MHAC Workshop Review Impact Drill Down Reports

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MHAC WorkshopReview Impact Drill Down Reports

Elizabeth C. McCullough 2 October 2009
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Impact Report Components

• Expected PPC Rate by APR DRG
• Test of Significance
• Marginal Charge Impact

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Expected Value

• The PPC expected value is the number of patients
  with a PPC that would occur if a hospitals mix
  of patients by APR DRG and severity of illness
  subclass had experienced the same PPC rate as
  that in a reference or norm set of hospitals.
• The technique by which the expected value or
  expected number of PPCs is calculated is called
  indirect standardization.
• The PPC rates in the normative database are
  calculated for each admission APR DRG and
  severity of illness subclass by dividing the
  observed number of PPCs by the total number of
  patients at risk.
• Once a set of PPC norms are calculated, they can
  be applied to individual hospitals to compute its
  expected PPC rate.
• Number of Excess or Avoided PPCs equals the
  difference between the actual number of cases
  assigned a PPC minus the expected number of cases
  for that PPC.

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Test of Significance

• A hospitals actual and expected PPC rate can be
  different. This can represent a true difference
  or can be caused by random variation.
• A difference between a hospitals actual and
  expected PPC rate is considered statistically
  significant if the probability that the
  difference can be the result of random variation
  is small.

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Test of Significance (cont.)

• In the PPC reports, a difference between the
  actual and expected PPC rate is considered
  statistically significant at the 0.05 level.
  This means that the probability that the
  difference between the actual and expected PPC
  rate is the result of random variation is five
  percent or less (i.e., less than one chance in
  twenty).
• The calculation of statistical significance of
  the difference between the actual and expected
  PPC rate uses the Cochran-Mantel-Haenszel test
  (CMH).

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Marginal Charge Impact

• Estimated marginal charge amount for a specific
  PPC
• PPC Impact equals the difference in the actual
  and expected number of PPCs times the marginal
  charge amount for a specific PPC
• Overall MHAC impact is the net sum of the PPC
  impact across the 50 PPCs defined in the MHAC
  policy for FY2010

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Report Drill Down

• Overall
• Service Line
• PPC
• PPC by Service Line
• PPC by Top 25 Base Admission APR DRGs
• PPC by Top 25 Base Admission APR DRGs and
  Severity of Illness Level

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Report Structure

• Drill down aggregation
• MHAC Total Impact
• Number of discharges at risk for PPC
• Observed (actual) number of cases assigned PPC
• Expected number of cases for PPC
• Number of observed and expected shown in rates
  per 1000
• Percent Difference between observed and expected
• Significance Level
• '' Statistically significant ( plt0.05 ) higher
  rate of PPCs
• ' Statistically significant ( plt0.05 ) lower
  rate of PPCs

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Report Tab 1 Overall
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Report Tab 1 byService Line
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Report Tab 2 PPC Impact
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Report Tab 3 PPC by Service Line
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Report Tab 4 Top 25 Base APR DRGs
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Report Tab 5 Top APR DRGs by SOI
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PPC v27 On-Line Access

• www.aprdrgassign.com
• User ID - MDHosp
• Password - aprdrg401
• PPC v27 Definition Manual
• Health Care Financing Review
• Spring 2006 Article on PPCs
• Methodology Overview
• PPC v27 Calculator