FACTORS AFFECTING THE QUALITY OF REHABILITATION CARE FOR INPATIENTS WITH SPINAL CORD INJURY HAIYAN QU

Transcription

1 FACTORS AFFECTING THE QUALITY OF REHABILITATION CARE FOR INPATIENTS WITH SPINAL CORD INJURY by HAIYAN QU RICHARD M. SHEWCHUK, COMMITTEE CHAIR HOWARD W. HOUSER, COMMITTEE CO-CHAIR JEFFREY H. BURKHARDT YU-YING CHEN J. SCOTT RICHARDS. A DISSERTATION Submitted to the graduate faculty of The University of Alabama at Birmingham, in partial fulfillment of the requirements for the degree of Doctor of Philosophy BIRMINGHAM, ALABAMA 2007

2 Copyright by Haiyan Qu 2007 ii

3 FACTORS AFFECTING THE QUALITY OF REHABILITATION CARE FOR INPATIENTS WITH SPINAL CORD INJURY HAIYAN QU HEALTH SERVICES ADMINISTRATION ABSTRACT The quality of inpatient rehabilitation for patients with spinal cord injury (SCI) has been evaluated in many ways. Few studies examined the effects of both structure and process of care on SCI patient outcomes. No empirical studies have examined the Medicare prospective payment system (PPS) as it relates to care outcomes for patients with SCI. The purpose of this study was to examine the quality of inpatient rehabilitation care for patients with SCI using Donabedian s structure, process, and outcome theoretical model combined with environmental factors (PPS) and patient characteristic factors. Data were abstracted from the National Spinal Cord Injury Database (NSCID) and combined with information obtained from surveying directors of SCI rehabilitation centers participating in the Model Spinal Cord Injury System (MSCIS). Patients were classified into different clusters (low, intermediate, and high functional groups) based on their initial functional status as measured by the functional independency measure (FIM) at admission to rehabilitation centers using a TwoStep Component cluster analysis. The analyses were conducted using a combination of general linear models (GLM) and hierarchical linear models (HLM). The results were consistent across these models in showing that the structure of care measured as physical and occupational therapists bed ratios was not associated patient outcomes measured as FIM change scores (FIMCSs) nor associated with the process of care measured as physical and occupational therapy hours per day. However, the process of care was positively related to patient FIMCSs. PPS iii

4 alone was not related to patient outcomes, but was related to patient outcomes when considering cluster memberships. The intermediate functional groups demonstrated the greater functional improvement than the lower and higher functional groups. The findings from this study provided some support for the Donabedian s model. The results also provide other researchers and policy analysts an alternative framework for examining other factors that influences the quality of rehabilitation care. iv

5 ACKNOWLEDGMENTS I would like to thank all of the individuals who have helped me throughout this research project and my education at University of Alabama at Birmingham. I cannot name each of you individually, but you know how much I appreciate your supports during past four years. First, I would like to thank my helpful dissertation committee for their encouragement and expertise guidance both individually and collectively. Dr. Richard M. Shewchuk has served as my chair, mentor, and role model during my education. He has provided me unique research opportunities and I have learned tremendously from his profuse research experience, precise scholarly habits, and diligent work. He encouraged, supported, and guided me through the entire process of this research project. I will never forget the days we discussed about my dissertation on the phone in the evenings, weekends, and even the days when he was out of town. Without his supervision, constant support, and patient instrument, this dissertation certainly could not have been done. He is not only an excellent professor but also a dependable friend. The friendship between us will last year in, year out, and never ending. Sincere thanks go to Dr. Howard W. Houser for agreeing to serve as my co-chair. His constant encouragement and support for both my course study and dissertation help me get through my doctorate education. I am very grateful for Dr. Jeffery H. Burkhardt s outstanding support from how to write a critique paper and prepare comprehensive exams to how to write a dissertation. He steadily influenced this project and was always v

6 available whenever I needed to ask him questions and discuss the project with him. I sincerely thank Dr. Yu-ying Chen for providing the data for my dissertation, devoting valuable efforts and time to help me understand the complicated database and collect additional data to the study, and suggesting constructive ideas to the study. I am extremely grateful for Dr. J Scott Richards s interest and efforts in my research. He generously helped me collecting the research data and shared his more than 30-year experience and scholarly ideas about SCI rehabilitation to make this research project better. He was always available when he was needed most. I also want to thank Dr. Michael J. DeVivo. He gave me valuable suggestions based on his more than 30-year research experience about SCI rehabilitation. I also want to thank my English teacher Ms. Nancy Abney, she helped me a lot during the 4-year study. I also want to thank all faculty members in this department, especially Drs. S. Robert Hernandez, Stephen J. O Connor, Gerald L. Glandon, Donna J. Slovensky, Shannon Houser, and Professor Pamela E. Paustian. I will never forget my friends who help me these years, especially Joy E. Ptacek, Martha E. Hilley, and Dr. Ann Keucher. Finally, I would like to thank all my family members, for their love and dedication. Their support and understanding made this dream possible. vi

