One of the uses of this secondary blog will be for me to use tools developed in greater detail at one of my primary blogs at PLOS Mind the Brain or Science Based Medicine to provide brief critiques of other studies. In this post, I will offer a critique of a recent paper in the high impact Journal of the National Cancer Institute (JIF = 13.7, among the top 3% for oncology journals) elaborating on my recent post at PLOS Mind the Brain, Cancer as a Psychological Trauma.
An author of the study in question was quoted in media coverage as claiming
“If we can identify potential risk factors for PTSD, when women are diagnosed with breast cancer, we could provide early prevention and intervention to minimize PTSD symptoms. This approach might also have an indirect impact on the observed racial disparity in breast cancer survival.”
The abstract for the article can be found here and you probably can get a PDF by writing directly to the first author at firstname.lastname@example.org The article represents yet another example of misapplying the concept of trauma to understanding the experience of cancer patients and addressing their unmet needs. The article exhibits misunderstandings of posttraumatic stress disorder (PTSD) and the limits of self-report questionnaires to assess it and perpetuates some common misunderstanding in the literature.
The investigators recruited 1139 women with newly diagnosed breast cancer, stages I to III, from 3 sites in the United States. The women were interviewed by telephone 3 times: baseline at about 2 to 3 months after diagnosis, 4 months after diagnosis, and then 6 months after diagnosis. The key measure of ”traumatic stress” was the Impact of Events Scale.
The basic findings
- Of the 1139 participants, 262 (23.0%) had “PTSD” at the baseline time point, but this dropped to 183 (16.5%) and 136 (12.6%), at the second and third time points.
- Among the participants, 247 (21.5%) responded moderately or greater to one or more single items on the IES at baseline. At the first time point, 192 (16.8%) women responded moderately or greater to at least one item on the IES; At the second time point, 177 (15.5%).
- High levels of PTSD were associated with being younger, African-American or Asian Asian.
The abstract concludes
“Nearly one-quarter of women newly diagnosed with breast cancer reported symptoms consistent with PTSD shortly after diagnosis, with increased risk among black and Asian women. Early identification of PTSD may present an opportunity to provide interventions to manage symptoms.“
What is wrong with this conclusion? I’m going to be very critical of the authors’ reliance on a self-report questionnaire and their absence of evidence of critical thinking. You can examine a copy of the questionnaire they used here, and using my previous blog post, readily get a grasp of how wildly inappropriate the authors’ inferences are.
- The rates of PTSD that the authors claim are much higher than what is found in studies using validated semi structured interviews. Note that the patients are newly diagnosed with breast cancer and as a group, they have good prognosis, with most early stage.
- From other studies we know that rates of PTSD among cancer patients overlap considerably with rates found in interview-based studies of community residing women.
- As for the association with race, IES scores are more associated with women being younger and they are coming particular hospitals. Overall the association with race is weak.
- This study relied exclusively on the Impact of Events Scale, which is a widely used off-the-shelf questionnaire for studying “PTSD symptoms” in cancer patients, but it is particularly inappropriate and leads to inflated estimates of PTSD symptoms.
- The IES is better seen as a measure of general psychological distress, rather than “PTSD symptoms.”
- The IES does not provide a diagnosis of PTSD and misses some of the key symptoms involved in making a diagnosis. As I note in my earlier blog
- The IES was not originally constructed to diagnose PTSD and it misses some constellations of symptoms contributing to a diagnosis. It misses hyperarousal symptoms altogether and does not cover some avoidance or intrusion symptoms.
- The IES does not provide an assessment of whether patients actually considered the breast cancer experience to be “traumatic” in the sense of inspiring them with intense fear, helplessness or horror.
- To put the authors’ results in a larger context, we could compare them to what was obtained when college students were asked to fill out the IES with respect a recent TV program that they watched that they detested. The scores of the college students were overlapping with the range of scores obtained from the sample of breast cancer patients
- Scores on the IES are more related to other measures of general distress and even to patients having low income and minority status than to a clinical diagnosis of PTSD.
- What the questionnaires seem to be registering is some general distress that is relatively transient for most breast cancer patients in comparable to what is found among patients recruited from primary care waiting rooms who are not suffering from breast cancer.
- It’s improbable that these investigators are uncovering “PTSD symptoms” because if they were, the symptoms would be more chronic and debilitating, rather than rapidly declining from one assessment to the next.
If we took the authors serious in the claim that their high rates of “PTSD symptoms” among blacks and Asians, then the appropriate evidence-based intervention would be to provide them with exposure therapy or cognitive reprocessing therapy. Is no evidence that these women would want the specialized mental health interventions or that they would benefit from them.
Important health disparities associated with race and social economic status should be addressed. But little is accomplished by construing those health disparities as a mental health issue. The larger strategy for addressing health disparities should be establishing equitable access to acceptable and affordable healthcare. Short term strategies for helping these women involve providing practical assistance and better information about available resources. Construing the health disparities in the framework of cancer as a a psychological trauma just confuses the issue and misdirect resources.
You can find more studies of cancer and PTSD by putting these words in the search box at Google Scholar. Do a search and see how pervasive the trauma framework is in misunderstanding the experience of cancer. But see also how dramatic claims make it into high impact journals and get media coverage.
Signs of hype: claims of high rates of PTSD, reliance on self-report questionnaires, failure to assess whether cancer patients actually consider their experience to be traumatic, recommendations that interventions be guided by a notion of cancer being traumatic or of patients having high rates of PTSD.