by David Mahony, PhD, ABPP
Dr. Mahony is a clinical psychologist from Lutheran Medical Center, Brooklyn, New York
Funding: There was no funding for the development of this article.
Financial Disclosures: The author reports no conflicts of interest relevant to the content of this article.
Bariatric Times. 2010;7(9):18–20
Bariatric surgery candidates are required to receive psychological clearance before they are eligible for surgery. In spite of this requirement, little is known about psychosocial complications, and even less is known about predicting complications. Psychologists have little empirical evidence for guidance and have resorted to using a wide variety of assessment practices. In an effort to standardize the presurgical evaluation and empirically identify psychosocial contraindications, the PsyBari was created. The PsyBari is a 115-item psychological test that measures constructs relevant to surgical outcomes. It was designed specifically for bariatric surgery patients and can be updated as new information becomes available. Reliability studies indicate that it is a reliable instrument [Cronbach’s a=0.930, (0.940 for men and 0.927 for women)]. Factor analysis results show that both men and women have six underlying factors. Some of these factors are similar for both genders while others are unique. The test can effectively identify subgroups within the bariatric surgery population and it can accurately predict psychosocial markers, such as a history of sexual abuse. As further work is done, the goal of the PsyBari is to identify surgical contraindications, including risk for substance/alcohol abuse, suicidal ideation, weight regain, and to determine if a patient is motivated enough to complete surgery.
In 1991, the National Institutes of Health (NIH) recommended that bariatric surgery patients receive presurgical psychological clearance. Since then, surgical associations and health insurance companies have begun to require presurgical psychological evaluations.[1,2] These evaluations aim to identify patients who are at increased risk for a wide variety of postsurgical psychological, interpersonal, behavioral, and/or medical problems, such as binge eating, substance/alcohol abuse, depression, suicidal ideation, anxiety, medical adherence, and weight regain. Despite of this requirement, empirical evidence on psychosocial outcomes to bariatric surgery remains sparse. Researchers are only beginning to understand the multifaceted and long-term responses to bariatric surgery and even less is known about using presurgical psychological profiles to predict surgical outcomes. Due to the lack of solid empirical evidence, psychologists have not been able to develop standardized criteria for these evaluations. They use a wide range of assessment procedures and ultimately have to rely on their own judgment when deciding which patients should receive surgical clearance.
The Creation of the PsyBari
Due to the lack of empirical evidence in this area, and the lack of standardized criteria for presurgical psychological evaluations, the PsyBari was created. The PsyBari is a 115-item psychological test designed specifically to evaluate bariatric surgery patients. It is a comprehensive test that assesses psychosocial constructs demonstrated to be, or considered to be, relevant to postsurgical functioning (Figure 1). This includes well-researched constructs, such as depression and binge eating, and those constructs that have not received much research attention, such as surgical anxiety and motivation to complete the surgery.
An Evolving Instrument
The PsyBari includes 11 scales as well as validity and response style indicators. It can be revised frequently as researchers identify new empirically validated constructs of interest, clarify the underlying structure of these constructs, and/or determine the utility of these constructs. For example, when multiple publications demonstrated that carbohydrate cravings can influence postsurgical weight regain, items assessing this craving pattern were included in the test. Conversely, when factor analyses did not reveal anger as a factor for women and publications did not report anger as a postsurgical problem for women, these items were removed from the female version of the test. In this way, as our understanding of the postsurgical psychosocial effects of bariatric surgery progresses, the PsyBari can incorporate the changes. At present, the test is updated every two years. As research efforts in this area ramp up and more users provide data, revisions could occur as frequently as once per year.