7 TABLE OF CONTENTS Page ABSTRACT... iii ACKNOWLEDGMENTS...v LIST OF TABLES...x LIST OF FIGURES... xii LIST OF ABBREVIATIONS... xiii CHAPTER I. INTRODUCTION...1 Background of the Study...1 Objective of the Study...4 Significance of the Study LITERATURE REVIEW...6 Research on the Quality of Inpatient Rehabilitation Care...6 The Effect of Structural Factors on Rehabilitation Outcomes...7 The Effect of Structural Factors on Outcome via Process of Rehabilitation Care...8 The Effect of Process Factors on Rehabilitation Outcomes...8 The Effect of Patient Characteristics on Rehabilitation Outcome...11 Age-at-injury and Outcomes...11 Race and Outcomes...12 The Effect of Environmental Factor on Rehabilitation Outcome THEORETICAL FRAMEWORK...16 Donabedian s Structure, Process, and Outcome Quality Assessment Theory...16 Structure, Process, and Outcomes in Rehabilitation Care Setting...19 Structure of Rehabilitation for Patients with SCI...19 Process of Rehabilitation Care for Patients with SCI...19 Outcome of Rehabilitation Care for Patients with SCI...20 Research Questions and Hypotheses...20 Research Question Research Question vii

8 Research Question Research Question Research Question METHODOLOGY...26 Data Data Sources...26 Data Characteristics...27 Data Collection...28 Sample...29 Measures...31 Outcome Variables...31 Structural Variables...35 Process Variables...36 Patient Characteristic Variables...37 Environmental Variable...38 Statistical Analyses...39 Descriptive Analyses...39 Cluster Analysis...40 Generalized Linear Model (GLM) Univariate Analysis...41 Hierarchical Linear Model Analysis (HLM) RESULTS...49 Descriptive Analysis Results...49 Patient Characteristics...49 Center Characteristics...51 Descriptive Statistics for the Main Outcomes and Process Variables...52 Cluster Analysis Results...54 Cluster Membership Distribution...54 Cluster Membership Distribution Before and After PPS Implementation...55 FIM scores at Admission in Different Clusters...56 Length of Stay for Patients in Different Clusters Before and After PPS Implementation...57 Physical and Occupational Therapeutic Services Delivery...57 Cluster Membership Distribution Across Centers...58 GLM Univariate Analysis Results...59 HLM Analysis Results...69 Unconditional Model...69 Intercept and Slope as Outcome Model...72 Disaggregated Analysis Results...78 Aggregated Analysis Results DISCUSSION AND CONCLUSION...83 viii

9 Significance of the Study...90 Limitation of the Study...91 Future Study...91 LIST OF REFERENCES...94 APPENDICES A STAFF RATIOS AND CENTER CHARACTERISTICS...99 B RANKING OF PERCENTAGE OF LOW FUNCTIONAL PATIENTS RECEIVED AT ADMISSION IN TERMS OF SELF-CARE CLUSTER MEMBERSHIP ACROSS CENTERS C RANKING OF PERCENTAGE OF LOW FUNCTIONAL PATIENTS RECEIVED AT ADMISSION IN TERMS OF MOBILITY-LOCOMOTION CLUSTER MEMBERSHIP ACROSS CENTERS D SELF-CARE CLUSTER MEMBERSHIP ACROSS CENTERS E MOBILITY-LOCOMOTION CLUSTER MEMBERSHIP ACROSS CENTERS F MEAN AND STANDARD DEVIATION OF FIM CHANGE SCORES ACROSS CLUSTERS PRE- AND POST- PPS IMPLEMENTATION G. INSTITUTIONAL REVIEW BOARD FOR HUMAN USE APPROVAL FORMS ix

10 LIST OF TABLES Tables Page 1 FIM Items in Self-care, Mobility, and Locomotion Domains and Scoring System Primary Measures and Scoring Demographic Characteristics of the Sample FIM Measures at Inpatient Rehabilitation Admission Descriptive of Main Outcome and Process Variables Cluster Membership of Self-care and Mobility-locomotion Domains Based on FIM Scores at Admission Cluster Membership of Self-care and Mobility-locomotion Domains based on FIM Scores at Admission Pre-and Post- PPS FIM Scores at Admission in Different Clusters Pre- and Post- PPS Implementation Mean and Standard Deviation of Length of Stay in Inpatient Rehabilitation for Penitents with SCI in Different Clusters Pre- and post-pps Mean and Standard Deviation of Physical and Occupational Therapy Hours per day of hospitalization in Different Clusters Pre- and Post- PPS Descriptive Statistics of FIM Change Scores a Tests of Between-Subjects Effects for Self-care FIM Change Scores b Parameter Estimations for Self-care FIM Change Scores...66 x

11 13a Tests of Between-Subjects Effects for Mobility-locomotion FIM Change Scores b Parameter Estimations for Mobility-locomotion FIM Change Scores Unconditional Models: Estimation of Fixed Effects Unconditional Model: Estimation of Variance Components a Estimation of Fixed Effects for Self-care Domain b Estimation of Fixed Effects for Mobility-locomotion Domain Intercept as Outcome Model: Estimation of Variance Components a 18b Coefficients from Disaggregated Regression Analysis for Self-care Domain...80 Coefficients from Disaggregated Regression Analysis for Mobility-locomotion Domain The Effect of Structure on Process of Care Hypotheses Tested...82 xi

