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PubMed2005

Do occupation and work conditions really matter? A longitudinal analysis of psychological distress experiences among Canadian workers.

This study analyses the relationship between occupation, work conditions and the experience of psychological distress within a model encompassing the stress promoted by constraints-resources embedded in macrosocial structures (occupational structure), structures of daily life (workplace, family, social networks outside the workplace) and agent personality (demography, physical health, psychological traits, life habits, stressful childhood events). Longitudinal data were derived from Statistics Canada's National Population Health Survey and comprised 6,359 workers nested in 471 occupations, followed four times between 1994-1995 and 2000-2001. Discrete time survival multilevel regressions were conducted on first and repeated episodes of psychological distress. Results showed that 42.9 per cent of workers had reported one episode of psychological distress and 18.7 per cent had done so more than once. Data supported the model and challenged the results of previous studies. The individual's position in the occupational structure plays a limited role when the structures of daily life and agent personality are accounted for. In the workplace, job insecurity and social support are important determinants, but greater decision authority increases the risk of psychological distress. Workplace constraints-resources are not moderated either by the other structures of daily life or by agent personality.

Adult↗
PubMedDate not supplied

The dentist's communicative role in prosthodontic treatment.

PURPOSE: Dentist-patient verbal communication is important for patient satisfaction. The aim of this study was to investigate the dentist's role in the provider-patient relationship as to verbal communication and patient satisfaction with the treatment outcome in prosthetic dentistry. The dentist-specific properties were analyzed in random coefficient modeling. MATERIALS AND METHODS: Sixty-one dentist-patient pairs were followed through 61 prosthodontic treatment periods. The treatment performed was fixed prosthodontic restorations on teeth or implants. One encounter at the end of each treatment period was tape recorded. The verbal communication on the recordings was analyzed using an interaction analysis instrument. Various measures of communication were used, summarizing the variational pattern of verbal interaction. Two different aspects of the patient satisfaction concept were used as dependent variables: cure (overall patient satisfaction with prosthodontic treatment), and care (patient satisfaction with a particular dental encounter during the prosthodontic treatment period). RESULTS: In the multilevel model for care, the dentist variance was mostly explained by the communication variables. In the cure model, there was no dentist variance. The communication patterns used by the dentists thus influenced patient satisfaction in a short-term perspective but not in an intermediate perspective. CONCLUSION: Patient evaluation of the care during an encounter is dependent on the dentist's verbal communication activity during the encounter, but this communication has no impact on the patient evaluation of overall prosthetic treatment outcome in the intermediate time perspective.

Adult↗
PubMed1995

Coding of hierarchical versus linear pattern structure in rats and humans.

In 3 experiments, rats and humans learned serial patterns composed of 24, 30, or 36 items. Patterns had a 2-, 3-, or 4-level hierarchical rule structure. In Experiments 1 and 2, patterns had either perfect hierarchical structure or 2 modified chunks that violated hierarchical structure, thus producing linear structure (i.e., nonhierarchical structure). For both rats and humans, pattern structure predicted pattern learning difficulty and also the nature and relative frequency of errors. Both treated chunks that were inconsistent with hierarchical structure as violation chunks, that is, they made errors that reflected their "tendency to regularize the perception of an irregular pattern" (F. Restle & B. L. Burnside, 1972). The results support the view that rats can abstract and encode a representation of multilevel hierarchical structure in serial patterns in much the same way as humans do in analogous tasks.

Animals↗
PubMed2000

Is malnutrition declining? An analysis of changes in levels of child malnutrition since 1980.

Nutritional status is the best global indicator of well-being in children. Although many surveys of children have been conducted since the 1970s, lack of comparability between them has made it difficult to monitor trends in child malnutrition. Cross-sectional data from 241 nationally representative surveys were analysed in a standard way to produce comparable results of low height-for-age (stunting). Multilevel modelling was applied to estimate regional and global trends from 1980 to 2005. The prevalence of stunting has fallen in developing countries from 47% in 1980 to 33% in 2000 (i.e. by 40 million), although progress has been uneven according to regions. Stunting has increased in Eastern Africa, but decreased in South-eastern Asia, South-central Asia and South America; Northern Africa and the Caribbean show modest improvement; and Western Africa and Central America present very little progress. Despite an overall decrease of stunting in developing countries, child malnutrition still remains a major public health problem in these countries. In some countries rates of stunting are rising, while in many others they remain disturbingly high. The data we have presented provide a baseline for assessing progress and help identify countries and regions in need of populationwide interventions. Approaches to lower child malnutrition should be based on successful nutrition programmes and policies.

