PALM SPRINGS, CALIF. – A single question asked of patients whose pain interferes with their activities may help identify those who also are depressed and rule out those without depression.
Investigators analyzed data on 5,595 participants in the National Epidemiologic Study for Alcohol and Related Conditions (NESARC) who said that pain interfered with their work inside and outside the home "quite a bit" or "extremely" during the past 4 weeks. When asked, "How much of the time during the past 4 weeks have you felt downhearted or depressed?" 33% answered, "None of the time" and 67% responded, "A little," "Some," "Most," or "All of the time."
The answers identified those with comorbid depression with a sensitivity of 84% and a specificity of 43%, Jana M. Mossey, Ph.D. and her associates reported in a poster presentation at the annual meeting of the American Academy of Pain Medicine. The question provided a positive predictive value of 46% and a negative predictive value of 82%, reported Dr. Mossey, professor of epidemiology and biostatistics at Drexel University, Philadelphia.
In other words, a report of recent depressed feelings identified 84% of individuals who had depression currently or within the past 12 months. The strong negative predictive value shows that people who said they hadn’t been downhearted or depressed were highly unlikely to have depression and were unlikely to be underreporting their negative feelings.
The diagnosis of depression was ascertained in the NESARC study by assessing participants using the AUDADIS-IV (Alcohol Use Disorder and Associated Disabilities Interview Schedule IV), a fully structured diagnostic interview to assess mental disorders specified in the DSM-IV. Use of the AUDADIS-IV to identify depressive disorders allowed for an assessment of sensitivity and specificity that rarely is obtained in pain clinics, the investigators noted.
The AUDADIS-IV is as reliable as the Diagnostic Interview Schedule or the World Health Organization Composite International Diagnostic Interview for assessing Axis I disorders, previous studies suggest.
Participants in the NESARC study also were assessed using the 12-item Short Form Health Survey version 2 (SF-12v2), which provided the question about how much they had felt downhearted or depressed in the past 4 weeks (J. Clin. Psychiatry 2005;66:1206-15).
The NESARC study was conducted in a community setting (in individuals’ homes), but Dr. Mossey and her associates restricted their analysis to a sample that was similar to patients seen in pain clinics in terms of the degree to which pain intensity interfered with their activities. Previous studies found that 66% of 15,537 patients in one pain practice and 85% of patients in another pain practice reported that pain interfered with their activities "quite a bit" or "extremely," the investigators noted.
In the current retrospective analysis, the sensitivity, specificity, and negative predictive value of the depression question were similar across subgroups by age, sex, and race. Overall, participants had a mean age of 44 years, 63% were female, 54% were non-Hispanic whites, 24% were black, and 22% were other races.
The sensitivity of the depression question increased as participants’ self-rated health worsened, from a 73% sensitivity in those who reported excellent health to a 94% sensitivity in those who reported poor health. The specificity of the depression question decreased with poorer self-rated health, from a 71% specificity in people reporting excellent health to a specificity of 24% in those reporting poor health.
Although the depression question may provide a quick and easy way to screen for depression in patients with significant activity-limiting pain, its utility is somewhat challenged by a large number of false positives, Dr. Mossey suggested. Among those who reported being downhearted or depressed, 64% had no DSM-IV diagnosis of depressive disorder. More study is needed comparing the true and false positives.
Patients with chronic pain commonly have depression that often goes undetected or undertreated, which can negatively affect patients’ clinical course, coping mechanisms, and chances of recovering from the pain, previous studies have shown.
Dr. Mossey reported having no financial disclosures.