Re: Fulk et al. (2011) Estimating clinically important change in gait speed in people with stroke undergoing outpatient rehabilitation. J Neurol Phys Ther, 35:82-89.
To start the discussion Dr. Fulk and Dr. Catherine Lang (associate editor of JNPT) post their thoughts on how can clinicians and researchers apply the results of this study.
Question: How can clinicians and researchers apply the results of this study? How will this study impact your clinical practice?
Routine, repeated measurements of gait speed, taken by physical therapists during outpatient rehabilitation for people with stroke, can be used for goal-setting and patient & caregiver education. After measuring gait speed at initial PT evaluations, the estimates from this paper can be used to set goals for patients. For example, a person who initially walks at 0.33 m/s (30 seconds to walk 10 m) could have a goal of walking at 0.50 m/s (20 seconds to walk 10 m) at a future evaluation point. This would be a change of 0.17 m/s, a clinically meaningful change to patients as established in this paper. Clinically meaningful change not only documents progress in therapy but could be also used to argue for continuation of therapy services. Lack of a clinically meaningful change in gait speed over several evaluation points can inform the treating PT that the intervention is not working as hoped, leading to a different intervention or discontinuation of PT services. An added value is that gait speed and changes in gait speed can be discussed with patients and their caregivers. Quantitative measurements of walking ability such gait speed may be highly motivating to people with stroke and provide encouragement during the long rehabilitation process.
Two aspects of this paper make the reader confident that the estimates of how much change in gait speed constitutes an important change are “trustworthy”. First, the authors used multiple approaches and analyses to estimate important changes in gait speed and always arrived at similar values. Second, the estimates obtained here are very close to other, published estimates as described in the Discussion. Thus, a “real” value (vs. an estimate) of a clinically meaningful change is likely between 0.15 and 0.20 m/s in the outpatient stroke population.
Gait speed is one of the most commonly used outcome measures of walking ability in people with stroke, both in clinical practice and in research studies. Because it is so widely used we wanted to identify how much change in gait speed is important to people with stroke that are undergoing out patient rehabilitation. Based on the results, we estimated that a change of approximately 0.175 m/s reflects an important change in walking ability to people with stroke.
We believe that these results can be very useful in clinical practice. Physical therapists can use these findings to help them assess patient improvement in walking ability and to determine the effectiveness of their interventions. Patients whose improvement in gait speed does not exceed 0.175 m/s over a period of time may lead the physical therapist to modify the plan of care or to discharge the patient from physical therapy services. This important change value could also be used to justify continued physical therapy services to third party payers. If the patient’s walking ability continues to improve as indicated by a change in gait speed greater than 0.175 m/s this might be a good indication that the patient has not plateaued and may benefit from continued rehabilitation services.
An important aspect of this research to note is that the important change value of 0.175 m/s should only be applied to patients that have similar characteristics to the subjects in this study. The subjects in this study were on average less than 2 months post stroke and had an initial gait speed of 0.56 m/s. An important change in walking ability as reflected in gait speed may be different for someone with a chronic stroke or someone whose gait speed is only 0.15 m/s. Because people with stroke are very heterogeneous further study is needed to determine how much change in gait speed is important in different sub-populations of people with stroke.