Proxy assessment of health-related quality of life in african american and white respondents with prostate cancer: perspective matters.
OBJECTIVE
An emerging issue in the proxy literature is whether specifying different proxy viewpoints contributes to different health-related quality of life (HRQL) assessments, and if so, how might each perspective be informative in medical decision making. The aims of this study were to determine if informal caregiver assessments of patients with prostate cancer differed when prompted from both the patient perspective (proxy-patient) and their own viewpoint (proxy-proxy), and to identify factors associated with differences in proxy perspectives (ie, the intraproxy gap).


METHODS
Using a cross-sectional design, prostate cancer patients and their informal caregivers were recruited from urology clinics in the Jesse Brown Veterans Affairs Healthcare System in Chicago. Dyads assessed HRQL using the EQ-5D visual analog scale (VAS) and EORTC QLQ-C30.


RESULTS
Of 87 dyads, most caregivers were female (83%) and were spouses/partners (58%). Mean difference scores between proxy-patient and proxy-proxy perspectives were statistically significant for QLQ-C30 physical and emotional functioning, and VAS (all P < 0.05), with the proxy-patient perspective closer to patient self-report. Emotional functioning had the largest difference, mean 6.0 (SD 12.8), an effect size = 0.47. Factors weakly correlated with the intraproxy gap included relationship (spouse) and proxy gender for role functioning, and health literacy (limited/functional) for physical functioning (all P < 0.05, 0.20 < r < 0.35).


CONCLUSIONS
Meaningful differences between proxy-patient and proxy-proxy perspectives on mental health were consistent with a conceptual framework for understanding proxy perspectives. Prompting different proxy viewpoints on patient health could help clinicians identify patients who may benefit from clinical intervention.
Pickard
A Simon
AS
Department of Pharmacy Practice and Pharmacy Administration, Center for Pharmacoeconomic Research, College of Pharmacy, University of Illinois at Chicago, Chicago, USA. pickard1@uic.edu
Lin
Hsiang-Wen
HW
Knight
Sara J
SJ
Knight
Sara L
SL
Sharifi
Roohollah
R
Wu
Zhigang
Z
Hung
Shih-Ying
SY
Witt
Whitney P
WP
Chang
Chih-Hung
CH
Bennett
Charles L
CL
D000223:Adaptation, Psychological; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000523:psychology*; D017028:Caregivers / Q000523:psychology; D002641:Chicago; D003430:Cross-Sectional Studies; D003469:Culture; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010147:Pain Measurement; D011471:Prostatic Neoplasms / Q000523:psychology*; D019727:Proxy / Q000706:statistics & numerical data*; D011788:Quality of Life / Q000523:psychology*; D012737:Sex Factors; D012803:Sick Role; D018454:Spouses / Q000523:psychology; D014728:Veterans / Q000523:psychology*; D044465:White People / Q000523:psychology*; D001741:Black or African American