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Health survey methods with minority populations: some lessons from recent experience.

Until recently, minority populations have been inadequately or inaccurately represented in health research. Researchers are now recognizing the need to improve the validity and reliability of data on the health status and health-related behaviors of minorities. This paper discusses important methodological issues in conducting health survey research in minority communities: construction of an appropriate sampling frame, response rates, attrition from panel studies, and response patterns. These themes are illustrated with data from three field studies at the New England Research Institute. Two of these studies focus on inner-city Puerto Rican youth, a group rapidly increasing in size. The extent and multiplicity of problems experienced by this group affect the complexity of survey protocols. The third study is a random-digit-dial telephone survey on health care utilization for coronary heart disease by black and white adults from three inner-city neighborhoods in Boston. The conclusions drawn from the Institute's experience are corroborated by other scientific studies. First, the sociocultural characteristics of the community or group selected for study must be considered in planning and implementing any survey research on minority populations. Second, ensuring the quality of field work with minority groups may be expensive because of high residential mobility and lack of preexisting sampling frames. Third, there is no reason to expect any diminution of data quality with minority groups, provided the resources for data collection are adequate. The quality of data is undoubtedly proportional to the field efforts expended, but the costs of high-quality survey work are often not appreciated. The paper questions the utility of the term "minority research," for it disregards the considerable variation between and within minority groups and subcultures.

Black or African American↗

Methodologic issues in collecting data from debilitated patients with cancer near the end of life.

PURPOSE/OBJECTIVES: To report the experience of a group of researchers who have had a year of experience in a clinical trial with homecare hospice patients. SAMPLE: 150 hospice patients with cancer and their primary caregivers who were accrued to a National Cancer Institute-funded clinical trial focusing on quality of life. METHODS: The investigative team kept careful records of the numbers of patient/caregiver dyads accrued to the study and the reasons for nonaccrual as well as reasons for attrition. Data were analyzed using descriptive statistics. FINDINGS: During a nine-month period, the hospice admitted 2,517 patients; 75% had cancer and 95% had caregivers, making them eligible for the study. However, after further screening, only 19% were eligible for contact and only 5% finally were accrued to the study. For the 125 patient/caregiver dyads actually accrued to the study, baseline data were obtained on only 50% and evaluable follow-up data on only 50%. CONCLUSIONS: Accruing patients to clinical trials and retaining them when they are critically ill and near death are extraordinarily difficult tasks. The inability to recruit and retain subjects for clinical trials has implications for integrity of data, data analysis, success of the project, and the cost of conducting such projects in the future.

Clinical Trials as Topic↗

Assessment of contaminant diffusivities in building materials from porosimetry tests.

Recent studies have shown that surface and gaseous contaminant interactions may play an important role in indoor air quality. Modeling is an important tool to improve our knowledge about the phenomena involved and define appropriate ventilation strategies. However, data for sorption isotherms and diffusion in building materials remain woefully lacking. This paper deals with the latter point. It aims at investigating a methodology based on an analysis of the material porosity first and then the application of Carniglia's mathematical model to determine the effective diffusivity of gaseous species in building materials. This methodology, whose main principles are presented in the first part of the paper, was applied to seven commonly found materials. Mercury intrusion porosimetry (MIP) tests, and the calculations using Carniglia's model, reveal typical total porosities and tortuosity factors for these materials. The analysis of pore size distributions (PSDs) also draws one's attention to the possible differences in the pore structures that may exist between two samples of the same type of material and the differences in the effective diffusivities of contaminants that may result from them. The computed effective diffusivities were subsequently compared to data from experiments carried out in the frame of the EC project MATHIS. An agreement was obtained, thus validating Carniglia's methodology - a methodology that offers many practical advantages compared to diffusion-cell methods.

Air Pollution, Indoor↗

Guidelines for improving the reproducibility of quantitative multiparameter immunofluorescence measurements by laser scanning cytometry on fixed cell suspensions from human solid tumors.

