Risk score combination more accurately predicts suicidal behavior

Adding Suicide Cognitions Scale questions to the commonly used Public Health Questionnaire-9 improved the accuracy of suicide risk screening in primary care clinics, data show.

From 1999 to 2017, the suicide rate in the U.S. increased more than 33%, according to Craig J. Bryan, PsyD, ABPP, a board-certified clinical psychologist at The Ohio State University Wexner Medical Center, and colleagues. Suicide rates have increased “at an even faster rate” among military members and veterans, they wrote.

Almost half of people who die by suicide had visited a primary care office in the months immediately before their death, the researchers noted.

“Existing methods for suicide risk screening, which focus on asking about suicidal ideation and/or planning, has very low specificity. As a result, screening in primary care results in very high false positive rates,” Bryan told Healio Primary Care. “This can result in misallocation of limited resources and, for many patients, costly and potentially unnecessary intervention and treatment. Improving the accuracy of suicide risk screening by reducing false positives could therefore improve care for patients who report suicidal ideation.”

Bryan and colleagues conducted a study to investigate potential strategies for improving suicide risk screening. The analysis included 2,744 patients from six military primary care clinics within the U.S. Department of Defense health system. The mean age of the patients was 40.4 years, about half were men and about two-thirds were white. All patients filled out the Public Health Questionnaire-9 (PHQ-9) and 16 items from the Suicide Cognitions Scale (SCS) during a routine primary care clinic visit.

The findings, published in Annals of Family Medicine, showed that 0.5% of patients engaged in suicidal behavior in the 30 days after screening and 1% showed suicidal behavior in the 90 days after screening.

The researchers reported that the addition of one or more SCS items to the PHQ-9 significantly enhanced screening. All 16 SCS items lowered the number of false-positive results, according to Bryan. However, the two items that assessed patients’ level of agreement with the statements “It is unbearable when I get this upset,” and “I can’t imagine anyone being able to withstand this kind of pain,” were considered “the best because they significantly improved accuracy without increasing the number of false negatives,” Bryan said.

Although previous tests have indicated the SCS is “a very good indicator of suicide risk,” the researchers were still “surprised that even a single item from the SCS could improve accuracy by such a large degree,” Bryan said.

“The primary conclusion of the study is that adding one or two items from the SCS can help clinicians to better identify the subset of patients who are most likely to attempt suicide after screening positive on a commonly used screening tool,” he said. “The results could therefore help clinicians to better triage their patients who screen positive for suicide risk.”