Stroke and aphasia quality of life scale in Kannada-evaluation of reliability, validity and internal consistency

Quality of life (QoL) dwells in a person's overall well-being. Recently, QoL measures have become critical and relevant in stroke survivors. Instruments measuring QoL of individuals with aphasia are apparently rare in the Indian context. The present study aimed to develop a Kannada instrument to measure the QoL of people with aphasia. Study objectives were to validate Stroke and aphasia quality of life-39 (SAQOL-39) into Kannada, to measure test-retest reliability and internal consistency.

The original English instrument was modified considering socio-cultural differences among native English and Kannada speakers. Cross-linguistic adaptation of SAQOL-39 into Kannada was carried out through forward-backward translation scheme. The scale was administered on 32 people from Karnataka (a state in India) having aphasia. For a direct understanding of the subject's QoL, scores were categorized into QoL severity levels. Item reliability of the Kannada version was examined by measuring Cronbach's alpha. Test-retest reliability was examined by calculating the intraclass correlation coefficient (ICC).

Kannada SAQOL-39 showed good acceptability with minimum missing data and excellent test-retest reliability (ICC = 0.8). Value of Cronbach's α observed for four items modified in the original version was 0.9 each and the mean α of all Kannada items was 0.9, demonstrating high internal consistency.

The present study offers a valid, reliable tool to measure QoL in Kannada-speaking individuals with aphasia. This tool is useful in a cross-center, cross-national comparison of QoL data from people with aphasia. This instrument also permits direct translation into other Indian languages as the items are culturally validated to the Indian population. This study promotes future research using the Kannada SAQOL-39.