Persian Handwriting Assessment Tool: Reliability in Students with Specific Learning Disorders

Background: Handwriting is one of the most common reasons for referral to occupational therapy among children with specific learning disorders (SLDs). The Persian handwriting assessment tool (PHAT) is a valid assessment instrument. It is important to clarify the reliability of this assessment tool for the accuracy of results and certain clinical uses in Iranian children with SLDs. Objectives: The present study aimed to investigate the internal consistency, test-retest, and inter-rater reliability of the PHAT in children with SLDs aged 10 to 12 years in the Iranian context. Methods: Thirty children (mean ± SD 132.33 ± 53.8 months) with SLDs, studying in grades 4 to 6, were recruited from special education schools and rehabilitation clinics from January to May 2022. Cronbach's alpha and intraclass correlation coefficient (ICC) were calculated to determine internal consistency, test-retest reliability, and inter-rater reliability, respectively. The standard error of measurement (SEM) and minimal detectable change (MDC) were computed to establish absolute reliability. Results: Internal consistency was excellent (α = 0.98 to 0.99), as was inter-rater reliability (ICC = 0.95 to 1.00). Test-retest reliability was good to excellent (0.86 to 1.00). The SEM and MDC values for test-retest reliability were 0 to 0.47 and 0 to 1.29, respectively. Finally, the SEM (0 - 0.21) and MDC (0 - 0.57) values were acceptable for inter-rater reliability. Conclusions: The PHAT is a reliable assessment tool for Iranian children with SLDs aged 10 to 12 years. Further, clinicians can utilize this tool to identify handwriting difficulties in children with SLDs aged 10 to 12 years, which leads to more targeted interventions.