Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “multilevel analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Multilevel analysis of infectious diseases.

Traditional study designs, such as individual-level studies and ecological studies, are unable to simultaneously examine the effects of individual-level and group-level factors on risk of disease. Multilevel analysis overcomes this limitation by allowing the simultaneous investigation of factors defined at multiple levels. Areas in which multilevel modeling can be applied to sexually transmitted infection (STI) research include examining how both group-level and individual-level factors are related to individual-level STI outcomes, assessing interactions between individual-level and group-level constructs, and exploring how factors at multiple levels contribute to group-to-group differences in rates of disease. In this article, we review the fundamentals of multilevel modeling, the applications of multilevel models for the examination of STIs, and the key challenges associated with using multilevel modeling for infectious-disease research.

Data Interpretation, Statistical↗

A brief conceptual tutorial of multilevel analysis in social epidemiology: linking the statistical concept of clustering to the idea of contextual phenomenon.

STUDY OBJECTIVE: This didactical essay is directed to readers disposed to approach multilevel regression analysis (MLRA) in a more conceptual than mathematical way. However, it specifically develops an epidemiological vision on multilevel analysis with particular emphasis on measures of health variation (for example, intraclass correlation). Such measures have been underused in the literature as compared with more traditional measures of association (for example, regression coefficients) in the investigation of contextual determinants of health. A link is provided, which will be comprehensible to epidemiologists, between MLRA and social epidemiological concepts, particularly between the statistical idea of clustering and the concept of contextual phenomenon. DESIGN AND PARTICIPANTS: The study uses an example based on hypothetical data on systolic blood pressure (SBP) from 25,000 people living in 39 neighbourhoods. As the focus is on the empty MLRA model, the study does not use any independent variable but focuses mainly on SBP variance between people and between neighbourhoods. RESULTS: The intraclass correlation (ICC = 0.08) informed of an appreciable clustering of individual SBP within the neighbourhoods, showing that 8% of the total individual differences in SBP occurred at the neighbourhood level and might be attributable to contextual neighbourhood factors or to the different composition of neighbourhoods. CONCLUSIONS: The statistical idea of clustering emerges as appropriate for quantifying "contextual phenomena" that is of central relevance in social epidemiology. Both concepts convey that people from the same neighbourhood are more similar to each other than to people from different neighbourhoods with respect to the health outcome variable.

Adult↗

Needle transfer among injection drug users: a multilevel analysis.

OBJECTIVE: The purpose of the study described here is to extend our understanding of needle transfer behaviors among injection drug users (IDUs) by combining both micro and macro variables in a multilevel model. METHODS: A sample of 8,404 IDUs interviewed at 18 sites of the National Institute on Drug Abuse (NIDA) Cooperative Agreement for AIDS Community-Based Outreach/Intervention Program (COOP) was used for the study. A multilevel model was employed to deal with intraclass correlation in the sample and to evaluate the impact of micro and macro variables on needle transfer among IDUs. RESULTS: A significant intraclass correlation was detected in the sample. Needle transfer was associated with both the individual characteristics and the features of the social setting in which they were embedded. Some of the micro slopes were fixed, while some varied from site to site, depending on the values of macro variables. The micro intercept and the micro slope of ethnicity vary randomly across social settings, while they are partially determined by macro variables. CONCLUSION: Considering the intraclass correlation in the data and the effects of contextual features on individual behaviors, multilevel analysis of HIV risk behaviors should be considered when combining data from micro and macro levels (e.g., individual and project site levels).

Acquired Immunodeficiency Syndrome↗

Neighborhood-level influences on physical activity among older adults: a multilevel analysis.

There is a need for greater understanding of setting-specific influences on physical activity to complement the predominant research paradigm of individual-centered influences on physical activity. In this study, the authors used a cross-sectional multilevel analysis to examine a range of neighborhood-level characteristics and the extent to which they were associated with variation in self-reported physical activity among older adults. The sample consisted of 582 community-dwelling residents age 65 years and older (M = 73.99 years, SD = 6.25) recruited from 56 neighborhoods in Portland, OR. Information collected from participants and neighborhood data from objective sources formed a two-level data structure. These hierarchical data (i.e., individuals nested within neighborhoods) were subjected to multilevel structural-equation-modeling analyses. Results showed that neighborhood social cohesion, in conjunction with other neighborhood-level factors, was significantly associated with increased levels of neighborhood physical activity. Overall, neighborhood-level variables jointly accounted for a substantial variation in neighborhood physical activity when controlling for individual-level variables.

