Validation of the psychometric properties of the Malay advance care planning questionnaire

Background There is a growing interest among the developing countries on advance care planning (ACP) due to the reported benefits of planning ahead in the developed countries. Validated instruments in various languages have been developed to facilitate study on the views of public prior to its implementation. However, instrument to explore the views on ACP in Malay has not been developed and validated yet, even though Malay is spoken extensively by approximately 220 million people in the Malay Archipelago. There is also a need for instrument in Malay language to facilitate the assessment of knowledge, attitude and practice (KAP) of Malaysians regarding ACP. Therefore, the aim of this study was to validate the psychometric properties of the Malay Advance Care Planning Questionnaire (ACPQ-M). Methods The ACPQ was translated according to international guidelines. This validation study was conducted from January to June 2018. Participants who were ≥ 21 years old, and able to understand Malay were recruited from an urban primary care clinic and a tertiary education institution in Malaysia. A researcher administered the ACPQ-M to participants via a face-to-face interview at baseline and 2 weeks later. Each interview took approximately 10–20 min. Results A total of 222/232 participants agreed to participate (response rate = 96.0%). Exploratory factor analysis and confirmatory factor analysis found that the ACPQ-M was a 4-factor model. The Cronbach’s α values for the four domains ranged from 0.674–0.947. Only 157/222 participants completed the test-retest (response rate = 71%). At test-retest, quadratic weighted kappa values for all domains ranged from 0.340–0.674, except for two domains which ranged from − 0.200-0.467. Conclusions The ACPQ-M was found to be a 4-factor model, and a valid and reliable instrument to assess the KAP regarding ACP. This instrument can contribute to profound understanding of the KAP of Malaysians regarding ACP, and assist policy makers in determining the readiness for legislation of ACP in Malaysia.