Gabriela Markovic , Marie-Louise Schult, Aniko Bartfai, Mattias Elg
Karolinska Institutet, Department of Clinical Sciences, , Division of Rehabilitation Medicine, Danderyd Hospital, 182 88 Stockholm, Sweden. E-mail: gabriela.markovic@sll.se
DOI: 10.2340/16501977-2172

Background: Progress in early cognitive recovery after acquired brain injury is uneven and unpredictable, and thus the evaluation of rehabilitation is complex. The use of time-series measurements is susceptible to statistical change due to process variation.
Objective: To evaluate the feasibility of using a time-series method, statistical process control, in early cognitive rehabilitation.
Method: Participants were 27 patients with acquired brain injury undergoing interdisciplinary rehabilitation of attention within 4 months post-injury. The outcome measure, the Paced Auditory Serial Addition Test, was analysed using statistical process control.
Results: Statistical process control identifies if and when change occurs in the process according to 3 patterns: rapid, steady or stationary performers. The statistical process control method was adjusted, in terms of constructing the baseline and the total number of measurement points, in order to measure a process in change.
Conclusion: Statistical process control methodology is feasible for use in early cognitive rehabilitation, since it provides information about change in a process, thus enabling adjustment of the individual treatment response. Together with the results indicating discernible subgroups that respond differently to rehabilitation, statistical process control could be a valid tool in clinical decision-making. This study is a starting-point in understanding the rehabilitation process using a real-time-measurements approach.

A new tool for statistics in early rehabilitation
Patients with acquired brain injury recover in an uneven and unpredictable way. Therefore it is difficult to evaluate the effectiveness of rehabilitation interventions. We studied the feasibility of a statistical technique called “statistical process control” in 27 patients with stroke or traumatic brain injury. It could be concluded that “statistical process control” is a promising tool to evaluate recovery in rehabilitation, especially when patients show different patterns like rapid, steady or stationary.