Proxy Responses Research Articles

Is centre-based provision of hearing aids better than community-based provision? A cluster-randomized trial among adolescents in Bangladesh

Purpose: In response to the need for hearing aids in low-income countries, an approach to provide hearing aids through trained community workers was developed. This study compares the effectiveness of the community-based approach with that of a centre-based approach.Methods: One hundred and forty adolescents (56% girls; 12–18 years; mean: 15 years) from eleven sub-districts participated in a cluster-randomized trial comparing a community-based service (n = 75) with a centre-based service (n = 65) in Bangladesh. The International Outcome Inventory for Hearing Aids (IOI-HA) was administered to the participants six weeks after fitting of a hearing aid, and its scores were analyzed by Mann–Whitney U-tests and an ordinal regression model.Results: The community-based approach performed as well as the centre-based approach on five out of seven outcome measures. The latter approach performed statistically significantly better on Residual participation restrictions (p = .007) and Impact on others (p = .012), but the effect sizes were small. Controlling for sex, age, hearing loss, place of living and proxy responses did not change the results.Conclusions: The community-based approach is a viable and effective option for hearing aid delivery in low-resourced settings. The approach needs to be adapted to particular contexts, and possible down-sides may need to be counteracted by special interventions.Implications for RehabilitationHearing aid use can contribute to improved activity, participation and quality of life among adolescents in low-income countries.Community-based approaches to delivering hearing aids can be viable and effective options to centre-based services.

Comparison of 2010 Census Nonresponse Follow-Up Proxy Responses with Administrative Records Using Census Coverage Measurement Results

Abstract The U.S. Census Bureau is currently conducting research on ways to use administrative records to reduce the cost and improve the quality of the 2020 Census Nonresponse Followup (NRFU) at addresses that do not self-respond electronically or by mail. Previously, when a NRFU enumerator was unable to contact residents at an address, he/she found a knowledgeable person, such as a neighbor or apartment manager, who could provide the census information for the residents. This was called a proxy response. The Census Bureau’s recent advances in merging federal and third-party databases raise the question: Are proxy responses for NRFU addresses more accurate than the administrative records available for the housing unit? Our study attempts to answer this question by comparing the quality of proxy responses and the administrative records for those housing units in the same timeframe using the results of 2010 Census Coverage Measurement (CCM) Program. The assessment of the quality of the proxy responses and the administrative records in the CCM sample of block clusters takes advantage of the extensive fieldwork, processing, and clerical matching conducted for the CCM.

Estimating Dementia and Receipt of Informal Care Using Behavioral Risk Factor Surveillance System Data.

Estimates of US adults with dementia differ widely and don't distinguish adults living in the community. Behavioral Risk Factor Surveillance System data from 120 485 households in 21 states that used a cognitive decline module in 2011 were used. Data for both respondents and other adults with subjective cognitive decline (SCD) were included through proxy responses. Using responses to questions about the receipt of informal care for their SCD and diagnosed dementia, estimates were made for each state. Overall, 2.9% (range: 1.5% in Tennessee to 5.3% in Arkansas) of all noninstitutionalized adults in these states received informal care for their SCD and 0.9% (range: 0.5% in Tennessee to 2.0% in Arkansas) were estimated to have dementia. Limiting results to respondents reduced estimates significantly. Combined results for respondents and nonrespondents from a representative telephone survey provide varying estimates of SCD-related measures across states, highlighting the need for state-specific estimates.

Systematic review of caregiver responses for patient health-related quality of life in adult cancer care.

