Abstract
According to 2015 statistics of Italy’s National Institute for Insurance Against Accidents at Work, 39.9% of work-related injuries in Italy affect the upper limbs, with anatomical loss in 0.5% of cases (Bencini, 2015). When neurological and congenital diseases involving the upper limbs are also considered, the burden of upper limb pathologies is high (Giustini et al., 2015).
To evaluate the proper use of the hand in activities of daily living (ADLs), occupational therapy practitioners assess clients’ movements during various activities. Jebsen and colleagues (1969) proposed that the ability to use one’s hands effectively in everyday activities depends on the limbs’ anatomic integrity, mobility, muscle strength, sensitivity, and coordination and is influenced by age, gender, and mental state. Following these principles, Jebsen et al. created the Jebsen–Taylor Hand Function Test (JTHFT) in 1969. The JTFHT allows the therapeutic assessment of patterns of hand functions commonly used in ADLs (Lynch & Bridle, 1989; Shiffman, 1992). It is a simple, fast, and easily administrable test and is therefore widely used in rehabilitation. The JTHFT has shown good intrarater and interrater reliability, Pearson’s r = .60–.99, p < .01; test–retest reliability of .86 for the dominant hand (DH) and .80 for the nondominant hand (NDH); and χ2 values at p < .05 (Jebsen et al., 1969).
The JTHFT has been translated into several languages and has shown good psychometric properties. For instance, a study in Portugal (Ferreiro et al., 2010) yielded the following results: Pearson’s r = .657, interrater intraclass correlation coefficient (ICC) = 1.0 (95% confidence interval [CI] [1.0, 1.0]), intrarater ICC = .997 (95% CI [.995, .998]), and Cronbach’s α = .924. The psychometric properties in a study in China (Li-Tsang et al., 2004) were also found to be favorable: test–retest reliability = .68–.98, interrater ICC = .70–.98, and independent t(23) = 4.00 for the DH and 3.49 for the NDH.
The JTHFT has also been validated for people with specific disorders affecting the upper limbs. Researchers have evaluated its use with people with cerebral stroke, unilateral cerebral palsy, hemiparesis, Parkinson’s disease, tetraplegia, spinal cord injury, carpal tunnel syndrome, upper limb fracture, rheumatic arthropathies, prosthetic rehabilitation, virtual rehabilitation, diabetes, burns, manual dexterity, spina bifida, Duchenne muscular dystrophy, and Huntington’s disease (Adler et al., 2015; Agnew & Maas, 1982; Aulicino, 1995; Bovend’Eerdt et al., 2004; Connolly et al., 2015; Goldfarb et al., 2002; Hackel et al., 1992; Hardin, 2002; Holavanahalli et al., 2007; Jarus & Poremba, 1993; Kamakura et al., 1980; Mak et al., 2015; McPhee, 1987; Sears & Chung, 2010; Stern, 1992).
Because the JTHFT was originally designed for the U.S. population, the instructions were developed in English; the instructions have since been translated and adapted for the Italian language and population. The first Italian validation of the JTHFT was applied using a group of people with no clinical evidence of disease or impairment of the upper limbs to test its validity and reliability in a prospective study (Culicchia et al., 2016). The following results were recorded: t(59) = 2.603, p = .143; interrater ICC = .282–.695 for the DH and .516–.814 for the NDH; and intrarater ICC = .297–.715 for the DH and .584–.892 for the NDH. Pearson’s correlation coefficient testing revealed a strong correlation for the DH (p < .01) and NDH (p < .05; Culicchia et al., 2016). Building on the previous validation study of the Italian JTHFT (JTHFT–IT), the current study aimed to investigate hand function in people with nonspecific disorders of the upper limbs and to evaluate the psychometric properties of the JTHFT–IT.
Method
This study was conducted by a research group composed of medical doctors and rehabilitation professionals from the Sapienza University of Rome and from the Rehabilitation & Outcome Measures Assessment (ROMA) association. In the past few years, ROMA has undertaken studies and validation of many outcome measures in Italy (Berardi et al., 2018; Galeoto, Berardi, et al., 2018; Galeoto, Sansoni, et al., 2018; Massai et al., 2018; Parente et al., 2017; Tofani et al., 2018).
Participants
Participants were recruited from Policlinico Umberto I University Hospital, Sant’Eugenio Hospital, and the spinal unit of CTO Andrea Alesini Hospital in Rome from March to September 2016. The inclusion criteria were men and women with at least one upper limb disorder diagnosis, age 6–90 yr, minimum of 30 days since initial trauma, ability to understand instructions and perform all JTHFT–IT tasks, and ability to sign the informed consent document (in the case of minors, the signature of the parent or legal guardian was required; Galeoto et al., 2015, 2016).
Participants with the following disorders were assessed: hemiparesis, cerebrovascular disease, arthrosis, rheumatoid arthritis, traumatic quadriparesis, burns, polyneuropathy, carpal tunnel syndrome, congenital disorder of the hand, and hand fracture. The JTHFT–IT was administered by two volunteer occupational therapists and one physical therapist. A stopwatch was used to time the completion of each test.
Data Analysis
All statistical analyses were performed using IBM SPSS Statistics (Version 20.0; IBM Corp., Armonk, NY). The variables were analyzed using frequency tables, means, and standard deviations.
