South African National Cancer Registry: Effect of withheld data from private health systems on cancer incidence estimates.

BACKGROUND

The National Cancer Registry (NCR) was established as a pathology-based cancer reporting system. From 2005 to 2007, private health laboratories withheld cancer reports owing to concerns regarding voluntary sharing of patient data.

OBJECTIVES

To estimate the impact of under-reported cancer data from private health laboratories.

METHODS

A linear regression analysis was conducted to project expected cancer cases for 2005-2007. Differences between actual and projected figures were calculated to estimate percentage under-reporting.

RESULTS

The projected NCR case total varied from 53,407 (3.8% net increase from actual cases reported) in 2005 to 54,823 (3.7% net increase) in 2007. The projected number of reported cases from private laboratories in 2005 was 26,359 (19.7% net increase from actual cases reported), 27,012 (18.8% net increase) in 2006 and 27,666 (28.4% net increase) in 2007.

CONCLUSION

While private healthcare reporting decreased by 28% from 2005 to 2007, this represented a minimal impact on overall cancer reporting (net decrease of <4%).