Re: Cohen data suspect at best

[Kai Kaletsch <info@eic.nu>]

This example would bias the results toward the null (i.e. true negative

correlation is bigger than that reported by Cohen), unless the number of

drunken census takers is related to the average radon level in a county.



Kai



From: "Rad health" <healthrad@HOTMAIL.COM>

>

> Ruth, I think you are wrong.  Can you document your statement concerning

the

> accuracy of census information?

>

> Dr. Field emailed me this reference below as an example of a factor that

> would not be linear between counties and could not be corrected for using

> Cohen's stratifications.  As Dr. Field put it to me, we know both smoking

> and lung cancer rates are higher for blacks than whites.  If you have data

> like Cohen's that under report blacks, Cohen will not be able to adjust

for

> it between counties and for sure not within counties.  This misreporting

of

> SES and smoking along with other covariates asssociated with SES is enough

> to explain the inverse association alone.  Dr. Cohen, I think this

warrants

> the $5000.00 don't you, please donate the money to the American Lung

> Association.

>

> Don

>

> Annals of  Epidemiology  2001 Apr 11:171-193

>

> The use of census data for determining race and education as SES

indicators:

> a validation study.

>

> Kwok RK, Yankaskas BC.

>

> Department of Epidemiology, School of Public Health, University of North

> Carolina at Chapel Hill, Chapel Hill, NC 27599-7515, USA.

>

> PURPOSE: Little research has examined the validity of using census data to

> determine an individual's socio-economic status (SES), as measured by race

> and

> educational level. This study assessed the accuracy of using aggregate

level

> data from United States Census Block Groups in determining race and

> education

> SES indicators in a cohort of women from North Carolina. METHODS: The

study

> analyzed patient data from the Carolina Mammography Registry and 1990

United

> States Census in 21 North Carolina counties. Women (n = 39,546) were

> geocoded to their census block group and their block group characteristics

> (surrogate

> measures) were validated with their self-reported values on race and

> education.

>

> An analysis was performed to explore whether using these surrogate

measures

> would affect measured associations with the self-reported values. RESULTS:

> Whites were accurately identified (84.8%) more consistently than Blacks

> (14.1%) regardless of their urban/rural status. Women without a high

school

> diploma or equivalent were accurately identified (56.2%) more often than

> those with higher education levels (45.9%). Analyses using the surrogate

> measures were significantly different than the true values according to

> chi-square statistics.

>

> CONCLUSIONS: Use of census data to derive SES indicators tends to be more

> accurate for the majority than the minority population. Researchers must

be

> sensitive to the ecologic fallacy when using aggregate level data such as

> the census to determine individual level characteristics.

>

>

>

> _________________________________________________________________

> MSN Photos is the easiest way to share and print your photos:

> http://photos.msn.com/support/worldwide.aspx

>

> ************************************************************************

> You are currently subscribed to the Radsafe mailing list. To unsubscribe,

> send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

> radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/

>



************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line. You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/