Child↗
PubMed1985

Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT.

A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics.

Adult↗
PubMed2005

The cross-classified multilevel measurement model: an explanation and demonstration.

The link between the hierarchical generalized linear model (HGLM) and the Rasch model's parameterization has already been demonstrated by several researchers. Extensions have been described that include higher clustering levels to model more appropriately the contextual effects that are frequently encountered in educational research. However, pure hierarchies are relatively rare and instead cross-classified data structures are more frequently encountered. Cross-classified random effect modeling (CCREM) is still not commonly used. Use of CCREM in combination with the multilevel measurement model (MMM) has been recently introduced and is described further in the current study. Specifically, the link between the MMM and the CCREM MMM (termed "CCMMM" model) is provided. A dataset was simulated to demonstrate interpretation of the CCMMM model's parameters and to compare results under a CCMMM versus HGLM analysis. An Appendix is provided to demonstrate SAS GLIMMIX code used to estimate HGLM and CCMMM models' parameters.

Data Interpretation, Statistical↗
PubMed2007

Comparison of multisegment anterior cervical fixation using bone strut graft versus a titanium rod and buttress prosthesis: analysis of outcome with long-term follow-up and interview by independent physician.

STUDY DESIGN: A retrospective study of 73 consecutive patients who underwent cervical corpectomy and anterior strut fixation over 3 or more disc levels between July 1989 and May 1999. OBJECTIVE: To compare the efficacy of cervical spine fixation by autologous strut graft from iliac crest or fibula versus a titanium prosthesis without bone graft. SUMMARY OF BACKGROUND DATA: Strut grafting after multilevel anterior cervical corpectomy remains a challenging procedure, with published dislocation rates from 0% to 71%, and nonunion from 0% to 54%. This paper describes a quicker and easier alternative to the use of a bone strut, imparting a very high degree of immediate spinal stability, and osseous integration equivalent to bone fusion. METHODS: Thirty-eight bone-graft operations and 38 titanium prosthesis operations were performed on 73 patients between July 24, 1989 and May 20, 1999. Average follow-up was 53.2 months (range 19.8-134). RESULTS: The group of patients who received the prosthesis was significantly older than the bone-grafted group and required significantly more segments excised, but operation times were significantly shorter than for the bone strut operation. The titanium prosthesis had a lower incidence of dislodgement in the early postoperative period (1/38 vs. 4/38 for bone struts) but a higher rate of late reoperation (4/38 vs. 1/38 for bone struts). The SF-36 scores in the domain of Physical Function (only) were significantly higher in the bone-grafted group (P = 0.016, Mann Whitney), consistent with the difference in mean ages of the 2 groups. The groups were indistinguishable by Odom criteria, patient verdict, pain scores, analgesic intake, length of hospital stay, radiologic fusion rate, and residual symptoms. CONCLUSION: A titanium rod and buttress prosthesis may be a faster and easier alternative to conventional iliac crest/fibula autograft after multisegmental cervical vertebral corpectomy.

Adult↗
PubMed2002

Size at birth and early childhood growth in relation to maternal smoking, parity and infant breast-feeding: longitudinal birth cohort study and analysis.

There is remarkably wide variation in rates of infancy growth, however, its regulation is not well understood. We examined the relationship between maternal smoking, parity, and breast- or bottle-feeding to size at birth and childhood growth between 0 and 5 y in a large representative birth cohort. A total of 1,335 normal infants had weight, length/height, and head circumference measured at birth and on up to 10 occasions to 5 y old. Multilevel modeling (MLwiN) was used to analyze longitudinal growth data. Infants of maternal smokers were symmetrically small at birth (p < 0.0005) compared with infants of nonsmokers, however, showed complete catch-up growth over the first 12 mo. In contrast, infants of primiparous pregnancies were thin at birth (p < 0.0005), showed dramatic catch-up growth, and were heavier and taller than infants of nonprimiparous pregnancies from 12 mo onwards. Breast-fed infants were similar in size at birth than bottle-fed infants, but grew more slowly during infancy. Among infants who showed catch-up growth, males caught up more rapidly than females (p = 0.002). In conclusion, early postnatal growth rates are strongly influenced by a drive to compensate for antenatal restraint or enhancement of fetal growth by maternal-uterine factors. The mechanisms that signal catch-up or catch-down growth are unknown but may involve programming of appetite. The importance of nutrition on early childhood growth is emphasized by the marked difference in growth rates between breast- and bottle-fed infants. The sequence of fetal growth restraint and postnatal catch-up growth may predispose to obesity risk in this contemporary population.

