Child Mortality at Pediatric and
Other Hospitals
John Moran, Penn State University
Robert Kanter, SUNY Upstate Medical University
Joseph Terza, University of North Carolina, Greensboro
Importance
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Regionalization of pediatric hospital care
advocated by:
– American Academy of Pediatrics
– American College of Critical Care Medicine
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Existing Evidence
– Cardiac surgery: Hannan, Pediatrics (1998)
– ICU care: Tilford, Pediatrics (2000)
– Inpatient care generally? None to our knowledge.
Definition of a “pediatric hospital”
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Kanter & Dexter, J. of Pediatrics, 2005
– Top decile statewide for clinical volume
– Top decile statewide for diversity of disorders
– Accredited pediatric residency program
Pediatric Hospitals in NYS
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Of 241 hospitals in NYS, the following 11 met all
three criteria:
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Albany Medical Center (Albany)
Children’s Hospital (Buffalo)
Columbia Presbyterian Medical Center (NYC)
Mount Sinai (NYC)
New York Weill / Cornell Medical Center (NYC)
North Shore University Hospital (Manhasset)
Schneider Children’s Hospital (Queens)
Strong Memorial Hospital (Rochester)
University Hospital (Stony Brook)
University Hospital / SUNY Upstate Medical University (Syracuse)
Westchester Medical Center (Valhalla)
The Problem: Case-Mix Bias
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Higher-quality hospitals attract sicker or
more difficult-to-treat patients
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Risk adjustment can help, but:
– Costly if done using detailed medical records
– May work best when confined to specific
ailments
– May not fully capture case-mix differences
Alternative Solution: Instrumental
Variables Estimation
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A form of pseudo randomization based on regression
analysis
Need a variable that affects treatment assignment
(type of hospital), but has no independent effect on
outcomes (inpatient mortality)
Standard candidate: differential distance
Home to nearest pediatric hospital – home to nearest hospital
Alternative Solution: Instrumental
Variables Estimation

Restrict comparisons to patients residing in the same
county
– Minimizes effect of urban / suburban / rural differences
– Minimizes effect of differences in absolute distance to a
hospital
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Validity of key assumption not directly testable, but
some heuristic checks are available
– Irrelevance of covariates if pseudo randomization successful
– Differential distance should be similar for high- and low-risk
patients
Analysis

Compare mortality rates at pediatric and
non-pediatric hospitals: 3 regression models
(1) Controlling for patient demographics
(2) Adding DRGs
(3) Using differential distance instrument
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For all patients
For a high-risk subgroup
– Chronic conditions, severe organ dysfunction,
severe trauma, infants (< 1 year)
Sample
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Data: NYS SPARCS, 1996-2002
All NYS inpatients, age 0-14, excluding neonatal DRGs, from
1996-2002
Complete data available for 903,388 children overall and
355,571 high-risk patients
Mean inpatient mortality rates: 0.0035 overall and 0.0078 for
high-risk group
27% of all patients and 34% of high-risk patients were
admitted to a pediatric hospital
Patient covariates
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Age, indicators for each year
Gender
Race (6 categories)
Hispanic ethnicity
Per capita income in patient’s zip code in 2000
Indicator for unscheduled admission
Payer type (13 categories)
County indicators (≈ 60)
Year indicators
DRG indicators (≈ 400)
Results – All Patients
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Patient demographics only
– Excess mortality at pediatric hospitals of 7.7
deaths / 1000 hospitalizations (p < 0.05)

Adding DRGs
– Excess mortality at pediatric hospitals of 3.0
deaths / 1000 hospitalizations (p < 0.05)
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Instrumental variable estimates
– Reduced mortality at pediatric hospitals of 4.7
deaths / 1000 hospitalizations (p < 0.05)
Checks
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IV estimate omitting covariates
– Reduced mortality at pediatric hospitals of 3.9
deaths / 1000 hospitalizations (p < 0.05)

Differential distance for high- vs. low-risk
patients
– Means: 11.25 miles vs. 11.49 miles
– Overall mean 11.40 miles, std dev 17.71 miles,
range 0 – 145.80 miles
Results – High-Risk Patients
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Patient demographics only
– Excess mortality at pediatric hospitals of 12.1
deaths / 1000 hospitalizations (p < 0.05)

Adding DRGs
– Excess mortality at pediatric hospitals of 5.6
deaths / 1000 hospitalizations (p < 0.05)
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Instrumental variable estimates
– Reduced mortality at pediatric hospitals of 13.9
deaths / 1000 hospitalizations (p < 0.05)
– Check: Without covariates, reduction of 13.0
deaths / 1000 hospitalizations
Conclusions
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Pediatric hospitals care for sicker patients
than other hospitals
Some of the difference in severity cannot be
observed in administrative data
Pediatric hospitals provide higher quality
care than other hospitals, especially for
high-risk patients
Implications

Findings support a role for regionalization of
hospital services for children
– Define necessary services at pediatric hospitals
– Influence appropriate utilization of these
facilities for high-risk children
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Suggests need to balance efficiency gains
from competition with superior clinical
outcomes that arise when patients have
appropriate access to pediatric hospitals