Predictive Value of Upper Extremity Outcome Measures After Stroke—A Systematic Review and Metaregression Analysis

Tell me in all seriousness whom the fuck cares about your predicting failure to recover? Useless. Maybe you want to solve stroke BEFORE you become the 1 in 4 per WHO that has a stroke?

Predictive Value of Upper Extremity Outcome Measures After Stroke—A Systematic Review and Metaregression Analysis

Silke Wolf, Christian Gerloff and Winifried Backhaus^*

• Experimental Electrophysiology and Neuroimaging (xENi), Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

A better understanding of motor recovery after stroke requires large-scale, longitudinal trials applying suitable assessments. Currently, there is an abundance of upper limb assessments used to quantify recovery. How well various assessments can describe upper limb function change over 1 year remains uncertain. A uniform and feasible standard would be beneficial to increase future studies' comparability on stroke recovery. This review describes which assessments are common in large-scale, longitudinal stroke trials and how these quantify the change in upper limb function from stroke onset up to 1 year. A systematic search for well-powered stroke studies identified upper limb assessments classifying motor recovery during the initial year after a stroke. A metaregression investigated the association between assessments and motor recovery within 1 year after stroke. Scores from nine common assessments and 4,433 patients were combined and transformed into a standardized recovery score. A mixed-effects model on recovery scores over time confirmed significant differences between assessments (P < 0.001), with improvement following the weeks after stroke present when measuring recovery using the Action Research Arm Test (β = 0.013), Box and Block test (β = 0.011), Fugl–Meyer Assessment (β = 0.007), or grip force test (β = 0.023). A last-observation-carried-forward analysis also highlighted the peg test (β = 0.017) and Rivermead Assessment (β = 0.011) as additional, valuable long-term outcome measures. Recovery patterns and, thus, trial outcomes are dependent on the assessment implemented. Future research should include multiple common assessments and continue data collection for a full year after stroke to facilitate the consensus process on assessments measuring upper limb recovery.

Introduction

From the time stroke patients enter the emergency care unit to the time they return home again, they have stayed in a series of different wards and clinics specialized in various recovery stages. This clinical recovery process is usually well-documented and quantified using a diverse spectrum of scales and assessments as subjective and objective outcome measures. This diversity enables clinicians to describe multiple different patient-specific aspects of the remaining symptoms, but it can also render comparisons across different stroke trials difficult or even impossible. Focusing on subsets of scales tends to lead to an incomplete description of individual recovery profiles. A consensus paper on general recommendations for stroke rehabilitation measurements concluded that many measures are inappropriate to measure recovery (1). The term “recovery,” commonly used in synonym with “motor recovery,” should describe true neurological repair and restitution (2). Both terms reflect the achievement to regain a near-similar state as prestroke concerning body structure and functions and activities of daily living (2–4). Levin et al. (4) stress the importance of the way recovery is achieved, by differentiating between motor recovery and motor compensation. The first is the restoration of function and performance in the same manner as before the incidence of stroke (motor recovery) opposing the recruitment of new tissue or effectors to reach the same goal (motor compensation) (2, 4). Such differentiation can potentially be attained by combining kinematic measures and clinical assessments (2). However, kinematic methods are resource-intensive, costly, and often not available in clinical reality. Although more frequently used, they still fall far short of the established scores [such as the Fugl–Meyer Assessment (F-M)] (5).

Rehabilitation is closely related to recovery and compensation. It is defined as “a process of active change by which a person who has become disabled acquires the knowledge and skills needed for optimum physical, psychological, and social function” (6). Rehabilitation may include improvement in body function going beyond the initial (prestroke) capabilities, a phenomenon that is present especially during later time points after stroke. The recommended time points of data acquisition have been inferred from biological processes following a stroke and comprise five time windows of recovery (2, 3). These include the hyperacute stage (0–24 h), the acute stage (1–7 days poststroke), the early subacute stage (7 days to 3 months after stroke), the late subacute stage (3–6 months after stroke), and the chronic stage for all time points beyond 6 months (2, 3). The initial months after a stroke are subject to multiple biological processes and thus described by three different time windows. A jitter in time of initial study recruitment (length of time since stroke onset) of individual studies can substantially influence its prognostic accuracy (2, 7). This is especially problematic in small and less powered studies (8). The recovery window also seems to exceed the previously defined limits, which further adds to the need for functional measurements (9). A meaningful core set of measurements targeting recovery of hand and arm function should represent all stages, from acute to chronic.

Here we make an attempt to disentangle scoring from common assessments after stroke and illustrate how they measure rehabilitation of upper limb motor function, in the following referred to as “recovery,” over time. With a main objective to assist the decision making process which outcome measures to choose in stroke rehabilitation and to increase the comparability of stroke studies, the aim is less to present the current literature but mainly to extract data from large comparable studies in the field, here defined as studies including at least 100 stroke patients. Methods of a systematic literature review are applied to check the quality of the included papers and to report the process in a transparent and comprehensible way. The following metaregression aims to illustrate the predictive utility of outcome measures most commonly used in stroke rehabilitation studies, focusing on motor recovery, especially upper limb control. Most stroke patients suffer from motor disorders, mainly affecting the arm and hand function, and for many, the impairment is persisting (10, 11). Upper limb rehabilitation is crucial for almost all activities of daily living. Additionally, it stands in close relationship to walking abilities (12). We hypothesized that, by summarizing results from well-powered studies, we could identify those assessments capable of showing change over time, detect redundancies between measures, and provide a basis for recommendations in longitudinal stroke rehabilitation studies.