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Led by University of Toronto professor Khosrow Adeli, a team of researchers at The Hospital for Sick Children has developed a comprehensive database that will directly contribute to improved assessment of Canadian children and youth with medical concerns.

Through the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) Project, the researchers invited healthy children and teens of varying ages, genders and ethnicities to submit blood samples. Nearly 2,200 participants provided blood samples and information that the researchers used to determine “normal” values for 40 serum biochemical markers -- substances that can be detected in blood, urine or other bodily fluids and reveal diseases or abnormalities.

“Age, gender and ethnicity can profoundly influence levels of biochemical markers,” said Dr. Adeli, who is cross-appointed to U of T's Departments of Laboratory Medicine and Pathobiology, and Biochemistry at the University of Toronto. “We hope this new database of healthy Canadian children and youth will help improve diagnosis and treatment for a variety of medical conditions.”

When a child undergoes blood tests to diagnose a specific medical condition, physicians, laboratory specialists and the family have one shared goal: to obtain accurate test results. If the test results indicate problems, the clinical team can then determine the best treatment options and provide the necessary care.

Since treatment can depend upon lab test results—and treatment efficacy is also usually monitored by doing these tests—accurate analysis of these results is critically important.” said Adeli, who is also head of the Division of Clinical Biochemistry and senior associate scientist at SickKids.

The ability of lab specialists to interpret the results accurately is dependent upon several important factors, including the availability of accurate reference values, which provide the “normal” result for a healthy child in the general population.

The new database of 40 biochemical markers is now available to hospitals and pediatricians, and will soon be available to the general public online. The researchers reported their development of the database in a recent online paper in the journal Clinical Chemistry.

These crucial reference values have existed in Canada, but until now, these numbers have had significant demographic gaps, experts say. Much of the current data is outdated and includes some reference values that were obtained in the 1980s, when the technology was not as advanced as it is today.

In addition, there has been a need to obtain a more accurate representation of the current population of children in Canada, including children of all pediatric age groups (birth to 18 years), both genders, and a variety of ethnicities that make up the multicultural Canadian population. These often previously-overlooked factors can affect the interpretation of test results.

While similar databases exist in the adult population, obtaining sufficient data from a general population of children is much more challenging. This is due to the significant differences between children at different ages, Adeli explained. For example, a two-year-old would not have the same results as a 10-year-old or a 17-year-old.

“Kids are constantly growing and changing,” said Adeli. “These differences are now documented in a more comprehensive way, which is a major step toward filling the gaps that exist in this area.”

Next steps in this research will include testing study participants for an additional 30 biochemical markers. The scientists will then use transference studies to run tests on different equipment in various hospitals across the country. This would account for any variations between hospitals and help ensure consistent results, regardless of the patient’s geographic location. Moving forward, the database is expected to be updated once every decade to account for technological and population changes.

In addition to SickKids, six other Canadian hospitals from coast to coast are collaborating on the CALIPER Project: Eastern Health/Janeway Children’s Health & Rehabilitation Centre, CHU Sainte-Justine, Children’s Hospital of Eastern Ontario, McMaster Children’s Hospital, Royal University Hospital and B.C. Children’s Hospital.

For more information about the CALIPER Project, or to participate, visit .

The study was supported by the Canadian Institutes of Health Research, Abbott Diagnostics and SickKids Foundation.