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At least 271 records · Page 15Linked to original sources
PubMed2005

Chinese version of the parent-proxy health-related quality of life measure for children with epilepsy: translation, cross-cultural adaptation, and reliability studies.

PURPOSE: The goal of this article is to report on the translation and reliability studies of the Parent-Proxy Response Scale of Quality of Life Measure for Children with Epilepsy for Hong Kong Chinese children. METHODS: In phase 1, forward and backward translations, expert panel review, and a series of pilot testing, cognitive interviewing, and pretesting with parents produced a Chinese translation. Content validity of the translated instrument was assessed. In phase 2, internal consistency was evaluated in 40 parents of children with epilepsy aged 8 to 18. Test-retest reliability was studied in 33 parents. RESULTS: The translation was judged to have good content validity by experts and was acceptable to parents. Internal consistency was good (Cronbach alpha=0.71-0.92). Test-retest reliability, determined with the intraclass correlation coefficient, ranged between 0.51 and 0.84. CONCLUSIONS: Our data suggest acceptable content validity, internal consistency, and reliability of the Chinese version of the Parent-Proxy Response Scale of the Quality of Life Measure for Children with Epilepsy. Studies with larger samples should be performed to further confirm other psychometric properties of the translated instrument.

Child↗
PubMed2003

The use of primary/national school absenteeism as a proxy retrospective child health status measure in an environmental pollution investigation.

As a result of community concerns over animal and human ill health centred around a rural town in the Republic of Ireland, a series of epidemiological studies were conducted. The absence of adequate health-information systems forced researchers to investigate alternative methods of assessing child health in the 'at-risk' area. This study aimed to examine annual primary/national school attendance data over a 10 year period as a proxy health status measure. Data from six geographical areas were analysed; one of these six areas was designated the 'high-risk' area on the basis of reports of animal ill health. Significantly higher absenteeism rates were noted in the 'high-risk' area in nine of the 10 years examined. Although caution is urged in the interpretation of these results, this study demonstrates that primary/national school absenteeism data can act as a useful, albeit crude, proxy measure of health status.

Absenteeism↗
PubMed2001

Floodplain lakes as sinks for sediment-associated contaminants--a new source of proxy hydrological data?

Lake and reservoir sediments often contain valuable records of sediment yield history and sediment-associated nutrient and contaminant transport spanning timescales from decades to millennia. Nevertheless, there have been few attempts to evaluate floodplain lakes as a source of proxy hydrological data for reconstructing short-term trends in sediment-associated nutrient and contaminant transport. Results from an analysis of floodplain lake sediment cores suggested good preservation of the 137Cs record, which provided an absolute dating control. Changes in the concentration of sediment-associated heavy metals and phosphorus were observed downcore and the analysis of mineral magnetic properties and particle size were used to identify the influx of sediment associated with high magnitude, low frequency flood events. Although floodplain lake-sediments only preserve a partial record, they may provide a valuable source of proxy hydrological data for reconstructing trends in sediment and sediment-associated contaminant transport where long-term sediment monitoring programmes are not available.

Cesium Radioisotopes↗
PubMed2000

Informed consent in palliative radiotherapy: participation of patients and proxies in treatment decisions.

Informed consent is regularly discussed, but little attention has been paid to the daily practice of the patient participation in treatment decisions regarding palliative care. Therefore, an exploratory study was conducted into shared decision making between radiation oncologists and patients and proxies in interviews where decisions regarding palliative radiotherapy have to be made. Interviews of 6 radiation oncologists with 26 outpatients were recorded on audiotape. Each verbal utterance was coded with the aid of the Roter Interaction Analysis System (RIAS). Results indicated that in over 75% of the interviews, patients and proxies were not asked for their opinion regarding treatment decisions. Other treatment options or the option of abstaining from treatment were discussed in 46% of the interviews. In conclusion, in this sample informed consent was not a natural part of the daily practice of palliative radiotherapy. The question remains to what extent informed consent in palliative radiotherapy is realistic.

Aged↗
PubMed2004

Enhancing specificity in proxy-design for the assessment of bioenergetics.