Age Factors↗

Racial disparities in low birthweight and the contribution of residential segregation: a multilevel analysis.

This study investigates the geography of racial disparities in low birthweight in New York City by focusing on racial residential segregation and its effect on the risk of low birthweight among African-American infants and mothers. This cross-sectional multilevel analysis uses birth records at the individual level (n=96,882) and racial isolation indices at the census tract or neighborhood level (n=2095) to measure their independent and cross-level effects on low birthweight. This study found that residential segregation and neighborhood poverty operate at different scales to increase the risk of low birthweight. At the neighborhood scale residential segregation is positively and significantly associated with low birthweight, after controlling for individual-level risk factors and neighborhood poverty. Residential segregation explains neighborhood variation in low birthweight means and race effects across census tracts, which cannot be accounted for by neighborhood poverty alone. At the individual scale-increasing levels of residential segregation does not significantly reduce or exacerbate individual-level risk factors for low birthweight; whereas increasing levels of neighborhood poverty significantly eliminates the race effect and reduces the protective effect of being foreign-born on low birthweight, after controlling for other individual-level risk factors and residential segregation. These findings are contradictory to previous health research that shows protective mechanisms associated with ethnic density in local areas. It is likely that structural factors underlying residential segregation, i.e., racial isolation, impose additional stressors on African-American women that may offset or disguise positive attributes associated with ethnic density. However, as poverty is concentrated within these neighborhoods, differences between races in low birthweight cease to exist. This study demonstrates that residential segregation and neighborhood poverty are important determinants of racial disparity in low birthweight in New York City.

Black or African American↗

Shared social environment and psychiatric disorder: a multilevel analysis of individual and ecological effects.

We examined associations, in terms of relative and population-attributable risks, between shared social environment at the neighbourhood level and (1) treated incidence of non-psychotic, non-organic disorders, and (2) subsequent level of service consumption. The multilevel analysis used linked records of all individuals in contact for the first time with any catchment area mental health service for non-psychotic, non-organic disorder over various specified time periods between 1981 and 1995. Socioeconomic indicators of 36 neighbourhoods in the city of Maastricht yielded a multivariately defined neighbourhood deprivation score. There were significant linear trends in the association between level of deprivation and treated incidence, especially in the population under 35 years of age (adjusted rate ratio for linear trend 1.17, 95% confident interval 1.11-1.23), who constituted around half of the patient population. The fraction of the incidence of psychiatric disorder attributable to deprivation was 17.8%. Multilevel analyses of rates of a second cohort, with cases divided according to level of service use over a standardised follow-up of 5 years after first contact with psychiatric services, revealed that the effect of deprivation scores on rates declined with intensity of out-patient service use, but increased with level of in-patient use. Up to 50% of in-patient episodes in this group could be attributed to neighbourhood level of deprivation. The increase in risk conferred by neighbourhood deprivation remained after adjustment for the individual-level equivalent. The findings therefore suggest that elements in the shared social environment influence both incidence and severity of non-psychotic, non-organic disorders, over and above any individual-level effect.

Adolescent↗

A brief conceptual tutorial of multilevel analysis in social epidemiology: using measures of clustering in multilevel logistic regression to investigate contextual phenomena.

STUDY OBJECTIVE: In social epidemiology, it is easy to compute and interpret measures of variation in multilevel linear regression, but technical difficulties exist in the case of logistic regression. The aim of this study was to present measures of variation appropriate for the logistic case in a didactic rather than a mathematical way. DESIGN AND PARTICIPANTS: Data were used from the health survey conducted in 2000 in the county of Scania, Sweden, that comprised 10 723 persons aged 18-80 years living in 60 areas. Conducting multilevel logistic regression different techniques were applied to investigate whether the individual propensity to consult private physicians was statistically dependent on the area of residence (that is, intraclass correlation (ICC), median odds ratio (MOR)), the 80% interval odds ratio (IOR-80), and the sorting out index). RESULTS: The MOR provided more interpretable information than the ICC on the relevance of the residential area for understanding the individual propensity of consulting private physicians. The MOR showed that the unexplained heterogeneity between areas was of greater relevance than the individual variables considered in the analysis (age, sex, and education) for understanding the individual propensity of visiting private physicians. Residing in a high education area increased the probability of visiting a private physician. However, the IOR showed that the unexplained variability between areas did not allow to clearly distinguishing low from high propensity areas with the area educational level. The sorting out index was equal to 82%. CONCLUSION: Measures of variation in logistic regression should be promoted in social epidemiological and public health research as efficient means of quantifying the importance of the context of residence for understanding disparities in health and health related behaviour.

