Screening Administrative Data To Assess the Accuracy Of Present-on-Admission (POA) Coding

Slide Presentation from the AHRQ 2008 Annual Conference

On September 9, 2008, Michael Pine, M.D., M.B.A., made this presentation at the 2008 Annual Conference. Select to access the PowerPoint® presentation (430 KB).

Slide 1

Screening Administrative Data To Assess the Accuracy Of Present-on-Admission (POA) Coding

Michael Pine, M.D., M.B.A.
Michael Pine and Associates, Inc.
Chicago, Illinois
773-643-1700
mpine@aol.com

Slide 2

Overview

• Rationale for Development of POA Screens
• Developmental Database and Selection of Cases
• Description and Aggregate Performance of 12 Screens
• Evaluation of Coding By Individual Hospitals
• Computation of Composite Scores for Hospitals

Slide 3

Rationale for Development of POA Screens

• POA Code Identifies Hospital-Acquired Complications:
  • Important in Computing Rates of Adverse Outcomes
  • Important in Risk-Adjusting Performance Measures
• Accurate Coding Requires Expertise and Teamwork
• Inaccurate Coding:
  • Affects Assessments of Clinical Quality
  • Affects Reimbursement
• Chart Reviews to Detect Coding Errors Are Expensive
• Well-Designed Screens Can Detect Problems Efficiently

Slide 4

Developmental Database

• New York State Statewide Planning and Research Cooperative System (SPARCS) Data from 2003 through 2005
• 8,388,179 Discharges from 246 Hospitals
• Secondary Diagnosis Codes Have POA Modifiers:
  • "1" = Present on Admission
  • "2" = Hospital-Acquired
  • "9" = Status on Admission Unknown

Slide 5

Selection of Cases for Screening

• High-Risk Conditions By Principal Diagnosis:
  • 33 Categories (e.g., septicemia, respiratory failure)
  • Mortality = 9.2%; 70% of Deaths; 22% of Discharges
• Elective Admissions for Selected Surgical Procedures:
  • 7 Procedures (e.g., hysterectomy, knee replacement)
  • Principal Diagnosis Consistent with Procedure
  • Operation During First 2 Days of Hospitalization
• Inpatient Childbirth By Diagnosis or Procedure Codes

Slide 6

Diagnoses Almost Always Present on Admission

• 231 Diagnosis Groups (e.g., malignancy, osteoporosis)
• Analyzed for Each of the 3 Sets of Cases Screened
• Aggregate Data for Each Set:
  • High-Risk Conditions:
    • Number of Codes: 5,506,043
    • Percent Inpatient: 1.13%
    • Percent Unknown: 5.75%
  • Elective Surgery:
    • Number of Codes: 588,874
    • Percent Inpatient: 0.63%
    • Percent Unknown: 4.52%
  • Inpatient Childbirth:
    • Number of Codes: 112,987
    • Percent Inpatient: 1.85%
    • Percent Unknown: 8.93%

Slide 7

Complications in High-Risk Conditions

• Chronic Diagnoses with and without Acute Components:
  • 21 Pairs (e.g., hernia with and without obstruction)
  • Rates At Which Coded As Hospital-Acquired:
    • Chronic without Acute: 1.06% of 1,612,079 Diagnoses
    • Chronic with Acute: 3.34% of 222,641 Diagnoses
• Diagnoses Frequently Hospital-Acquired (e.g., anuria):
  • 3 Categories Based on Frequency Hospital-Acquired
  • 27 Diagnosis Groups in Category A; 59 in B; 54 in C:
    • Category A—63.5% of 172,472 Codes Hospital-Acquired
    • Category B—34.7% of 469,970 Codes Hospital-Acquired
    • Category C—24.8% of 772,049 Codes Hospital-Acquired

Slide 8

Mortality with Hospital-Acquired Complications

• Only for High-Risk Conditions
• Mortality Greater When Diagnosis Hospital-Acquired:
  • 3 Categories Based on Ratio of Mortality Rates
  • 66 Diagnosis Groups in Category A; 54 in B; 64 in C
  • Aggregate Data for Each Category:
    • A:
      • Number POA Dx: 348,860
      • Percent Dead:12.6%
      • Number Hosp Dx: 27,406
      • Percent Dead: 27.0%
      • Odd Ratio: 2.57
    • B:
      • Number POA Dx: 747,172
      • Percent Dead: 15.3%
      • Number Hosp Dx: 80,856
      • Percent Dead: 25.2%
      • Odd Ratio: 1.87
    • C:
      • Number POA Dx: 1,335,879
      • Percent Dead: 21.2%
      • Number Hosp Dx: 247,144
      • Percent Dead: 30.5%
      • Odd Ratio: 1.64