The purpose of this study was to examine the hypothesis that improved prediction of bioenergetics may be achieved when proxies are designed to simulate closely gold standard laboratory protocols. To accomplish this, a modified 'square' variation (SST) of the classical 20m Multistage Shuttle Run Test (MST) was designed aiming to reduce the stopping, turning and side-stepping manoeuvres. Within two weeks, 50 male volunteers (age 21.5+/-1.6, BMI 24.4+/-2.2) randomly underwent three maximal oxygen uptake (VO2max) assessments using a treadmill test (TT), the SST and MST. To assess SST reproducibility, 10 randomly-selected subjects performed the test twice. Validity results showed that mean predicted VO2max from SST was not significantly different compared to TT VO2max (p>0.05). In contrast, the equivalent value from MST was significantly higher (p<0.001) than TT. Furthermore, TT VO2max correlated with SST and MST at r=0.88 (p<0.001) and r=0.61 (p<0.05), respectively. The '95% limits of agreement' analysis (LIM(AG)) for SST and MST indicated a range of error equal to -0.5+/-5.4 and 8.1+/-8.0 (ml.kg(-1).min(-1)) with a coefficient of variation of +/-6 and +/-8.2%, respectively. Test-retest results for SST revealed no mean difference in VO2max (p>0.05) and a correlation coefficient of r=0.98 (p<0.001), while LIM(AG) demonstrated a range of error equal to -0.2+/-2.6 (ml.kg(-1).min(-1)) with a coefficient of variation of +/-5.6%. It is concluded that, compared to MST, the SST had a higher agreement with TT. The latter may well be explained by the closer simulation in bioenergetics between the two protocols (ie, the continuous nature of SST provides a closer proxy of TT).

Adult↗
PubMed1996

Descriptive epidemiology of Parkinson's disease through proxy measures.

BACKGROUND AND OBJECTIVE: In preparation for analytic study we undertook to describe areas of relative excess and deficit of Parkinson's Disease (PD) in Nebraska and tested two methodologic tools for inexpensive assessment of descriptive epidemiology of PD. METHODS: In lieu of large-scale population screening and diagnosis, we obtained sales information of anti-PD drugs in the state in 1988-1990 as well as listings of all people dying from 1984 to 1993 who had Parkinson's Disease mentioned anywhere on their death certificate. The anti-PD drug sales data are intended as a proxy for prevalence, while the death certificate data are intended as a proxy for incidence. RESULTS: Sales divided by population over age 54 indicates where anti-PD drug sales differ from expected. We found high correlation of drug sales rates with several farming exposures. Age-adjusted death rates, however, showed a low degree of association with sales or farming variables. This may be attributable to differences in death certificate completion or in underlying incidence versus prevalence. CONCLUSIONS: These techniques provide a useful tool for delineating possible differences in incidence and prevalence. While not as accurate as full community survey with expert diagnosis, they are not as expensive, and can be followed by local cluster investigations and individual-level etiologic studies to test hypotheses resulting from the initial study.

Epidemiologic Methods↗
PubMed2006

Direct use of unassigned resonances in NMR structure calculations with proxy residues.

We present a method that significantly enhances the robustness of (automated) NMR structure determination by allowing the NOE data corresponding to unassigned NMR resonances to be used directly in the calculations. The unassigned resonances are represented by additional atoms or groups of atoms that have no interaction with the regular protein atoms except through distance restraints. These so-called "proxy" residues can be used to generate NOE-based distance restraints in a similar fashion as for the assigned part of the protein. If sufficient NOE information is available, the restraints are expected to place the proxies at positions close to the correct atoms for the unassigned resonance, which can facilitate subsequent assignment. Convergence can be further improved by supplying additional information about the possible identities of the unassigned resonances. We have implemented this approach in the widely used automated assignment and structure calculation protocols ARIA and CANDID. We find that it significantly increases the robustness of structure calculations with regard to missing assignments and yields structures of higher quality. Our approach is still able to find correctly folded structures with up to 30% randomly missing resonance assignments, and even when only backbone and beta resonances are present! This should be of significant value to NMR-based structural proteomics initiatives.

Journal Article↗
PubMed2000

Changes in peak expiratory flow indices as a proxy for changes in bronchial hyperresponsiveness. Dutch Chronic Non-Specific Lung Disease study group.