Adolescent↗

[Variability in preventive activities among primary care teams in Catalonia. Application of a multilevel analysis].

OBJECTIVES: To determine whether variability exists among primary care teams (PCTs) in Catalonia in opportunistic screening activities (screening for smoking, drinking, hypertension and tetanus vaccination) and to analyze the explanatory factors in the individual characteristics of the population treated and the characteristics of the PCT. METHODS: A multilevel analysis with individual and PCT explanatory variables was performed. The data were draw from a sample of 3,000 clinical histories from the adult population treated in 1995 in 30 PCTs from the restructured primary care network in Catalonia and from PCT characteristics. RESULTS: The recording of preventive activities in the clinical histories increased with the number of risk factors and/or diseases diagnosed, the number of other preventive activities recorded, and age. Recording of arterial pressure was more frequent in women while the remaining preventive activities were more frequent in men. Workload impeded opportunistic detection. Greater recording of antitetanus vaccination was associated with the number of years that the PCT had been functioning and with wider geographical area. Recording of smoking was higher in urban areas. CONCLUSIONS: Variability in opportunistic detection exists among PCTs in Catalonia. The characteristics of the PCT and the population treated that explain part of this variability are identified. Lower workload favors preventive activities in primary care.

Alcoholism↗

Improvement of scintigram reliability by isocount scanning and multilevel analysis.

Given the target source conditions and the detector parameters, the isocount scanning uses optimally the available observation time by maintaining the statistical reliability of each measurement in the composition of a scintigram and by devoting all the observation time to the region of interest through logic circuits which allows quick skipping of the background region. The multilevel analysis is an effective enlargement of the dynamic range of the displayer screen density characteristics that emphasizes small uptake ratios in any density level. It also makes the features extraction very easy by producing an animated sequence of pictures of the observed organ on the screen. The detectability of small uptake ratios significantly improved, specially in regions of low counting rate where the fluctuation of data severely degrades the picture quality in the conventional constant speed scanning method.

Brain Neoplasms↗

Work organization, area labor-market characteristics, and depression among U.S. nursing home workers: a cross-classified multilevel analysis.

Associations between forms of work organization that follow globalization and depression were examined in U.S. nursing home assistants. A cross-sectional study of 539 nurse assistants in 49 nursing homes in three states in 2000 assessed nursing home ownership type, managerial style, wage policy, nurse assistants' emotional stresses, and area labor-market characteristics (county income inequality, median household income, and social capital) in relation to the prevalence of depression among the nurse assistants. A cross-classified multilevel analysis was used. For-profit ownership, emotional strain, managerial pressure, and lack of seniority pay increases were associated with depression. Labor-market characteristics were not associated with depression once work organization was taken into account. The deregulation of the nursing home industry that accompanies globalization is likely to adversely affect the mental health of nursing home assistants.

Adult↗

Reduced likelihood of cancer screening among women in urban areas and with low socio-economic status: a multilevel analysis in Japan.

OBJECTIVES: To elucidate socio-economic predictors of participation in cancer screening in Japanese women, paying attention to regional variations. METHODS: In a nationally representative sample of women aged 40--64 years (n=15,224) in Japan, the relationships of self-reported attendance at screening for stomach, colon, uterine and breast cancers with individual characteristics (marital status, occupation and household income) and regional variables (living in a metropolitan area or not, and per capita income) were examined using multilevel analysis. RESULTS: The participation rate ranged from 21.6% for colon cancer to 32.5% for uterine cancer. Being married, employed and having a higher household income were significantly associated with a higher likelihood of cancer screening for all types of cancer: the adjusted odds ratio in the lowest income quintile ranged from 0.45 for uterine cancer to 0.53 for colon cancer compared with the highest income quintile. There was significant regional variance, and living in a metropolitan area and per capita income were associated with a reduced likelihood of cancer screening. CONCLUSIONS: Women with lower socio-economic status and living in urban areas are less likely to participate in cancer screening in Japan. Cancer screening should be encouraged in urban areas, taking account of the socio-economic inequalities.

Adult↗

p53 status and response to radiotherapy in rectal cancer: a prospective multilevel analysis.

