Notturni Francesco [CRT, Clinica di Riabilitazione Toscana, Montevarchi (AR), Italy]
Ugolini Alessandro [Independent research, Empoli (FI), Italy]
Piscitelli Daniele [Department of Kinesiology, University of Connecticut, Storrs, CT, USA]
Pometti Lorena Sabrina [IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy]
Ferrarello Francesco [Unit of Functional Rehabilitation, Department of Allied Health Professions, Azienda USL Toscana Centro, Prato, Italy]
Coppari Andrea [Physical and Rehabilitation Medicine Unit, Azienda Sanitaria Territoriale, Jesi (AN), Italy]
Caselli Serena [Azienda Ospedaliero-Universitaria di Modena, Modena, Italy]
La Porta Fabio [IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy]
Pellicciari Leonardo [IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy]
Individuals with stroke commonly experience upper extremity (UE) sensorimotor deficits, which impact quality of life. Deficits persist in about 80% of survivors. The Wolf Motor Function Test (WMFT, 17 items) is widely used to assess UE function post-stroke; it assesses both motor capacity (subscale, Functional Ability Scale [FAS]) and performance time (subscale, TIME). Additional versions of the WMFT have been proposed. The Graded WMFT (gWMFT, 13 items) was developed for the accurate assessment of moderate to severe UE impairment, and a short form version of WMFT, the Streamlined WMFT (sWMFT, 6 items), targeted people with stroke at different stages of recovery (subacute and chronic). To date, a comprehensive evaluation of the WMFT psychometric properties is lacking. Therefore, we aimed to perform a systematic review (SR) with meta-analysis to assess the reliability, validity, and responsiveness of the WMFT when utilized to assess individuals with stroke.
Six databases (i.e., MEDLINE, CINAHL, EMBASE, PsycINFO, CENTRAL, Web of Science) were searched to retrieve studies investigating WMFT psychometric properties, as defined by the COSMIN taxonomy domains. Two independent reviewers performed literature search, study selection, data extractions, and quality assessment (according to the COSMIN Risk of Bias checklist).To pool the data, we considered Cronbach’s alpha for internal consistency, the intraclass correlation coefficient (ICC), Cohen’s kappa, and weighted linear (or quadratic) kappa for intra- and inter-rater reliability. Measurement error was assessed by the standard error of measurement (SEM) and minimum detectable change (MDC). For construct validity, Pearson or Spearman correlation coefficients were examined. For responsiveness, effect size (ES) and standardized response mean (SRM) were considered. The level and grading of evidence were defined for each psychometric property according to the COSMIN modifed GRADE approach.
Out of 4127 titles screened after removing the duplicates, 25 studies involving 2009 individuals with stroke were included in the SR, and 23 in the meta-analysis. Table 1 shows the pooled results. FAS and TIME WMFT’s subscales internal consistency (alpha≥0.88) intra- (ICC≥0.97) and inter-rater (ICC≥0.92) reliability, construct validity (strong correlation with Fugl-Meyer Assessment for upper limb [FMA-UL] and Action Research Arm Test [ARAT]), and responsiveness (ES≥0.48) were rated with quality of evidence ranging from very low to high, as well as the structural validity of FAS and the measurement error of TIME subscales (Table 1). Measurement error for FAS was assessed as inconsistent with moderate quality of evidence. Cross-cultural validity was rated as indeterminate with very low quality of evidence. Content validity and structural validity for TIME were not assessed in the included studies. Pooled findings on gWMFT reliability and sWMFT responsiveness are showed in Table 1.
Most studies focused on the WMFT, demonstrating its strong psychometric properties, while fewer explored the gWMFT and sWMFT. The SR provides valuable insights into the reliability, validity, and responsiveness of WMFT, supporting its clinical utility in individuals with stroke. The reliability of the WMFT is well-established for the FAS and the TIME subscales. Strong correlations with other established motor function assessments, such as the FMA-UL and ARAT, support construct validity. Few studies have evaluated the psychometric properties of the gWMFT and sWMFT; therefore, their reliability and validity are not well-established as those of the original WMFT. Studies that reaserched the sWMFT and gWMFT are promising, but the evidence for their psychometric properties is currently insufficient for widespread recommendation. Future research should focus on enhancing the content and cross-cultural validity of the WMFT, and the psychometric properties of WMFT’s modified versions.
Gagnier JJ, Lai J, Mokkink LB, Terwee CB. COSMIN reporting guideline for studies on measurement properties of patient-reported outcome measures. Qual Life Res. 2021 Aug;30(8):2197-2218. doi: 10.1007/s11136-021-02822-4.
Wolf SL, Lecraw DE, Barton LA, Jann BB. Forced use of hemiplegic upper extremities to reverse the effect of learned nonuse among chronic stroke and head-injured patients. Exp Neurol. 1989 May;104(2):125-32. doi: 10.1016/s0014-4886(89)80005-6.
