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PubMed2001

Management matters: the link between hospital organisation and quality of patient care.

Some hospital trusts and health authorities consistently outperform others on different dimensions of performance. Why? There is some evidence that "management matters", as well as the combined efforts of individual clinicians and teams. However, studies that have been conducted on the link between the organisation and management of services and quality of patient care can be criticised both theoretically and methodologically. A larger, and arguably more rigorous, body of work exists on the performance of firms in the private sector, often conducted within the disciplines of organisational behaviour or human resource management. Studies in these traditions have focused on the effects of decentralisation, participation, innovative work practices, and "complementarities" on outcome variables such as job satisfaction and performance. The aim of this paper is to identify a number of reviews and research traditions that might bring new ideas into future work on the determinants of hospital performance. Ideally, future research should be more theoretically informed and should use longitudinal rather than cross sectional research designs. The use of statistical methods such as multilevel modelling, which allow for the inclusion of variables at different levels of analysis, would enable estimation of the separate contribution that structure and process make to hospital outcomes.

Health Services Research↗
PubMed2006

Outcomes of clinical trial: tinnitus masking versus tinnitus retraining therapy.

A controlled clinical study was conducted to evaluate prospectively the clinical efficacy of tinnitus masking (TM) and tinnitus retraining therapy (TRT) in military veterans having clinically significant tinnitus. Qualifying patients were placed into the two groups in an alternating manner (to avoid selection bias), and treatment was administered at 0, 3, 6, 12, and 18 months. Outcomes of treatment were evaluated using three self-administered tinnitus questionnaires (Tinnitus Handicap Inventory, Tinnitus Handicap Questionnaire, Tinnitus Severity Index) and the verbally administered TRT interview forms. Findings are presented from the three written questionnaires, and from two of the interview questions (percentage time aware of, and annoyed by, tinnitus). Outcomes were analyzed on an intent-to-treat basis, using a multilevel modeling approach. Of the 123 patients enrolled, 118 were included in the analysis. Both groups showed significant declines (improvements) on these measures, with the TRT decline being significantly greater than for TM. The greater declines in TRT compared to TM occurred most strongly in patients who began treatment with a "very big" tinnitus problem. When patients began treatment with a "moderate" tinnitus problem, the benefits of TRT compared to TM were more modest.

Acoustic Stimulation↗
PubMedDate not supplied

[Use of statistical analysis in studying the conformational oscillations of chloroplasts].

Conformational oscillations of chloroplasts have been studied by the statistic analysis technique. Statistic characteristics of the parameters describing the process of chloroplast cross-section oscillations in time are given. According to the statistic analysis results it can be suggested that conformational oscillations of chloroplasts have the multilevel structure. The suggestions concerning causative factors of that multilevel organization of oscillating process are also advanced.

Chloroplasts↗
PubMed2006

Concordance in the mental health of spouses: analysis of a large national household panel survey.

BACKGROUND: Spousal concordance for common mental disorders provides evidence of the relevance of social contextual factors. There are, however, limitations within the existing literature examining spousal similarity in mental health and little consensus as to the causes of spousal similarity. This study considers a large representative sample and examines an extensive range of risk factors using multilevel statistical methods to explore spousal similarity in common mental disorders. METHOD: Data were from the Household, Income and Labour Dynamics in Australia (HILDA) Survey, a large nationally representative survey of Australian households. Analysis focused on 3808 mixed-sex couples in marriage and de facto relationships. Multilevel models assessed the mental health scale of the SF-36. Analyses considered risk factors at the individual, couple and area levels, examined the effects of relationship duration on concordance, and considered longitudinal data to assess the consistency with cross-sectional analysis. RESULTS: Significant spousal concordance on the mental health scale was demonstrated (r=0.25) and was independent of, and unexplained by mental health risk factors, including experience of multiple shared life events. Spousal similarity for mental health increased across the first 5 years of relationships. CONCLUSIONS: Evidence of spousal concordance for common mental disorders highlights the importance of the social context of marriage in the aetiology of mental illness and identifies an important direction for further research.