The aim of this study was to evaluate, in a prospective study, the predictive role of p53 status analysed at four different levels in identifying the response to preoperative radiotherapy in rectal adenocarcinoma. Before treatment, 70 patients were staged and endoscopic forceps biopsies from the tumour area were taken. p53 status was assessed by total cDNA sequencing, allelic loss analysis, immunohistochemistry, and p53 antibodies. Neoadjuvant treatment was based on preoperative radiotherapy or radiochemotherapy. Response to therapy was evaluated after surgery by both pathologic downstaging and histologic tumour regression grade. In all, 35 patients (50.0%) had p53 gene mutations; 44.4% of patients had an allelic loss; nuclear p53 overexpression was observed in 39 patients (55.7%); and p53 antibodies were detected in 11 patients (16.7%). In the multilevel analysis of p53 status, gene mutations correlated with both nuclear protein overexpression (P < 0.0001) and loss of heterozygosity (P = 0.013). In all, 29 patients (41.4%) were downstaged by pathologic analysis, and 19 patients (29.2%) were classified as tumour regression grade 1. Whatever the method of evaluation of treatment response, no correlation between p53 alterations and response to radiotherapy was observed. Our results do not support the use of p53 alterations alone as a predictive marker for response to radiotherapy in rectal carcinoma.

Adenocarcinoma↗

Accumulation of health risk behaviours is associated with lower socioeconomic status and women's urban residence: a multilevel analysis in Japan.

BACKGROUND: Little is known about the socioeconomic differences in health-related behaviours in Japan. The present study was performed to elucidate the effects of individual and regional socioeconomic factors on selected health risk behaviours among Japanese adults, with a particular focus on regional variations. METHODS: In a nationally representative sample aged 25 to 59 years old (20,030 men and 21,076 women), the relationships between six risk behaviours (i.e., current smoking, excessive alcohol consumption, poor dietary habits, physical inactivity, stress and non-attendance of health check-ups), individual characteristics (i.e., age, marital status, occupation and household income) and regional (N = 60) indicators (per capita income and unemployment rate) were examined by multilevel analysis. RESULTS: Divorce, employment in women, lower occupational class and lower household income were generally associated with a higher likelihood of risk behaviour. The degrees of regional variation in risk behaviour and the influence of regional indicators were greater in women than in men: higher per capita income was significantly associated with current smoking, excessive alcohol consumption, stress and non-attendance of health check-ups in women. CONCLUSION: Individual lower socioeconomic status was a substantial predictor of risk behaviour in both sexes, while a marked regional influence was observed only in women. The accumulation of risk behaviours in individuals with lower socioeconomic status and in women in areas with higher income, reflecting an urban context, may contribute to their higher mortality rates.

Adult↗

Individual and area factors associated with general practitioner integration in Australia: a multilevel analysis.

The further integration of primary care within the wider health system is an imperative for reform in all countries. The aim of this paper is to determine the factors associated with general practitioner (GP) integration using the GP Integration Index which has been recently developed and is demonstrating good reliability. The analysis is based on a database derived from an Australia-wide mail questionnaire survey of 1874 GPs drawn from a 20% stratified random sample of 123 Divisions of General Practice (47.8% adjusted response rate). The GP Integration Index measures the level of GPs' integration with the health care system based upon a description of their own behaviour. It consists of nine GP integration factors, and their two associated higher-order factors-Primary Care Management (PCM) and Community Health Role (CHR)-as well as five GP integration enabling factors. A multivariate multilevel analysis was undertaken. An explanatory model for both PCM and CHR was tested based on the GP integration factors as well as general practice, GP and regional characteristics. CHR and PCM were most strongly associated with GP integration enabling factors (mainly at the individual-level) and, for CHR only, with urban-rural location (mainly at the area-level). The most important single explanatory variable for both PCM and CHR was the GP integration enabling factor, "Knowledge of local resources." The important explanatory variables were those reflecting the way GPs work, rather than their broad 'classification' within individual or GP-setting groupings. Based on these results, some revision to the proposed model was necessary. We conclude that processes of care factors (as compared to structure of care factors) are more important in relation to GP integration than previously recognised. Future policy initiatives to promote GP integration should focus on programs to improve GP's knowledge of local resources.

Adult↗

Bringing context back into epidemiology: variables and fallacies in multilevel analysis.