BACKGROUND: Laser scanning Cytometry (LSC) is a versatile technology that makes it possible to perform multiple measurements on individual cells and correlate them cell by cell with other cellular features. It would be highly desirable to be able to perform reproducible, quantitative, correlated cell-based immunofluorescence studies on individual cells from human solid tumors. However, such studies can be challenging because of the presence of large numbers of cell aggregates and other confounding factors. Techniques have been developed to deal with cell aggregates in data sets collected by LSC. Experience has also been gained in addressing other key technical and methodological issues that can affect the reproducibility of such cell-based immunofluorescence measurements. METHODS AND RESULTS: We describe practical aspects of cell sample collection, cell fixation and staining, protocols for performing multiparameter immunofluorescence measurements by LSC, use of controls and reference samples, and approaches to data analysis that we have found useful in improving the accuracy and reproducibility of LSC data obtained in human tumor samples. We provide examples of the potential advantages of LSC in examining quantitative aspects of cell-based analysis. Improvements in the quality of cell-based multiparameter immunofluorescence measurements make it possible to extract useful information from relatively small numbers of cells. This, in turn, permits the performance of multiple multicolor panels on each tumor sample. With links among the different panels that are provided by overlapping measurements, it is possible to develop increasingly more extensive profiles of intracellular expression of multiple proteins in clinical samples of human solid tumors. Examples of such linked panels of measurements are provided. CONCLUSIONS: Advances in methodology can improve cell-based multiparameter immunofluorescence measurements on cell suspensions from human solid tumors by LSC for use in prognostic and predictive clinical applications.

Cell Aggregation↗

Measurement of side-chain carboxyl pK(a) values of glutamate and aspartate residues in an unfolded protein by multinuclear NMR spectroscopy.

A triple-resonance NMR pulse scheme is presented for measuring aspartic and glutamic acid side-chain pK(a) values in unfolded protein states where chemical shift overlap is limiting. The experiment correlates side-chain carboxyl carbon chemical shifts of these residues with the backbone amide proton chemical shift of the following residue. The methodology is applied to an (15)N, (13)C labeled sample of the N-terminal SH3 domain of the Drosophila protein drk, which exists in equilibrium between folded (F(exch)) and unfolded (U(exch)) states under nondenaturing conditions. Residue-specific pK(a) values of side-chain carboxyl groups are presented for the first time for an unfolded protein (drk U(exch) state), determined from a pH titration. Results indicate that deviations from pK(a) values measured for model compounds are likely due to local effects, while long-range electrostatic interactions appear to be of minor importance for this protein.

Animals↗

A metasynthesis: mothering other-than-normal children.

The author used Noblit and Hare's 1988 comparative method of synthesizing qualitative studies to address the need for collective knowledge development related to mothering other-than-normal children. Twelve studies were included in a metasynthesis for a total sample of 79. The nature of the child's disability, demographics, and methodology used varied widely. Initially, 13 common themes were extracted using reciprocal translation. Further analysis revealed 4 steps common to the mothering experience under which themes were categorized. Suggestions for application to practice include keeping in mind qualities of a supportive health professional from the mothers' perspective, encouraging mothers to challenge societal definitions of normalcy, and recognizing the significance of hope in fueling maternal caregiving.

Adaptation, Psychological↗

Enzymatic determination of soluble and insoluble dietary fiber in rice and wheat bran.

The information about dietary fiber presents controversies in many research areas such as in nomenclature, related illnesses, recommended quantities and terminology, mainly because of lack of analytical data. Different needs and interests for the dietary fiber composition of foods and forages have led to a proliferation of methods for its analysis. This research, a further adaptation of the enzymatic method of Asp et al. (1983) for its application is proposed for rice and wheat bran, byproducts of agroindustries in the southern region of Rio Grande do Sul (Brazil). The inclusion of Amyloglucosidase in the proposed methodology contributed to the decrease in the content of residual starch at the end of the experiment, like Prosky et al (1992). To increase the efficiency of the enzyme system in this type of samples, other changes were made with respect to incubation time and proteolytic enzyme concentration. In the final adaptation, a decrease of 51.33% of the starch content was observed in rice bran (RB) and of 52.93% in wheat bran (WB). This decrease was also verified in the model system (MS) (52.08%), which demonstrates the adequacy of the proposed adaptation. With respect to the residual protein, it was verified that the measures adopted provoked a reduction of 42.15% (RB), 52.19% (WB) and 42.11% (MS) as compared to the original method. Then the proposed conditions has been shown to be efficient in decreasing the level of interference (indigestible starch and protein) in the quantification of dietary fiber in rice and wheat bran.

