BALTIMORE – Veterans who screen positive for posttraumatic stress disorder but are not clinically diagnosed with the condition have significantly different presentation from that of clinically diagnosed veterans, Kathryn M. Magruder, Ph.D., reported at the annual meeting of the International Society for Traumatic Stress Studies.
In one of the only two studies that have reported the percentage of veterans correctly diagnosed with PTSD in primary care clinics, Dr. Magruder of the department of psychiatry and behavioral sciences, Medical University of South Carolina, and her colleagues at the Ralph H. Johnson Veterans Affairs Medical Center, both in Charleston, previously found that primary care physicians correctly identified PTSD in 47% of veterans who had the condition (Gen. Hosp. Psychiatry 2005;27:169-79).
The other study, an Israeli national sample of primary care providers, reported a “pretty dismal rate of recognition” of PTSD of only 2% (Psychol. Med. 2001;31:555-60).
Dr. Magruder and her associates wanted to determine why primary care clinicians frequently miss PTSD diagnoses, so they randomly selected 819 primary care patients from four VA medical centers to participate. Of 98 (12%) patients who screened positive for PTSD on the Clinician-Administered PTSD Scale, only 42 (43%) were correctly recognized as having PTSD (defined as an ICD-9 diagnosis of PTSD).
Many researchers have suggested that somatic symptoms, such as pain, might divert the attention of primary care physicians so that they pursue a medical diagnosis rather than a psychiatric one. But previous studies have had conflicting results, with pain symptoms found both to make physicians more apt to miss a psychiatric diagnosis and to increase the likelihood they will make a correct psychiatric diagnosis, Dr. Magruder said.
In this study, veterans aged 65 years and older who tested positive for PTSD on the Clinician-Administered PTSD Scale were significantly more likely to have their PTSD go unrecognized by a primary care clinician (67%, 12 of 18 patients) than to have it diagnosed (33%, 6 of 18). Veterans without war zone service who screened positive also had significantly higher rates of unrecognized PTSD (75%, 21 of 28) than rates of diagnosed PTSD (25%, 7 of 28).
Patients who had worse functioning on the role-emotional subscale of the Short Form-36 quality of life questionnaire were more likely to be recognized as having PTSD. Mental health and pain subscales on the SF-36 did not show significant differences between patients according to their PTSD recognition status.
Patients who had an ICD-9 musculoskeletal pain diagnosis were 3.5 times more likely to be recognized as having PTSD than were those who did not have such a diagnosis, after adjusting for age, race, gender, and war zone service.
In addition, patients with substance use disorders were nearly 10 times more likely to be recognized as having PTSD than were patients without substance use problems.
“This study argues that we really ought to pay better attention to screening results” and that physicians should receive additional training in nonclassic PTSD presentations, Dr. Magruder said at the meeting, which was also sponsored by Boston University.
In the study, “providers may have picked up on more of the obvious presentations of PTSD,” such as poor emotional functioning, persistent reexperiencing, and increased arousal.
One limitation of the study is that the data were collected prior to Operation Enduring Freedom and Operation Iraqi Freedom. The younger group of patients in those conflicts could have “sensitized clinicians to look more closely at presentations in younger patients,” Dr. Magruder suggested.
The study also did not take into account provider-level factors and problems in the scheduling or duration of clinical visits.