Revealed: drug tests in California prisons yielded false positives, affecting thousands of people
Thousands of drug tests used by a major US diagnostic company in California prisons last year are suspected to have generated false positive results, an enormous error that has jeopardized the parole requests of some incarcerated people, according to civil rights lawyers and prison medical records.
California prison officials have known about the issue for months, but have failed to clear people’s records or reverse the consequences people have faced from the tests.
The problem originated with tests conducted by Quest Diagnostics, a company used by healthcare professionals across the country, and the sole firm contracted to do clinical drug screening for the California department of corrections and rehabilitation (CDCR).
From mid-April through July of last year, Quest’s urine opiate drug screenings in CDCR prisons used an “alternative” reagent, the chemical meant to detect drug traces, while the company’s lab faced a backorder of its usual reagent.
The switch resulted in “more presumptive positive results” than registered in tests with its usual chemical, and when Quest restored its original reagent, the positivity rate “returned to its historical average”, according to a letter the firm sent to prison healthcare officials.
UnCommon Law, an Oakland-based non-profit that represents people seeking parole, obtained the letter when one of its clients received it from his provider. UnCommon Law also obtained public records and testing data that it shared with the Guardian.
The letter said the alternative reagent “passed all quality-control metrics” and that the change in performance was only “slightly different”.
But state data, obtained by UnCommon Law, showed the spike in positive tests was substantial.
From January through April, when the normal chemical was being used, the monthly positive opiate rate across CDCR prisons ranged from 6.6% to 6.8% each month, according to the records from California Correctional Health Care Services (CCHCS), the state agency that provides prison medical care. The rate then suddenly rose to 17.1% in May, 20.5% in June and 17.1% in July. The positivity rate returned to 6.8% in August, when the company returned to the original reagent, and stayed in that range for the rest of year.
The state acknowledged the issue in January to the Prison Law Office (PLO), a civil rights firm that monitors CDCR’s medical care, which is under a court-appointed oversight due to longstanding violations. Prison healthcare officials told PLO in a letter they had “generated a list of patients that may have received a false positive result” from Quest.
Alison Hardy, a PLO attorney, said officials sent her office a list of roughly 6,000 individual patients who got positive results under the alternative reagent.
There should be a mandate to go back and review all of the medical records, and whether the lab results had any bearing on parole board decisions
Dr Fred Rottnek
A data analysis by UnCommon Law suggests there could have been more than 5,000 false positives, which could include multiple tests for the same person. The figure is a rough estimate based on the total number of tests from April through July and assuming the positivity rate would’ve stayed consistent if the reagent hadn’t changed.
Dr Fred Rottnek, a family medicine professor and addiction expert at Saint Louis University, who reviewed some of the Quest records for UnCommon Law, said the 300% jump in positivity rates rendered the tests “basically worthless”.
“There should be a mandate to go back and review all of the medical records, and whether the lab results had any bearing on parole board decisions,” said Rottnek, who previously served as the St Louis county jail medical director.