BACKGROUND: Reportable disease surveillance permits local public health agencies (LPHAs) to confirm cases through laboratory and provider reporting. When disease rates change it may be due to an outbreak or more comprehensive screening practices. Without complementary screening data, LPHAs cannot differentiate between increased incident cases or improved screening practices. Electronic health record (EHR) data have the potential to assess screening test frequency and unique individuals screened, within a jurisdiction. This study compared recent trends in gonorrhea and influenza screening with gonorrhea cases and influenza-associated hospitalization (IAH) events for Denver County residents who visited Denver Health hospital to assess if increased screening was associated with increased confirmed cases.
METHODS: Denver Health EHR data from 2011 to 2015 identified gonorrhea and influenza screening tests (regardless of laboratory outcome) performed for Denver County patients. For gonorrhea, a current procedural terminology (CPT) code of 87591 identified patients for gonorrhea screening; for influenza, patients with CPT codes of 86710, 87252, 87254, 87663, or 87804 were included (influenza-specific, and respiratory or viral panel screening tests included). The Colorado Department of Public Health and Environment provided gonorrhea case and IAH event counts for Denver County, as both are reportable in Colorado.
RESULTS: Between 2011 and 2015, gonorrhea cases and IAH events increased significantly. Gonorrhea cases increased 74%, from 875 in 2011 to 1,526 in 2015, while the rate per 100,000 increased 57% from 141 to 224; IAH events increased 81% from 151 to 273 with a peak of 535 in 2014. Gonorrhea screenings increased by 12%, from 27,911 in 2011 to 31,323 in 2015; Denver County residents screened for gonorrhea at Denver Health increased by 10%, with an average of 1.3 screens per patient. Influenza screening increased from 634 to 1,705 (169%), with most patients being screened only once. Unique patients screened for influenza was highest in 2015 (1,506 individuals).
CONCLUSIONS: Reported gonorrhea cases increased from 2011 to 2015, at a rate that outpaced increased gonorrhea screening; increased screening alone was unlikely to have driven overall increases in cases reporting. Reported IAH events increased at a rate less than influenza screening. While increased screenings may explain some increased reporting, there was no clear link for increased reports for either condition. EHR data were useful in providing complementary epidemiologic information to support LPHA disease control efforts.