The ICC was used to determine intrarater, interrater, and test–retest reliability. One therapist assessed the same participant twice to examine intrarater reliability, and two therapists independently assessed the same participant to examine interrater reliability. The therapists were blind to each other during the assessments. The test was administered twice over 6 days (Wild et al., 2005).
Pearson’s correlation coefficient and Cronbach’s α were used to determine internal consistency and reliability, respectively. Consistent with the literature and other validation studies, we measured grip strength with a Jamar dynamometer (Sammons Preston Roylan, Chicago), considered the gold standard (Trampisch et al., 2012). We then used Pearson’s correlation coefficient to compare the dynamometer measurements with scores on the JTHFT–IT subtests. Acceptability was assessed by recording the time required to administer the JTHFT–IT subtests.
Results
Participants
The JTHFT–IT was administered to 136 participants with various disorders of the upper limb. Their mean ± standard deviation age was 54.79 ± 22.39 yr, and 80 (58.8%) were female. Sample characteristics are provided in Table 1.
Sample Characteristics (N = 136)
Note. M = mean; SD = standard deviation.
Intrarater and Interrater Reliability
The interrater and intrarater reliability procedures were applied to 51 of the 136 participants who completed both testing sessions. The intrarater ICC was .814 (95% CI [.615, .936]) for the DH and .981 (95% CI [.948, .993]) for the NDH. The interrater ICC was .818 (95% CI [.615, .936]) for the DH and .821 (95% CI [.432, .953]) for the NDH (Table 2).
Intrarater and Interrater Reliability of the JTHFT–IT (N = 51)
Note. CI = confidence interval; ICC = intraclass correlation coefficient; JTHFT–IT = Jebsen–Taylor Hand Function Test, Italian version.
Internal Consistency and Construct Validity
Internal consistency and construct validity were calculated using data for all 136 participants. Strong correlations were found between all subtests (p < .01) and between the subtests and grip force measured with the dynamometer (p < .05; Table 3).
Construct Validity: Correlations Between JTHFT–IT Subtests and Dynamometer Measures (N = 136)
Note. JTHFT–IT = Jebsen–Taylor Hand Function Test, Italian version.
p < .05 (two-tailed). **p < .01 (two-tailed).
Reliability
The reliability of the JTHFT–IT was α = .829 for the DH and α = .415 for the NDH. The DH is one of the assessment criteria proposed by Nunnally and Bernstein (1994), who stated that Cronbach’s α should range between .70 and .90; however, the values for the NDH did not fall within the range recommended by Nunnally and Bernstein.
Acceptability
The average time to complete all subtests was 89.47 ± 67.98 s for the DH and 167.11 ± 257.58 s for the NDH (Table 4).
Test Run Time for JTHFT–IT Subtests
Note. JTHFT–IT = Jebsen–Taylor Hand Function Test, Italian version; M = mean; SD = standard deviation.
Discussion
The aim of this study was to investigate hand function in people with nonspecific disorders of the upper limbs and to evaluate the intrarater, interrater, and test–retest reliability of the JTHFT–IT. Our results showed good intrarater and interrater reliability. The Simulated Feeding subtest had higher interrater and intrarater reliability for the DH than the NDH, reflecting results of both the original and the Chinese studies (Jebsen et al., 1969; Li-Tsang et al., 2004). In contrast, the study conducted in Portugal (Ferreiro et al., 2010) revealed lower reliability for the Stacking subtest for the NDH.
Regarding test–retest reliability, all participants maintained their position in the distribution of scores, indicating that subtests yielded sufficiently consistent results over time. Internal consistency was significant at p < .05 for the DH and p < .01 for the NDH, except for the Writing subtest. Significant correlations with dynamometer measures supported the construct validity of the JTHFT–IT subtests except for the Picking Up Small Common Objects subtest for the DH and the Writing, Stacking, and Simulated Feeding subtests for the NDH, likely because grip strength is not as relevant to the completion of these activities. Good correlations between grip strength and the JTHFT subtests were also demonstrated in the Chinese study (Li-Tsang et al., 2004).
All results of the current study are consistent with those of a previous validation study of the JTHFT–IT (Culicchia et al., 2016). Moreover, a comparison of this study’s results with those in the literature (Culicchia et al., 2016; Ferreiro et al., 2010; Jebsen et al., 1969; Li-Tsang et al., 2004) confirmed their statistical significance and comparability with studies carried out internationally.
Limitations
The current study has some limitations. First, the small number of participants with each pathology did not permit stratification and comparison of results. Second, no specific classification system was used, which would have been useful for examining differences within categories of hand disorder. Further investigation with expanded samples, including participants with the most relevant and widespread diagnoses, would help clarify hand function in people with specific diagnoses.
Implications for Occupational Therapy Practice
The results of this study have the following implications for occupational therapy practice:
The Italian version of the JTHFT is a useful and reliable instrument to assess the functioning of the hand in everyday activities in people with nonspecific upper limb disorders.
Practitioners can now use the JTHFT–IT with more confidence.
Conclusion
The JTHFT is a widely used tool for the assessment of hand disorders. This study reveals the utility of the JTHFT–IT for both research and clinical practice as a valid and reliable tool for the assessment of hand function. Now Italian health and rehabilitation professionals can use the instrument with more confidence.
Footnotes
Acknowledgments and Disclosures
The authors declare no conflict of interest. No author has commercial associations or disclosures that may pose or create a conflict of interest with the information presented in this article.
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008. Informed consent was obtained from all study participants.