Longitudinal analysis of health outcomes after exposure to toxics, Willits California, 1991–2012: application of the cohort-period cross-sequential designReportar como inadecuado

Longitudinal analysis of health outcomes after exposure to toxics, Willits California, 1991–2012: application of the cohort-period cross-sequential design - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Environmental Health

, 13:88

First Online: 24 October 2014Received: 18 August 2014Accepted: 12 October 2014DOI: 10.1186-1476-069X-13-88

Cite this article as: Remy, L.L. & Clay, T. Environ Health 2014 13: 88. doi:10.1186-1476-069X-13-88


BackgroundAbout 1963, a factory in Willits, Mendocino County County, California added chrome plating to the manufacture of steel products. After years of residents reporting high illness rates, the State undertook a series of investigations. They found exposures had been high and warranted further research into possible health effects. Applying the seldom-used cross-sequential design, we tested if Willits had an excess rate of adverse health conditions, compared to people of the same sex and cohort living in the rest of county ROC. This is the first report on long-term health outcomes for Willits.

MethodsHospital discharge data for 1991–2012 were searched to find admissions for people born between 1940 and 1989 who ever gave the County as their residence. Diagnoses and procedures were classified to Level 1 body systems of the Multi-level Clinical Classification Software CCS. We analyzed 796,917 diagnoses and 289,980 procedures found on 117,799 admissions of 43,234 patients who lived in the County at some time between 1991 and 2012. Of these, 7,564 lived in Willits. We summarized data to the person-level then the group level over cohort-period cross-sequential to control the age by time relationship, then calculated incidence rates, relative risk, and excess case statistics, each with confidence limits. A secondary analysis focused on whether Willits differed markedly from the rest of County ROC. Specifically, other than the presence of the Plant, did Willits differ so much that those differences could plausibly explain outcome differences?

ResultsIllness was excessive in the exposed group Willits compared to the unexposed ROC. Overall number of excess cases attributable to living in Willits was estimated: Men, 301 95% confidence limit CL 200–398, women: 696 CL 569–820.

ConclusionsThis study demonstrates the strength of the cross-sequential design. Willits and ROC had comparable disadvantages relative to the State. Yet, when stratified by cohort, Willits had more illness per population. Little is known about the health effect of chemicals used at Willits on a non-occupationally exposed population. We recommend a follow-up study to evaluate the long-term health of people who lived in Willits during childhood and the reproductive age.

KeywordsCross-sequential Cohort-by-period Longitudinal Population health Data linkage Non-occupational exposure Hexavalent chromium Cr6 AbbreviationsAHRQAgency for Healthcare Research and Quality

ATSDRAgency for Toxic Substance and Disease Registry

BDBreslow-Day Chi-square test for homogeneity

CCSClinical Classification Software

CDHSCalifornia Department of Health Services

CL95% confidence limit

CMHAdjusted Cochran-Mantel-Haenzel Chi-Square test

Cr6Hexavalent chromium

ECExcess cases attributable to living in Willits

LCLLower 95% confidence limit

PDDPatient discharge data

PHAPublic Health Assessment

ROCRest of County

RRRelative risk

SSNSocial Security number, encrypted to protect confidentiality

UCLUpper 95% confidence limit.

Electronic supplementary materialThe online version of this article doi:10.1186-1476-069X-13-88 contains supplementary material, which is available to authorized users.

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Autor: Linda L Remy - Ted Clay

Fuente: https://link.springer.com/

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