persistence
over time”. The AHRQ project team reviewed the literature and found
a two-stage implicit review of randomly selected deaths by Hannan et
al. They found that “patients in low-mortality DRGs (<0.5%) were
5.2 times more likely than all other patients who died (9.8% versus
1.7%) to have received “care that departed from professionally
recognised standards,” after adjusting for patient demographic,
geographic, and hospital characteristics. In 15 of these 26 cases (58%)
of substandard care, the patient’s death was attributed at least partially
to that care. The association with substandard care was stronger for
the DRG-based definition of this indicator than for the procedurebased
definition (5.7% versus 1.7%, OR=3.2)”(3).
The AHRQ PSI software was applied to Veteran Affairs (VA)
administrative data to identify potential instances of compromised
patient safety; determine occurrence rates of PSI events in the VA;
and examine the construct validity of the PSIs. The study population
was 97% male, with a mean age of 65 years, 54% were age 65 and
older. Mean length of stay was 7.1.days. All together 11411 PSI
events were identified, 46% of PSI events occurred in surgical
hospitalisation and 54% in medical hospitalisation. The observed PSI
rate per 1000 discharges was 3.23 for death in low-mortality DRGs.
This PSI was significantly associated with the AHRQ PSI for failure
to rescue. Statistically significant differences were found for
hospitalisations with this PSI event and those without PSI events for
longer lengths of stay and costs (4).
The performance of the AHRQ PSIs was analysed to: 1) provide a
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descriptive analysis of the incidence of PSI events from 2001 to 2004
in the VA; 2) examine trends in national PSI rates at the hospital
discharge level over time; and 3) assess whether hospital
characteristics (teaching status, number of beds, and degree of quality
improvement implementation) and baseline safety-related hospital
performance predict future hospital safety-related performance. Riskadjusted
rates of the PSI for iatrogenic pneumothorax and failure to
rescue demonstrated no clear trend in the rate over time. It was
concluded, that the PSI is a useful tool for tracking and monitoring
patient safety events. Future research should investigate whether trends
reflect better or worse care or increased attention to documenting
patient safety events (5).
The Agency for Healthcare Research and Quality PSI algorithms were
applied to administrative data across four years of 1.92 million
discharges from children's hospitals. The mean risk-adjusted rates of
PSI events ranged from 0.1 events per 1000 discharges for a foreign
body left in during a procedure to 140 events per 1000 discharges for
failure to rescue. The researchers concluded: “PSIs derived from
administrative data are indicators of patient safety concerns and can be
relevant as screening tools for children's hospitals; however, cases
identified by these indicators do not always represent preventable
events. Some, such as a foreign body left in during a procedure,
iatrogenic pneumothorax, infection attributable to medical care,
decubitus ulcer, and venous thrombosis, seem to be appropriate for
paediatric care and may be directly amenable to system changes. In
their present form, two of the indicators, namely, failure to rescue and
death in low-mortality DRGs, are inaccurate for the paediatric
population, do not represent preventable errors in the majority of
paediatric cases, and should not be used to estimate quality of care or
preventable deaths in children's hospitals”(6).
Administrative data from community hospitals in 16 US states with
reliable race/ethnicity measures using the AHRQ PSIs was analysed to
determine whether racial and ethnic differences in patient safety
events disappear when income (a proxy for socioeconomic status) is
taken into account. Deaths in low-mortality DRGs occur significantly
less often among Hispanic people and Asian Pacific Islander than
among white. It was concluded that: ”The AHRQ PSIs are a broad
screen for potential safety events that point to needed improvement in
the quality of care for specific populations” (7).
The results suggest that this PSI may be useful as a measure of patient
safety – Though special thoughts should be given to application of this
PSI to the paediatric population. (3-6).
AHRQ is determining the feasibility and practicality in a project
concerning validation of selected AHRQ Quality Indicators (8).
Evidence of Clinically use
of Standards
No evidence of clinically use of standards was found.
PSI category Disease Disease Specific PSI
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Data definitions In-hospital deaths per 1000 patients in DRGs with less than 0.5%
mortality.
Numerator Description Discharges with dispositions of “deceased”.
Denominator Description Patients, 18 years and older or MDC (pregnancy, childbirth and
puerperium), in DRGs with less than 0.5% mortality rate, based on NIS
2003 low-mortality DRG.
If a DRG is divided into “without/with complications”, both DRGs
must have mortality rates below 0.5% to qualify for inclusion.
Exclude cases with any code for trauma, immunocompromised state, or
cancer.
Data Source Administrative data.
Identifying the
institutional context
The impact of deaths in low-mortality DRGs related to adverse events
makes this PSI important in quality improvement policies.
Care Setting The PSI applies for quality health care.
Professionals Responsible
for Health Care
All authorised health care workers.
Lowest Level of Health
Care Delivery Addressed
Individual clinical department.
Allowance for Patient
Factors
No risk adjustment described.
Stratification by
Vulnerable Populations
Because the denominator includes many heterogeneous patients cared
for by different services, this PSI should be stratified by DRG type i.e.,
adult medical, paediatric medical, adult surgical, paediatric surgical,
psychiatric, obstetric and neonatal (3;4).
Standard of Comparison No specific standards given.
Scoring AHRQ has PSI software for scoring.
This indicator should be evaluated separately by type of DRG when
used as an indicator of quality. For example, the PSI Software reports
the low-mortality DRG rate for all the included DRGs and separately
by DRG type: adult medical, adult surgical (with and without an
operating room procedure), paediatric medical, paediatric surgical
(with and without an operating room procedure), and obstetric and
psychiatric (3).