Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: R: st: Population attributable fractions (PAFs) in discrete-time survival analysis. -punaf-


From   "Roger B. Newson" <[email protected]>
To   [email protected]
Subject   Re: R: st: Population attributable fractions (PAFs) in discrete-time survival analysis. -punaf-
Date   Mon, 01 Jul 2013 13:09:10 +0100

Thanks to Carlo for this reference. Yes, the attributable hazard fraction (AHF) in Equation (4) of Samuelsen and Eide (2008) is the same as the population attributable fraction (PAF) produced by -punafcc- after using -stcox-. The confidence interval formulas are a little different. Samuelson and Eide use the percentile bootstrap, whereas the online help for -punafcc- recommends the user to use Shah variances by specifying the option -vce(unconditional)-. You could presumably write a program to use the percentile bootstrap with -punafcc-, though.

Best wishes

Roger

References

Sven Ove Samuelsen and Geir Egil Eide. 2008. Attributable fractions with survival data. Statistics in Medicine 2008; 27:1447–1467.

Roger B Newson BSc MSc DPhil
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group
National Heart and Lung Institute
Imperial College London
Royal Brompton Campus
Room 33, Emmanuel Kaye Building
1B Manresa Road
London SW3 6LR
UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: [email protected]
Web page: http://www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/

Opinions expressed are those of the author, not of the institution.

On 01/07/2013 12:21, Carlo Lazzaro wrote:
I suppose that Angelo refers to the following reference (access to the full
text conditional on subscription to Stat Med):

Samuelsen SO, Eide GE. Attributable fractions with survival data. Stat Med.
2008 Apr 30;27(9):1447-67.

Kind regards,
Carlo
-----Messaggio originale-----
Da: [email protected]
[mailto:[email protected]] Per conto di Roger B. Newson
Inviato: lunedì 1 luglio 2013 12:57
A: [email protected]
Oggetto: Re: st: Population attributable fractions (PAFs) in discrete-time
survival analysis. -punaf-

Yes, you can use -punaf- after a generalized linear model (GLM) with a
complementary log-log link and a binomial error function. Or after any other
GLM that gives positive-valued conditional expectations (which includes
proportions and also Gamma and inverse-Gaussian means).

For proportional-hazard models (and also for case-control data), there is a
package -punafcc-, which you can also download from SSC, and which estimates
population attributable hazard factions (after proportional-hazard
regressions), or population attributable fractions (after logit regressions
on case-control data).

Angelo has not given the Samuelsen & Eide (2008) reference on PAHFs in full.
However, I would guess that the PAHFs of that reference would be either the
same as, or similar to, those produced by -punafcc-. I would very much like
to know the full reference, so I can read it and find out more.

I hope this helps.

Best wishes

Roger

Roger B Newson BSc MSc DPhil
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group National Heart and Lung
Institute Imperial College London Royal Brompton Campus Room 33, Emmanuel
Kaye Building 1B Manresa Road London SW3 6LR UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: [email protected]
Web page: http://www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgene
tics/reph/

Opinions expressed are those of the author, not of the institution.

On 01/07/2013 00:13, Angelo Belardi wrote:
Dear All,

I am working on discrete-time proportional hazard models with a
non-parametric baseline hazard function, using -cloglog- in
person-period formatted datasets.

I would like to additionally calculate population attributable
fractions (PAFs) in these models.
However, I have never worked with PAFs in survival analyses before and
therefore don't know which functions to use and how to correctly
interpret the results.

Previously, I calculated PAFs in STATA with the -punaf- package from
Roger Newson, e.g.
for logistic regressions.

Can I use -punaf- here as well, just after calculating the estimates
over -cloglog-?

Or is there another function/package for this situation?

Or would it be better to calculate population attributable hazard
fractions (PAHFs) as described in Samuelsen & Eide (2008)?


Thanks for any help or advice on the subject.

Regards,
Angelo


Ref:
S. O. Samuelsen, G. E. Eide, Statist. Med. 27, 1447 (2008).
http://onlinelibrary.wiley.com/doi/10.1002/sim.3022/abstract
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index