In surveys and in research, proxies such as family members may be used to assess patient health-related quality of life. The aim of this research is to help cancer researchers select a validated health-related quality of life tool if they anticipate using proxy-reported data. Systematic review and methodological appraisal of studies examining the concordance of paired adult cancer patient and proxy responses for multidimensional, validated HRQOL tools. We searched PubMed, CINAHL, PsycINFO and perused bibliographies of reviewed papers. We reviewed concordance assessment methods, results, and associated factors for each validated tool. A total of 32 papers reporting on 29 study populations were included. Most papers were cross-sectional (N = 20) and used disease-specific tools (N = 19), primarily the FACT and EORTC. Patient and proxy mean scores were similar on average for tools and scales, with most mean differences <10 points but large standard deviations. Average ICCs for the FACT and EORTC ranged from 0.35 to 0.62, depending on the scale. Few papers (N = 15) evaluated factors associated with concordance, and results and measurement approaches were inconsistent. The EORTC was the most commonly evaluated disease-specific tool (N = 5 papers). For generic tools, both concordance and associated factor information was most commonly available for the COOP/WONCA (N = 3 papers). The MQOL was the most frequently evaluated end-of-life tool (N = 3 papers). Proxy and patient scores are similar on average, but there is large, clinically important residual variability. The evidence base is strongest for the EORTC (disease-specific tools), COOP/WONCA (generic tools), and MQOL (end-of-life-specific tools).

Differences between Proxy and Patient Assessments of Cancer Care Experiences and Quality Ratings.

To assess the impact of proxy survey responses on cancer care experience reports and quality ratings. Secondary analysis of data from Cancer Care Outcomes Research and Surveillance (CanCORS). Recruitment occurred from 2003 to 2005. The study was a cross-sectional observational study. The respondents were patients with incident colorectal or lung cancer or their proxies. Analyses used linear regression models with an independent variable for proxy versus patient responses as well as study site and clinical covariates. The outcomes were experiences with medical care, nursing care, care coordination, and care quality rating. Multiple imputation was used for missing data. Among 6,471 respondents, 1,011 (16 percent) were proxies. The proportion of proxy respondents varied from 6 percent to 28 percent across study sites. Adjusted proxy scores were modestly higher for medical care experiences (+1.28 points [95 percent CI:+ 0.05 to +2.51]), but lower for nursing care (-2.81 [95 percent CI: -4.11 to -1.50]) and care coordination experiences (-2.98 [95 percent CI: -4.15 to -1.81]). There were no significant differences between adjusted patient and proxy ratings of quality. Proxy responses have small but statistically significant differences from patient responses. However, if ratings of care are used for financial incentives, such differences could be exaggerated across practices or areas if proxy use varies.

Defining Arthritis for Public Health Surveillance: Methods and Estimates in Four US Population Health Surveys

To determine the variability of arthritis prevalence in 4 US population health surveys. We estimated annualized arthritis prevalence in 2011-2012, among adults age ≥20 years, using 2 definition methods, both based on self-report: 1) doctor-/health care provider-diagnosed arthritis in the Behavioral Risk Factor Surveillance Survey (BRFSS), National Health and Nutrition Examination Survey (NHANES), National Health Interview Survey (NHIS), and Medical Expenditure Panel Survey (MEPS); and 2) three arthritis definitions based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) criteria in MEPS (National Arthritis Data Workgroup on Arthritis and Other Rheumatic Conditions [NADW-AORC], Clinical Classifications Software [CCS], and Centers for Disease Control and Prevention [CDC]). Diagnosed arthritis prevalence percentages using the surveys were within 3 points of one another (BRFSS 26.2% [99% confidence interval (99% CI) 26.0-26.4], MEPS 26.1% [99% CI 25.0-27.2], NHIS 23.5% [99% CI 22.9-24.1], NHANES 23.0% [99% CI 19.2-26.8]), and those using ICD-9-CM were within 5 percentage points of one another (CCS 25.8% [99% CI 24.6-27.1]; CDC 28.3% [99% CI 27.0-29.6]; and NADW-AORC 30.7% [99% CI 29.4-32.1]). The variation in the estimated number (in millions) affected with diagnosed arthritis was 7.8 (BRFSS 58.5 [99% CI 58.1-59.1], MEPS 59.3 [99% CI 55.6-63.1], NHANES 51.5 [99% CI 37.2-65.5], and NHIS 52.6 [99% CI 50.9-54.4]), and using ICD-9-CM definitions it was 11.1 (CCS 58.7 [99% CI 54.5-62.9], CDC 64.3 [99% CI 59.9-68.6], and NADW 69.9 [99% CI 65.2-74.5]). Most (57-70%) reporting diagnosed arthritis also reported ICD-9-CM arthritis; respondents reporting diagnosed arthritis were older than those meeting ICD-9-CM definitions. Proxy response status affected arthritis prevalence differently across surveys. Public health practitioners and decision makers are frequently charged with choosing a single number to represent arthritis prevalence in the US population. We encourage them to consider the surveys' purpose, design, measurement methods, and statistical precision when choosing an estimate.

