Proxy (statistics)

About: Proxy (statistics) is a research topic. Over the lifetime, 5257 publications have been published within this topic receiving 94504 citations. The topic is also known as: proxy variable & proxy measurement.

Health status in patients with Alzheimer's disease: an investigation of inter-rater agreement.

Abstract: Objective: The purpose of the present study was to examine the level of agreement between health status ratings provided by patients with Alzheimer’s disease and by their proxies Background: Because proxy-completed responses are often necessary in assessing health outcomes for the elderly, it is necessary to determine the feasibility and potential limitations of using proxies as a patient substitutes Methods: To assess the potential utility of proxy responses on health status when subjects present a cognitive impairment, this study compared the responses of 70 subjects with Alzheimer‘s disease and those of their family and/or care provider proxy using the SF-36 Agreement between proxies and patients was measured by intraclass correlation coefficients (ICCs) Results: The proportion of exact agreement between patients and proxies on the 36 items ranged from 33 to 417% Results reveal poor to moderate agreement between patient and proxy reports Proxy reliability varied according to the relationship of the proxy to the index subject Agreement decreased significantly with increasing severity of dementia and with increasing severity of Physical status (Katz ADL) Agreement was better for measures of functions that are directly observable and relatively poor for more subjective measures Conclusions: Our results confirm the importance of the information source used for patient health status

Evaluation of Patient and Proxy Responses on the Activity Measure for Postacute Care

Abstract: Background and Purpose—Our objective was to examine the agreement between adult patients with stroke and family member or clinician proxies in activity measure for postacute care (AM-PAC) summary scores for daily activity, basic mobility, and applied cognitive function. Methods—This study involved 67 patients with stroke admitted to a hospital within the Kaiser Permanente of Northern California system and were participants in a parent study on stroke outcomes. Each participant and proxy respondent completed the AM-PAC by personal or telephone interview at the point of hospital discharge or during ≥1 transitions to different postacute care settings. Results—The results suggest that for patients with a stroke proxy, AM-PAC data are robust for family or clinician proxy assessment of basic mobility function and clinician proxy assessment of daily activity function, but less robust for family proxy assessment of daily activity function and for all proxy groups' assessments of applied cognitive function. The pa...

IQ estimate smackdown: Comparing IQ proxy measures to the WAIS-III

Abstract: Brief assessments of general cognitive ability are frequently needed by neuropsychologists, and many methods of estimating intelligence quotient (IQ) have been published. While these measures typically present overall correlations with the Wechsler Adult Intelligence Scale (WAIS) Full Scale IQ, it is tacitly acknowledged that these estimates are most accurate within 1 standard deviation of the mean and that accuracy diminishes moving toward the tails of the IQ distribution. However, little work has been done to systematically characterize proxy measures at the tails of the IQ distribution. Additionally, while these measures are all correlated with the WAIS, multiple proxy measures are rarely presented in one manuscript. The current article has two goals: (1) Examine various IQ proxies against Wechsler Adult Intelligence Scale (Third Version) scores, showing the overall accuracy of each measure against the gold standard IQ measure. This comparison will assist in selecting the best proxy measure for particular clinical constraints. (2) The sample is then divided into three groups (below, average, and above-average ability), and each group is analyzed separately to characterize proxy performance at the tails of the IQ distribution. Repeated measures multivariate analysis of variance compares the different proxy measures across ability levels. All IQ estimates are represented in tables so that they can be examined side by side.

Design and implementation of a soft caching proxy

Abstract: In this paper we address a set of modifications to classical proxy caching algorithms which allow the implementation of a soft caching proxy system. Changes to replacement algorithms are detailed and image size and recoding issues are discussed. We also present our working soft caching testbed based on the Squid proxy, detail the modifications we have made and present the experiences obtained.