The SF-36 Offers a Strong Measure of Mental Health Symptoms in Survivors of Acute Respiratory Failure. A Tri-National Analysis.

Abstract

Survivors of acute respiratory failure commonly experience long-term psychological sequelae and impaired quality of life. For researchers interested in general mental health, using multiple condition-specific instruments may be unnecessary and inefficient when using the Medical Outcomes Study Short Form (SF)-36, a recommended outcome measure, may suffice. However, relationships between the SF-36 scores and commonly used measures of psychological symptoms in acute survivors of respiratory failure are unknown. Our objective is to examine the relationship of the SF-36 mental health domain (MH) and mental health component summary (MCS) scores with symptoms of depression, anxiety, and post-traumatic stress disorder (PTSD) evaluated using validated psychological instruments. We conducted a cross-sectional analysis of 1,229 participants at 6- and 12-month follow-up assessment using data from five studies from the United States, the United Kingdom, and Australia. Symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS), Depression Anxiety Stress Scales, the Davidson Trauma Scale, Impact of Event Scale (IES), and IES-Revised (IES-R). At 6-month assessment there were moderate to strong correlations of the SF-36 MH scores with HADS depression and anxiety symptoms (r = -0.74 and -0.79) and with IES-R PTSD symptoms (r = -0.60) in the pooled analyses. Using the normalized population mean of 50 on the SF-36 MH domain score as a cut-off, positive predictive values were 16 and 55% for substantial depression; 20 and 68% for substantial anxiety (Depression Anxiety Stress Scales and HADS, respectively); and 40, 44, and 67% for substantial PTSD symptoms (IES-R, IES, and Davidson Trauma Scale, respectively). Negative predictive values were high. The area under the receiver operating characteristics curve of the SF-36 MH score was high for depression, anxiety, and PTSD symptoms (0.88, 0.91, and 0.84, respectively). All results were consistent for the MCS, across the individual studies, and for the 12-month assessment. For researchers interested in general mental health status, the SF-36 MH or MCS offers a strong measure of psychological symptoms prevalent among survivors of acute respiratory failure. For researchers interested in specific conditions, validated psychological instruments should be considered.