Guidelines for asthma management advocate home peak expiratory flow (PEF) monitoring. It is commonly stated that PEF variability is a good proxy of bronchial hyperresponsiveness (BHR), a hallmark of asthma. However, this has hardly been tested longitudinally, as required to monitor asthma. This study assesses which PEF index correlates best with BHR longitudinally and whether the correlation improves when correcting PEF values for the known nonlinearity of mini-Wright PEF meters. Every 6 months, for a period of 2 yrs, PEF diary cards were filled in and BHR to histamine was tested in 104 patients with BHR and reversible airways obstruction, who started treatment with bronchodilators with (n=33) or without (n=71) inhaled corticosteroids. Within each subject, PEF indices and BHR were correlated longitudinally. The highest median correlation coefficients were obtained in the group of patients using inhaled corticosteroids. The PEF indices providing the best correlation with BHR were: mean PEF bronchodilator response (rho=-0.50) and within-day variation (% mean or % maximum) (with postbronchodilator values, rho=-0.50; without postbronchodilator values, rho=-0.40). Using PEF data corrected for the nonlinearity of the PEF meters did not result in higher correlation coefficients. Since current guidelines on asthma management recommend only bronchodilators on demand, the most useful peak expiratory flow index for reflecting bronchial hyperresponsiveness longitudinally is mean within-day peak expiratory flow variation (% mean or % maximum) (without postbronchodilator values). Since the correlation coefficients are not very strong, the authors suggest that peak expiratory flow measurements are not used as a proxy for bronchial hyperresponsiveness longitudinally but as a measurement in its own right. The use of corrections of peak expiratory flows for the nonlinearity of mini-Wright peak expiratory flow meters does not improve the correlation between peak expiratory flow and bronchial hyperresponsiveness.

Administration, Inhalation↗
PubMed2005

Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data.

A number of reconstructions of millennial-scale climate variability have been carried out in order to understand patterns of natural climate variability, on decade to century timescales, and the role of anthropogenic forcing. These reconstructions have mainly used tree-ring data and other data sets of annual to decadal resolution. Lake and ocean sediments have a lower time resolution, but provide climate information at multicentennial timescales that may not be captured by tree-ring data. Here we reconstruct Northern Hemisphere temperatures for the past 2,000 years by combining low-resolution proxies with tree-ring data, using a wavelet transform technique to achieve timescale-dependent processing of the data. Our reconstruction shows larger multicentennial variability than most previous multi-proxy reconstructions, but agrees well with temperatures reconstructed from borehole measurements and with temperatures obtained with a general circulation model. According to our reconstruction, high temperatures--similar to those observed in the twentieth century before 1990--occurred around ad 1000 to 1100, and minimum temperatures that are about 0.7 K below the average of 1961-90 occurred around ad 1600. This large natural variability in the past suggests an important role of natural multicentennial variability that is likely to continue.

Climate↗
PubMed2005

Probing peroxisomal beta-oxidation and the labelling of acetyl-CoA proxies with [1-(13C)]octanoate and [3-(13C)]octanoate in the perfused rat liver.

We reported previously that a substantial fraction of the acetyl groups used to synthesize malonyl-CoA in rat heart is derived from peroxisomal beta-oxidation of long-chain and very-long-chain fatty acids. This conclusion was based on the interpretation of the 13C-labelling ratio (malonyl-CoA)/(acetyl moiety of citrate) measured in the presence of substrates that label acetyl-CoA in mitochondria only (ratio < 1.0) or in both mitochondria and peroxisomes (ratio > 1.0). The goals of the present study were to test, in rat livers perfused with [1-(13C)]octanoate or [3-(13C)]octanoate, (i) whether peroxisomal beta-oxidation contributes acetyl groups for malonyl-CoA synthesis, and (ii) the degree of labelling homogeneity of acetyl-CoA proxies (acetyl moiety of citrate, acetate, beta-hydroxybutyrate, malonyl-CoA and acetylcarnitine). Our data show that (i) octanoate undergoes two cycles of peroxisomal beta-oxidation in liver, (ii) acetyl groups formed in peroxisomes contribute to malonyl-CoA synthesis, (iii) the labelling of acetyl-CoA proxies is markedly heterogeneous, and (iv) the labelling of C1+2 of beta-hydroxybutyrate does not reflect the labelling of acetyl-CoA used in the citric acid cycle.

Acetates↗
PubMed2001

Differing approaches to the identification of Munchausen by Proxy Syndrome (MBPS): a case of professional training or role of experiental exposure.

