Comparison of research case definitions for carpal tunnel syndrome

Abstract

Objective The aim of our study was to assess agreement between different case definitions of carpal tunnel syndrome (CTS) for epidemiological studies. Methods We performed a literature search for papers suggesting case definitions for use in epidemiological studies of CTS. Using data elements based on symptom questionnaires, hand diagrams, physical examinations and nerve conduction studies collected from 1107 newly-hired workers, each subject in the study was classified according to each of the case definitions selected from the literature. We compared each case definition to every other case definition, using the Kappa statistic to measure pairwise agreement on whether each subject met the case definition. Results We found six unique papers in a twenty year period suggesting a case definition of CTS for use in population-based studies. We extracted seven case definitions. Definitions included different parameters: symptoms only, symptoms and physical examination, symptoms and either physical examination or median nerve conduction study, symptoms and nerve conduction study. When applied to our study population, the prevalence of CTS using different case definitions ranged from 2.5% to 11.0%. The percentage of misclassification was between 1 to 10%, with generally acceptable levels of agreement (Kappa values ranged from 0.30 to 0.85). Conclusion Different case definitions resulted in widely varying prevalences of CTS. Agreement between case definitions was generally good, particularly between those that required very specific symptoms or the combination of symptoms and physical examination or nerve conduction. The agreement observed between different case definitions suggests that the results can be compared across different research studies of risk factors for CTS.

Prevalence and work‐relatedness of carpal tunnel syndrome in the working population, United States, 2010 national health interview survey

“…Clinical diagnosis of CTS is complex and a variety of research and/or surveillance case definitions for CTS and work-related musculoskeletal disorders in general have been proposed and evaluated, many of which are based on combinations of reported symptoms, physical exam findings, and/or electrodiagnostic studies [e.g., Silverstein et al, 1997;Rempel et al, 1998;Descatha et al, 2011]. Unfortunately, due to the nature of this study (i.e., relying on data collected from a few questions that were part of a broad health questionnaire), we were only able to use a very crude case definition for CTS: self-report of a clinician diagnosis of CTS.…”

Validation of the ACGIH TLV for hand activity level in the OCTOPUS cohort: a two-year longitudinal study of carpal tunnel syndrome

“…This finding is in line with the results of a recent systematic review that highlighted that complex case definitions (eg, based on examinations) for upper-limb disorders (including CTS) yield similar associations with occupational determinants to those obtained using simple case definitions based on Bonfiglioni et al symptoms (35). Moreover, findings from a review on the case definitions for CTS in epidemiological studies suggested the possibility of comparing the results obtained in studies adopting various case definitions of CTS, based on different combinations of symptoms, clinical examination, and/or NCS (36).…”

The Prevalence of Cubital Tunnel Syndrome: A Cross-Sectional Study in a U.S. Metropolitan Cohort

“…Descatha et al demonstrated that the prevalence of carpal tunnel syndrome varied according to the case definition employed, leading to the misclassification of 1% to 10% cases. Despite this finding, the agreement between different case definitions was found to be acceptable and allowed for the comparison of prevalence rates across different studies 31 . Our difficulty with the definitive identification of cubital tunnel syndrome in the setting of possible carpal tunnel syndrome resulted in considerable uncertainty and variability in observed cubital tunnel syndrome frequency.…”

“…In this study, the combination of a hand diagram and the BCTQ was chosen to create a diagnostic test with the ability to identify cubital tunnel syndrome and carpal tunnel syndrome-related symptoms (hand diagram) and to identify patients with a symptom severity consistent with carpal tunnel syndrome or cubital tunnel syndrome. We also chose this definition on the basis of evidence that these tests both demonstrate strong correlation with electrophysiologic diagnosis 21,31 . Typically, screening for cubital tunnel syndrome relies on multiple methods (patient-reported history of symptoms, clinical examination, electrodiagnostic testing, ultrasonographic examination) that all have diagnostic limitations 1,32,33 .…”