Validity and Reliability of the Persian Version of Lawton Instrumental Activities of Daily Living Scale in Patients with Dementia

Background Appropriate information about the functional capacity of patients with dementia disease plays an important role in assessment of their health status and functional independence. The purpose of the present study is to investigate the reliability and validity of the Lawton IADL Persian version in patients with dementia. Method: International Quality Of Life Assessment (IQOLA) approach was used for translation process and then content validity was assessed by five experts. To evaluate the reliability of the scale, test-retest, inter-rater reliability and items’ internal consistency methods were used. To analyze the construct validity, the Functional Assessment Staging Test (FAST) was used. The results were reported based on the data collected from the Iranian Alzheimer Associations of 60 patients with dementia. (53.3% female, 46.7% male, Mean age=75.91 (SD=7.72)) Results: No significant statistically differences were observed in the distribution of the experts’ opinions (p>0.05). The correlations between first and second administrations of the test (SEM=0. 238, r=0.993, CI: 0.988-0.996) and first and second raters (r=0. 961, p<0.001) were very high. Internal consistency between items and the total score (0.606 >r>0.427) had almost an average power. There was a significant negative relationship between the participants’ score in IADL and FAST (p<0.001). Conclusion: These results confirm that the Persian version of the Lawton IADL Scale has excellent reliability and validity for dementia patients. And it can be used as clinical and research tool for assessment IADL and determine disease progression by professionals.