Delay Adjustment

Delay Adjustment

2017 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 2014 year of diagnosis was first submitted in late 2016). 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 trends.

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). Starting in 2015, for the first time, delay factors were released based on a joint effort by NCI, CDC, and the North American Association of Central Cancer Registries (NAACCR) to develop a unified approach for estimating and reporting delay-adjusted rates across all of the U.S. and Canada. The delay-adjusted rates for NAACCR registries, including SEER registries reported in the Cancer Statistics Review, is based on the data submitted to the North American Association of Central Cancer Registries (NAACCR).

2017 is the third year that delay factors for NAACCR registries and for SEER are based on NAACCR submission data.  In this year’s release, the statistical model is the same as the one used in the 2016 release of CiNA report with only slight modifications. For the details of the statistical modeling, please refer to the Development of the Delay Model in the website

The NAACCR-based factors are stratified by Cancer Site, Registry, Age Group, Race, Ethnicity and Year of Diagnosis. The 2017 delay model now includes ethnicity and race x ethnicity (race by ethnicity combination).  The races considered are All races, White, Black, API and AI/AN.  The ethnicity includes Hispanic and Non-Hispanic.

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 2017, each of these groups is able to produce delay-adjusted rates and make their results available to the public.


State-Level Delay Adjustment Factors

We encourage 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 contact .


NAACCR Delay Model Exclusions

Exclusions across all cancer sites to remove obvious aberrant data

In order to produce stable estimates, the data are carefully examined before fitting the model. Some data are apparent outliers and are removed (e.g. a single submission with a sudden spike up in cases and then a decline in the next submission). These data are removed because the purpose of delay modeling is to project future counts of cases from the most current submission, and an aberrant submission is not likely to occur in the future.

Registries included in the Analysis

In the analysis of 2016 NAACCR submission, there are 56 US registries and 13 Canadian registries. The 56 US registries include 4 states that are divided into 9 sub-state registries, 46 state registries and District of Columbia. There are 69 registries with US and Canadian registries combined. Totally, 3 US registries and 6 Canadian registries are excluded in the analysis.

Additional information about the development of the Delay Model and the Methodology, included reference articles, is available on the SEER Website:


Additional Information

Plenary presentation on this project was presented at the NAACCR Annual Meeting in Charlotte on Thursday, June 18, 2015 at 10:00 am.

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

Additional information about the development of the Delay Model and the Methodology, included reference articles, is available on the SEER Website:

For questions about the delay model, please contact Recinda Sherman, Program Manager of Research and Data Use at .

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