Slide 9

Complications in Elective Surgical Admissions

• Diagnoses Frequently Hospital-Acquired Complications:
  • 64 Diagnosis Groups (e.g., septicemia, shock)
  • Of 138,655 Codes, 68.3% Hospital-Acquired
• Chronic Diagnoses with and without Acute Components:
  • 21 Pairs (e.g., asthma with and without exacerbation)
  • Rates At Which Coded As Hospital-Acquired
    • Chronic without Acute: 0.39% of 187,453 Diagnoses
    • Chronic with Acute: 18.72% of 2,174 Diagnoses

Slide 10

Risk-Adjusted Post-Op Lengths of Stay (LOS)

• High Rates of Prolonged LOS in Uncomplicated Cases
• Develop Predictive Equations for Routine Post-Op LOS:
  • Compute Observed (OBS) Minus Predicted (PRED) Post-Op LOS
  • For All Live Discharges at Each Hospital:
    • Create XmR Control Charts of OBS minus PRED LOS
    • Remove Outliers with Prolonged Post-Op LOS
    • Repeat Process Until No Further Outliers Identified
    • Set Upper Bound at Median Outlier Rate for All Hospitals
  • Repeat Process Using Only Uncomplicated Cases:
    • Compute Outlier Rates for Each Hospital
    • Identify Hospitals with Rates Greater Than Upper Bound

Slide 11

Risk-Adjusted Post-Op Lengths of Stay: Live Discharges with and without Reported Complications

The graph measures the "Average," "3 Std Dev," "Normal LOS," "Long LOS with Cpl," and "Long LOS without CPL." The graph's vertical axis, "OBS LOS minus PRED LOS-days," goes from -10 to 60 and the horizontal axis, "Sequence Identifier," goes from 1 to 511. "Average" was 0 days; "3 Std Dev" was 5 days; "Normal LOS" had a range between -4 to 6 days; "Long LOS with Cpl" had a range between 6 to 42 days; and "Long LOS without Cpl" was recorded only three times at 5, 6, and 16 days.

Slide 12

Risk-Adjusted Post-Op Lengths of Stay: Live Discharges with and without Reported Complications

The graph measures the "Average," "3 Std Dev," "Normal LOS," and "Long LOS without CPL." The graph's vertical axis, "OBS LOS minus PRED LOS-days," goes from -10 to 60 and the horizontal axis, "Sequence Identifier," goes from 1 to 491. "Average" was 0 days; "3 Std Dev" was 5 days; "Normal LOS" had a range between -3 to 4 days, and "Long LOS without Cpl" was recorded only six times at 7, 6, 5, 16, 6, and 5 days.

Slide 13

Complications in Obstetrical Admissions

• Diagnoses Usually Present on Admission:
  • 7 Diagnosis Groups (e.g., multiple gestation)
  • Of 448,242 Codes, 5.19% Hospital-Acquired
• Fifth Digit Codes Incompatible with Inpatient Delivery:
  • 737,125 Inpatient Deliveries
  • Fifth Digit = "0" or "3" or "4" in 0.27%
• Inpatient Post-Partum Complications:
  • 74,669 Cases with Obstetrical Fifth Digit = "2"
  • No Diagnosis Coded As Hospital-Acquired in 36.5%

Slide 14

Initial Analyses of Hospital Coding

• 226 Hospitals Screened with One or More Measures
• 22 Hospitals Have More Than 10% Unknowns
• Diagnoses Almost Always Present on Admission:
  • Less Than 2% of Diagnoses Hospital-Acquired:
    • High-Risk Conditions:
      • Number of Hospitals: 200
      • Percent Meeting Criterion: 91.5%
      • Elective Surgery
      • Number of Hospitals: 123
      • Percent Meeting Criterion: 89.4%
    • Inpatient Delivery:
      • Number of Hospitals: 48
      • Percent Meeting Criterion: 45.8%