Dietary Fiber↗

[Reflections on some methodological errors in the evaluation of drugs. Ten years experience at the National Marketing Authorization Commission].

A ten year experience at the national french marketing authorization committee has permitted to notice the most commonly methodological errors in the field of clinical research and, particularly, in the dossiers for drug approval: a frequent insufficient sample size resulting in lack of statistical power, an unsatisfactory optimal dosing research, a misuse of the so-called surrogate markers, an erroneous opinion about the meaning of the p value, an abusive claim for equivalence in non significant superiority trials, a misuse of unadjusted multiple comparisons and too much confidence in subgroup analysis results.

Bias↗

Reliability of in vitro microleakage tests: a literature review.

PURPOSE: The literature contains conflicting data about in vitro microleakage evaluations and their usefulness and reliability. No standardization has yet been established. Here we consider features of published studies that might affect the results of the in vitro microleakage tests. MATERIALS AND METHODS: We reviewed 144 in vitro microleakage studies, published in 14 international reviews between 1992 and 1998, which comprised 917 sets or groups of experiments. The published studies were entered in a database and compared using selected literature criteria: sample, cavities, restoration procedures, thermocycling and mechanical cycling, evaluation method. RESULTS: The methods employed vary widely. The most frequent methodological choices (%) were (1) specimen storage after extraction: duration (unspecified, 59.2), medium (distilled or deionized water, 33.8), temperature (unspecified, 52.2), additives (none, 47.0); (2) aging method (79.1): duration before aging (< 24 h, 35.9); medium and temperature of storage before aging (distilled or deionized water, 26.8; 37 degrees C, 54.3); (3) medium of cycling (tap water, 50.5), number of cycles ([250-500], 34.6), number of baths (2, 84.0), bath temperature (5 degrees C to 55 degrees C, 60.6), immersion dwell time (30 s, 44.3); (4) tracer: type (basic fuchsin, 40.7), time of immersion (after thermocycling and/or mechanical cycles, 64.1), immersion duration (basic fuchsin: 24 h, 59.5); assessment of dye penetration of sections (91.7): direction (perpendicular, 88.5), number (1, 47.1). CONCLUSION: The great variability in the methods used in these 144 studies prevented meta-analysis and comparison of the results, thus reducing the value of these methods.

Coloring Agents↗

The healthcare experiences of Arab Israeli women in a reformed healthcare system.

UNLABELLED: Arab Israeli women are subject to unique social stresses deriving from their status as part of an ethno-political minority and from their position as women in a patriarchal community. Collectively, their health profiles rate poorly in comparison to Jewish Israeli women or to women in the vast majority of developed countries. OBJECTIVES: To examine the experiences of Arab Israeli women in the contemporary Israeli healthcare system, following implementation of the National Health Insurance Law (NHIL). METHODS: The study combined quantitative and qualitative research methodologies. A telephone survey utilizing a structured questionnaire was conducted during August-September 1998 among a random national sample of 849 women, with a response rate of 83%. Between the months of January and July of 2000, qualitative data was attained via participant-observation, long and short semi-structured interviews, and focus groups in one large Muslim Arab Israeli village. FINDINGS: Arab Israeli women in the national survey reported poorer self-assessed health, lower rates of care by a woman primary care physician, lower satisfaction ratings for primary care physicians and more frequently foregoing medical care than did native or immigrant Jewish Israeli women. Three major factors contributing to Arab Israeli women's healthcare experiences were elucidated by the qualitative study: (1) the threat of physical and social exposure (2) difficulties in communicating with male physicians and (3) the stifling effect of family politics and surveillance on healthcare. DISCUSSION: We discuss our findings in relation to structural changes associated with the recent reform of the Israeli health care system. We conclude by suggesting policy measures for better adapting primary care services to the needs of Arab Israeli women, and note the relevance to other systems that aim to provide service to cultural and ethno-political minorities, in which healthcare delivery is shaped by unique local circumstances.

