Case completeness and data accuracy in the Centers for Disease Control and Prevention's National Program of Cancer Registries.

BACKGROUND: Issues of case completeness (CC) and data quality within the National Program of Cancer Registries (NPCR)-Cancer Surveillance System (NPCR-CSS) are assessed in part by the NPCR Technical Assistance and Audit Program (NPCR-TAA). In addition, the NPCR Annual Program Evaluation Instrument (NPCR-APEI) provides information about NPCR-supported central cancer registries (CCRs). The current report includes a unique, national-level analysis of NPCR-TAA results linked with NPCR-APEI data and other covariates.
METHODS: NPCR-TAA results for 34 CCRs were aggregated across diagnosis years 1998 to 2001 for analysis of average CC rates and site-specific data accuracy (DA) rates by covariates obtained from the NPCR-APEI, United States Cancer Statistics (USCS) publications, and the North American Association of Central Cancer Registries (NAACCR) Web site. Site-specific DA rates were calculated for the 13 data elements examined in the audit program. Small-sample Student t tests were used to determine statistically significant differences in covariates (alpha = .05).
RESULTS: Overall, the average CC and DA rates were 96.4% and 95%, respectively. Both site- and data element-specific DA issues were highlighted. Higher CC and DA rates were observed for CCRs that were staffed with more certified tumor registrars, had supplementary sources reporting, and met USCS publication standards and/or achieved NAACCR certification.
CONCLUSIONS: Study findings underscored the importance of CCRs having adequate, well-trained staff, procuring supplemental reporting sources, and attaining compliance with national data standards. The study results also demonstrated the overall high completeness and quality of NPCR-CSS data and provided guidance to users of the data.