Role of eruption season in reconciling model and proxy responses to tropical volcanism

The response of the El Niño/Southern Oscillation (ENSO) to tropical volcanic eruptions has important worldwide implications, but remains poorly constrained. Paleoclimate records suggest an "El Niño-like" warming 1 year following major eruptions [Adams JB, Mann ME, Ammann CM (2003) Nature 426:274-278] and "La Niña-like" cooling within the eruption year [Li J, et al. (2013) Nat Clim Chang 3:822-826]. However, climate models currently cannot capture all these responses. Many eruption characteristics are poorly constrained, which may contribute to uncertainties in model solutions-for example, the season of eruption occurrence is often unknown and assigned arbitrarily. Here we isolate the effect of eruption season using experiments with the Community Earth System Model (CESM), varying the starting month of two large tropical eruptions. The eruption-year atmospheric circulation response is strongly seasonally dependent, with effects on European winter warming, the Intertropical Convergence Zone, and the southeast Asian monsoon. This creates substantial variations in eruption-year hydroclimate patterns, which do sometimes exhibit La Niña-like features as in the proxy record. However, eruption-year equatorial Pacific cooling is not driven by La Niña dynamics, but strictly by transient radiative cooling. In contrast, equatorial warming the following year occurs for all starting months and operates dynamically like El Niño. Proxy reconstructions confirm these results: eruption-year cooling is insignificant, whereas warming in the following year is more robust. This implies that accounting for the event season may be necessary to describe the initial response to volcanic eruptions and that climate models may be more accurately simulating volcanic influences than previously thought.

Differential proxy responses to late Allerød and early Younger Dryas climatic change recorded in varved sediments of the Trzechowskie palaeolake in Northern Poland

High-resolution biological proxies (pollen, macrofossils, Cladocera and diatoms), geochemical data (μ-XRF element scans, TOC, C/N ratios, δ18Ocarb and δ13Corg values) and a robust chronology based on varve counting, AMS 14C dating and tephrochronology were applied to reconstruct lake system responses to rapid climatic and environmental changes of the Trzechowskie palaeolake (TRZ; Northern Poland) during the late Allerød – Younger Dryas (YD) transition. Palaeoecological and geochemical data at 5–15 years temporal resolution allowed tracing the dynamics of short-term shifts of the ecosystem triggered by abrupt climate change. The robust age control together with the high-resolution sampling allowed the detection of leads and lags between different proxies to the climate shift at the Allerød-Younger Dryas transition. Our results indicate (1) a water level decrease and an increase in wind activities during the late Allerød and the Allerød-YD transition, which caused intensified erosion in the catchment, (2) a two-decades delayed vegetation response in comparison to the lake depositional system. Comparison with the Lake Meerfelder Maar record revealed slightly different vegetation responses of the Trzechowskie palaeolake at the YD onset.

