A Quantitative Systematic Review of Clinical Outcome Measure Use in Peripheral Nerve Injury of the Upper Limb

Abstract

Background: Peripheral nerve injury (PNI) is common, leading to reduced function, pain, and psychological impact. Treatment has not progressed partly due to inability to compare outcomes between centers managing PNI. Numerous outcome measures exist but there is no consensus on which outcome measures to use nor when.

Objective: To perform a systematic review in order to describe and classify outcome measures used in PNI.

Methods: A search of Ovid Medline, Ovid Embase, Allied and Complementary Medicine Database (AMED), and CENTRAL (Cochrane Clinical Trials) was conducted. Randomized control trials (RCTs), cohort studies, and case-controlled and case series (≥5 participants) published from inception of the database until 2019 investigating adult patients with a traumatic upper limb PNI in which an outcome measurement was utilized were included.

Results: A total of 96 studies were included (15 RCTs, 8 case-control studies, 18 cohort studies, 5 observational studies, and the remainder were case series or retrospective reviews). A total of 56 individual outcome measures were identified, utilized across 28 different countries and 7097 patients. Ten core domains were defined: sensory subjective, sensory objective, motor subjective, motor objective, sensorimotor function, psychology and well-being, disability, quality of life, pain and discomfort, and neurotrophic measures.

Conclusion: Lack of consensus on outcome measure use hinders comparison of outcomes between nerve injury centers and the development of novel treatments. Development of a core outcome set will help standardize outcome reporting, improve translation of novel treatments from lab to clinical practice, and ensure future research in PNI is more amenable to systematic review and meta-analysis.

Keywords: Outcome assessment; Peripheral nerve injury; Systematic review.

FIGURE 1.

Flowchart demonstrating study selection for inclusion in systematic review.

FIGURE 2.

Cumulative bar chart of time points for sensory outcome measure use. Time points for the usage of sensory outcome measures varied widely; however, there was a clear trend in their use. Most studies obtained a baseline or early estimate of sensation at time 0, 3 wk, or 1 mo after surgery (or after injury in observational studies). After this, the majority of studies utilized sensory outcome measures at 3 and 6 mo with the final assessment at 12 mo. A small minority of studies continued sensory assessments of any modality past 12 mo, with no study making a sensory assessment after 24 mo.

FIGURE 3.

Cumulative bar chart of time points for motor outcome measure use. Time points for the usage of motor outcome measures followed a common trend. No study undertook a baseline assessment up to 1 mo after surgery or injury. Instead, all studies measured outcomes at 3, 6, and 12 mo. Similarly, to sensory outcomes, the end point for motor outcome assessment was 12 mo with only 1 study making an assessment after this at 36 mo.

FIGURE 4.

Frequency of outcome measure use by anatomical location of peripheral nerve injury (brachial plexus, mixed (motor/sensory) upper limb nerves, purely sensory nerves of the hand) (4 studies did not specify anatomical location of nerve injuries).