Adolescent↗
PubMed1993

The application of computerized analysis of nuclear images and multivariate analysis to the understanding of the effects of antineoplastic agents and their mechanism of action.

The present work involves the creation of a model that makes the rapid study of anticancer drugs possible. In order to make possible the multilevel study of antineoplastic derivatives (their effects on cell proliferation, their cell kinetics, their chromatin texture and the study of their potential operating mechanisms), the computerized analysis of nuclear images linked to multivariate analysis was chosen, and, in so doing, took into account 15 computer-calculated morphonuclear parameters for Feulgen-stained cell nuclei. In order to validate the method it was subjected to a series of well-known cancer drugs. The present results are in agreement with those obtained by conventional methods similar to those used for the study of the cytotoxicity of anticancer molecules or their effect on cell kinetics. Multivariate analysis applied to the parameters described by image analysis should make possible the rapid study of new anticancer drugs together with the rapid orientation of studies undertaken to ascertain their operating mechanisms.

Animals↗
PubMed2002

The statistical analysis of data from small groups.

The authors elaborate the complications and the opportunities inherent in the statistical analysis of small-group data. They begin by discussing nonindependence of group members' scores and then consider standard methods for the analysis of small-group data and determine that these methods do not take into account this nonindependence. A new method is proposed that uses multilevel modeling and allows for negative nonindependence and mutual influence. Finally, the complications of interactions, different group sizes, and differential effects are considered. The authors strongly urge that the analysis model of data from small-group studies should mirror the psychological processes that generate those data.

Humans↗
PubMed1997

Help-seeking among Asian and Pacific Americans: a multiperspective analysis.

The attitudes of Asian Americans and Pacific Islanders toward mental health and help-seeking at least partly account for rates of underutilization of formal mental health services. This article explores cultural themes and concepts associated with service utilization to better understand patterns and trends in help-seeking by these groups. A multilevel framework based on traditional behavioral and cognitive styles helps explain patterns of help-seeking in a Western context. An analysis of the norms and values governing Asian and Pacific Islander behaviors reveals numerous implications of sensitive and effective treatment.

Acculturation↗
PubMed1993

Alternating Wenckebach periods and allied arrhythmias.

Alternating Wenckebach periods (AWPs) are episodes of 2:1 block during which the PR, AH, or AV intervals of the conducted beats gradually increase until a greater degree of block ensues. Most episodes occur at the AV node, but some have also been reported in other structures. AWPs are usually attributed to multilevel block due to transverse (horizontal) dissociation. This assumption was initially based on a method in which the solutions to difficult electrocardiographic rhythms were arrived at by analysis and deduction based on the knowledge existing at that particular time. Subsequently, it was reinforced by information extrapolated from intracardiac recordings performed in patients with documented multilevel block in separate anatomical structures (atria, AV node, and His bundle), as well as from microelectrode studies and computer simulations. Although AWPs are frequently observed in clinical tracings, those occurring at the AV node are best categorized during incremental atrial stimulation because then they occupy a specific point in the wide spectrum of tachycardia dependent AV nodal conduction disturbances. In fact, the A:H ratios occurring in the episodes where the degree of block increases can be represented by "universal" mathematical formulas. However, in the clinical setting, drugs affecting the electrophysiology of the node can alter the pacing induced symmetry by producing additional differential effects on the various levels. The latter still requires further elucidation.

Atrioventricular Node↗
PubMed2000

Multilevel integrative analyses of human behavior: social neuroscience and the complementing nature of social and biological approaches.

Social and biological explanations traditionally have been cast as incompatible, but advances in recent years have revealed a new view synthesized from these 2 very different levels of analysis. The authors review evidence underscoring the complementing nature of social and biological levels of analysis and how the 2 together can foster understanding of the mechanisms underlying complex behavior and the mind. Specifically, they review the utility of considering social influences on biological processes that are often viewed as outside the social domain including genetic constitution, gene expression, disease, and autonomic, neuroendocrine, and immune activity. This research underscores the unity of psychology and the importance of retaining multilevel integrative research that spans molar and molecular levels of analysis. Especially needed in the coming years is more research on the mechanisms linking social and biological events and processes.