12 LIST OF FIGURES Figures Page 1 An Extended Theoretical Framework Flow Chart of Sample Selection Steps Distribution of Self-care FIM Change Scores Distribution of Mobility-Locomotion FIM Change Scores Distribution of Physical and Occupational Therapy Hours per day of Hospitalization Estimated Marginal Means of Self-care FIMCSs Estimated Marginal Means of Mobility-locomotion FIMCSs...64 xii

13 LIST OF ABBREVIATIONS ASIA American Spinal Injuries Association FIM Functional Independent Measure, now known as FIM TM instrument FIMCS--FIM change score IFG Intermediate functional group IRF Inpatient Rehabilitation Facility HFG High functional group LFG Low functional group LOS Length of Stay ML Mobility-locomotion MSCIS Model Spinal Cord Injury Systems NSCID National Spinal Cord Injury Database NSCISC National Spinal Cord Injury Statistical Center PPS Prospective Payment System SCI Spinal Cord Injury SC Self-care SD Standard deviation SE Standard error SPO Structure, Process and Outcome xiii

14 1 CHAPTER 1 INTRODUCTION Background of the Study It has been estimated that the incidence of spinal cord injury (SCI) per million population is 15 to 40 cases worldwide (Jackson, et al., 2004; Joyce, 2005; Sipski and Richards, 2005) and 30 to 40 cases in the United States (Cifu et al., 1999; Fries, 2005). Given the current US population, nearly 9,000 to 12,000 people suffer SCI each year in the United States. Due in part to advances in technology and emergency services, about 65% of the new SCI patients now survive their initial injury, and most of them receive inpatient rehabilitation care following acute medical stabilization (Center, 2001). The goal of inpatient rehabilitation care for persons with SCI is to maximize the recovery of physical and cognitive functions, to minimize the decline in patient health status, and to prevent medical complications, so that they can be discharged to the least restrictive setting, such as to the community (private living). According to the National Spinal Cord Injury Association, it is estimated that as many as 450,000 people across the country are living with an SCI, which costs the nation an estimated $9.7 billion annually for medical care and household assistance (ASIA, 2000). Spinal cord injury is a traumatic damage of neural elements in the spinal cord, resulting in any degree of sensory and/or motor deficit, autonomic dysfunction, and bladder/bowel dysfunction (ASIA, 2000). The neurologic deficit or dysfunction can

15 2 be temporary or permanent and may be incomplete or complete. Neurologic level and extent of injury are defined using the international standards set forth by the American Spinal Cord Injury Association (ASIA) (ASIA, 2000). Neurologic level is defined as tetraplegia and paraplegia. Specifically, tetraplegia (preferred to "quadriplegia") refers to impairment or loss of motor and/or sensory function in a cervical segment (C1-C8) of the spinal cord caused by damage of neural elements within the spinal canal (Maynard, et al., 1997, p.267). Paraplegia refers to impairment or loss of motor and/or sensory function in a thoracic (T1-T12), lumbar (L1-L5), or sacral segment (S1-S5) of the spinal cord following damage to the spinal cord (Maynard, et al., 1997, p.267). According to the revised 2002 International Standards for Neurological Classification of Spinal Cord Injury from ASIA, the levels of injury are classified as high tetraplegia/paraplegia (ASIA A-C), low tetraplegia/paraplegia (ASIA A-C) and tetraplegia /paraplegia ASIA D. More than 30 years ago, Avedis Donabedian proposed a three-element model based on structure, process and outcome (SPO) of care to assess quality of care. He defined structure of care as where care occurs and by whom it is provided; process of care as how care is delivered; and outcome of care as the change in health status that results from care (Donabedian, 1972). During the last two decades, quality assessment emphasized measurement of outcomes. Outcome alone, however, has limited effect for improving quality of care, partly because of the difficulty of measuring patient case-mix. Recently, researchers have focused on examining the association of process and outcome of care rather than outcome per se. Despite many studies on process and

16 3 outcome, few studies have looked at structural and process factors that would affect the outcome for SCI inpatient rehabilitation. To fill this gap, this study analyzed the SCI rehabilitation structure, process and outcomes using the National Spinal Cord Injury Database (NSCID) by applying the Donabedian theoretical model of health service assessment. SPO provides a framework to assess the quality of rehabilitation care, but does not consider the environmental and patient factors. Environmental factors (e.g., the change of reimbursement policy) and patient characteristics (e.g., severity of SCI) also have effects on quality of rehabilitation care. The Centers for Medicare and Medicaid Services mandated inpatient rehabilitation facilities (IRF) to implement prospective payment system (PPS) on January 1, 2002 although there was some difference in phase-in dates. Although the policy of PPS is primarily for Medicare beneficiaries who only account for about 7% of all new SCI patients, it represents a significant change of reimbursement from fee-for-services. This study examined the effect of PPS on the outcomes of rehabilitation care for SCI patients after controlling for structural factors, process factors and patient characteristics. The World Health Organization (WHO) suggested that rehabilitation could be considered to include the use of all possible means to reduce the impact of impairments and disabilities (Hurn, et al, 2006, p756). Rehabilitation providers include freestanding rehabilitation hospitals, rehabilitation units affiliated with acute care hospitals, and nursing home rehabilitation. Rehabilitation interventions used to help patients include physical, occupational, vocational, speech and recreation therapies.