HELP INDEX:HOEGLUNDINA ELEGANSPRESERVATION INDEX FOR MARINE SEDIMENTS IN THE WESTERN SOUTH ATLANTIC

The purpose of this study is to evaluate the abundance and preservation state of the tests of Hoeglundina elegans , with the goal to propose a new preservation index for deep-sea sediments. In seawater, aragonite is more soluble than calcite; the benthic foraminiferal species H. elegans produces aragonitic tests, thereby providing potential proxies for subtle variations in carbonate preservation. Using two proxies based on H. elegans , as well as three other carbonate-dissolution proxies, we interpret the main drivers of carbonate dissolution in the western South Atlantic Ocean from a core, GL-854 (water depth 2220 m) from the western South Atlantic Ocean, Santos Basin. The H. elegans (>150 μm) abundance and the HelP Index ( Hoeglundina elegans Preservation Index), based on five test-preservation degrees, were assessed to determine the state of aragonite preservation. Images were taken using SEM to demonstrate each degree of preservation and to observe the ultrastructural breakdown of the tests’ walls. The other parameters determined were planktonic foraminiferal Fragmentation Index (FI), %CaCO3 and sand fraction (>63 μm). The H. elegans abundance, HelP Index, and sand fraction correlated positively, and those proxies correlated inversely with the FI. The weakest correlations were between %CaCO3, and the other proxies. Subtle differences in proxy responses were consistent with specific stages of carbonate dissolution, ranging from the aragonite lysocline to the Calcite Compensation Depth. The results revealed alternating modes of high and low carbonate preservation throughout the core and the primary driver of carbonate dissolution appeared to be variation in the aragonite saturation state influenced by circulation-induced changes in water masses. The carbonate dissolution observed in specific intervals, probably due to shoaling of the Aragonite Compensation Depth, suggests a mixing zone with more corrosive southern-sourced water and less corrosive northern-sourced water at the depth where the core was located.

Model selection for CO2 sequestration using surface deformation and injection data

Incorporating time-lapse observations from sources such as remote sensing and seismic is important for monitoring the migration of CO2 plumes in carbon capture and storage projects. Significant computational costs make it impractical to run coupled flow-geomechanical simulations for all plausible geologic scenarios in a prior ensemble. This study presents a model selection framework that integrates a fast approximator as a proxy to evaluate flow and geomechanical responses of geologic models. The proxy utilizes a particle tracking algorithm to mimic flow paths of injected CO2 within the geologic models. Pressure changes and rock deformation resulting from CO2 injection are estimated using a finite-element algorithm. The reliability of the proposed proxy is tested by comparing simulation and proxy results with regards to the shapes and extents of CO2 plumes, reservoir pressure, and vertical displacement at the top layer of a given reservoir. Models showing similar proxy responses are grouped into clusters by invoking multi-dimensional scaling followed by k-means clustering. A representative model of each cluster is selected, and its dynamic responses are evaluated by running flow-geomechanical simulations. The posterior ensemble consists of the models in the cluster whose representative conforms to given observation data. The proposed model selection approach is applied to history matching of a realistic channelized reservoir and a fractured reservoir inspired from In Salah, Algeria. The two case studies demonstrate that the incorporation of surface deformation data within model selection contributes to reduction in geologic uncertainty by improving the matching quality of well responses.

Foraminiferal proxy response to ocean temperature variability and acidification over the last 150 years in the Santa Barbara Basin (California)

The last 150 years on the California margin have been marked by high variability in precipitation, temperature, sea surface temperature, and ocean chemistry, in response to both natural and anthropogenic changes. Deciphering climate history from ocean sediments is dependent on our understanding of the various influences on marine proxies. Sediment from Santa Barbara Basin (SBB), California (box core SPR0901-10BC) provides an opportunity to compare multiple marine proxies with instrumental records of climate of the past 150 years and extend them beyond the historical record. Here we use three planktonic foraminiferal proxies, δ18Ocalcite, Mg/Ca, and size-normalized shell weight, to reconstruct the surface temperature and δ18Owater in SBB California at near-annual resolution from AD 1850–2000. Results indicate that Globigerina bulloides Mg/Ca reflects the instrumental temperature trends over the last 150 years, with average Mg/Ca temperatures approximately 2 °C lower than instrumental values, due to the slightly deeper habitat preference of G. bulloides. Similarly, temperature is the dominant control on G. bulloides δ18Ocalcite, and both Mg/Ca and δ18Ocalcite reflect variability consistent with changes in the intensification of ENSO over the past 150 years.Shell weights of the planktic foraminifer G. bulloides are inversely correlated with historical sea surface temperatures over the last 150 years in SBB sediments. Greater shell weight associated with cooler surface ocean temperatures does not support the anticipated relationship between coastal upwelling of cool, low pH water and shell thinning due to CO32− undersaturation. However, in contrast to the previous 130 years, G. bulloides shells deposited on the sea floor since the late 1970s exhibit a distinctive smooth shell structure indicative of partial dissolution. We hypothesize that a mid-1970s shift in intermediate water flow from predominantly equatorward to anomalously poleward led to the influx of relatively corrosive bottom water into SBB with subsequent carbonate dissolution at the sediment–water interface.

