A systematic review of the validity of neuropathic pain screening tools

BACKGROUND: Screening tools can be particularly useful in clinical and research practice to identify a potential condition and act as a gateway to diagnostic assessment or treatment.1 The most important measurement properties of a self-report screening tool are content validity (the match between the content of the tool and the condition the tool intends to screen for) and criterion validity (the match between the scoring of the tool and a gold standard measure).2 These types of validity hinge on a definition of the condition and a diagnostic test.3 Changes in how a condition is defined, classified, or diagnosed, pose a threat to the validity of existing screening tools. Ensuring the ongoing validity of screening tools over time is a methodological challenge, and may require continuous evaluation, modification of existing tools, or development of new tools. This is a potential challenge with screening tools for neuropathic pain (NP). In the early 2000’s, a number of screening tools for NP had been developed and their validity tested.4 In the past 2 decades, significant advances have been made in our understanding of NP including: (1) an updated definition of NP in 2008 which significantly differed from the 1994 definition, (2) diagnostic grading system introduced in 2008 and updated in 2016, and (3) diagnostic classification system introduced in 2019. OBJECTIVE: To critically appraise the content and criterion validity of NP screening tools. METHODS: Systematic Review Search strategy The search strategy will be developed in consultation with a medical research librarian. Searches will be conducted in multiple databases (MEDLINE, Embase, CINAHL) from inception and will be limited to peer-reviewed papers published in the English language. Search terms will include terms pertaining to NP screening tools (names of known tools, screening, NP) and a validated search filter for measurement properties.7 This search will undergo a systematic approach to screening, study selection, and data extraction. Eligibility criteria Study inclusion criteria include: (1) purpose of the tool is to screen for NP, (2) study describes tool development, and/or content validity and/or criterion validity; and (3) study describes the English language version of the tool. Exclusion criteria include: (1) sole purpose of the tool is to quantify symptom severity of previously established NP, (2) sole purpose of the tool is to screen for neurological lesion or disease (e.g., neuropathy). Data extraction Data will be extracted on bibliographic information including publication year, tool name, intended purpose of the tool, patient characteristics (age, diagnoses (including diagnosis of neurological lesion or disease)), sample size, methods used to establish content and/or criterion validity, definition of NP, and for studies of criterion validity, details of the gold standard test of NP. Critical appraisal Tool development and content validity studies will be critically appraised using the COSMIN manual. Criterion validity studies will be critically appraised using the QUADAS-2 manual References 1. Felson D. Screening for Disease. Accessed May 14, 2021. https://sphweb.bumc.bu.edu/otlt/mph-modules/ep/ep713_screening/EP713_Screening_print.html 2. Mokkink LB, Terwee CB, Patrick DL, et al. The COSMIN study reached international consensus on taxonomy, terminology, and definitions of measurement properties for health-related patient-reported outcomes. J Clin Epidemiol. 2010;63(7):737-745. doi:10.1016/j.jclinepi.2010.02.006 3. Terwee CB, Prinsen C a. C, Chiarotto A, et al. COSMIN methodology for evaluating the content validity of patient-reported outcome measures: a Delphi study. Qual Life Res Int J Qual Life Asp Treat Care Rehabil. 2018;27(5):1159-1170. doi:10.1007/s11136-018-1829-0