Adult↗

[Illness experiences of women following first incidence of acute myocardial infarction].

Purpose sampling methods were used to recruit 17 participants from a medical center in southern Taiwan. Data were collected via participant observations and interviews, with an emphasis on following Denzin's interpretative interactionism principles. Interviews were audiotaped and transcribed and the texts analyzed using constant comparative methodology. Three themes and twelve subthemes were identified. The first theme, "I have something wrong," embraced six subthemes associated with body symptom awareness and diagnosis. The second theme, "I am a patient," included three subthemes tied to patient roles and making use of rational strategies to maintain stability and self within a complex medical system. The last theme, "I can still be myself," included three subthemes connected with the struggle to return to old roles and functions to overcome limitations. The findings offer a picture of Taiwanese women's illness experiences that can be used by medical and nursing school professional to increase awareness of special needs among female patients.

Aged↗

Development of a static headspace gas chromatographic/mass spectrometric method to analyze the level of volatile contaminants biodegradation.

Volatile compound biodegradation analysis usually requires the time-consuming step of extraction of the analytes from the matrix using organic solvents or costly radioactive-compounds. Thus, it is desirable to have a simple and fast technique to generate a good evaluation of bacterial biodegradation. The goal of this research was to develop a methodology on the basis of static headspace-gas chromatography/mass spectrometry (HS-GC/MS) to evaluate the level of volatile contaminant biodegradation. The effects of the following parameters were studied: temperature and time of equilibration. The biodegradation experiments were carried out with bacteria inoculation in mineral media in presence of volatile hydrocarbon compounds (toluene, p-xylene, nonane and naphthalene). Autoclaved inoculates were used as control and reference sample. The optimal headspace conditions were observed when the vials were heated at 80 degrees C for 20 min, the syringe at 81 degrees C and an injection volume of 0.4 mL was used. This methodology has the advantage of being relative free from matrix effects.

Biodegradation, Environmental↗

Optimized blood sampling protocols and sequential design of kinetic experiments.

Design of optimal blood sampling protocols for kinetic experiments is discussed and evaluated, with the aid of several examples--including an endocrine system case study. The criterion of optimality is maximum accuracy of kinetic model parameter estimates. A simple example illustrates why a sequential experiment approach is required; optimal designs depend on the true model parameter values, knowledge of which is usually a primary objective of the experiment, as well as the structure of the model and the measurement error (e.g., assay) variance. The methodology is evaluated from the results of a series of experiments designed to quantify the dynamics of distribution and metabolism of three iodothyronines, T3, T4, and reverse-T3. This analysis indicates that 1) the sequential optimal experiment approach can be effective and efficient in the laboratory, 2) it works in the presence of reasonably controlled biological variation, producing sufficiently robust sampling protocols, and 3) optimal designs can be highly efficient designs in practice, requiring for maximum accuracy a number of blood samples equal to the number of independently adjustable model parameters, no more or less.

Animals↗

Researching domestic violence against women: methodological and ethical considerations.

The results of three population-based studies on violence against women in Nicaragua are compared in this article. Two of the studies were regional in scope (León and Managua) and focused specifically on women's experiences of violence, whereas the third study was a Demographic and Health Survey (DHS) conducted with a nationally representative sample of women. The lifetime prevalence estimates for women's undergoing physical violence from a partner were significantly higher in the León study (52 percent) and Managua study (69 percent), compared with that given in the DHS (28 percent). Possible explanations for the differences are examined through pooled multivariate logistic regression analysis, as well as analysis of six focus-group discussions carried out with field-workers and staff from the three studies. The most important differences that were found concerned ethical and safety procedures and the interview setting. The results indicate that prevalence estimates for violence are highly sensitive to methodological factors, and that underreporting is a significant threat to validity.