17 4 Rehabilitation goals are also different for patients with different conditions. Variability in health status across patients is evident even among patients with the same conditions. Environmental changes also bring pressure to the rehabilitation care industry. All these variations pose challenges to study rehabilitation quality, especially SCI rehabilitation quality. The literature of the empirical studies of SCI rehabilitation quality is limited. Although the structural factors (i.e., types of providers), process factors (i.e., intervention procedures), as well as outcome goals vary greatly in SCI rehabilitation treatment, scholars asserted that SPO model provides a framework to systematically examine the quality of rehabilitation care (Hoenig et al, 1999). Objective of the Study The purpose of this study was to assess the quality of inpatient rehabilitation for patients with SCI by 1) investigating the relationship among structure, process, and outcome; 2) identifying the structural and process factors influencing the outcome of inpatient rehabilitation; and 3) identifying the factors other than the structural and process factors of providers (e.g., environmental factors and patient characteristics) influencing the outcome of inpatient rehabilitation. The data for this study were obtained from the Initial Hospitalization and Rehabilitation Form I (originally abstracted from medical records) of NSCID. The NSCID has a large patient sample size, representing variations in age, gender, race, injury level and extent, and geographic region. It also includes standard injury-related and functional assessment information.

18 5 Significance of the Study This study advances our understanding of the quality of rehabilitation care in several ways. First, this study is the first study to investigate the factors that influence the quality of SCI rehabilitation under an SPO theoretical framework. This represents an advance from previous studies that only examined either process and outcome relationship or structure and outcome relationship, but not both. A more complete framework, therefore, was presented in this study. Second, this study examined the environmental and patient factors that influence the quality of rehabilitation care for patients with SCI outside the SPO framework. The findings of this study contributed to our understanding of factors that could affect the rehabilitation outcomes for patients with SCI. Third, the analytic approach used in this study provides an additional perspective for understanding SCI rehabilitation, and a strategy for identifying patient subgroups based on their initial functional status at rehabilitation that help to address case-mix when examining the influencing factors on patient outcome. It also provided a strategy for examining the quality of rehabilitation care at both patient level and center level.

19 6 CHAPTER 2 LITERATURE REVIEW In this chapter, the literature on quality of inpatient rehabilitation for patients with SCI was reviewed. The first section reviews the relationships between the structure and outcomes of rehabilitation, between structure and process of rehabilitation, and between process and outcomes of rehabilitation. The second section provides a review of studies related to the effect of patient characteristics on outcomes. The last section reviews the effect of PPS on patient outcomes. Research on the Quality of Inpatient Rehabilitation Care Inpatient rehabilitation care differs in several ways from other acute medical care. It focuses on impairment and disability rather than pathology, with its primary aim of enhancing patient function and improving patient quality of life. Inpatient rehabilitation usually admits patients from acute care hospitals, involving a waiting period and a patient selection process based on various criteria. The average length of stay (LOS) in inpatient rehabilitation care hospitals/units is relatively longer than that in other inpatient settings. Finally, rehabilitation is a lifelong process and does not end with the discharge from inpatient hospitals (Eddar, 2000). Many empirical studies have used the structure, process, and outcomes model to assess the quality of health care, but very few empirical studies that used the SPO

20 7 model to assess the quality of rehabilitation care have been reported in the literature. This lack might be because there is no integrated, theoretical framework for such research and the special characteristics of rehabilitation care. Some studies focus on either the effects of structural factors or the effects of process factors on rehabilitation outcomes, but not on both. The Effects of Structural Factors on Rehabilitation Outcomes Structure of care is where and by whom the care is delivered. Researchers have examined the relationship between structure and outcome of rehabilitation care, but their findings are not consistent. For example, some studies revealed that structure of care has only an indirect association with outcome of rehabilitation care (Sìösteen, 2005; Hoenig, et al, 2002) while others reported that structure did affect the outcome of rehabilitation care (Reker et al, 2000; Chaves et al, 2004). Reker et al (2000) examined structure and outcomes relationships in a sample of 2,982 VA stroke patients in After adjusting for other structural covariates, they found that four structural variables (i.e., diversity of allied health professionals, availability of prefabricated ankle/foot orthoses, treating therapist, and MD workload ratio) were associated with LOS or patient functional improvement. It was concluded that structure of rehabilitation had an impact on outcomes of rehabilitation.

21 8 The Effects of Structural Factors on Outcomes via Process of Rehabilitation Care Process of care is how the care is provided and how the care is received. Researchers have paid attention to the impact of structural factors on process of care recently. Sìösteen (2005) and co-workers examined the associations among staff ratio, patient-staff agreement, and patient outcomes for SCI patients in Sweden. They suggested that a high staff density and a long stay and/or prolonged contact with patients would probably improve the communication between rehabilitation staff and patients and help staff to better understand patients physical and emotional conditions. That in turn might be helpful to improve the quality of services (Sìösteen, et al, 2005). Hoenig and associates (2002) designed a prospective study to examine the effect of structure on the process of rehabilitation, and the effect of structure on outcomes after adjusting for process factors. They found that structure (systemic organization, staff expertise, and technological sophistication) of rehabilitation in a VA hospital did not have a significant effect on patient functional outcomes after controlling for patient demographic characteristics and process factors. The process of care, however, did have a positive effect on patient outcomes. They concluded that improving key structural elements of care might have positive effect on improving process of care for stroke patients. The Effects of Process Factors on Rehabilitation Outcomes Studies on SCI have also investigated the effect that different processes of care might have on the outcome. Many researchers believe that patient outcomes are the