Much recent research recognises that a multidisciplinary team approach is best to manage Munchausen by Proxy Syndrome (MBPS), an extreme manifestation of factitious disorder by proxy (FDBP). Generally described as fabricating illness symptoms in a child to serve the adult caretaker's attention seeking needs, identification of the disorder remains problematic. Various relevant professionals differ in their emphasis and vary in their knowledge of the condition which in turn can inhibit collaborative investigation and intervention. Reasons for these difficulties are described together with a rationale for better interagency co-operation, not least because the outcome in some cases is the death of the child. The present paper discusses the implications of professional training in identification of MBPS and the value of previous exposure to cases in increasing likelihood of detection. An empirical study is described that presents working models used by different professionals to identify cases of MBPS (n=12). Analysis of qualitative interview material by means of a multidimensional scaling procedure revealed no clear grouping in terms of occupational specialism, rather commonalities of approach appeared related to previous experience with MBPS. The range of salient factors elicited was used to devise a parsimonious screening checklist intended for use by different professional groups. Finally, future research in terms of investigating psychometric profiles of MBPS child abusers and demonstrating the utility of the checklist for use by multidisciplinary teams in early detection and subsequent management of MBPS is discussed.

Journal Article↗
PubMed1997

Geochemistry of corals: proxies of past ocean chemistry, ocean circulation, and climate.

This paper presents a discussion of the status of the field of coral geochemistry as it relates to the recovery of past records of ocean chemistry, ocean circulation, and climate. The first part is a brief review of coral biology, density banding, and other important factors involved in understanding corals as proxies of environmental variables. The second part is a synthesis of the information available to date on extracting records of the carbon cycle and climate change. It is clear from these proxy records that decade time-scale variability of mixing processes in the oceans is a dominant signal. That Western and Eastern tropical Pacific El Niño-Southern Oscillation (ENSO) records differ is an important piece of the puzzle for understanding regional and global climate change. Input of anthropogenic CO2 to the oceans as observed by 13C and 14C isotopes in corals is partially obscured by natural variability. Nonetheless, the general trend over time toward lower delta18O values at numerous sites in the world's tropical oceans suggests a gradual warming and/or freshening of the surface ocean over the past century.

Journal Article↗
PubMed1989

Decision-making ability and advance directive preferences in nursing home patients and proxies.

We studied 39 nursing home patients and proxies to assess their decision-making capability and preferences regarding advance directives (ADs) or "living wills." Most patients willingly stated preferences; over half opted to forego burdensome measures when death appeared imminent. Patients perceived as decisionally capable were more likely to forego life-sustaining measures than those of questionable capability. The vast majority of proxies disapproved of using life-sustaining measures, even in some cases with limited knowledge of patients' preferences.

Aged↗
PubMed1983

Proxy consent and counterfactual wishes.

I discuss conditions for the validity of proxy consent to treatment on behalf of an incompetent person. I distinguish those incompetents who, when previously competent, expressed an opinion on the treatment in question from those who were never competent or who, though previously competent, never expressed an opinion on the proposed treatment. In the former case valid proxy consent usually requires respecting the stated wishes of the patient. The latter case is more difficult. I consider a widely-held principle which appeals to the counterfactual wishes of the incompetent person. I argue that it is unacceptable and propose in its place a principle having to do with the best interests of the patient.

Beneficence↗
PubMed1997

Reliability and validity of proxy respondent information about childhood injury: an assessment of a Canadian surveillance system.

The reliability and validity of proxy respondent information in the Canadian Hospitals Injury Reporting and Prevention Program surveillance system was assessed. A standardized form was used to collect data on injury date, location, context (activity at the time), breakdown factor (what went wrong), mechanism, product involvement, safety precaution use, and motor vehicle involvement. The test-retest method determined reliability, with the kappa coefficient quantifying agreement between respondent information provided in the emergency department and later during a telephone interview. Of 421 eligible respondents, 325 (77%) completed the telephone interview, with a median time to interview of 33 hours (range 24-70 hours). Agreement was high for all items; kappa coefficients ranged from 0.79 (substantial agreement) to 1.00 (perfect agreement). Reliability was not significantly modified by respondent view of the injury event, age of the child, language of the form, or level of respondent education. Validity was determined by measuring the agreement between respondent information and that provided by an independent witness. Witness information was considered to represent the truth. Of the 140 injury events selected, 92 (66%) had the form completed by both the original respondent and an independent witness. Kappa coefficients were greater than 0.65 for all but one item (safety precaution use), and the positive predictive value of respondent information for item categories whose prevalence was > or = 0.25 ranged from 0.82 to 0.95. The authors conclude that proxy respondent data on childhood injury are both reliable and valid.

