INTRODUCTION
Dr. Landers and colleagues should be complimented on their contribution to accumulating evidence supporting the use of several standardized clinical tests in the physical therapy examination of persons with Parkinson's disease (PD).1-4 Although Landers et al studied multiple clinical tests, in the interest of space, this discussion focuses on the Berg balance scale (BBS).
In our practice, the primary rationale for the use of clinical balance tests, such as the BBS, is to contribute to the identification of those persons at risk of falls and who would likely benefit from treatment. With this in mind, consideration of the literature summarized and the results presented by Landers et al led me to question what role standardized tests play in clinical decision making regarding fall risk. A clearer picture of the utility of the current research is apparent when considered in the context of the following clinical cases.
Clinical Case 1
A 71-year-old man with Hoehn and Yahr stage 3 PD presents with akinesia, freezing, and rigidity. He reports four falls in the previous year.
As Landers et al point out, there is strong evidence that a history of falls is a strong predictor of future falls.5,6 Certainly, this argues for the inclusion of fall history in the patient interview. In our practice, a history of falls in a person with PD is adequate justification for further examination and treatment targeted at prevention of fall-related morbidity. Even in the absence of standardized tests, there is useful information to glean from the interview.
Clinical Case 2
An 82-year-old woman with Hoehn and Yahr stage 3 PD presents with bradykinesia and dystonic cramping in her left foot. She reports no history of falls but scores 40/56 on the BBS.
Using a cutoff score of 44, Landers et al calculated an odds ratio of 48.90 (95% confidence interval, 5.68-428.86) for the BBS. Applying this odds ratio to this 82-year-old woman would suggest that she is at least five times and potentially close to 50 times more likely to be a faller than someone who scores above 44/56 on the BBS. Armed with this knowledge, a clinician can have a great deal of confidence that this patient is at high fall risk and should begin treatment to mitigate this risk.
Clinical Case 3
A 65-year-old man with Hoehn and Yahr stage 2.5 PD presents with tremor and rigidity. He has no history of falls, scores 52/56 on the BBS, and reports a history of mild peripheral neuropathy as well as cataracts.
The findings of Landers et al are limited in this situation. Because the patient has scored above the cutoff score, is the clinician to assume that the person is without risk? Certainly not. As an illustration, 32% of the persons scoring above 44 on the BBS in the Landers et al study still had a history of falls. A score above the cutoff score does not reflect a lack of fall risk. Interpretation of BBS only as a positive or negative result ignores the gradient of risk that it was intended to provide.7 In this clinical case, consideration of an alternative cutoff score, the collective interpretation of multiple tests8 or the presence of sensory deficits may be the clinical findings more relevant to identify this patient's fall risk and justify treatment.
Summary
In summary, the identified cutoff scores and the odds ratios calculated by Landers et al provide one component of the information needed to make an appropriate clinical decision. In clinical practice, these results should be synthesized with the medical and surgical history, comorbidities, anddisease-specific characteristics based on the unique presentation of each individual with PD.
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