2015 Release of Delay Adjustment Factors and Rates
Timely and accurate calculation of cancer incidence rates is
hampered by reporting delay. Reporting delay is the time elapsed before a
diagnosed cancer case is reported to the cancer registries. For national
reporting, cases are first submitted about two years after the end of a
diagnosis year (e.g., a complete 2012 year of diagnosis was first submitted in
late 2014). In subsequent submissions, the data for that diagnosis year are
updated to reflect: 1) new cases found
to have been diagnosed within that diagnosis year; and 2) new information that
has been received about previously submitted cases.Modeling reporting delay is used to adjust
the current case count to account for anticipated future corrections to the
data.These adjusted counts are needed
to produce cancer incidence trends that are not impacted by late reporting.The adjustment for undercounts is largest in
the most recent diagnosis year reported and diminishes each successive reporting
year.But most recent data points are
considered the most important, because the current data is used for cancer
control and planning activities and is interpreted as a potential harbinger of future
Previously, delay adjustment was available only for a subset
of the SEER registries that had been established in the 1970’s through the
early 1990’s (i.e. the SEER9 and SEER13 registry groups).However, as registries throughout North
America continued to mature, a joint effort by NCI, CDC, and the North American
Association of Central Cancer Registries (NAACCR) was mounted to develop a
unified approach for estimating and reporting delay-adjusted rates across all
of the U.S. and Canada.This new
approach estimates delay factors for each registry, and then combines the
factors from the selected registries to derive delay adjusted rates.For more details on this unified approach see
These new delay adjustment factors and rates are available starting with the
2015 release of data (using the December 2014 NAACCR submission).
The NAACCR-based factors are stratified by Cancer Site,
Registry, Age Group, Sex, Race, and Year of Diagnosis. The factors are linked
to the appropriate cases (based on the stratifications above) in data
submissions for each of the three partners in this joint effort (SEER, NAACCR,
and NPCR).As of 2015, each of these groups
is able to produce delay-adjusted rates using SEER*Stat.
While the eventual goal is to release delay adjustment
factors and rates for individual registries, the goal in this first year of
release is to produce delay adjusted rates for groups of registries (which are
more stable than individual registry estimates). In 2015, NAACCR will release delay adjusted
estimates for the US and Canada, while SEER will release delay adjusted rates
for the SEER9, SEER13, and SEER 18 registry groups.
State-Level Delay Adjustment Factors
states to evaluate their state-specific delay adjustment factors and rates. To
obtain access to the delay adjustment data for your state in SEER*Stat, please
NAACCR Delay Model Exclusions
The delay model was not able to be conducted on every
Registry. States excluded from the model were notified in May 2015. Registries
were excluded from the delay modeling for one of four reasons.
- Decline to participation: A registry chose not to participate in delay modeling;
- 75% Rule: Because of
missing cells for combinations of submission and diagnosis years (either
because they were not submitted or deemed not “fit for use”).For diagnosis years 1997-2012 with
submissions from 1999-2014, a registry could have up to 16 1stsubmissions of data, up to 15 2ndsubmissions of data,… , and up to 4 13th
submissions data. The proportion of
cells with data was computed for the 1st through 13th submissions. If this
calculated average was below 75%, the registry was excluded from consideration.
- Unexpected results: Some
models for a specific registry, race group, or cancer site were difficult to
model across submissions and produced results that did not accurately reflect
the underlying data.This does not mean
that the data were incorrect, but simply that the current models were not
sufficiently flexible to fit some unusual pattern.
- Lacking 2012 diagnosis year data: Some registries were
included in the delay modeling, but do not have 2012 data included in their
Fall. 2014 submission. Therefore, delay adjusted rates for 2012 cannot be
Plenary presentation on this project was presented at the NAACCR Annual Meeting in
Charlotte on Thursday, June 18, 2015 at 10:00 am (Click here for the presentation).
In July 2015, each state included in the model received a state-level assessment of their delay adjustment estimates.
On July 23, 2015 NAACCR hosted a webinar that will outline how to produce rates and trends using delay adjusted data (Click here for the presentation)
information about the development of the Delay Model and the Methodology,
included reference articles,is
available on the SEER Website: http://surveillance.cancer.gov/delay/.
questions about the delay model, please contact Recinda Sherman, Program
Manager of Research and Data Use at email@example.com.