22 9 best measure of health-care quality; however, patient outcomes are influenced by the severity of the illness even when patients have the same conditions (Norcini, 2005). To reduce the effects of case-mix, the quality assessment shifts from outcome and volume to process of care. Researchers (Norcini, 2005) suggest that outcome-related process measures are more suitable for evaluating quality of care because they are more directly under physician control than patient outcomes alone, and so they are much better indicators of the quality of care. Access to care is one of the process factors. Early admission to a system spinal cord injury center is important to prevent medical complication for patients with SCI. DeVivo and associates (1990a) compared 315 SCI patients who were admitted to the SCI model system within 24 hours and 401 patients who were admitted after more than one day and reported that delay in admission to the system resulted in prolonged rehabilitation and more medical complications (e.g., 8.1% of the earlier admitted patients developed pressure sores versus 25.5% of later admitted patients) (Inman, 1999). In 1999, Chen and associates examined the effect of declines in acute care LOS on the frequency of common secondary medical complications during the rehabilitation based on 1,649 patients with new SCI included in NSCID between 1996 and mid They reported that the time from injury to admission to rehabilitation decreased from an average of 38 days before 1992 to 19 days since Declines in the time from injury to admission to rehabilitation center increases the probability of suffering secondary medical complication during the rehabilitation (Chen, et al., 1999).

23 10 Scivoletto and colleagues (2005) conducted a retrospective study to examine the effect of injury-to-rehabilitation interval on outcome for 150 SCI patients in Italy. They found that early admission to acute rehabilitation led to a greater improvement in activities of daily living (ADLs) than delayed admission. In another study, McKinley and associates (2004) examined the association between early surgical intervention (<72 hours after injury) versus late or no surgical intervention and outcomes for SCI patients who completed inpatient rehabilitation at one of the 18 centers participating in Model Spinal Cord Injury Care System between 1995 and Based on analyses of data from 779 patients, they reported that patients who received early surgical intervention had shorter total hospital LOS and reduced pulmonary complications relative to late surgical intervention. However, they found no differences in neurologic or functional improvement and rehabilitation LOS between patients who received early surgical intervention and those who received late surgical intervention. Hoenig and colleagues (2002) also examined the relationship between process and outcomes of rehabilitation care in their study of VA stroke patients. They found that process (e.g., compliance with post-acute stroke care guidelines) of rehabilitation had a significant relationship with the patient functional outcomes after controlling for patient demographic characteristics, structure and process of rehabilitation care. They reported that process of care had a positive association with 6-month functional outcomes and concluded that improving process of care probably would improve stroke outcomes.

24 11 The Effect of Patient Characteristics on Rehabilitation Outcomes Many existing studies focus on the effects of patient demographic characteristics (e.g., age, gender, race /ethnicity, level of injury, et al.) on outcomes of rehabilitation. This is due partly to the limitation of data available and/or most authors assessing patient outcomes from the clinician s perspective. Age-at-injury and Outcomes Patients with SCI are relatively young: approximately 60% of them are age 16 to 30 (DeVico, 1999; Cifu, 1999; McKinley, 2003). McKinley and colleagues (2003) reviewed four previous studies that examined the age-related outcomes for patients with SCI using NSCID. These studies showed that age was not an isolated factor that affected the outcomes for patients with SCI and that it always interacted with other patient characteristics, such as etiology and level of injury. Age is a factor in making a decision about whether to admit a patient with SCI to a rehabilitation care unit since some providers contend that older patients are less likely to make significant rehabilitation progress (McKinley, et al., 2003). The studies reported that older patients were more likely to suffer from incomplete tetraplegia and that older patients usually had longer total LOS (acute plus rehabilitation) than younger patients did. One of the studies revealed that age had adversely affected the functional status at discharge, functional independence measure (FIM) changes from admission to discharge, and efficacy scores for patients with paraplegia, while age had no significant effects on functional outcomes for patients with tetraplegia. The results from these studies are con-

25 12 sistent with previous studies that older patients (aged 65 and older) were more likely and younger patients (aged 18 to 29) were least likely to be discharged to an institutional setting (Cifu, et al, 1999). McKinley and associates (2003) concluded that study design might contribute to the mixed results from previous studies about age-related outcomes. DeVivo and colleagues (1990b) examined the impact of age-at-injury on rehabilitation outcomes and found that older patients (age over 61) were more likely to develop medical complications (e.g., pneumonia, gastrointestinal hemorrhage, and pulmonary emboli) than younger patients (age 16-30). Race and Outcomes Similar to findings of effects of age on SCI outcome, the effects of race/ethnicity on functional outcomes after SCI are also mixed. Putzke and coworkers (2002) conducted two case control studies and examined the impact of race on acute rehabilitation and long-term outcomes for a sample of 187 pairs of patients and another sample of 158 pairs of patients, respectively. They found no significant difference in functional outcomes across race groups in either group and concluded that race seemed a proxy for other variables (e.g., injury level, age, educational level), which might be associated with poor outcomes after SCI. Another retrospective study conducted by Burnett and colleagues (2002) analyzed the relationship between minority status (e.g., non-minorities (White) vs. minority (over 90% are African American)) and patient outcomes using data from 4,176 pa-