Forecasting↗
PubMed2005

A multilevel modelling solution to mathematical coupling.

Owing to mathematical coupling, statistical analyses relating change to baseline values using correlation or regression are erroneous, where the statistical procedure of testing the null hypothesis becomes invalid. Alternatives, such as Oldham's method and the variance ratio test, have been advocated, although these are limited in the presence of measurement errors with non-constant variance. Furthermore, such methods prohibit the consideration of additional covariates (e.g., treatment group within trials) or confounders (e.g., age and gender). This study illustrates the more sophisticated approach of multilevel modelling (MLM) which overcomes these limitations and provides a comprehensive solution to the analysis of change with respect to baseline values. Although mathematical coupling is widespread throughout applied research, one particular area where several studies have suggested a strong relationship between baseline disease severity and treatment effect is guided tissue regeneration (GTR) within dental research. For illustration, we use GTR studies where the original data were found to be available in the literature for reanalysis. We contrast the results from an MLM approach and Oldham's method with the standard (incorrect) approach that suffers from mathematical coupling. MLM provides a robust solution when relating change to baseline and is capable of simultaneously dealing with complex error structures and additional covariates and/or potential confounders.

Data Interpretation, Statistical↗
PubMed2006

Factors associated with physicians' choice of working sector: a national longitudinal survey in Finland.

OBJECTIVE: To analyse factors affecting physicians' choice to work in either the public or the private sector. METHOD: We undertook a longitudinal data analysis in the years 1988, 1993, 1998 and 2003 (n = 12 909) using a multilevel modelling technique. Factors related to economic factors, physician identity, appreciation as well as demographic factors were hypothesised to influence sector choice. RESULTS: Physicians seem to make their career choices prior to graduation, at least to some extent. Wage levels, the physician's personal characteristics and whether or not the physician knew his or her place of work before graduation were the key factors affecting the decision-making process in the years 1988, 1993, 1998 and 2003. Physicians for whom wages were important were less likely to choose the public sector. Also, physicians who regarded themselves as entrepreneurial preferred to work in the private sector. If a physician had worked in the public sector during his or her medical training before graduation, the probability of applying for a vacancy in the public sector was higher. CONCLUSION: It is not only economic factors, such as salary, that are involved in the physician's decision to choose the working sector.

Adult↗
PubMed1995

Predictors of skilled nursing placement in a multilevel long-term-care facility.

OBJECTIVE: To determine if cognitive and functional data gathered before admission to residential care (i.e., board and care) placement can predict nursing home placement. DESIGN: Retrospective study using Cox proportional hazards analysis and pairwise assessment of adjusted relative risk factors to determine which independent variables predicted skilled nursing placement. Subjects were followed for an average of 23.7 months (SD = 18.6 months). SETTING: Multilevel 1,735-bed long-term care facility, Jewish Home for the Aging, Reseda, California. PARTICIPANTS: Of the 248 consecutive residential care admissions studied, 80% were women. Subject's mean age was 84.8 years (SD = 5.0); 67% had no significant cognitive impairment. INDEPENDENT VARIABLES: Categorical variables were classifications with respect to dementia status, incontinence, hearing, and ambulation. Interval variables were number of medications, Katz ADL, and five neuropsychological tests. Demographic variables were gender, age, language of origin, and education. OUTCOME VARIABLE: Time between preadmission testing and the move up to skilled nursing placement. RESULTS: Pairwise assessment of adjusted potential risk factors indicated that cognitive dysfunction, less than perfect Katz ADL performance, and hearing loss were the most important independent risk factors for nursing placement. CONCLUSIONS: The findings remind us to pay careful attention to residents exhibiting even relatively mild cognitive deficits upon admission because these residents are likely to need increased environmental support.

Aged↗
PubMed2006

A meta-analysis of teen cigarette smoking cessation.

