VALUE OF CAREGIVER RATINGS IN EVALUATING THE QUALITY-OF-LIFE OF PATIENTS WITH CANCER

Purpose: To evaluate the usefulness of caregiver ratings of cancer pat ients' quality of life (QL), we examined the following: (1) the compar ability of responses to a brief standardized QL questionnaire provided by patients, physicians, and informal caregivers; and (2) the relativ e validity of these ratings. Methods: The study sample included cancer patients receiving chemotherapy, their treating physicians, and signi ficant others involved closely in the (informal) care of the patients. During an early phase of treatment and 3 months later, patients and c aregivers completed independently the COOP/WONCA charts, covering seve n QL domains. At baseline, all sources of information were available f or 295 of 320 participating patients (92%). Complete follow-up data we re obtained for 189 patient-caregiver triads. Results: Comparison of m ean scores on the COOP/WONCA charts revealed close agreement between p atient and caregiver ratings. At the individual patient level, exact o r global agreement wets observed in the majority of cases (73% to 91%) . Corrected for chance agreement, moderate intraclass correlations (IC C) were noted (0.32 to 0.72). Patient, physician, and informal caregiv er COOP/WONCA scores were all responsive to changes over time in speci fic QL domains, but differed in their relative performance. Relative t o the patients, the physicians were more efficient in detecting change s over time in physical fitness and overall health, but less so in rel ation to social function and pain. Conclusion: For studies among patie nt populations at risk of deteriorating self-report capabilities, phys icians and informal caregivers con be useful as alternative or complem entary sources of information on cancer patients' QL. (C) 1997 by Amer ican Society of Clinical Oncology.