A large portion of current epidemiologic research is based on methodologic individualism: the notion that the distribution of health and disease in populations can be explained exclusively in terms of the characteristics of individuals. The present paper discusses the need to include group- or macro-level variables in epidemiologic studies, thus incorporating multiple levels of determination in the study of health outcomes. These types of analyses, which have been called contextual or multi-level analyses, challenge epidemiologists to develop theoretical models of disease causation that extend across levels and explain how group-level and individual-level variables interact in shaping health and disease. They also raise a series of methodological issues, including the need to select the appropriate contextual unit and contextual variables, to correctly specify the individual-level model, and, in some cases, to account for residual correlation between individuals within contexts. Despite its complexities, multilevel analysis holds potential for reemphasizing the role of macro-level variables in shaping health and disease in populations.

Epidemiologic Measurements↗

Does the context matter? Utilization of sedative drugs in nursing homes--a multilevel analysis.

BACKGROUND: The aim of this study is to assess the utilization of sedative drugs in nursing homes by means of a multilevel approach taking into account individual as well as institutional characteristics. METHODS: A retrospective chart review of the drugs consumed in nursing homes in an urban region of Germany was conducted. Individual characteristics were measured by analyzing nursing home files, by staff assessment and by a structured interview conducted by trained psychologists and physicians. Institutional characteristics were assessed by interviewing the management of each facility and ward and by using a staff questionnaire survey. The sample consisted of 1903 residents from 27 nursing homes with a total of 96 wards. Data analysis was carried out by means of a multilevel analysis, a strategy for analyzing hierarchically structured data. RESULTS: The utilization of sedative drugs (low potency neuroleptics, anxiolytics, hypnotics) in nursing homes is remarkably high. Thus, 33.3 % of the residents used sedative drugs on a regular basis. PRN prescriptions existed for 13.1 % of the residents, 5.3 % had been using sedative medication prescribed as PRN. Results indicate the influence of individual as well as institutional characteristics on residents' sedative drug utilization. In particular, the use of PRN medicine is determined by characteristics of the ward the individuals are living in. CONCLUSION: Methodological implications: The data analysis concerning the drug utilization of residents of nursing homes requires multilevel models and a distinction between regular and PRN medicine. Further research should focus on explaining institutional variance. PRACTICAL IMPLICATIONS: Staff training in nonpharmacological strategies to manage disturbing behavior of residents is required.

Adult↗

Social trust and self-rated health in US communities: a multilevel analysis.

This study assessed the contextual and individual effects of social trust on health. Methods consisted of a multilevel regression analysis of self-rated poor health among 21,456 individuals nested within 40 US communities included in the 2000 Social Capital Community Benchmark Survey. Controlling for demographic covariates, a strong income and education gradient was observed for self-rated health. Higher levels of community social trust were associated with a lower probability of reporting poor health. Individual demographic and socioeconomic predictors did not explain the association of community social trust with self-rated health. Controlling for individual trust perception, however, rendered the main effect of community social trust statistically insignificant, but a complex interaction effect was observed, such that the health-promoting effect of community social trust was significantly greater for high-trust individuals. For low-trust individuals, the effect of community social trust on self-rated health was the opposite. Using the latest data available on community social trust, we conclude that the role of community social trust in explaining average population health achievements and health inequalities is complex and is contingent on individual perceptions of social trust. Future multilevel investigations of social capital and population health should routinely consider the cross-level nature of community or neighborhood effects.

Benchmarking↗

Places, people and mental health: a multilevel analysis of economic inactivity.

This paper investigates multilevel associations between the common mental disorders of anxiety, depression and economic inactivity measured at the level of the individual and the UK 2001 census ward. The data set comes from the Caerphilly Health & Social Needs study, in which a representative survey of adults aged 18-74 years was carried out to collect a wide range of information which included mental health status (using the Mental Health Inventory (MHI-5) scale of the Short Form-36 health status questionnaire), and socio-economic status (including employment status, social class, household income, housing tenure and property value). Ward level economic inactivity was measured using non-means tested benefits data from the Department of Work and Pensions (DWP) on long-term Incapacity Benefit and Severe Disablement Allowance. Estimates from multilevel linear regression models of 10,653 individuals nested within 36 census wards showed that individual mental health status was significantly associated with ward-level economic inactivity, after adjusting for individual-level variables, with a moderate effect size of -0.668 (standard error=0.258). There was a significant cross-level interaction between ward-level and individual economic inactivity from permanent sickness or disability, such that the effect of permanent sickness or disability on mental health was significantly greater for people living in wards with high levels of economic inactivity. This supports the hypothesis that living in a deprived neighbourhood has the most negative health effects on poorer individuals and is further evidence for a substantive effect of the place where you live on mental health.

Adolescent↗