Nancy A. Melville

April 12, 2017

SAN FRANCISCO – Adherence to treatment for posttraumatic stress disorder (PTSD) may largely depend on giving patients a choice in the type of treatment they receive, new research shows.

In a randomized trial, the dropout rate for PTSD patients who did not have a choice of therapy was three times higher than that for patients who had "bought in" to their treatment choice.

In addition, other factors that are commonly thought to compromise treatment adherence, such as severity of trauma history, were found to be associated with greater adherence.

"The findings suggest that we need to be thinking more about what to do about treatment preference," said investigator Norah C. Feeny, PhD, of Case Western University in Cleveland, Ohio.

"We need to be asking patients up front about what their preference is. We need to be more engaging in an ongoing discussion about the rationale of treatment options and focus on treatment buy-in."

The study was presented here at the Anxiety and Depression Association of America (ADAA) Conference 2017.

High Dropout Rate

Dropout rates for PTSD treatment can range from an estimated 18% for psychotherapy to as high as 30% for pharmacotherapy. The key factors placing patients at the greatest risk for dropout or failure to adhere to treatment are unclear.

The double-blind, randomized trial included 200 men and women aged 18 to 65 years with chronic PTSD. The cohort was divided into those who could choose their treatment and those who were not given a choice. The study population was 75.5% female and 65.5% white.

Those given a choice of therapy could choose between prolonged exposure therapy or treatment with the selective serotonin reuptake inhibitor sertraline (Zoloft, Pfizer). Those who did not have the option to choose were randomly allocated to receive one of the two treatments.

In all groups, treatment duration was up to 10 weeks. The sertraline group received a flexible dosing schedule of 25 mg to 200 mg. The prolonged exposure therapy group received 10 weekly sessions, with each session lasting 90 to 120 minutes.

The authors considered an extensive range of factors that could be predictive of dropout. Those factors were divided into four clusters: demographics, baseline pathology, trauma-related factors, and treatment-related factors.

Dropout was defined as receiving six or fewer sessions. The results showed that 66 patients dropped out; the strongest predictors were receiving a nonpreferred treatment (odds ratio [OR], 3.14; P = .001) and being African American (OR, 2.21; P = .03).

There were no significant differences in dropout rates between the groups receiving either prolonged exposure therapy or sertraline.

A total of 134 patients completed treatment. Among those who completed treatment, baseline trauma severity was a strong predictor of better adherence, which reflected their stronger desire for help, Dr Feeny said.

"You can imagine these are people with lots of symptoms who may be more motivated," she said.

"If your symptoms are more impairing, they're getting in the way of work and your relationships, and you are going to be more motivated to do treatment that's going to require more of you."

The finding that failure to receive the preferred treatment was a key predictor of dropout underscores the need for better discussion of options with patients, Dr Feeny said.

She added that the higher risk for dropout among African Americans is consistent with emerging literature regarding both civilian patients and combat veterans and suggests greater mistrust of mental health services among African Americans.

"A focus on treatment early on may be especially important for these patients," she said.

The study is the first large randomized controlled trial to compare the effectiveness of prolonged exposure therapy to pharmacologic therapy with respect to adherence to PTSD treatment.

Although the study included a large, diverse, and clinically complex sample, much larger sample sizes are needed to better understand the bigger picture, Dr Feeny underscored.

"If we really want to understand who adheres to treatment and who is at risk for dropout, we need to think about doing mega-analyses and pulling data sets across groups," she emphasized.

"So, while our study is well powered, we should start looking at those broader datasets."

Choice a Key Determinant of Success

Commenting on the findings, Brian P. Marx, PhD, of the VA National Center for PTSD and Boston University School of Medicine, in Massachusetts, noted that the study helps inform which patients are at risk of dropping out of therapy.

"Definitions matter here," he said. "Across studies, one of the problems we face in the literature is defining dropout and attrition, which can vary from study to study.

"There are questions, for instance, of whether we start tracking people before we randomize or after and how many sessions are necessary before a patient is considered a treatment dropout."

The findings of higher risk among people who do not receive a preferred therapy underscores the influence of patient expectations on the success of that treatment approach, he noted.

"Expectation can be a key factor in why treatments work, and it's clearly important to think about how we can alter people's expectations about the treatments they're receiving," he said.

The authors and Dr Marx have disclosed no relevant financial relationships.

Anxiety and Depression Association of America (ADAA) Conference 2017. Abstract 315R, presented April 8, 2017.


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