Results and their implications from comparing respondents and proxy responses for non-respondents with cognitive difficulties on a telephone survey

BackgroundLimited study has been done on proxy responses for non-respondents with subjective cognitive decline (SCD) on the Behavioral Risk Factor Surveillance System (BRFSS). ObjectiveTo directly compare results for survey respondents with SCD with those for proxies provided for non-respondents with SCD. MethodsPublicly available 2011 BRFSS data from 120,485 households in 21 states were analyzed using Stata. Respondents ages 40 and older with SCD (n = 10,831) were compared with proxy responses for non-respondents ages 40 and older with SCD (n = 4296) living in households where the respondent did not have SCD. Outcome measures included functional difficulties associated with their SCD, needing help, receiving informal care, talking with a healthcare provider about their SCD, getting treatment, and having a dementia diagnosis. Logistic regression for each outcome controlled for age, household income, state of residence, and number of household adults. ResultsNon-respondents were significantly more likely than respondents by Pearson chi square tests with alpha = 0.05 to report all 6 outcomes. Adjusted odds ratios comparing non-respondents with respondents ranged from 2.61 (95% confidence interval: 2.22–3.07) for needing help, to 8.99 (6.60–12.24) for a dementia diagnosis and confirmed unadjusted results. ConclusionRespondent results only represent adults capable of answering a telephone survey. To represent all household adults and avoid nonresponse bias that may under-represent the true population parameters by as much as 70%, results must include both respondents and non-respondents. Other measures may be similarly affected if they inhibit one's ability to respond to a telephone survey (e.g. disability, stroke).

The Brain Metastases Symptom Checklist as a Novel Tool for Symptom Measurement in Patients with Brain Metastases Undergoing Whole-Brain Radiotherapy

We evaluated the feasibility, reliability, and validity of the Brain Metastases Symptom Checklist (bmsc), a novel self-report measure of common symptoms experienced by patients with brain metastases. Patients with first-presentation symptomatic brain metastases (n = 137) referred for whole-brain radiotherapy (wbrt) completed the bmsc at time points before and after treatment. Their caregivers (n = 48) provided proxy ratings twice on the day of consultation to assess reliability, and at week 4 after wbrt to assess responsiveness to change. Correlations with 4 other validated assessment tools were evaluated. The symptoms reported on the bmsc were largely mild to moderate, with tiredness (71%) and difficulties with balance (61%) reported most commonly at baseline. Test-retest reliability for individual symptoms had a median intraclass correlation of 0.59 (range: 0.23-0.85). Caregiver proxy and patient responses had a median intraclass correlation of 0.52. Correlation of absolute scores on the bmsc and other symptom assessment tools was low, but consistency in the direction of symptom change was observed. At week 4, change in symptoms was variable, with improvements in weight gain and sleep of 42% and 41% respectively, and worsening of tiredness and drowsiness of 62% and 59% respectively. The bmsc captures a wide range of symptoms experienced by patients with brain metastases, and it is sensitive to change. It demonstrated adequate test-retest reliability and face validity in terms of its responsiveness to change. Future research is needed to determine whether modifications to the bmsc itself or correlation with more symptom-specific measures will enhance validity.

Incidence and impact of proxy response in measuring patient experience: secondary analysis of a large postal survey using propensity score matching.