Adolescent↗

Female genital cutting and reproductive experience in Minya, Egypt.

In African populations practicing female genital cutting (FGC), beliefs exist that these procedures enhance reproduction and that their medicalization may diminish adverse effects, yet available findings are mixed in part for methodological reasons. We use data from a representative sample of ever-married women aged 17-55 years in Minya, Egypt, to examine the effects of type of FGC and type of circumciser on a woman's risks of primary infertility and pregnancy loss. Contrary to previous studies in Egypt, neither type of circumcision nor type of circumciser is associated with adverse fertility outcomes among circumcised women in Minya.

Adolescent↗

Paleoparasitology of Chagas disease revaled by infected tissues from Chilean mummies.

Mummified tissues were sampled from bodies stored at the Museo Arqueologico de San Pedro de Atacama, northern Chile, dated from 2000 years BP-1400 AD, and Trypanosoma cruzi DNA was recovered using polymerase chain reaction (PCR) methodology. Amplification of the conserved region of the minicircle molecule of T. cruzi was achieved in four of the six samples tested. Amplified products corresponding to genetic fragments of the parasite were tested by hybridization experiments with positive results for T. cruzi specific molecular probe. The origin and dispersion of T. cruzi human infection is discussed as well as the molecular paleoparasitological approach, and what it may represent in an evolutionary perspective.

Animals↗

Study of the effects of particle-phase carbon on the gas/particle partitioning of semivolatile organic compounds in the atmosphere using controlled field experiments.

A controlled field experiment (CFE) methodology with a filter/sorbent sampler was used to minimize artifact effects when measuring values of the gas/particle (G/P) partitioning constant (Kp, m3 microg(-1)) for semivolatile organic compounds (SOCs) in the atmosphere. CFE sampling was conducted at three different locations (Beaverton, OR; Denver, CO; and Hills, IA). Kp values were measured for a series of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs). To examine the possible effects on the G/P partitioning of the amounts of organic material (om) phase, organic carbon (OC), and elemental carbon (EC) in the sampled particulate material, the measured Kp values were normalized by the aerosol mass fractions f(om), f(OC), and f(EC) according to Kp/ f(om), Kp/f(OC), and Kp/f(EC). Using a log-log format, the resulting normalized values were all found to be more highly correlated with the subcooled liquid vapor pressure p(L)o than were the unnormalized Kp values. For the PAHs,the one-parameter model assuming Kp = Kp,OC f(OC) yielded only slightly less variability in the predicted Kp values than did the one-parameter model Kp = Kp,EC f(EC). The two-parameter model Kp = Kp,OC f(OC) + Kp,EC f(EC) was found to provide only small improvements over each of the one-parameter models. Overall, the data are more consistent with an absorptive mechanism of partitioning to the particulate material but do not rule out some role for adsorption to particle surfaces. The data suggest that small amounts of organic carbon (f(OC) approximately 0.02) can have significant effects on the G/P partitioning of SOCs.

Absorption↗

Perceptual rating instrument for speech evaluation of stuttering treatment.

A rating instrument is described that can be used to assess the results of stuttering treatments. The instrument is designed for use with naive listeners. It yields a comprehensive and detailed description of the speech quality in terms of articulation, phonation, pitch, and loudness; in addition, it includes a naturalness scale. Analysis of ratings obtained with the instrument show that naturalness is a multidimensional characteristic. Moreover, the speech characteristics that determine the naturalness ratings appear to be different pretreatment, posttreatment, and at follow-up treatment. The psychometric characteristics of the instrument are analyzed in detail. It is concluded that mixing of samples of stutterers and nonstutterers in one rating experiment may artificially inflate the reliability of the ratings. Also, ratings on equal-appearing interval scales cannot be interpreted in an absolute sense. Solutions for this methodological problem are suggested.

Adolescent↗