Examining the Reliability and Validity of RTI-E for use with Intellectual Disability Population in Singapore

So Sin Sim, Kai'en Hong, Yong Yun Kuan, Swee Ting Quek, Wei'en Joel Tan

Research output: Contribution to conferenceAbstract


Currently, there is a lack of standardised functional assessment tools that are validated
with the ID population. The RTI-E is an observational assessment of functional cognition
which omits the need for standardised instructions.
The purpose of this study was to examine the reliability and validity of the Routine Task
Inventory-Expanded (RTI-E) in the intellectually disabled population in Singapore.
The subjects included 24 clients with ID who were selected through purposive sampling.
The Executive Function Performance Test (EFPT) was used as a criterion measure for
validation of the RTI-E. Psychometric properties (internal consistency, interrater reliability,
concurrent criterion validity, known-group validity) of the RTI-E were examined.
Results/practice implication:
Interrater reliability was supported by high Spearman’s correlation coefficient (r = .991).
Internal consistencies of the RTI-E subscales using Cronbach’s Alpha were found to
acceptable (community = .903; communication = .830; work readiness = .892) with the
exception of physical scale (α = .683). One-way analysis of variance revealed significant
overall group (low vs moderate vs high functioning) effect (F = 12.432, p = .000). High
Spearman correlations were found between RTI-E total scores (r = - .920, p = .000), RTI-E
subscale scores (physical = - .837, p = .000; community = - .857, p = .000; communication
= - .792, p = .000; work readiness = - .818, p = .000) and EFPT total scores, supporting
criterion validity.
Results show the RTI-E to be valid and appropriate for use by occupational therapists
with the ID population in SM-EDC. Reliability, construct validity and criterion validity
were all supported. However, the study’s small sample size limits the generalisability of
the findings. It is recommended that further research be done on the RTI-E with larger
and more diverse ID populations.
Original languageEnglish
Publication statusPublished - 15 Sept 2015
Externally publishedYes
EventAsia Pacific Occupational Therapy Conference 2015: Doing Well Together - Rotorua energy Events Centre, Rotorua, New Zealand
Duration: 14 Sept 201517 Sept 2015
Conference number: 6th


ConferenceAsia Pacific Occupational Therapy Conference 2015
Country/TerritoryNew Zealand

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