Birth Weight↗
PubMed2004

Cytomics--new technologies: towards a human cytome project.

BACKGROUND: Molecular cell systems research (cytomics) aims at the understanding of the molecular architecture and functionality of cell systems (cytomes) by single-cell analysis in combination with exhaustive bioinformatic knowledge extraction. In this way, loss of information as a consequence of molecular averaging by cell or tissue homogenisation is avoided. PROGRESS: The cytomics concept has been significantly advanced by a multitude of current developments. Amongst them are confocal and laser scanning microscopy, multiphoton fluorescence excitation, spectral imaging, fluorescence resonance energy transfer (FRET), fast imaging in flow, optical stretching in flow, and miniaturised flow and image cytometry within laboratories on a chip or laser microdissection, as well as the use of bead arrays. In addition, biomolecular analysis techniques like tyramide signal amplification, single-cell polymerase chain reaction (PCR), and the labelling of biomolecules by quantum dots, magnetic nanobeads, or aptamers open new horizons of sensitivity and molecular specificity at the single-cell level. Data sieving or data mining of the vast amounts of collected multiparameter data for exhaustive multilevel bioinformatic knowledge extraction avoids the inadvertent loss of information from unknown molecular relations being inaccessible to an a priori hypothesis. CHALLENGE: It seems important to address the challenge of a human cytome project using hypothesis-driven molecular information collection from disease associated cell systems, supplemented by systematic and exhaustive knowledge extraction. This will allow the description of the molecular setup of normal and abnormal cell systems within a relational knowledge system, permitting the standardised discrimination of abnormal cell states in disease. As one of the consequences, individualised predictions of further disease course in patients (predictive medicine by cytomics) by characteristic discriminatory data patterns will permit individualised therapies, identification of new pharmaceutical targets, and establishment of a standardised framework of relevant molecular alterations in disease. This special issue of Cytometry, on new technologies in cytomics, focuses on prominent examples of this presently fast-moving scientific field, and represents one of the preconditions for the formulation of a human cytome project.

Cell Biology↗
PubMed2005

Stability and change of neuroticism in aging.

Data from the Longitudinal Aging Study Amsterdam were used to study the relationship between neuroticism and aging. At baseline, cross-sectional analyses of data from 2,117 respondents (aged 55-85 years, M = 70) showed no significant age differences. The magnitude of the 3- and 6-year stability coefficients was high, and 12% of the elderly participants showed a clinically relevant mean level change. Longitudinal multilevel analyses showed a small but statistical significant change with aging, but the mean change was not considered clinically relevant. A U-formed course was found, showing a slight decrease until respondents reached the age of 70. Adjusting the model for physical health-related variables slightly increased the stability. An additional interaction analysis showed that the individual trajectory of neuroticism was not affected by the physical health status. In conclusion, neuroticism remains rather stable in middle and older adulthood, with some apparent increase in late life.

Aged↗
PubMed2003

Children's health-related quality of life, neighbourhood socio-economic deprivation and social capital. A contextual analysis.

Neighbourhood objective socio-economic indicators and community-reported subjective measures of social capital were examined in relation to children's health-related quality of life in the Netherlands. Three different data-sources were used: (1) objective neighbourhood socio-economic indicators, (2) subjective neighbourhood data on social capital, and (3) individual data of a family cohort study, including questions on children's health-related quality of life, and family socio-economic status. Multilevel analyses were conducted using both neighbourhood level and individual level data. Neighbourhood socio-economic status and social capital were associated. Measures of socio-economic deprivation and social capital were both non-specifically associated with children's general health and satisfaction, independent of possible individual-level confounders. However, children's mental health and behaviour were specifically associated with one aspect of social capital, the degree of informal social control in the neighbourhood.

