Evidence map›Paper›PMID 15911637›Full record

ReviewJournal of epidemiology and community health2005

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

Juan Merlo, Basile Chaix, Min Yang, John Lynch, Lennart Råstam

Abstract readReview
In one paragraph

Review in Journal of epidemiology and community health, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 353 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
353citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

353 citing papers in PubMed, 1 synthesis or guideline pooled it.

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  12. From Averages to Heterogeneity: A Plain-Language Guide to MAIHDA in Epidemiology.International journal of social determinants of health and health services · 2026
    Review
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293 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors.

Juan MerloDepartment of Clinical Sciences (Community Medicine), Malmö University Hospital, Faculty of Medicine (Campus Malmö), Lund University, S-205 02 Malmö, Sweden. juan.merlo@med.lu.se
Basile Chaix
Min Yang
John Lynch
Lennart Råstam

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

STUDY

objectiveThis 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

participantsThe 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.

resultsThe 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.

conclusionsThe 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.

Indexed as

Epidemiologic MethodsAdultCluster AnalysisHealth StatusHumansMiddle AgedModels, StatisticalRegression AnalysisResidence CharacteristicsSociology, Medical

Identifiers

PMID15911637
PMCPMC1757045

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.