Self and proxy symptom reporting in patient-caregiver dyads coping with a primary brain tumor: The role of psychosocial function in rating agreement.

223 Background: Patients with glioma experience high levels of symptom burden with often sudden performance declines. As such, family caregivers tend to report on the patient’s symptoms; yet previous research examining the validity of proxy symptom reporting points to inconsistent findings. While prior studies focused on identifying patient clinical variables that may be related to agreement, caregiver characteristics may also be important for accurately perceiving patient symptoms. We examined the associations between symptom agreement and patient and caregiver perceived illness communication, depressive symptoms, and QOL. Methods: As part of a behavioral intervention trial, baseline assessments were collected prior to randomization in 67 dyads. We report on patient symptom burden (MDASI-BT) and patient and caregiver depressive symptoms (CES-D), illness communication (CICS), and QOL (SF-36). Paired t-tests, difference scores and inter-correlations coefficients (ICCs) were used to test for agreement, accuracy and congruence in proxy symptom scores, respectively. Bivariate correlations were calculated to examine the association between psychosocial function variables and symptom agreement. Dyadic level associations between symptom agreement and QOL were examined using multi-level modeling. Results: Thirty-nine percent of patients (63% male; 93% non-Hispanic White; mean age=47 years; 84% Grade III-IV) and 49% of caregivers (79% female; 90% non-Hispanic White; mean age=51 years) endorsed clinical levels of depression. Clinically significant disagreement was found for all means scores of the MDASI-BT subscales except for GI symptoms and general symptoms. 22% of caregivers overestimated and 13% underestimated overall symptom severity and 32% overestimated and 21% underestimated symptom interference. ICCs of patient and caregiver proxy ratings were significant (except cognitive and GI subscales) ranging from small to moderate coefficients (.09 - .50). Patient illness communication was associated with agreement in overall symptom severity (r=-.27, p=.03) and affective symptom subscale (r=-.34, p<.01). Caregiver illness communication (r=-.33, p<.01) and depressive symptoms (r=.46, p<.0001) were associated with symptom interference agreement. Caregiver overestimation of patient symptom severity was significantly associated with poor caregiver physical QOL, while underestimation was significantly associated with poor patient physical and mental QOL and poor caregiver mental QOL. Conclusions: The psychosocial context of the family plays an important role in the accuracy of proxy symptom reporting. Moreover, inaccurately understanding patients' experience is related to poor QOL for both patients and caregivers, which points to important targets for symptom management interventions that involve family caregivers.