Researchers develop new scale to measure anxiety outcomes

To determine the impact of treatment on any medical disorder, it is necessary to evaluate outcomes. Standardized scales are increasingly recommended as an outcome measurement tool in the treatment of psychiatric disorders. If scales are to be incorporated into clinical practices, it is necessary to develop measures that are feasible and have good psychometric properties. With this in mind, Mark Zimmerman, MD, director of outpatient psychiatry at Rhode Island Hospital, and his colleagues developed the Clinically Useful Anxiety Outcome Scale (CUXOS).

As Zimmerman says, "If the optimal delivery of mental health treatment ultimately depends on examining outcome, then precise, reliable, valid, informative, and user-friendly measurement is critical to evaluating the quality and efficiency of care in clinical practice." He also notes, "Clinicians are already overburdened with paperwork, and adding to this load by requiring repeated detailed evaluations using instruments that are available is unlikely to meet success." The researchers note that only 11 percent of the psychiatrists are routinely using standardized measures to assess outcomes when treating depression or anxiety disorders.

The CUXOS was designed to be brief for patients to complete and then quickly scored by a clinician. In their study, nearly 1,000 psychiatric outpatients completed the CUXOS, which took less than one and a half minutes to complete. Clinicians rated the severity of depression, anxiety, and anger on standardized scales and each CUXOS could be scored in less than 15 seconds.

The researchers also had a subset of patients complete other self-report symptom severity scales in order to examine discriminant and convergent validity. Another subset completed the CUXOS twice in order to examine test-retest reliability. In addition, sensitivity to change was examined in patients with panic disorder and generalized anxiety disorder.

Zimmerman, who is also an associate professor of psychiatry and human behavior at The Warren Alpert Medical School of Brown University, says that the scale was found to have high internal consistency and test-retest reliability. Further, it was more highly correlated with other self-report measures of anxiety than with measures of depression, substance abuse problems, eating disorders and anger. It was also more closely aligned with clinician severity ratings of anxiety than depression and anger, and the CUXOS scores were significantly higher in psychiatric outpatients with anxiety disorders than other psychiatric disorders. Finally, it was found to be a valid measure of symptom change.

Zimmerman says, "We believe that the use of standardized scales should be the standard of care and routinely used to measure outcome when treating psychiatric disorders. Only in this way can we ensure that we are having an impact on our patients."

The researchers also note that there is no shortage of self-report questionnaires, and the development of any new scale should be questioned. They believe, however, that the CUXOS distinguishes itself in several respects and is intended as a general measure of the severity of psychic and somatic anxiety.

"We have developed what we believe to be an effective tool that can easily be incorporated into clinicians' routines. However, future research should explore both clinicians' and patients' perspectives as to whether the use of a general or disorder specific scales is preferred," Zimmerman concludes.

The study was based on work in the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project, for which Zimmerman is the principal investigator. It is a unique integration of research quality diagnostic methods into a community-based outpatient practice affiliated with an academic medical center.

Provided by Lifespan (news : web)