abstract - Cancer Epidemiology
Background
Ascertaining
incident cancers
is a critical component of cancer-focused epidemiologic cohorts and of
cancer prevention trials. Potential methods: for cancer case
ascertainment include active follow-up and passive linkage with state
cancer registries. Here we compare the two approaches in a large cancer
screening trial.
Methods
The
Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial
enrolled 154,955 subjects at ten U.S. centers and followed them for
all-cancer incidence. Cancers were ascertained by an active follow-up
process involving annual questionnaires, retrieval of records and
medical record abstracting to ascertain and confirm cancers. For a
subset of centers, linkage with state cancer registries was also
performed. We assessed the agreement of the two methods in ascertaining
incident cancers from 1993 to 2009 in 80,083 subjects from six PLCO
centers where cancers were ascertained both by active follow-up and
through linkages with 14 state registries.
Results
The
ratio (times 100) of confirmed cases ascertained by registry linkage
compared to active follow-up was 96.4 (95% CI: 95.1–98.2). Of cancers
ascertained by either method, 86.6% and 83.5% were identified by active
follow-up and by registry linkage, respectively. Of cancers missed by
active follow-up, 30% were after subjects were lost to follow-up and 16%
were reported but could not be confirmed. Of cancers missed by the
registries, 27% were not sent to the state registry of the subject’s
current address at the time of linkage.
Conclusion
Linkage
with state registries identified a similar number of cancers as active
follow-up and can be a cost-effective method to ascertain incident
cancers in a large cohort.
0 comments :
Post a Comment
Your comments?
Note: Only a member of this blog may post a comment.