Slide 15

Hospital Coding for High-Risk Conditions

• Chronic Diagnoses with Acute Components:
  • Hospital-Acquired Rate Greater Than 2% AND Greater Than Twice Rate for Chronic Codes
  • Of 145 Hospitals, 71.7% Met Criteria
• Diagnoses Frequently Hospital-Acquired:
  • Hospital-Acquired Rate Greater Than 15% for Category B Diagnoses AND Rate Monotonically Decreasing from Category A to Category C
  • Of 181 Hospitals, 83.4% Met Criteria

Slide 16

Hospital Mortality Rates for High-Risk Conditions

• Compute Predicted Mortality Rates:
  • Indirect Standardization within Each Category
  • Based on Rates for Diagnoses Present on Admission
• Odds Ratio of Observed to Predicted Mortality Rates:
  • Greater Than 1.60 for All Diagnoses OR
  • Greater Than 1.30 for All Diagnoses AND Greater Than 1.60 for Diagnoses in Categories A and B
• Of 184 Hospitals, 82.6% Met Criteria

Slide 17

Hospital Coding for Elective Surgical Admissions

• Diagnoses Frequently Hospital-Acquired Complications:
  • Hospital-Acquired Rate Greater Than 65%
  • Of 175 Hospitals, 61.1% Met Criterion
• Chronic Diagnoses with Acute Components:
  • Compute 2 Standard Deviation Lower Bounds for Hospital-Acquired Rates:
    • Hospital-Acquired Rate Greater Than 12% AND Greater Than Three Times Rate for Chronic Codes OR
    • Lower Bound Greater Than Twice Rate for Chronic Codes
  • Of 93 Hospitals, 96.8% Met Criteria

Slide 18

Prolonged Risk-Adjusted Post-Op Length of Stay

• Median Outlier Rate for All Live Discharges = 5.36%
• Outlier Rates for Uncomplicated Cases Less Than Upper Bound:
  • In 81.5% of 178 Hospitals
  • In 98.4% of 64 Reference Hospitals
  • In 71.9% of 114 Remaining Hospitals

Slide 19

Hospital Coding for Obstetrical Admissions

• Diagnoses Usually Present on Admission:
  • Hospital-Acquired Rate Less Than 3%
  • Of 134 Hospitals, 63.4% Met Criterion
• Fifth Digit Codes Incompatible with Inpatient Delivery:
  • Less Than 0.5% of Obstetrical Codes Incompatible
  • Of 134 Hospitals, 87.3% Met Criterion
• Cases with Inpatient Post-Partum Complications:
  • Less Than 20% without Hospital-Acquired Diagnosis
  • Of 123 Hospitals, 41.5% Met Criterion

Slide 20

Composite Hospital Scoring

• Range of Points Assigned to Each Measure:
  • Range from 1 to N with N = 4, 5, 8, or 10
  • Score Only for 204 Hospitals with Adequate Data
  • Score Measure Only When Volume Criteria Met
• For Each Hospital, Compute:
  • Total of Points Scored for Each Measure
  • Maximum and Minimum Possible Points
• For Each Measure, Compute Average of Points Scored
• Obtain Final Adjusted Hospital Scores By Interpolation

Slide 21

Final Adjusted Hospital Scores

• Hospital Average:
  • Total: 77.8
  • Maximum: 96
  • Minimum: 12
  • Adjusted Score: 77.8
  • Adjusted Score percent: 81.1%
• Hospital A:
  • Total: 96
  • Maximum: 96
  • Minimum:12
  • Adjusted Score: 96.0
  • Adjusted Score percent: 100%
• Hospital B:
  • Total: 61
  • Maximum: 61
  • Minimum: 8
  • Adjusted Score: 96.0
  • Adjusted Score percent: 100%
• Hospital C:
  • Total: 66
  • Maximum: 96
  • Minimum: 12
  • Adjusted Score: 66.0
  • Adjusted Score percent: 68.8%
• Hospital D:
  • Total: 61
  • Maximum: 68
  • Minimum: 8
  • Adjusted Score: 82.7
  • Adjusted Score percent: 86.2%
• Hospital E:
  • Total: 54
  • Maximum: 57
  • Minimum: 7
  • Adjusted Score: 88.8
  • Adjusted Score percent: 92.5%
• Hospital F:
  • Total: 48
  • Maximum: 82
  • Minimum: 10
  • Adjusted Score: 55.7
  • Adjusted Score percent: 58.0%

Slide 22

Screening and Improvement of POA Coding

The flow chart shows the cycle:

• POA Screening
• Performance Evaluation
• Process Analysis
• Identification of Opportunities for Improvement
• Plan for Improvement
• Intervention in Process