cohort and period approaches...hybrid analysis (brenner & rachet, eur j cancer 2004) model based...

1/27/2014

Cohort and Period Approaches

Hermann Brenner

Division of Clinical Epidemiology and Aging ResearchDivision of Clinical Epidemiology and Aging Research

German Cancer Research Center, Heidelberg

Period approaches - brief history (1)

• Introduced in 1996 (Brenner & Gefeller, Cancer 1996)

• Aim: More up-to-date survival estimates

• Ignored / boycotted for several years

• Comprehensive empirical evaluations

Hermann Brenner, German Cancer Research Center23.1.2014

• Comprehensive empirical evaluations

(e.g. Brenner & Hakulinen, IJE 2002, JCO 2002; Talbäck et al , EJC 2004)

• User friendly computer programs

(e.g. SAS, Brenner , Hakulinen & Gefeller, Epidemiology 2002

Stata

SEER Stat

R, Holleczek, Gondos & Brenner, Meth Inform Med 2009)

Period approaches - brief history (2)

• Extensions

Hybrid analysis (Brenner & Rachet, Eur J Cancer 2004)

Model based period analysis

Hermann Brenner, German Cancer Research Center23.1.2014

(Brenner & Hakulinen AJE 2006, CEBP 2007 etc)

• Increasing application

including EUROCARE, SEER etc.

Principle of period versus cohort approaches

Cohort

Hermann Brenner, German Cancer Research Center23.1.2014

Period

Complete

Example of period versus cohort approaches

ACCIS Project, Childhood Cancer Survival in Europe

period

cohort

period

cohort

Hermann Brenner, German Cancer Research Center23.1.2014

Brenner et al, Ann Oncol 2007

Emprirical evaluation of period versus cohort approaches

Observed

Cohort

Hermann Brenner, German Cancer Research Center23.1.2014

Observed

Period

Emprirical evaluation of period versus cohort analysis (Finland 1983-87)

Cohort

Period

Observed

Hermann Brenner, German Cancer Research Center23.1.2014

Brenner & Hakulinen, JCO 2002

PeriodCohort

Observed

Emprirical evaluation of period versus cohort analysis (Finland 1963-97)

Period Cohort

Hermann Brenner, German Cancer Research Center23.1.2014

Brenner & Hakulinen, AJE 2002

Period Cohort

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

1997

1998

1999

2000

Follow-up

Dx

Beyond standard period analysis

Hermann Brenner, German Cancer Research Center23.1.2014

2001

2002

2003

2004

2005

2006

,

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

1997

1998

1999

2000

Follow-up

Dx

Model-based period analysis

=> precision, trends, tests, covariates, projections

Hermann Brenner, German Cancer Research Center23.1.2014

2001

2002

2003

2004

2005

2006

Brenner & Hakulinen, AJE 2006

Example for projections: multiple myeloma, USA

Hermann Brenner, German Cancer Research Center23.1.2014

Example for projections: multiple myeloma, USA

Hermann Brenner, German Cancer Research Center23.1.2014

Pulte et al, Haematologica 2009

Some practical issues: Cohort versus period modeling ?

DX 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

1997

1998

1999

2000

2001

Follow-up

Hermann Brenner, German Cancer Research Center23.1.2014

2001

2002

2003

2004

2005

2006

Brenner & Hakulinen IJC 2007: Period modeling mostly superior

Some practical issues: analyses of time trends

Avoid combinations of cohort and period analyses

Hermann Brenner, German Cancer Research Center23.1.2014

Some practical issues: analyses of time trends

Show period trends instead

Hermann Brenner, German Cancer Research Center23.1.2014

What to do if incidence is less up-to-date than mortality follow-up?

„Truncated period analysis“ ?

Hermann Brenner, German Cancer Research Center23.1.2014

What to do if incidence is less up-to-date than mortality follow-up?

Less up-to-date period analysis ?

Hermann Brenner, German Cancer Research Center23.1.2014

What to do if incidence is less up-to-date than mortality follow-up?

Hybrid analysis !

Hermann Brenner, German Cancer Research Center23.1.2014

Brenner & Rachet EJC 2004, Brenner & Hakulinen, EJC 2007

Full

Period

estimate

Some practical issues:

Which study population to describe for period analyses („Table 1“)?

Hermann Brenner, German Cancer Research Center23.1.2014

Full

Restricted

Length offollow-up

Length of period

2-year period 5-year period 10-year period

5-year RS Full Full Full

Some further practical issues:

Which study population to describe for period analyses („Table 1“)?

Empirical evaluation, Finnish Cancer Registry, Summary results

Hermann Brenner, German Cancer Research Center23.1.2014

5-year RS Full Full Full

10-year RS Full Full Restricted. Full Restricted

15-year RS Full

20-year RS Full

Jansen, Hakulinen & Brenner, Br J Cancer 2013

Full

Period

estimate

Some practical issues (yet to be clarified):

Which DCO proportions are relevant for period analysis?

Hermann Brenner, German Cancer Research Center23.1.2014

Full

Restricted

Hermann Brenner, German Cancer Research Center23.1.2014

Thank you for your attention!