OBJECTIVE: This article presents a meta-analysis of 48 teen cigarette smoking cessation studies, the 1st meta-analysis of its kind. The authors conducted searches of electronic databases and unpublished manuscripts from 1970 to 2003. Fifty contextual elements were coded from each article. A weighted least squares random effects method was used to pool results from individual study net effects estimates. Multilevel random coefficients modeling was applied to control for the intrastudy variation. MAIN OUTCOME MEASURES: The primary outcome for the present analysis was quit rate. Data were entered as intent-to-treat (ITT) quit rates (not compliance sample rates). Overall treatment effect size and treatment effect sizes as a function of program content, modality, number of sessions, and length of follow-up were examined. RESULTS: Across studies, program conditions, compared with control conditions, appeared to give smokers a 2.90% (95% confidence interval = 1.47-4.35%) absolute advantage in quitting, increasing the probability of quitting by approximately 46% (9.14% vs. 6.24%). Relatively higher quit rates were found in programs that included a motivation enhancement component, cognitive-behavioral techniques, and social influence approaches. Also, relatively higher quit rates were found in school-based clinic and classroom modalities. Furthermore, relatively higher quit rates were found for programs consisting of at least 5 quit sessions. Data also indicated that the effects were maintained at short-term (1 year or less) and longer term (longer than 1 year) follow-ups. CONCLUSION: Much more teen smoking cessation research is needed, but teen smoking cessation programming is effective, and the present study provides a framework to move forward.

Adolescent↗
PubMed1992

Multi-level statistical models in studies of periodontal diseases.

Periodontal data typically have a hierarchical structure, with sites grouped within individuals, and individuals grouped within communities. Also, the occasion may be regarded as another level since the acquired knowledge indicates that periodontal disease activity may vary over time. Conventional statistical tests are based on unilevel analysis of data. However, this approach to statistical analysis is often inconvenient in periodontal research because of the variation in the outcome variables between the various levels in the hierarchy. Lately there have been important developments in the statistical theory which have made available powerful statistical techniques for analyzing multilevel or hierarchical data. This report describes a new approach for analyzing periodontal data and uses an illustrative example to build a model which explains part of the variability in the response variable. The results from this analysis are then compared to results from an earlier report which uses unilevel methods and the findings discussed. The present multilevel approach has several advantages over unilevel methods, mainly due to its statistical validity and efficiency. Further, it permits the incorporation of explanatory variables measured at the site and the subject levels, and those which vary across the time points. Multilevel analyses have a promising potential and are expected to have a significant impact on periodontal research.

Age Factors↗
PubMed2002

Interrelations between three proxies of health care need at the small area level: an urban/rural comparison.

STUDY OBJECTIVE: To examine the relations between geographical variations in mortality, morbidity, and deprivation at the small area level in the south west of England and to assess whether these relations vary between urban and rural areas. DESIGN: A geographically based cross sectional study using 1991 census data on premature limiting long term illness (LLTI) and socioeconomic characteristics, and 1991-1996 data on all cause premature mortality. The interrelations between the three widely used proxies of health care need are examined using correlation coefficients and scatterplots. The distribution of standardised LLTI residuals from a regression analysis on mortality are mapped and compared with the distribution of urban and rural areas. Multilevel Poisson modelling investigates whether customised deprivation profiles improve upon a generic deprivation index in explaining the spatial variation in morbidity and mortality after controlling for age and sex. These relations are examined separately for urban, fringe, and rural areas. SETTING: Nine counties in the south west of England. PARTICIPANTS: Those aged between 0-64 who reported having a LLTI in the 1991 census, and those who died during 1991-1996 aged 0-74. MAIN RESULTS: Relations between both health outcomes and generic deprivation indices are stronger in urban than rural areas. The replacement of generic with customised indices is an improvement in all area types, especially for LLTI in rural areas. The relation between mortality and morbidity is stronger in urban than rural areas, with levels of LLTI appearing to be greater in rural areas than would be predicted from mortality rates. Despite the weak direct relations between mortality and morbidity, there are strong relations between the customised deprivation indices computed to predict these outcomes in all area types. CONCLUSIONS: The improvement of the customised deprivation indices over the generic indices, and the similarity between the mortality and morbidity customised indices within area types highlights the importance of modelling urban and rural areas separately. Stronger relations between mortality and morbidity have been revealed at the local authority level in previous research providing empirical evidence that the inadequacy of mortality as a proxy for morbidity becomes more marked at lower levels of aggregation, especially in rural areas. Higher levels of LLTI than expected in rural areas may reflect different perceptions or differing patterns of illness. The stronger relations between the three proxies in urban than rural areas suggests that the choice of indicator will have less impact in urban than rural areas and strengthens the argument to develop better measures of health care need in rural areas.

