Methods of Outcome Measures
Good science and good clinical practice both depend on sound information which in turn relies on sound measurement. Measurement, the process of assigning numbers to represent quantities of a trait, attribute or characteristic (Nunnally & Bernstein 1995), enables health care professionals and researchers to describe, predict and evaluate in order to provide benchmarks and summarize change (Law 1987; Wade 2004) related to the condition and care of individuals with spinal cord injury.
Despite past evidence that suggested clinicians in the rehabilitation field did not regularly use outcome measures (Cole et al. 1994; Deathe et al. 2002; Skinner et al. 2006), there is mounting evidence that now confirms more clinicians are now reporting their findings using some ordinal or quantifiable outcome tool (Kay et al. 2001; Skinner et al. 2006). Beyond the administrative push to use datasets to track patient outcomes in relation to health care costs, clinical investigators recognize that using an appropriate outcome tool, to determine the validity of a therapeutic intervention, is the key to establishing or changing the models of best practice (Cole et al. 1994). There is a sincere desire to move beyond minimal data collected through datasets such as the mandatory Canadian Institutes of Health Information (CIHI) Rehabilitation Minimum Data Set or the Functional Independence Measure (FIM). Nevertheless there is a lack of validated tools for many disciplines within rehabilitation research. There is also uncertainty as to the strength and limitations for each type of assessment. It is hoped that this book will help demystify the various tools and provide the reader with the necessary confidence to move their clinical practice and research forward on a more rigorous basis.
The language used when discussing methods used (e.g. screen, tool, instrument, measure, scale) is often misused leading to confusion (Wade 2004). For the purposes of this review the terms listed will be used interchangeably to indicate a method used to capture data in a standardized manner.