Child↗
PubMed2003

New diagnostic tool for robotic psychology and robotherapy studies.

Robotic psychology and robotherapy as a new research area employs a systematic approach in studying psycho-physiological, psychological, and social aspects of person-robot communication. An analysis of the mechanisms underlying different forms of computer-mediated behavior requires both an adequate methodology and research tools. In the proposed article we discuss the concept, basic principles, structure, and contents of the newly designed Person-Robot Complex Interactive Scale (PRCIS), proposed for the purpose of investigating psychological specifics and therapeutic potentials of multilevel person-robot interactions. Assuming that human-robot communication has symbolic meaning, each interactive pattern evaluated via the newly developed scale is assigned certain psychological value associated with the person's past life experiences, likes and dislikes, emotional, cognitive, and behavioral traits or states. PRCIS includes (1) assessment of a person's individual style of communication with the robotic creature based on direct observations; (2) the participant's evaluation of his/her new experiences with an interactive robot and evaluation of its features, advantages and disadvantages, as well as past experiences with modern technology; and (3) the instructor's overall evaluation of the session.

Animals↗
PubMed2004

Application of a vital fluorescent staining method for simultaneous, near-real-time concentration monitoring of two bacterial strains in an Atlantic coastal plain aquifer in Oyster, Virginia.

Two differentially labeled bacterial strains were monitored in near-real time during two field-scale bacterial transport experiments in a shallow aquifer in July 2000 and July 2001. Comamonas sp. strain DA001 and Acidovorax sp. strain OY-107 were grown and labeled with the vital fluorescent stain TAMRA/SE (5 [and -6]-carboxytetramethylrhodamine, succinimidyl ester) or CFDA/SE (5 [and -6]-carboxyfluorescein diacetate, succinimidyl ester). Fluorescently labeled cells and a conservative bromide tracer were introduced into a suboxic superficial aquifer, followed by groundwater collection from down-gradient multilevel samplers. Cells were enumerated in the field by microplate spectrofluorometry, with confirmatory analyses for selected samples done in the laboratory by epifluorescence microscopy, flow cytometry, and ferrographic capture. There was general agreement in the results from all of the vital-stain-based enumeration methods, with differences ranging from <10% up to 40% for the analysis of identical samples between different tracking methods. Field analysis by microplate spectrofluorometry was robust and efficient, allowing thousands of samples to be analyzed in quadruplicate for both of the injected strains. The near-real-time data acquisition allowed adjustments to the predetermined sampling schedule to be made. The microplate spectrofluorometry data sets for the July 2000 and July 2001 experiments allowed the transport of the injected cells to be related to the site hydrogeology and injection conditions and enabled the assessment of differences in the transport of the two strains. This near-real-time method should prove effective for a number of microbial ecology applications.

Biodegradation, Environmental↗
PubMedDate not supplied

English language learners, LD, and overrepresentation: A multiple-level analysis.

Continuing unresolved problems in the field of special education include the continued use of discrepancy models; the need for better identification models; continued debate over programmatic issues, ranging from inclusion to self-contained models; and the continued overrepresentation of certain ethnic and racial groups in the learning disabilities (LD) category. This article focuses on students with mild learning disorders in general, and LD in particular, providing a perspective on how this problem has been addressed and suggesting a multilevel approach in which local context plays a central role. We suggest that overrepresentation is best conceptualized as an indicator of underlying issues rather than as the proper focal point of remediation efforts.

Child↗
PubMed1996

An index of need for psychiatric services based on in-patient utilisation.

BACKGROUND: The paper describes the development of an index of the relative need for psychiatric services for the purposes of distributing NHS funds in England. METHOD: The study is based on an empirical analysis of all psychiatric in-patient completed episodes in England in 1991/92. Any index of need should be independent of the effect of variations in health care supply on the use of psychiatric services. In order to disentangle the influences of supply from social and clinical determinants of utilisation, two stage least squares regression and multilevel modelling techniques were used. RESULTS: The outcome was an index comprising six health and socio-economic variables. This is now being used by the NHS Executive to distribute about pound 2.2 billion of annual NHS expenditure for psychiatric services between English health authorities. CONCLUSION: It is shown that the index is much more sensitive to needs and therefore more redistributive than the previous index of need used in the NHS.

