I've heard of patients feeling anxious before undergoing a colonoscopy, while receiving a flu shot, or while having blood drawn for a bog-standard CBC or sed-rate.

But it turns out there's a large pool of patients who are anxious about the stuff they might learn from a genetic test.

So in Canada researchers have taken to dealing with pre-genetic-testing anxieties on a clinical level by developing a screening tool to identify individuals who may need additional post-test counseling.

It's no secret that some people might be anxious about finding they carry a gene that makes them more likely to develop diseases like Alzheimer's disease — there's no cure for it — or that they are BRCA-positive and must consider draconian prophylactic procedures.

The Canadian researchers, from the Toronto General Research Institute at the University Health Network, and the de Souza Institute in Toronto claim they have developed a genetic-testing "psychosocial risk screening tool" that they are now "refining the reliability and validity of it in populations of patients undergoing genetic testing."

According to Mary Jane Esplen, a nurse in the de Souza Institute, between 10 percent and 25 percent of patients "experience anxiety disorder or depression after receiving unwelcome genetic testing results," and between 4 percent and 15 percent "meet the criteria for stress response syndrome."

"Results [of genetic tests] may also lead to stigmatization and an increased sense of isolation," she said during her presentation, according to an article appearing yesterday in MedScape Today. "By contrast, results that are negative may cause survivor guilt and, potentially, isolation from other family members. In addition, an ambiguous result may lead to ongoing anxiety and a sense of risk and vulnerability."

The Canadians' tool aims "to assist clinicians working in the field of genetics to 'screen' or identify those who would potentially benefit from added psychosocial resources," Esplen was quoted as saying. "This would include patients who might have coping or adaptation challenges or difficulties adjusting to or processing risk and genetic information."

"We hope this will assist in targeting those who require added resources, for example extra follow-up appointments, follow-up calls, support group attendance, or additional psychological counseling," she added.

According to the article, the researchers evaluated the tool, called GPRS, "in individuals going through genetic testing (at the pretest stage or awaiting test results) at participating genetic clinic sites."

The GPRS — MedScape calls it an "instrument" — was originally developed to include 56 "measures" taken published literature, and was eventually "refined with focus groups of providers and with input from patients undergoing testing."

The Canadian researchers are currently validating the GPRS in 800 patients undergoing testing for Huntington's disease, hemochromatosis, and "various cancers," according to the article. "The GPRS was administered at baseline (prior to test results) and 1 month after test results were given to patients."

Based on the results of the study, patients will be classified "according to level of risk for psychological distress, and guidelines for identifying and managing risk for distress will be developed."

According to Bettina Meiser, a researcher from the School of Psychiatry at the University of New South Wales, in Sydney, Australia, who specializes in studying the psychological impact of genetic testing, the GPRS "will fill a gap and will be a very useful clinical tool for genetics practitioners."

"Although a lot of empirical evidence has become available on the impact of genetic testing, to my knowledge, no screening tools have been developed and validated for use in the clinical setting specifically in the context of genetic testing," she was quoted as saying. "Those that exist have not been rigorously validated."