The Strengths and Limitations of Linking Medicare Claims Data Across Clinical Settings to Study Patients with Pressure Injuries

UNIVERSITY OF CALIFORNIALos AngelesThe Strengths and Limitations of Linking Medicare Claims DataAcross Clinical Settings to Study Patients with Pressure InjuriesA dissertation submitted in partial satisfaction of therequirements for the degree Doctor of Philosophyin Health Policy and ManagementbyLee Sook Hee Squitieri2017 Copyright byLee Sook Hee Squitieri2017ABSTRACT OF THE DISSERTATIONThe Strengths and Limitations of Linking Medicare Claims DataAcross Clinical Settings to Study Patients with Pressure InjuriesbyLee Sook Hee SquitieriDoctor of Philosophy in Health Policy and ManagementUniversity of California, Los Angeles 2017Professor Carol Mangione, ChairPressure injuries represent a major public health problem among older adults in theUnited States. Over the past decade, numerous policies and payment reforms have focused onreducing the incidence of pressure injuries and improving their quality of care. Pressure injuriestypically occur in medically complex patients that receive treatment from multiple differentproviders over short periods of time, and the quality of care delivered in one setting may impactmeasured quality, patient outcomes, and cost/utilization in another. Despite the recent nationalfocus on pressure injury quality of care, there is a paucity of national research evaluating patientswith this condition across different clinical encounters and settings of care.In this dissertation, we explored three distinct research aims using linked Medicareclaims data to study pressure injury coding and population characteristics on a national level.The first aim studied consistency of pressure injury documentation across interfacility transferiiencounters. The second aim compared hospital-reported present-on-admission status for pressureinjuries to diagnostic history in claims data, and the third aim used linked claims data to studythe overall pressure injury population across different settings of care.Our results demonstrated that pressure injury coding was not consistent across adjacentfacility claims highlighting issues of documentation reliability and potential inaccuracy in claimsdata. We also found a substantial discrepancy between hospital-reported present-on-admissionstatus of pressure injuries and diagnostic patient history in claims data. This finding hasimportant implications for quality measurement and payment reimbursement in the acuteinpatient setting, because current quality measures for pressure injuries rely on hospital-reportedPOA data to evaluate provider performance. Finally, we identified baseline differences in patientdemographics, clinical comorbidity, and risk-adjusted mortality among patients diagnosed withpressure injuries in different settings of care that may inform future research, policy, andpayment reform.Taken together these results provide an important overview of the strengths andlimitations of linking Medicare claims data to study patients with pressure injuries. The findingsof this work may inform future research and quality measure development for pressure injuriesand other chronic conditions.iiiThe dissertation of Lee Squitieri is approved.Daniel A. WaxmanDavid A. GanzClifford Y. KoJack NeedlemanDebra SalibaCarol M. Mangione, Committee ChairUniversity of California, Los Angeles2017ivTo my husband Matthew and our amazing children Joseph and Isabella.You make life beautiful.vTable of ContentsChapter 1. Introduction to Pressure Injuries.1.1 Clinical and Financial Burden of Pressure Injuries in the United States1.2 Nomenclature and Staging Guidelines.1.3 Etiology and Risk Factors for Developing Pressure Injuries.1.4 Treatment Guidelines.Chapter 2. Pressure Injury Policy and Payment Reform.2.1 Hospital-Acquired Conditions Payment Provision (2008).2.2 Hospital-Acquired Conditions Reduction Program (2014)Chapter 3. Pressure Injury Quality Measurement in the Acute Inpatient Setting3.1 Hospital-Reported Present-on-Admission Indicator.3.2 Pressure Injury Coding Guidelines.3.3 The Agency for Healthcare Research and Quality Patient Safety Indicator 03.Chapter 4. Preface to My Original Research.4.1 Limitations of Existing Literature .4.2 Specific Research Aims.4.3 Description of Data Sources and Approach4.4 Significance and Innovation.Chapter 5. Pressure Injury Documentation Consistency in Claims Data acrossInterfacility Transfers.5.1 Abstract.5.2 Introduction.5.3 Methods.5.4 Results.5.5 Discussion.Chapter 6. Hospital-Reported Pressure Injury Present-on-Admission Status vs.Diagnostic History in Claims Data.6.1 Abstract.6.2 Introduction 6.3 Methods.6.4 Results.6.5 Discussion.11245778101011121414151619202021232632363637394350viChapter 7. Demographics and Clinical Characteristics of Patients Diagnosed withPressure Injuries across Settings of Care7.1 Abstract.7.2 Introduction.7.3 Methods.7.4 Results.7.5 Discussion.Chapter 8. Conclusions and Recommendations.8.1 Summary of Findings. .8.2 Strengths and Limitations of Linking Medicare Claims Data across Settings.8.3 Future Recommendations.Appendix.References.535354555966686870717478viiList of Tables and FiguresTablesTable 1.1 NPUAP Pressure Injury Stage Definitions.Table 1.2 Intrinsic and Extrinsic Risk Factors for Pressure Injury DevelopmentTable 2.1 List of Hospital-Acquired Conditions.Table 3.1 AHRQ PSI 03 Exclusion Criteria.Table 4.1 Sources of Medicare Claims DataTable 4.2 Data Sources for Each Specific Research AimTable 5.1 Characteristics of Acute Inpatient Admissions with a Pressure InjuryDiagnosis in 2012.Table 5.2 Facility Characteristics among Transfers between Acute Inpatient Hospitals.Table 5.3 Transfers to an Acute Inpatient Hospital with a Present-on-AdmissionPressure Injury Diagnosis.Table 5.4 Transfers with an Advanced Stage (Stage III, IV, or Unstageable) PressureInjury Diagnosis at the Transferring Facility.Table 6.1 Characteristics of Acute Inpatient Admissions with a Pressure InjuryDiagnosis in 2011.Table 6.2 Hospital-Reported Pressure Injury Present-on-Admission Status Stratifiedby Pressure Injury Stage.Table 6.3 National Pressure Injury Rates per 1000 Acute Inpatient Admissions (2011).Table 6.4 Admissions with a Pressure Injury Diagnosis Meeting AHRQ PSI 03 PatientExclusion Criteria in 2011.Table 7.1 Characteristics of New Pressure Injury Patients Stratified by DiagnosticClinical Setting.Table 7.2 Prevalence of Elixhauser Comorbidity Categories Among Patients with aNew Pressure Injury Diagnosis Compared to the General Fee-for-ServiceMedicare Population.Table 7.3 Risk-Adjusted All-Cause Mortality Among Patients with a New PressureInjury by Clinical Setting of Diagnosis.FiguresFigure 4.1 Illustrative Example of Linking Medicare Claims Data at the Patient Level.Figure 4.2 Pressure Injury ICD-9 Diagnosis and CPT Procedure Codes.Figure 5.1 Sample of Interfacility Transfer Encounters.Figure 6.1 Sample of Acute Inpatient Admissions with a