State health officials note on the data webpage that all COVID-19 lab results are able to be reported to the Arizona Department of Health Services. A majority of the results in the data the state updates daily are received through Electronic Laboratory Reporting. All the data on the state dashboard is compiled from the Electronic Laboratory Reporting, according to the ADHS website.
On May 19, the state reported 5.9% of all tests completed in Arizona resulted in a positive test result—that includes both serology and polymerase chain reaction, known as PCR, tests. The state reported 14,597 confirmed COVID-19 cases May 19, and reported 6.9% of all PCR tests yielded a positive result. The PCR test is used to determine if someone is currently infected with COVID-19.
Maricopa County, with more than half of the state's population, has the highest number of tests reported than any other Arizona county, according to ADHS, with 139,509 on May 19.