Broader probe urged after hair test error
Woman in custody fight accused of pot abuse when Motherisk delivers false-positive result
Sarah was in the midst of a bitter child custody fight with her ex when she got drug test results she feared could tip the scales in his favour.
With both partners levelling allegations of substance abuse, they agreed last spring to submit hair samples to the Motherisk Laboratory at the Hospital for Sick Children for testing.
“I had zero concerns. Sick Kids is a wellknown, respected hospital,” says the 34year-old health-care worker, who claims she has only an occasional glass of wine, and does not do drugs.
But when she got the results, they indicated she had used marijuana — at a rate, she was told, of at least three to five joints per week — in the previous three months.
“I started almost hyperventilating, because I didn’t know what to do,” says Sarah, whose name has been changed to protect the identity of her young daughter. “I was terrified.”
It would take days of pleading with Motherisk to retest her sample, and nearly a month of waiting for the results, before the lab confirmed in a letter that the analysis was, in fact, incorrect.
“(Sarah’s) hair sample should be considered negative for cannabinoids,” Motherisk manager Joey Gareri wrote in a letter last June. “It is highly likely that the initial positive finding for cannabinoids ... was a false-positive result.”
According to York University’s Innocence Project, the case suggests that the problems at Motherisk may have continued beyond 2010.
Following a Star investigation, the province appointed a retired judge in November to probe the “reliability and adequacy” of five years’ worth of hair drug tests performed by Motherisk and used in child protection and criminal cases, from 2005 to 2010.
In light of Sarah’s story, the Innocence Project is asking the province to expand the scope of the review to include more recent cases, as well as child custody battles that do not involve protection issues.
“In order to have the best and more informed perspectives on (Motherisk’s) problems, it is necessary to look at other instances where they may have made mistakes,” reads a letter sent to Justice Susan Lang last month, signed by all 12 of the project’s law students and law professor Alan Young.
“The case at hand is evidence that these problems have persisted past 2010 and that they have occurred in a variety of currently unexamined contexts.”
The Star started asking questions after an appeal court decision in October cast doubt on the reliability of the screening test used before 2010. At the time, Motherisk’s hair drug test results were routinely accepted without challenge in courts as evidence of parental substance abuse.
The terms of the review were set after the investigation revealed that Motherisk used a screening technique called enzyme-linked immunosorbent assay (ELISA), to test hair for cocaine from at least 2005 to 2010, when the lab said it switched to a gold-standard technique for the drug.
As the Star has reported, the literature in the field of hair testing states that results using a screening method such as the ELISA test must be confirmed using a gold-standard test before being presented in a court of law.
Experts agree that this analysis should be done in a forensic lab, which has more rigorous standards than a clinical lab, such as Motherisk.
In response to questions for this story, the hospital confirmed that Motherisk used the ELISA screening method to test hair for evidence of marijuana use until May 2014.
Sarah’s test was performed a few weeks earlier, on April 16, 2014.
Citing privacy concerns, Sick Kids spokeswoman Gwen Burrows said she could not discuss the case. But she said Motherisk’s switch last year to the new technique, called liquid chromatography tandem-mass spectrometry (LC-MS/MS), “was not prompted by any specific cases.”
Burrows continued to defend the reliability of the ELISA screening technique.
“Based on our proficiency testing history, the test exhibits no evidence of false-positive risk,” Burrows said, adding that retesting is considered “when results are close to detection limits.”
“We cannot be sure that we’re covering everything”
That appears to contradict the letter from Gareri.
Sick Kids and Motherisk “have the utmost respect to the families, their rights and vulnerabilities,” she said. “If the results of a hair test are disputed by the mother, the family or their lawyer, the test is repeated by (Motherisk) and/or by an outside laboratory.”
In Sarah’s case, Gareri said in his letter that after she disputed the findings, Motherisk retested her hair sample on-site, using LC-MS/MS technology, and sent a sample to the United States Drug Testing Laboratories in Illinois, which tested it using gas chromatography-mass spec- trometry (GC-MS), another goldstandard technique. Both of those tests came back negative.
Burrows said Motherisk has performed gold-standard testing on-site since 2010 to analyze hair samples for evidence of opioids (such as heroin), meperidine, methadone, amphetamine, methamphetamine, MDMA and cocaine.
She did not explain why the lab continued using the screening method to test for marijuana use until 2014. But the Innocence Project’s Bethany McKoy said this discrepancy “highlights the urgency” of broadening the scope of the review.
“What it really says is there may be other questions that we haven’t even begun to probe. There may be other areas for review that we haven’t even considered,” said McKoy, a secondyear law student.
“Unless the review shows that sort of flexibility . . . we cannot be sure that we’re covering everything.”
Justice Lang is not giving interviews to media “to preserve her impartiality,” her counsel, Linda Rothstein, said.
Rothstein said Lang does not have the authority to change the terms of the review, which were established through an order of the Ministry of the Attorney General and “can only be expanded through a new order.”
BETHANY MCKOY THE INNOCENCE PROJECT