26 13 tients with SCI who completed inpatient rehabilitation during a 10-year period from 1988 to The authors found significant differences between minorities and nonminorities with regard to LOS, FIM change scores (FIMCSs) and discharge setting. On average, non-minority patients stayed 5.39 more days and gained 1.26 more points on their FIMCSs than minority copartners. Although both non-minorities and minorities were mostly discharged to private residences and nursing homes, a relatively greater proportion of non-minorities were discharged to hotel/motel settings while minorities were discharged to correctional facilities. The Effects of Environmental Factors on Rehabilitation Outcomes The environmental factor refers to the indicators reflect the context in which health care is delivered (Aday, et al., 1998). The change of reimbursement policy is an important environmental factor. According to the experience learned from the implementation of DRGs for acute care hospitals in early 1980s, the PPS changed the way of reimbursement only for Medicare beneficiaries, but it could have great impact on other patients as well. To date, there is no empirical study examining the effect of PPS on the inpatient rehabilitation care for patients with SCI. Hoffman and colleagues (2003) conducted a retrospective cohort study to examine the potential effect of PPS on LOS and functional outcomes for patients (N=1807) with traumatic brain injury admitted to 14 IRFs from 1998 to The results from the study suggested that IRFs might reduce LOS and/or reduce resource use in order to maintain functional status and those IRFs either improve their effi-

27 14 ciency or discharge patients with lower FIM scores with a decreased LOS (Hoffman, et al., 2003). Deborah and colleagues (2004) conducted a simulation study for stroke patients who were admitted to a rehabilitation hospital between 1994 and They compared costs and expected PPS reimbursement and found that patient s actual costs are $10,825 (37%) higher than PPS reimbursement. They also reported that hospitals had many options to reduce costs and maintain patient functional improvement at discharge. In a more recent study, DeJong and coworkers (2005) investigated the early impact of IRF-PPS on stroke rehabilitation with a sample size of 539 for three IRFs during the period of 2001 to The results from this study revealed that IRF-PPS had no short-term effect on stroke rehabilitation case-mix and LOS for the study facilities. They found that facilities shifted therapy (i.e., physical and occupational) services from patients in the most severe case-mix groups to those in moderate case-mix groups and concluded that IRF-PPS has no effect on the therapy utilization and outcome among these study facilities. In summary, a review of literature reveals that studies have examined the effects of structure factors on outcome of rehabilitation and that their results are not consistent. Other studies have also investigated the relationships between structure and process as well as between process and outcome for inpatient rehabilitation care. Few studies have been done to examine the structural and process factors and their impact on outcome of patients with SCI. The existing studies on rehabilitation looked

28 15 at the rehabilitation outcome from one dimension--either structure and outcome or process and outcome, but not with structure and process variables within the same framework and examining their effects together. This could bias the study results. None of the studies reviewed focus on the structure, process and outcome for SCI rehabilitation using the SPO model.

29 16 CHAPTER 3 THEORETICAL FRAMEWORK The study examined the quality of rehabilitation care based on Donabedian s structure, process and outcome quality assessment theory. First, a brief overview of the Donabedian quality assessment model is presented. Then, structure, process, and outcomes in a rehabilitation setting are discussed. Finally, hypotheses are presented based on the theory. Donabedian s Structure, Process and Outcome Quality Assessment Theory In 1966, Avedis Donabedian proposed that health care quality should be examined in three domains: structure, process and outcomes. Today this remains as the dominant paradigm for evaluating of the quality of care. He treated all three domains as equally important and emphasized that these three approaches are complementary and should be used collectively to monitor healthcare quality (Donabedian, 1966, p698). Structure was defined as the relatively stable characteristics of the providers of care, of the tools and resources they have at their disposal, and of the physical and organizational settings in which they work (Donabedian, 1980, p81). The structure of providers of care includes 1) material resources such as facilities, equipment, and money; 2) human resources such as the number and qualifications of personnel; and 3) organizational elements (e.g., hospital facility, staffing ratios) such as medical staff

30 17 organization, method of peer review and methods of reimbursement. In short, structure includes staff qualifications, organizational elements, financial policies, and the operation of programs (Larson & Muller, 2002). Process refers to a two-way procedure of activities involving providing care and receiving care. Providers activities include diagnosing, recommending and implementing treatment. Patients activities include seeking care and carrying it out. Process also includes technical and interpersonal aspects of care. Technical aspects of care consist of diagnosis, treatment procedures, correct prescriptions, accurate drug administration, and pharmaceutical care, waiting time, and cost. Interpersonal aspects include communication, dignity and respect, compassion and concern (Donabedian, 1966). The third domain of care is outcome. Outcome refers to the effects of the health status of patients, including improvement in patient knowledge, changes in patient health status and behavior, and degree of patients satisfaction (Graham, 1995). Some outcomes such as mortality are easy to measure, while those such as patient attitudes and satisfaction, social restoration and physical disability, and rehabilitation are difficult to measure (Lee, et al., 2000). Donabedian (1966) states, Outcomes, by and large, remain the ultimate validators of the effectiveness and quality of medical care (p.694). The three components of quality of care discussed are not independent but are linked in an underlying framework (Donabedian, 1966, p699). An appropriate structure of care is a prerequisite for a proper process of care, and proper process of care in

