Development of the Delay Model

Historically, statistical models that estimate "reporting delay" for cancer incidence rates were developed for both the SEER 9 registries and the SEER 13 registries. The delay-adjusted rates produced by these models have been reported by NCI in the SEER Cancer Statistics Review since 2003.

Starting from the 2015 release, for the first time, the delay-adjusted rates reported in Cancer Statistics Review were based on the data submitted to the North American Association of Central Cancer Registries (NAACCR). NAACCR is a registry member organization that includes registries in SEER and registries for the remainder of the US funded by the Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR) (some registries are co-funded by both NCI and CDC), and some Canadian registries. Annual cancer incidence and survival data are reported by US registries to SEER and NPCR, while registries throughout the US and Canada report annually to NAACCR. It was a coordinated effort by NCI, NPCR and NAACCR to expand delay modeling to registries throughout the US and Canada.

Unified Effort to Estimate Delay Adjustment Factors for All NAACCR Registries

Instead of developing delay-adjusted rates separately, a coordinated effort by NCI, CDC, and NAACCR has led to a unified approach to estimate and report delay-adjusted rates. A joint NAACCR, SEER, NPCR delay model workgroup was formed. The goals of this joint effort are as follows:

  1. Produce delay factors (and standard errors) for every (or almost every) US and Canadian registry. Registries may be excluded if they do not meet criteria established for this analysis.
  2. Ensure that the factors can be combined across registries to allow the calculation of delay-adjusted incidence rates and standard errors for any registry combination. This will be accomplished by making the delay-adjusted rates available in SEER*Stat.
  3. Establish methodology that accounts for the varying first submission years of registries and potential holes in the registry data.

In 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. With too many missing cells, the model parameters are not estimable or may be unstable. The 69 registries are comprised of 15 SEER-funded (including those NPCR co-funded, i.e., Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland/San Jose-Monterey, Seattle-Puget Sound, Utah, Los Angeles, Greater California (without Los Angeles and San Francisco-Oakland/San Jose- Monterey), Kentucky, Louisiana, New Jersey, Georgia (without Atlanta), 41 solely NPCR-funded, and 13 Canadian registries.

The 2019 Release of Delay Adjustment Factors and Rates

Delay adjustment factors have been produced from the December 2018 NAACCR submission. The NAACCR-based factors are stratified by:

  • Cancer Site
  • Registry
  • Age Group
  • Race
  • Ethnicity
  • 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 2019, each of these groups is able to produce delay-adjusted rates and make their results available to the public.

A SEER*Stat file with these registry specific factors can be requested as a SEER Specialized Dataset. In the general SEER research data set, these factors are provided but only for SEER 9, SEER 13, and SEER 18.