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Published in: BMC Public Health 1/2008

Open Access 01-12-2008 | Research article

Monitoring trends in socioeconomic health inequalities: it matters how you measure

Authors: Young-Ho Khang, Sung-Cheol Yun, John W Lynch

Published in: BMC Public Health | Issue 1/2008

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Abstract

Background

Odds ratio (OR), a relative measure for health inequality, has frequently been used in prior studies for presenting inequality trends in health and health behaviors. Since OR is not a good approximation of prevalence ratio (PR) when the outcome prevalence is quite high, an important problem may arise when OR trends are used in data in which the outcome variable (e.g., smoking or ill-health) is of relatively high prevalence and varies significantly over time. This study is to compare time trends of odds ratio (OR) and prevalence ratio (PR) for examining time trends in socioeconomic inequality in smoking.

Methods

A total of 147,805 subjects (71,793 men and 76,017 women) aged 25–64 from three Social Statistics Surveys of Korea from 1999 to 2006 were analyzed. Socioeconomic position indicators were occupational class and education.

Results

While there were no significant p values for trend in ORs of occupational class among men, trends for PRs were significant. In women, p values for OR trends were similar to those for PR trends. In males, RII by log-binomial regression showed a significant increasing tendency while RII by logistic regression was stable between years. In females, trends of RIIs by logistic regression and log-binomial regression produced a similar level of p values.

Conclusion

Different methods of measuring trends in socioeconomic health inequalities may lead to different conclusions about whether relative inequalities are increasing or decreasing. Trends in ORs may overstate or understate trends in relative inequality in health when the outcome is of relatively high prevalence and that prevalence varies significantly with time.
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Metadata
Title
Monitoring trends in socioeconomic health inequalities: it matters how you measure
Authors
Young-Ho Khang
Sung-Cheol Yun
John W Lynch
Publication date
01-12-2008
Publisher
BioMed Central
Published in
BMC Public Health / Issue 1/2008
Electronic ISSN: 1471-2458
DOI
https://doi.org/10.1186/1471-2458-8-66

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