Background: Aggregation of spatial data is intended to protect privacy, but some effects of aggregation on spatial methods have not yet been quantified. Methods: We generated 3,000 spatial data sets and evaluated power of detection at 12 different levels of aggregation using the spatial scan statistic implemented in SaTScan v6.0. Results: Power to detect clusters decreased from nearly 100% when using exact locations to roughly 40% at the coarsest level of spatial resolution. Conclusion: Aggregation has the potential for obfuscation.
