NDLI: Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities

Content Provider	PubMed Central
Author	Saez, M. Figueiras, A. Ballester, F. Perez-hoyos, S. Ocana, R. Tobias, A.
Abstract	STUDY OBJECTIVE—The objective of this paper is to introduce a different approach, called the ecological-longitudinal, to carrying out pooled analysis in time series ecological studies. Because it gives a larger number of data points and, hence, increases the statistical power of the analysis, this approach, unlike conventional ones, allows the complementation of aspects such as accommodation of random effect models, of lags, of interaction between pollutants and between pollutants and meteorological variables, that are hardly implemented in conventional approaches. DESIGN—The approach is illustrated by providing quantitative estimates of the short-term effects of air pollution on mortality in three Spanish cities, Barcelona, Valencia and Vigo, for the period 1992-1994. Because the dependent variable was a count, a Poisson generalised linear model was first specified. Several modelling issues are worth mentioning. Firstly, because the relations between mortality and explanatory variables were non-linear, cubic splines were used for covariate control, leading to a generalised additive model, GAM. Secondly, the effects of the predictors on the response were allowed to occur with some lag. Thirdly, the residual autocorrelation, because of imperfect control, was controlled for by means of an autoregressive Poisson GAM. Finally, the longitudinal design demanded the consideration of the existence of individual heterogeneity, requiring the consideration of mixed models. MAIN RESULTS—The estimates of the relative risks obtained from the individual analyses varied across cities, particularly those associated with sulphur dioxide. The highest relative risks corresponded to black smoke in Valencia. These estimates were higher than those obtained from the ecological-longitudinal analysis. Relative risks estimated from this latter analysis were practically identical across cities, 1.00638 (95% confidence intervals 1.0002, 1.0011) for a black smoke increase of 10 µg/m3 and 1.00415 (95% CI 1.0001, 1.0007) for a increase of 10 µg/m3 of sulphur dioxide. Because the statistical power is higher than in the individual analysis more interactions were statistically significant, especially those among air pollutants and meteorological variables. CONCLUSIONS—Air pollutant levels were related to mortality in the three cities of the study, Barcelona, Valencia and Vigo. These results were consistent with similar studies in other cities, with other multicentric studies and coherent with both, previous individual, for each city, and multicentric studies for all three cities.   Keywords: air pollution; mortality; longitudinal studies
Related Links	http://dx.doi.org/10.1136/jech.55.6.423
Starting Page	423
File Format	PDF
ISSN	14702738
e-ISSN	14702738
Journal	Journal of Epidemiology and Community Health
Issue Number	6
Volume Number	55
Language	English
Publisher	BMJ Group
Publisher Date	2001-06-01
Access Restriction	Open
Rights Holder	BMJ Group
Subject Keyword	Research in Higher Education
Content Type	Text
Resource Type	Article
Subject	Public Health, Environmental and Occupational Health Epidemiology

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities.

Outdoor air pollution and infant mortality: analysis of daily time‐series data in 10 English cities

Acute and Subacute Effects of Urban Air Pollution on Cardiopulmonary Emergencies and Mortality: Time Series Studies in Austrian Cities

Outdoor air pollution and infant mortality: analysis of daily time‐series data in 10 English cities

Time series analysis of air pollution and mortality: effects by cause, age and socioeconomic status

Effects of ambient air pollution measurement error on health effect estimates in time series studies: a simulation-based analysis

Sepsis-related hospital admissions and ambient air pollution: a time series analysis in 6 Chinese cities

Short term effects of air pollution on health: a European approach using epidemiologic time series data: the APHEA protocol.

Fine particle components and health—a systematic review and meta-analysis of epidemiological time series studies of daily mortality and hospital admissions

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities

Similar Documents

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities.

Outdoor air pollution and infant mortality: analysis of daily time‐series data in 10 English cities

Acute and Subacute Effects of Urban Air Pollution on Cardiopulmonary Emergencies and Mortality: Time Series Studies in Austrian Cities

Outdoor air pollution and infant mortality: analysis of daily time‐series data in 10 English cities

Time series analysis of air pollution and mortality: effects by cause, age and socioeconomic status

Effects of ambient air pollution measurement error on health effect estimates in time series studies: a simulation-based analysis

Sepsis-related hospital admissions and ambient air pollution: a time series analysis in 6 Chinese cities

Short term effects of air pollution on health: a European approach using epidemiologic time series data: the APHEA protocol.

Fine particle components and health—a systematic review and meta-analysis of epidemiological time series studies of daily mortality and hospital admissions

Comparing meta-analysis and ecological-longitudinal analysis in time-series studies. A case study of the effects of air pollution on mortality in three Spanish cities