Adolescent↗
PubMed2001

Genetic structures and linguistic boundaries in Italy: a microregional approach.

The amount of genetic data (sequences, gene frequencies, and isonymy) available for the Province of Ferrara, Italy, makes this area one of the world's best known. In an effort to infer the underlying demographic processes, we studied the province's population structure by comparing geological, palaeoclimatic, archeological, historical, and linguistic data. This multilevel approach allowed us to date some characteristics of the population structure from prehistoric times to the Roman and Middle Ages, and to detect overlapping biological, cultural, and geographic boundaries. To detect linguistic boundaries within this area we turned pronunciation differences into phonetic notation. We then computed pairwise distances by using methods for multiple genetic sequence analysis, in order to obtain a distance matrix of the overall pronunciation variability. This approach enabled us to test the association among linguistic, geographical, and genetic distance matrices using the same statistical tests. Results indicate that demographic phenomena can be traced in an area as small as the Province of Ferrara and that, on a microregional scale, recent events may have influenced important aspects of the overall genetic variation.

Genetics, Population↗
PubMed2001

Combined temperature-controlled radiofrequency tongue reduction and UPPP in apnea surgery.

The objective of this study was to investigate the effects on outcomes and morbidity of combining temperature-controlled radiofrequency (TCRF) tongue reduction with uvulopalatopharyngoplasty (UPPP) as an initial site-directed approach to the surgical treatment of obstructive sleep apnea syndrome (OSAS). This investigation was a prospective, nonrandomized, open-enrollment study of 20 consecutive eligible patients with OSAS. Seven patients had a single-level velopharyngeal obstruction (Fujita type I or IIa), and they were assigned to undergo UPPP only (group 1). Thirteen patients had a multilevel velopharyngeal and retroglossal obstruction (Fujita type IIb), and they were assigned to undergo TCRF tongue reduction in addition to UPPP (group 2). Patients who had only a retroglossal obstruction (Fujita type III) were not included in this study. Following their initial operation, nine patients in group 2 underwent two subsequent in-office TCRF tongue treatments under local anesthesia. Three patients in group 2 were lost to followup, and one patient underwent only one TCRF procedure at the initial operation; data on the latter patient are included in some of the outcomes measures reported here where indicated, but no data are reported on the three who were lost to followup. The primary post-treatment outcomes measures were the results of comparative polysomnography and clinician and patient evaluations regarding morbidity and symptom improvement. Analysis of these data showed that there was no difference between the two groups in terms of postoperative pain or dysphagia following the initial operative session. The degree of symptom improvement in the two groups was similar. Overall success rates--as measured by the apnea/hypopnea index (group 1: 57.1% success; group 2: 50.0%) and by the apnea index (group 1: 71.4% success; group 2: 70.0%)--were statistically comparable, given the small size of the sample (figures are based on 10 patients in group 2). The author concludes that combining TCRF tongue reduction with UPPP in patients with multilevel obstruction improves response rates to a degree that is comparable to that seen with UPPP alone in patients with single-level velopharyngeal obstruction. Moreover, the combination treatment does not increase the risk of additional pain, morbidity, and complications compared with UPPP alone.

Body Temperature↗
PubMed1982

Aortofemoral graft for multilevel occlusive disease. Predictors of success and need for distal bypass.

Results of aortofemoral reconstruction of 181 consecutive patients with multilevel occlusive disease were reviewed and correlated with possible predictors of outcome. Overall, 74% of patients attained satisfactory relief of ischemic symptoms with proximal operation alone. Forty-six patients (26%) had an unsatisfactory result, 31 (17%) of whom underwent distal bypass grafts. Of 42 variables studied, 12 achieved statistical significance as predictors of outcome, and multivariate analysis identified five factors an independent indicators. Factors documenting hemodynamically significant inflow disease were associated most strongly with a good result. Several noninvasive laboratory variables were found helpful, particularly in assessing the hemodynamic compensation of distal disease. While no single variable reliably indicated the definite need for distal grafting, careful consideration of important factors together with the clinical situation will aid the surgeon in selection of the small group of patients best treated by synchronous aortofemoral and femoropopliteal grafts.

Adult↗