Comparison of proxy ratings of main family caregivers and physicians on the quality of dying of terminally III cancer patients

Objective: Proxy data collection is a prevalent and important source of information in palliative medicine, and few studies have evaluated the level of agreement between different types of proxies. Methods: A study was conducted to compare the agreement in quality of dying of terminally ill cancer patients from the perspective of (i) the main family caregiver and (ii) the main caregiving physician. The Kappa statistic was applied to measure agreement between the proxies in a prospective study. Using the good death scale and the audit scales, 126 dyads (70%) were compared from a tertiary medical center in Taiwan. Results: In general, the physicians rated quality of dying higher than did family caregivers. The kappa ranged from 0 to 0.232 for the five items, indicating marginal agreement. The prevalence index was applied to correct the Kappa statistic and showed the data to be asymmetrically distributed. Both proxies tended to agree at higher scores (P_neg = 0.745-0.996) in all five items and the total good death scale. For the audit scale, both proxies tended to agree at higher scores in most of the 12 items, except 'alleviation of anxiety', 'resolution of depression' and 'fulfillment of last wishes'. Conclusion: The observed agreement between the two proxies was good, except the psychological aspects, demonstrating the validity of proxy rating of patients between physicians and main caregivers. More communications toward the end-of-life issues should be encouraged and conducted in this population. Further research is needed to determine how to best use proxy assessments to evaluate the quality of the dying process.