2024 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 case diagnosed in 2021 was first submitted in December 2023). 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. 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).
Since 2015, a new statistical model has been applied to NAACCR data. For the details of the statistical modeling, please refer to the Development of the Delay Model in the website http://www.surveillance.cancer.gov/delay/.
The NAACCR-based factors are stratified by Cancer Site, Registry, Age Group, Race, Ethnicity and Year of Diagnosis. The 2024 delay model produce delay factors using 2023 submission for race and ethnicity combination including All races, White, Black, Hispanics, White Hispanics, Black Hispanics, White non-Hispanics, Black non-Hispanics, API non-Hispanics, and AI/AN non-Hispanics. The ethnicity includes Hispanic and Non-Hispanic.
The factors are linked to 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 2024, we produce delay-adjusted rates for each of these groups and make their results available to the public.
A note on Impact of COVID in 2020
In 2020, we saw a large decrease in case counts likely due to pandemic related disruptions in medical care. However, the delay model calculates the delay factors by conditioning on the count in the first submission and then models the percent change in count in the subsequent submissions. Thus the delay factors will not be impacted by the real drop in the pandemic year.
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 make a request through DaRT.
NAACCR Delay Model Exclusions
Exclusions across all cancer sites to remove obvious aberrant dataIn 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 2023 NAACCR submission, there is a total of 69 US and Canadian registries potentially eligible for delay modeling. Some of these 69 registries are excluded because they have too many combinations of reporting and diagnosis years either missing (not submitted) or did not meet the NAACCR’s “fit for use” criteria.
Additional information about the development of the Delay Model and the Methodology, included reference articles, is available on the SEER Website: Cancer Incidence Rates Adjusted for Reporting Delay
For questions about the delay model, please contact Recinda Sherman, Program Manager of Research and Data Use at [email protected].