Adolescent↗
PubMed1982

Subjective towers: depth relationships in multilevel subjective contours.

The perceived depth associated with subjective contours was studied with a three-level subjective contour configuration. An analysis of subjects' size judgments showed significant size-constancy scaling consistent with the prediction that subjects would perceive the various subjective surfaces as superimposed upon one another in depth. Direct depth estimations, however, showed only weak depth effects, easily reversed by conflicting depth cues, and observed with real, as well as subjective contours. The discrepant results point to the possibility of different functional depth cues for the two tasks. The order of tasks, indicative of priming, further suggested that depth processing may be secondary to pattern recognition rather than being causal in the formation of subjective contours.

Adult↗
PubMed2006

Molecular analysis of deep subsurface Cretaceous rock indicates abundant Fe(III)- and S(zero)-reducing bacteria in a sulfate-rich environment.

A multilevel sampler (MLS) was emplaced in a borehole straddling anaerobic, sulfate-rich Cretaceous-era shale and sandstone rock formations approximately 200 m below ground surface at Cerro Negro, New Mexico. Sterile quartzite sand contained in chambers in the sampler allowed in situ colonization and recovery of nucleic acids for molecular analyses. Denaturing gradient gel electrophoresis and 16S rRNA gene cloning results indicated a homogeneously distributed bacterial community across the shale-sandstone interface. delta-Proteobacteria sequences were common at all depths, and were dominated by members of the Geobacteraceae family (Pelobacter, Desulphuromonas and Geobacter). Other members of this group are capable of dissimilatory Fe(III) and/or S degrees reduction, but not sulfate reduction. RNA hybridization data also suggested that Fe(III)-/S degrees -reducing bacteria were predominant. These findings are striking considering the lack of significant concentrations of these electron acceptors in this environment. The next most abundant bacterial group indicated was the sulfate reducers, including Desulfobacterium, Desulfocapsa and Desulfobulbus. Sequences related to fermenters, denitrifiers and acetogens were also recovered. The presence of a phylogenetically and functionally diverse microbial community in this deep subsurface environment likely reflects the complex nature of the primary energy and carbon sources, kerogen associated with the shale.

Base Sequence↗
PubMed2005

Lung function in patients operated for chronic pleural empyema.

OBJECTIVES: To evaluate lung function after lung decortication in patients operated for chronic pleural empyema. METHODS AND MATERIALS: To determine the lung function after lung decortication in 20 men (71.4%) and 8 women (28.6%) a prospective evaluation of blood gases, spirometry, lung perfusion, ventilation, and alveolar permeability were performed 28 weeks (15-60 weeks) after the operation. RESULTS: Median lung perfusion on the affected side was 45.2% (26.1-55.3%) in 13 right and 36% (13.8-47.2%) in 15 left empyemas, and was within normal limits in 4/28 cases. The mean lung ventilation was 44.4% (21.5-54%) and 37% (18.9-50.6%) in patients affected on the right or left side, respectively. Ventilation perfusion inequality occurred in 22 patients (78.6%). Dynamic ventilation scintigraphy revealed impairment of epithelial integrity in 10 cases (35.7%). Individual analysis revealed that 15 patients (53.6%) showed a severe reduction in one of the examinations and 8 (28.6%) in more than one. CONCLUSIONS: Although the separate analysis of the different functional parameters revealed a mild reduction of lung function after decortication, in the majority of patients the impairment was more severe due to multilevel functional lung damage.

Adolescent↗