To determine whether use of proxy respondents in a patient experience survey was related to patient characteristics, and to compare patient and proxy responses. Secondary analysis, using propensity score matching, of the NHS adult inpatient survey, a large cross-sectional survey. Hospitals (n = 161) providing inpatient services in England in 2011. The survey received 70 863 responses: 10 661 (15.6%) involved proxy respondents in some way. None. Prevalence of proxy response was explored by patient demographic characteristics. Responses were compared using seven composite domains and one overall rating. Cases involving proxy responses were matched to similar independent responses via propensity score matching and mean scores compared using t-tests. Use of proxy respondents was common, with 15.7% of responses involving a proxy in some way: higher than in other similar collections internationally. Proxy response was more common for some patient groups, such as older people and those from black and minority ethnic groups. Reports made by or with the assistance of proxy respondents were markedly less positive than those from patients completing the survey unaided. This pattern was consistent across all tested variables, although the biggest differences were observed for a subjective 'overall rating' question. The prevalence of proxy response varied according to patient characteristics, but proxies were consistently less positive than patients responding unaided. Possible explanations include genuine differences in care, differential health outcomes or differences in perceptions. Patient experience surveys should collect information on use of proxy respondents to enable more refined analysis.

Abstract TP160: Degree of Functional Independence After an Ischemic Stroke Affects Quality of Life Similarly in Men and Women

Background: Women have worse quality of life (QoL) after an ischemic stroke (IS) compared with men for unclear reasons. We hypothesized that men and women may value functional independence differently. We assessed the association between sex, functional outcome, and quality of life within a large prospective cohort of ischemic stroke patients. Methods: Within the Greater Cincinnati/Northern Kentucky catchment area of 1.3 million we prospectively screened local hospital stroke admission diagnoses in 2005 and 2010. A subset of physician-confirmed IS patients were interviewed at baseline and followed longitudinally. Medical history and stroke-related data were collected through standardized retrospective chart review. Pre-stroke and 3-month modified Rankin Scale (mRS) was assessed, and European Quality of Life (EQ-5D) was administered at 3 months. Multiple regression analysis was used to compare QoL between men and women across mRS categories, adjusted for age, race, baseline mRS, stroke severity history of depression, diabetes, and use of proxy responses. Results: The GCNK follow-up cohorts from 2005 and 2010 included 964 adult IS patients, of which 797 were interviewed at 3 months post stroke. Women comprised 50% of the cohort and were older than men on average (68.4 ± 14.2 vs. 65.2 ± 13, p&lt;.001) years at the time of their stroke. Women had worse functional outcomes (median mRS 3 vs. 2, p=.02) and quality of life (EQ-5D 0.55 vs. 0.65, p=.03), even after adjustment for the covariates listed above. The EQ-5D index was no different in men and women for each point on the mRS spectrum (i.e., there was no interaction between sex and 3-month mRS; Figure). Conclusion: In this cohort study, we confirmed worse functional outcome and worse quality of life in women after stroke. However, at each level on the mRS spectrum, men and women valued their quality of life similarly. Further research is needed on the reasons for worse outcomes in women than men.

Agreement Between Community-Dwelling Persons With Stroke and Their Proxy Responders on the Neuro-QoL Instruments

