METHODS: This study involved: (1) four English teachers (translators) for forward and backward translation procedures; (2) 10 experts in the field of occupational therapy (expert reviewers) for content validity testing; and (3) 60 undergraduate students (participants) for test-retest reliability testing.
RESULTS: PPT-M had excellent content validity with Item-Content Validity Index = 0.9-1.0, Scale-Content Validity Index/Average = 0.93-0.95, and a slightly lower Scale-Content Validity Index/Universal Agreement = 0.25-0.75. Test-retest reliability for 3-trial administration (n = 30; Intraclass Correlation Coefficients, ICCs = 0.76-0.85; good) was higher compared to 1-trial administration (n = 30; ICCs = 0.34-0.46; poor) for all subtests. Both trial administrations were mostly affected by systematic errors, especially practice effect as the retests gave higher scores. Random errors mostly affected Subtest 3 of 1-trial administration, evident by its Minimal Detectable Change Percent values = 30.84% that fell beyond the acceptable range.
CONCLUSION: PPT-M has the potential to be a valuable instrument for measuring hand dexterity among Malay speaking individuals especially when the 3-trial administration is used.