Background:

Effective advance care planning depends on clinician-patient communication quality. However, ACP-CAT, the only validated observer-rated instrument, remains untested in real-world clinical encounters and non-Western contexts.

Aim:

Validating ACP-CAT in assessing clinician-patient communication quality with advanced cancer and chronic kidney disease in Hong Kong, comparing against patient and family ratings of clinician communication.

Design:

Cross-sectional study of adult patients with advanced cancer or chronic kidney disease from five hospitals and one hospice service. Two independent raters evaluated audiotaped advance care planning conversations using ACP-CAT, while patients and family members assessed communication quality using the Chinese Quality of Communication Questionnaire (C-QOC). We assessed the psychometric properties, including interrater reliability, convergent and discriminant validity.

Setting/participants:

One hundred and thirty-seven advance care planning conversations involving 84 cancer patients, 53 renal patients, 107 family members, and 20 clinicians.

Results:

ACP-CAT demonstrated high interrater reliability (mean Gwet’s AC1 = 0.81; 88.6% agreement). Convergent validity was demonstrated through significant correlations between ACP-CAT total score and patient-rated C-QOC End-of-life planning subscale (r = 0.29, p < 0.01), family-rated C-QOC summary score (r = 0.27, p < 0.05), and family-rated C-QOC End-of-life planning subscale (r = 0.34, p < 0.01). Discriminant validity was supported by absence of correlations with patients’ self-rated health status and information or decision-making preferences (all p > 0.05). Clinicians frequently explored patients’ fears and health goals, but rarely discussed nonmedical priorities, valued activities, or surrogate decision makers.

Conclusions:

ACP-CAT demonstrates strong concurrent validity with patient- and family-rated measures and ecological validity in real clinical settings. These findings support its reliability for assessing advance care planning communication quality across diverse cultural contexts.