Adolescent↗
PubMed1996

Use of the Nottingham Health Profile to test the validity of census variables to proxy the need for health care.

BACKGROUND: Data on health or health service use are invariably used to test the validity of proxy measures of need, for use in resource allocation formulae. Perceived health state is a good measure to use in this respect, as it is closely linked to perceived need and the decision to consult health services. This being the case, a large community based study was undertaken which collected data on perceived health, using the Nottingham Health Profile (NHP), with the aim of testing the validity of a variety of Census based measures as proxy measures of the need for health care. METHOD: A postal questionnaire survey of 9565 people living in the former South East Thames Regional Health Authority was conducted and the relationship between their perceived health state and the socio-economic characteristics of their electoral ward of residence analysed. RESULTS: A relatively low response rate (59 per cent) weakened any conclusions to be drawn from the results. However, significant correlations between perceived health and a variety of the Census based indicators were found. The highly skewed distribution of responses to the NHP statements made the results difficult to analyse and interpret. CONCLUSIONS: Although the study gave an indication of those variables that might be incorporated into resource allocation formulae, the NHP is not a particularly efficient instrument to use in a community setting. It is argued that the appropriateness of an approach to determining appropriate needs weights in allocation formulae, which attempts to find one indicator of all health care needs at the District Health Authority level, must be questioned.

Adolescent↗
PubMed2001

Discordance between proxy-reported and observed assessment of functional ability of children with juvenile idiopathic arthritis.

OBJECTIVE: To determine the level of agreement between parents and clinicians in rating dysfunction in children with juvenile idiopathic arthritis (JIA). METHODS: A parent of each patient completed the Italian version of the Childhood Health Assessment Questionnaire (CHAQ). Subsequently, an examiner assessed, in a specially equipped room, the child's performance of tasks as described by the CHAQ. Demographic and clinical variables were recorded for all patients. RESULTS: Seventy consecutive JIA patients and their parents were included. The mean proxy-reported and observed CHAQ score was 0.64+/-0.53 and 0.47+/-0.62 respectively, the difference ranging from -1.75 to 1.5. There were 30 cases (43%) of agreement (difference < or =0.25 CHAQ units) between the parent's and clinician's ratings, whereas in 40 cases (57%) there was discordance (difference >0.25 CHAQ units). In 30 cases the parent rated the child's functional ability as worse than that observed by the clinician (i.e. the parent underestimated the child's function), whereas in 10 cases the parent rated the child's functional ability as better than that observed by the clinician (i.e. overestimated the child's function). Multivariate regression analysis showed that children's functional ability was overestimated by parents with increasing erythrocyte sedimentation rate and global articular severity score and underestimated with increasing level of pain. Among the functional areas of the CHAQ, the level of agreement was poorest in the areas of eating and hygiene and was best for activities. CONCLUSIONS: Discordance between proxy-reported and observed functional ability was frequent in our patients with JIA. The children's functional ability was overestimated by parents as the severity of arthritis increased and underestimated as the level of pain increased.

Adolescent↗
PubMed1991

Hemorrhagic colitis and pseudomelanosis coli in ipecac ingestion by proxy.

This report describes a toddler with chronic diarrhea, vomiting, and hypotonia due to surreptitious administration of syrup of ipecac by his mother (Munchausen's syndrome by proxy). Several features of this case distinguish it from previous reports of chronic ipecac ingestion in childhood: the development of grossly bloody stools; radiologic, endoscopic, and biopsy evidence of a chronic moderate colitis resembling ulcerative colitis; and the histologic finding of pseudomelanosis coli, providing an important clue to toxic ingestion. The significance and possible mechanism for genesis of pseudomelanosis coli is discussed. This case emphasizes the variability in presentation and difficulty in diagnosing long-term ipecac ingestion by proxy. Ipecac toxicity should be considered in children with unexplained colitis and vomiting.

Biopsy↗