TY - JOUR
T1 - Proxy reliability
T2 - Health-related quality of life (HRQoL) measures for people with disability
AU - Andresen, Elena M.
AU - Vahle, Victoria J.
AU - Lollar, Donald
N1 - Funding Information:
This research was funded by a special interest project from the Centers for Disease Control and Prevention (CDC) through the Saint Louis University Prevention Research Center grant # U48/ CCU710807 (special interest project SIP3-96) and supported in part by the Veterans Administration Medical Center, St. Louis, MO. The Massachusetts longitudinal study is supported, in part, by a Co-operative Agreement (#U59/CCU103370) with the Secondary Conditions Prevention Branch, United States Centers for Disease Control and Prevention, and grants from the National Institute on Disability and Rehabilitation Research (NIDRR; grants # H133660037, for field-initiated research, and # H133N50014, for the N.E. Regional SCI Center, Boston Medical Center, Boston, MA). Asma Ahmed and Gracie Gonzales assisted in the preparation of the manuscript and analyses, respectively. We are especially indebted to the excellent work of our colleague, Dr Allan Meyers from Boston University, who died in May of 2000. The authors especially wish to thank Dave Moriarty of the Centers for Disease Control and Prevention for his support, assistance, and helpful advice throughout the course of the project, and Dr Kathleen Wyrwich, for her generous assistance in providing a program to calculate weighted κ values.
PY - 2001
Y1 - 2001
N2 - Objectives: Research and surveillance activities sometimes require that proxy respondents provide key exposure or outcome information, especially for studies of people with disability (PWD). In this study, we compared the health-related quality of life (HRQoL) responses of index PWD to proxies. Methods: Subjects were selected from nursing home, other assisted living residences, and from several clinic samples of PWD. Each index identified one or more proxy respondents. Computer-assisted interviews used a random order of measures. Proxy reliability was measured by intraclass correlation (ICC) and κ statistics. HRQoL measures tested included the surveillance questions of the Behavioral Risk Factor Surveillance System (BRFSS), basic and instrumental activities of daily living (ADLs and IADLs), medical outcomes study short-form 36 and 12 (SF-36 and SF-12). Results: A total of 131 index-proxy sets were completed. In general, agreement and reliability of proxy responses to the PWD tended to be best for relatives, with friends lower, and health care proxies lowest. For example, the ICC for the physical functioning scale of the SF-36 was 0.68 for relatives, 0.51 for friends, and 0.40 for healthcare proxies. There was a tendency for proxies to overestimate impairment and underestimate HRQoL. This pattern was reversed for measures of pain, which proxies consistently underestimated. The pattern among instruments, proxy types, and HRQoL domains was complex, and individual measures vary from these general results. Conclusions: We suggest caution when using proxy respondents for HRQoL, especially those measuring more subjective domains.
AB - Objectives: Research and surveillance activities sometimes require that proxy respondents provide key exposure or outcome information, especially for studies of people with disability (PWD). In this study, we compared the health-related quality of life (HRQoL) responses of index PWD to proxies. Methods: Subjects were selected from nursing home, other assisted living residences, and from several clinic samples of PWD. Each index identified one or more proxy respondents. Computer-assisted interviews used a random order of measures. Proxy reliability was measured by intraclass correlation (ICC) and κ statistics. HRQoL measures tested included the surveillance questions of the Behavioral Risk Factor Surveillance System (BRFSS), basic and instrumental activities of daily living (ADLs and IADLs), medical outcomes study short-form 36 and 12 (SF-36 and SF-12). Results: A total of 131 index-proxy sets were completed. In general, agreement and reliability of proxy responses to the PWD tended to be best for relatives, with friends lower, and health care proxies lowest. For example, the ICC for the physical functioning scale of the SF-36 was 0.68 for relatives, 0.51 for friends, and 0.40 for healthcare proxies. There was a tendency for proxies to overestimate impairment and underestimate HRQoL. This pattern was reversed for measures of pain, which proxies consistently underestimated. The pattern among instruments, proxy types, and HRQoL domains was complex, and individual measures vary from these general results. Conclusions: We suggest caution when using proxy respondents for HRQoL, especially those measuring more subjective domains.
KW - Disabled persons
KW - Health status indicators
KW - Proxy
KW - Quality of life
KW - Questionnaires
KW - Reproducibility of results
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U2 - 10.1023/A:1013187903591
DO - 10.1023/A:1013187903591
M3 - Article
C2 - 11822794
AN - SCOPUS:0035681276
SN - 0962-9343
VL - 10
SP - 609
EP - 619
JO - Quality of Life Research
JF - Quality of Life Research
IS - 7
ER -