Objective(s): To identify differences in agreement between communitydwelling persons with stroke and their proxy responses on the short-form versions of the Quality of Life in Neurological Disorders (Neuro-QoL) instruments. Design: Cross-sectional observational sub-study of the longitudinal, multisite, multi-condition Neuro-QoL validation study. Setting: In-person interview-guided patient-reported outcomes. Participants: Convenience sample of 86 dyads of community-dwelling persons with stroke and their proxy respondents. Interventions: N/A. Main Outcome Measure(s): Dyads concurrently completed short-forms of 8 or 9 items each for the 13 Neuro-QoL domains using the patient-proxy perspective. Difference scores, intraclass correlation coefficients (ICCs), effect size statistics, and Bland-Altman plots were examined to determine the nature and extent of proxy response bias. Results: We found no differences between patient and proxy scores on the Applied Cognition-General Concerns, Depression, Satisfaction with Social Roles and Activities, Stigma, and Upper Extremity Function (Fine Motor) short forms. Stroke patients rated themselves more favorably on the Applied Cognition-Executive Function, Ability to Participate in Social Roles and Activities, Lower Extremity Function (Mobility), Positive Affect and Well-Being, Anxiety, Fatigue, Emotional and Behavioral Dyscontrol, and Fatigue short-forms. We found no consistent pattern of differences in physical, mental-cognitive, mental-emotional, or social health HRQOL domains. The largest mean patient-proxy difference observed was 3 T-score points on the Lower Extremity Function (Mobility), which represents 0.3 SD on the T-score metric. However, Bland-Alman plots demonstrated substantial variation in difference scores among dyads. Conclusions: Proxy responses on Neuro-QoL short forms can complement or substitute for responses of moderate to high-functioning communitydwelling persons with stroke in the evaluation of post stroke research interventions; however proxy individual proxy responses may vary substantially. Additional validation is needed for other stroke populations.

Differences in proxy-reported and patient-reported outcomes: assessing health and functional status among medicare beneficiaries.

BackgroundProxy responses are very common when surveys are conducted among the elderly or disabled population. Outcomes reported by proxy may be systematically different from those obtained from patients directly. The objective of the study is to examine the presence, direction, and magnitude of possible differences between proxy-reported and patient-reported outcomes in health and functional status measures among Medicare beneficiaries.MethodsThis study is a pooled cross-sectional study of a nationally representative sample of community-dwelling Medicare beneficiaries from 2006 to 2011. Survey respondents can respond to the Medicare Current Beneficiary Survey either by themselves or via proxies. Health and functional status was assessed across five domains: physical, affective, cognitive, social, and sensory status. Propensity score matching was used to get matched pairs of patient-reports and proxy-reports.ResultsAfter applying the propensity score matching, the study identified 7,780 person-years of patient-reports paired with 7,780 person-years of proxy-reports. Except for the sensory limitation, differences between proxy-reported and patient-reported outcomes were present in physical, affective, cognitive, and social limitations. Compared to patient-reports, a question regarding survey respondents’ difficulties in managing money was associated with the largest proxy response bias (relative risk, RR = 3.83). With few exceptions, the presence, direction, and magnitude of differences between proxy-reported and patient-reported outcomes did not vary much in the subgroup analysis.ConclusionsWhen there is a difference between proxy-reported and patient-reported outcomes, proxies tended to report more health and functional limitations among the elderly and disabled population. The extent of proxy response bias depended on the domain being tested and the nature of the question being asked. Researchers should accept proxy reports for sensory status and objective, observable, or easy questions. For physical, affective, cognitive, or social status and private, unobservable, or complex questions, proxy-reported outcomes should be used with caution when patient-reported outcomes are not available.

Pain in Community-Dwelling Older Adults with Dementia: Results from the National Health and Aging Trends Study.

To report prevalence, correlates, and medication management of pain in community-dwelling older adults with dementia. Cross-sectional. In-person interviews with self- or proxy respondents living in private residences or non-nursing home residential care settings. Nationally representative sample of community-dwelling Medicare beneficiaries aged 65 and older enrolled in the National Health and Aging Trends Study 2011 wave. Dementia status was determined using a modified previously validated algorithm. Participants were asked whether they had had bothersome and activity-limiting pain over the past month. A multivariable Poisson regression model was used to determine the relationship between bothersome pain and sociodemographic and clinical characteristics. Of the 7,609 participants with complete data on cognitive function, 802 had dementia (67.2% aged ≥80, 65.0% female, 67.9% white, 49.7% proxy response, 32.0% lived alone, 18.8% lived in residential care); 670 (63.5%) participants with dementia experienced bothersome pain, and 347 (43.3%) had pain that limited activities. These rates were significantly higher than in a propensity score-matched cohort without dementia (54.5% bothersome pain, P < .001, 27.2% pain that limited activity, P < .001). Proxies reported slightly higher rates of pain than self-respondents, but differences were statistically significant only for activity-limiting pain (46.6% proxy vs 40.1% self, P = .03). Correlates of bothersome pain included arthritis, heart and lung disease, less than high school education, activity of daily living disability, depressive and anxiety symptoms, and low energy. Of those reporting pain, 30.3% stated that they rarely or never took any medications for pain. Community-living older adults with dementia are at high risk of having pain. Creative interventions and programs are needed to manage pain adequately in this vulnerable population.

