Date of Award

1-1-2016

Document Type

Dissertation

Degree Name

Ph.D.

Department

Quantitative Research Methods

First Advisor

Duan Zhang

Keywords

Disability Rating Scale, Functional Independence Measure, Individual Growth Curve, Longitudinal Analyses, Payer Source, Traumatic Brain Injury

Abstract

Author: Melissa C. Hofmann

Title: A Descriptive Study of the Effect of Payer Source on Multiple Longitudinal Outcome Measures within the TBI Model Systems National Database using Longitudinal HLM Analyses

Advisor: Dr. Kathy E. Green

Degree Date: June 2016

Using longitudinal data from the TBIMS ND, this study utilized a longitudinal hierarchical linear modeling approach to describe the effect of primary payer source on individual level change in outcomes including the FIM and DRS. To facilitate the use of parametric statistics, Rasch-transformed FIM and DRS scores were utilized; thus approaching an interval level of measurement. The FIM was separated into 3 separate cognitive, mobility, and self-care subscales. In this way, rehabilitation professionals including speech, physical, and occupational therapists for this TBI sample could reference results to inform current clinical practice.

Results indicated that FIM and DRS trajectories were best modelled using a negative exponential model. Significant variability was found in each growth parameter (Asymptote, Pseudo-Intercept, and Rate) (p < .05) for all unconditional models (FIM Cognitive, FIM Mobility, FIM Self-Care, and DRS). Reduced conditional models for the FIM Cognitive, FIM Mobility, FIM Self-Care, and DRS outcome variables were constructed including only covariates that related significantly to the growth parameters. Conditional model results showed that as a group, the functional status of individuals measured by the FIM and DRS outcomes in the TBIMS ND improved rapidly and then plateaued as a result of floor and ceiling effects. Characteristics such as age, education, employment, length or rehab stay, marital status, PTA, race, and sex were found to impact baseline FIM and DRS scores and the rate and extent of improvement over time.

More importantly, and a primary focus of this study was the effect of payer source on FIM and DRS outcomes. At the individual and group level, primary payer source was significantly related to the growth parameters for each FIM and DRS outcome. The strong association found between primary payer and the growth parameters suggested that initial successful rehabilitation outcomes were a function of the type of rehabilitation received and dependent on the payment source for services. These findings are especially important to rehabilitation clinicians. Clinicians can use this information to secure further funding and care resources from third party payers that will advance an individual's course in successful functional outcomes and quality of life over their lifetime.

Provenance

Recieved from ProQuest

Rights holder

Melissa Carole Hofmann

File size

175 p.

File format

application/pdf

Language

en

Discipline

Statistics, Health sciences

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