31 18 turn may increase the likelihood of good outcome of care (Graham, 1995). According to Donabedian s quality assessment model, quality of care is represented by the entire integration from structure to process and to outcomes and not by one or the other independently. Health services researchers have applied the SPO model to examine relationships between structure and outcomes, between process and outcomes, as well as between structure and process. Assessing the quality of care with a whole framework consisting of these three elements rather than considering them separately can provide a more accurate assessment of the quality of care. It is important to understand the peculiarity of these three elements of quality of care. Structures of care are relatively easy to determine, but they are relatively difficult to interpret and often show a loose connection with process of care. Processes of care can be obtained from experienced experts in the relevant fields, but they identify themselves only from the connection with outcomes. The significant advantage of outcome of care is that it can be directly observed (Farin, et al., 2004). Recently, more and more outcome indicators have been used to evaluate the quality of care in addition to mortality and morbidity. These include functional status, cost effectiveness, physiological measures, clinical events (e.g., stroke), symptoms (e.g., pain) and patient satisfaction (Norcini, 2005).

32 19 Structure, Process, and Outcomes in the Rehabilitation Setting The definitions of structure, process, and outcomes in the rehabilitation setting are consistent with those in other medical settings. However, the features of structure, process and outcomes are not the same due to the differences in provider, patient, and goals of rehabilitation. For patients with SCI, the goal of inpatient rehabilitation is optimizing physical function, facilitating social independence, minimizing medical complications, enhancing emotional adaptation, and promoting reintegration into the community (Inman, 1999, p.26). In the SCI rehabilitation setting, the three elements of quality are similar to those in other rehabilitation facilities but with the specialized SCI rehabilitation characteristics. Structure of Rehabilitation Care for Patients with SCI Structure in a rehabilitation setting refers to the input necessary to provide rehabilitation care, including: (1) Facilities (e.g., beds, modified ward et al.); (2) Qualified professionals, including specialty (e.g., physical therapist, occupational therapist, and vocational therapist, et al.), education, training and experience, as well as staff ratio; and (3) Special medical and technical equipment for SCI patients (Eldar, 2000). Process of Rehabilitation Care for Patients with SCI Process of rehabilitation care is rehabilitation intervention therapy and additional activities, including (1) activities of rehabilitation professionals (e.g., diagnosis, treatment, and therapy); (2) activities of prevention (e.g., preventing conditions that

33 20 threaten life and secondary co-morbidities); (3) activities of patient education (e.g., enhancement of motivation and co-operation and expansion of social support, discharge plan); and (4) other activities (e.g., admission, time of the first enrollment in rehabilitation, and patient functional assessment) (Eldar, 2000). Outcome of Rehabilitation Care for Patients with SCI In rehabilitation settings, patient outcomes are assessed by improvement of function (including physical, emotional, and social functions) and the level of support required for the post discharge living setting (Gladman, 2001). The functional improvement and the level of support required by patients in post discharge living setting could be viewed as a function of rehabilitation effectiveness. Considering functional improvement relative to patient LOS provides a measure of rehabilitation efficiency. Research Questions and Hypotheses This study examined SCI outcomes during the period of 2000 to 2004 in SCI centers by applying the Donabedian SPO model. The study investigated the following questions with the hypotheses based on the Donabedian SPO framework. Research Question 1 What are the structural factors (e.g., staff-bed ratios and the volume of patient flow) influencing inpatient rehabilitation functional outcomes as measured by

34 21 FIMCSs for SCI patients? Proposition: The structure of SCI rehabilitation care has an effect on patient functional outcomes. Hypothesis 1 (H1): The staff-bed ratio measured by physical and occupational therapists per SCI bed and the volume of patient flow measured by patient days per bed are positively associated with FIMCSs. Research Question 2 What process factors (e.g., time to initial MSCIS admission and therapy hours per LOS pay) influence inpatient rehabilitation functional outcomes as measured by FIMCSs for SCI patients? Proposition: The process of rehabilitation care has a direct effect on patient functional outcomes. Hypothesis 2a (H2a): Direct System admission measured by day-oneadmission is positively associated with FIMCSs. Hypothesis 2b (H2b): Physical and occupational therapy hours per day of hospitalization are positively associated with FIMCSs. Research Question 3 What are the effects of the structure (physical and occupational therapists per beds and the volume of patient flow) of care on the process (physical and occupational therapy hours per day of hospitalization) of rehabilitation care?