Agreement Between Responses From Community-Dwelling Persons With Stroke and Their Proxies on the NIH Neurological Quality of Life (Neuro-QoL) Short Forms

ObjectiveTo examine agreement between patient and proxy responses on the Quality of Life in Neurological Disorders (Neuro-QoL) instruments after stroke. DesignCross-sectional observational substudy of the longitudinal, multisite, multicondition Neuro-QoL validation study. SettingIn-person, interview-guided, patient-reported outcomes. ParticipantsConvenience sample of dyads (N=86) of community-dwelling persons with stroke and their proxy respondents. InterventionsNot applicable. Main Outcome MeasuresDyads concurrently completed short forms of 8 or 9 items for the 13 Neuro-QoL adult domains using the patient-proxy perspective. Agreement was examined at the scale-level with difference scores, intraclass correlation coefficients (ICCs), effect size statistics, and Bland-Altman plots, and at the item-level with kappa coefficients. ResultsWe found no mean differences between patients and proxies on the Applied Cognition–General Concerns, Depression, Satisfaction With Social Roles and Activities, Stigma, and Upper Extremity Function (Fine Motor, activities of daily living) short forms. Patients rated themselves more favorably on the Applied Cognition–Executive Function, Ability to Participate in Social Roles and Activities, Lower Extremity Function (Mobility), Positive Affect and Well-Being, Anxiety, Emotional and Behavioral Dyscontrol, and Fatigue short forms. The largest mean patient-proxy difference observed was 3 T-score points on the Lower Extremity Function (Mobility). ICCs ranged from .34 to .59. However, limits of agreement showed dyad differences exceeding ±20 T-score points, and item-level agreement ranged from not significant to weighted kappa=.34. ConclusionsProxy responses on Neuro-QoL short forms can complement responses of moderate- to high-functioning community-dwelling persons with stroke and augment group-level analyses, but do not substitute for individual patient ratings. Validation is needed for other stroke populations.

Accelerating Monte Carlo Markov chains with proxy and error models

In groundwater modeling, Monte Carlo Markov Chain (MCMC) simulations are often used to calibrate aquifer parameters and propagate the uncertainty to the quantity of interest (e.g., pollutant concentration). However, this approach requires a large number of flow simulations and incurs high computational cost, which prevents a systematic evaluation of the uncertainty in the presence of complex physical processes. To avoid this computational bottleneck, we propose to use an approximate model (proxy) to predict the response of the exact model. Here, we use a proxy that entails a very simplified description of the physics with respect to the detailed physics described by the “exact” model. The error model accounts for the simplification of the physical process; and it is trained on a learning set of realizations, for which both the proxy and exact responses are computed. First, the key features of the set of curves are extracted using functional principal component analysis; then, a regression model is built to characterize the relationship between the curves. The performance of the proposed approach is evaluated on the Imperial College Fault model. We show that the joint use of the proxy and the error model to infer the model parameters in a two-stage MCMC set-up allows longer chains at a comparable computational cost. Unnecessary evaluations of the exact responses are avoided through a preliminary evaluation of the proposal made on the basis of the corrected proxy response. The error model trained on the learning set is crucial to provide a sufficiently accurate prediction of the exact response and guide the chains to the low misfit regions. The proposed methodology can be extended to multiple-chain algorithms or other Bayesian inference methods. Moreover, FPCA is not limited to the specific presented application and offers a general framework to build error models.