The Short-Form Health Survey (SF-36) can be used to effectively determine the presence of major depressive disorder (MDD) and generalized anxiety disorder (GAD) in patients with rheumatoid arthritis (RA). The use of a threshold of ≤38 on the mental component summary may most optimally screen for the presence of depression or anxiety.
In a study recently published in BMC Musculoskeletal Disorders, Faith Matcham, from the Department of Psychological Medicine at the Institute of Psychiatry, Psychology, and Neuroscience at King’s College in London, United Kingdom, and colleagues conducted an analysis of the SF-36 survey to assess its accuracy in determining probable MDD or GAD in patients with RA.1
High Yield Data Summary
- The SF-36 is an effective screening tool for MDD and GAD in patients with RA
- An MCS cut-off point of 38 was associated with a sensitivity of 87.5% and a specificity of 80.3%, correctly identifying 82.8% of patients with RA with either MDD or GAD (likelihood ratio 4.4)
“The SF-36 has been extensively validated as a measure of QoL [quality of life] in multiple populations and is the most widely used and evaluated QoL outcome measure,” the authors explained. “The SF-36 consists of 8 domains, which assess physical function, role physical, bodily pain, global health, vitality, social function, role emotional and mental health.”
The researchers collected SF-36 data from 100 patients with RA, treated as outpatients. They compared mental health subscale and mental component summary scores with validated depression and anxiety data. In addition, scientists compared SF-36 components with the Patient Health Questionnaire (PHQ-9) used for the “screening, diagnosing, monitoring and measuring the severity of depression,” and the GAD-7 questionnaire.2, 3
The results showed that a mental health subscale with a threshold ≤52 had 81.0% sensitivity and 71.4% specificity in detecting anxiety, and correctly classified 73.5% of patients with probable GAD.
A threshold ≤56 had 92.6% sensitivity and 73.2% specificity to detect depression, and correctly classified 78.6% of patients. Depression or anxiety could also be detected using this threshold, with 87.9% sensitivity, 76.9% specificity, and 80.6% accuracy.
When researchers analyzed the mental component scores, they found that a threshold ≤35 had 85.7% sensitivity and 81.9% specificity in detecting anxiety, and correctly classified 82.8% of patients with probable GAD. A threshold ≤40 had 92.3% sensitivity and 70.2% specificity in detecting depression, thus adequately categorizing 76.3% of patients.
Finally, the researchers noted that depression or anxiety could be detected using a mental component score with a threshold ≤38 with 87.5% sensitivity, 80.3% specificity, and 82.8% accuracy.
Summary and Clinical Applicability
The analysis found that the SF-36 survey was an effective diagnostic tool for MDD and GAD in patients with RA. Utilizing a threshold of ≤38 on the mental component summary appears to most accurately identify patients with psychological disease comorbidity.
“The addition of regular [quality of life hazard ratio] HRQoL measurement to routine RA clinical care would be beneficial, as QoL is a key outcome of importance to patients, and doing so would also support the need for embedded mental health care within rheumatological management practice,” the authors concluded.
Limitations and Disclosures
- The researchers noted that there was a lack of a “gold-standard” measure of depression to validate the SF-36 domains, as the participants were not diagnosed by a psychologist or psychiatrist.
- Patients who were unable to give consent because of learning disabilities or dementia were not included in the study, which excluded many older patients with higher levels of pain or disability.
- Matcham F, Norton S, Steer S, Hotopf M. Usefulness of the SF-36 Health Survey in screening for depressive and anxiety disorders in rheumatoid arthritis. BMC Musculoskelet Disord. 2016;17(1):224.
- The Patient Health Questionnaire (PHQ-9). Available at: http://www.cqaimh.org/pdf/tool_phq9.pdf. Accessed on August 1, 2016.
- Generalized Anxiety Disorder 7-item (GAD-7) scale. Available at: http://www.integration.samhsa.gov/clinical-practice/GAD708.19.08Cartwright.pdf. Accessed on August 1, 2016.
This article originally appeared on Psychiatry Advisor