35 22 Proposition: The structure of rehabilitation care has a direct effect on process of rehabilitation care, which in turn affects the patient functional outcomes. Hypothesis 3 (H3): Staff to bed ratio (Physical and occupational therapists per bed), patient volume (patient days per bed), and average severity of entry (Aggregated average FIMs at admission) are positively associated with utilization of therapy hours for patients with SCI. The framework used in this study assumed that the care structure and processes are potential drivers of patient outcomes in rehabilitation settings and that are under controlled by providers. However, there are a number of other factors that are not under providers control that may influence patient outcomes. Factors that not under the control of providers, for example, environmental factors and patient characteristics might also influence patient outcomes (Larson, Muller, 2002). Although the Donabedian SPO model has been widely applied in outcome research, it does not account for other factors outside these three domains, such as environmental changes (e.g., change of reimbursement policy) and patient characteristics (e.g., functional status at admission), that might also have significant influence on patient outcome. Environmental factors are indicators reflecting the context in which health care services are delivered (Aday, et al., 1998). Environmental variables are outside providers and usually mean policy change. One such variable that potentially important has been studied in the context in other chronic conditions concerns the structure and methods of reimbursement policy. The effects of PPS implementation in rehabilitation care outcomes were examined in this study at two time points, pre- and post- imple-

36 23 mentation of PPS. The research question and hypotheses are as follow: Research Question 4 What are the effects of PPS on functional outcomes (as measured by FIMCSs for SCI patients) after controlling structural and process factors? Proposition: Patient functional outcomes as measured by FIMCSs are inversely related to the implementation of PPS in the short run because providers adjust their services (e.g., shift therapy services from patients in most severe case-mix groups to those in moderate case-mix groups) to accommodate the change of the environmental factor (DeJong, et al., (2005). Rehabilitation facilities may either improve their efficiency or discharge patients with lower FIM scores with a decreased LOS and a reduced resource use (Hoffman, et al., 2003). Hypothesis 4 (H4): FIMCSs are larger for patients who were admitted and discharged before PPS implementation than for those who were admitted and discharged after PPS implementation. Research Question 5 What are the effects of patient characteristics on functional outcomes (as measured by FIMCSs for SCI patients) after controlling for structure and process factors? Proposition: Patient characteristics such as the extent of injury likely influenced patient outcomes in rehabilitation settings. However, injury severity as meas-

37 24 ured by FIM admission scores as a patient level of characteristics has not been examined as potential influence of outcome. Although ASIA scales and the extent of injury as measured by complete vs. incomplete (tetraplegia or paraplegia) have been examined as potential influence of rehabilitation outcomes, the unobserved heterogeneity within the SCI patient population and the possibility that different subgroups may have different outcomes has not been addressed. In this study, distinct clusters (subgroups) of patients who varied in terms of their initial functional status as measured by FIM admission scores can be identified. Patients having profiles reflecting greater impairment across the FIM self-care and FIM mobility-locomotion components will have smaller FIMCS than patients with profiles reflecting less impairment across their FIM admission scores. Hypothesis 5 (H5): Lower initial functional status at admission to rehabilitation is positively associated with the function improvement measured by FIMCSs. Propositions and hypotheses can be depicted schematically as an expanded theoretical framework (See Figure 1). In schematic figure, it is hypothesized that with each relationship among constructs as labeled by single arrows.

38 25 Figure 1. An Extended Theoretical Framework Environmental Factor (PPS) Patient Characteristics (Cluster memberships, The extent of injury) H 4 H 5 Outcome (FIM change scores) H 1 H 2 Structure (Staff ratios per bed, Patient days per bed) H 3 Process (Day-one-admission, Therapy hours per day) Donabedian s SPO Model

39 26 CHAPTER 4 METHODOLOGY In this chapter, the methods used in conducting this study are described. First, the data source, data characteristics and the procedures used to identify the sample used for analysis are presented. Second, variable measurements and operationalization are described. Finally, overviews of the various procedures used for data analyzing are provided Data Data Sources Patients with newly acquired traumatic SCI who completed inpatient rehabilitation during the period of October 2000 to December 2004 in one of the SCI rehabilitation centers participating in the Model Spinal Cord Injury System (MSCIS) program are the units of analysis. Data for this study were extracted from the National Spinal Cord Injury Database (NSCID). The NSCID has been established since 1973 and is believed, both internationally and nationally, to be the authoritative database about outcomes of inpatient rehabilitation care for patients with SCI. All 13 rehabilitation centers reporting data were participants in the MSCIS program funded by the National Institute on Disability and Rehabilitation Research. The database has both longitudinal and cross-sectional information about SCI patients. Patients included in the cross-

40 27 sectional part of NSCID account for approximately 13% of all newly injured patients with SCI each year in the United States (DeVivo, et al., 1999). Data Characteristics The data for the present study have several characteristics that complicated the analyses and limited the sample size. First, the rehabilitation centers and variables included in the NSCID have varied at different periods over the years for which data have been collected for the NSCID. Although some rehabilitation centers have always provided data to the NSCID, the specific centers contributing data have varied in any given 5-year period as a function of the status as an MSCIS grant recipents in a given period. The NSCID does not include the same cohort of patients over time. New patients were added into the NSCID every year. In addition, patients enter the MSCIS at different time points following injury. Some variables are not available over time. Since the NSCID has more than a 30-year history, the number of variables has been adjusted several times, leading to missing values for some variables. For example, FIM scores have been reported since 1989 and therapy hours were reported only during 2000 to In addition, some variables are only available for those patients who were admitted to MSCIS within 24 hours following injury. Second, there are not a large enough number of centers included in the database each year to allow for using a traditional growth model to do analysis. Third, the variability in terms of policy change (actual dates of PPS implementation) across rehabilitation centers made it complex to examine the effect of PPS implementation on patient outcome. Finally, the