The test items, scales, and scoring can also be modified for specific subgroups since not all bariatric surgery patients are the same and a meaningful psychological assessment has to recognize these differences. For example, many studies have found differences in the patterns of depression between men and women with obesity. This includes the finding that women are more likely to report feeling depressed because their weight impairs their social functioning while men are more likely to report feeling depressed because their weight impairs their physical abilities. With these results, the depression scale was individually configured for each gender so that it accurately measures the underlying structures of depression of each gender. Future studies can clarify if response styles, such as social desirability, are involved in these underlying structural differences. In these ways, the PsyBari evolves to incorporate new findings, remove outdated items and/or constructs, and over time, improve its overall utility.
Since the PsyBari was designed specifically for bariatric surgery patients, many of the test’s items will give the clinician information that is normally obtained during the clinical interview (Figures 1 and 2). Clinicians can review patient scores, as well as individual responses, and determine which areas need an in-depth assessment. For example, there are items that assess the patient’s understanding of postsurgical responsibilities, such as being limited to eating four or five ounces of food. Patients that are not knowledgeable about these responsibilities can be further evaluated during the interview and educated, if necessary. It is important to note that although the test does not replace the need for a clinical interview, it can provide guidance to the interviewer as to which areas need to be addressed in depth.
In order to determine how the response styles may influence a patient’s results, the PsyBari includes validity indicators including overall level of denial, endorsement of items infrequently endorsed by others, “all-or-nothing” response style (i.e., patients who predominantly endorse 1’s or 5’s on a 5-point scale), and the “sometimes” response styles (i.e., patients who predominantly endorse 3’s, or “sometimes,” on a 5-point scale). Similar to other psychological tests, clinicians can interpret the PsyBari results with an understanding of how a patient’s response style may have influenced the results. For example, if the validity indicators indicate that a patient was not entirely forthcoming (e.g., high levels of denial), the clinician can interpret the test results with this in mind and further probe for denial during an interview.
For researchers, the test can be customized to fit the needs of their specific topics. Research subjects are often inundated with questionnaires and researchers often do not need to collect data on the entire test. For example, binge eating researchers can administer the binge eating scale items while leaving out other items that assess constructs that do not relate to their research topic. In this way, more data are collected to validate the test and the researcher can use a reliable instrument instead of an ad-hoc measure.
Reliability and Validity
The PsyBari has undergone a series of reliability and validity studies and the results are encouraging.[8–10] The overall Cronbach’s a is 0.930, (0.940 for men and 0.927 for women; Table 1). When looking at the individual subscales, 9 out of 11 have good reliability (a>0.70). Exploratory factor analyses identified six factors for each gender.8 Some factors were common for both genders, some were unique for each gender, and some consisted of mixed constructs. The six factors for women are awareness of eating habits, early life problems due to weight, dysphoric feelings about weight, weight-related impairment, surgical anxiety, and guilty feelings related to eating. The six factors for men were physical impairment with depression, awareness of eating habits, early life problems due to weight, interpersonal support with anxiety about weight, anger, and guilty feelings about eating habits.
As can be seen from the exploratory factor analysis, one of the main findings from the validation studies is that male and female patients have different psychological profiles. Additionally, when looking at presurgical differences between the genders, women are more experienced at dieting, more depressed, more socially anxious, and more likely to report a history of panic attacks. Differences were also found between patients that disclosed a history of sexual abuse as compared to those that did not disclose a history of sexual abuse. Specifically, patients that disclosed a history of sexual abuse were more likely to also disclose a history of physical abuse, psychological treatment, psychiatric treatment, and psychiatric hospitalization. In addition, women were more likely than men to also disclose a history of suicidal ideation. Most studies on bariatric surgery patients assume that these patients are a homogeneous group. These results show that men and women have distinct psychological profiles and they also indicate that surgical contraindications may differ depending on gender. In other words, factors that place men at risk for postsurgical problems may not be the same ones that place women at risk.
Other subgroups may also exist within the bariatric surgery population, such as age, race, and age of obesity onset. A recent finding that female bariatric surgery patients under age 24 are at risk for postsurgical suicide offers a clue in this area.11 The implication is that young female patients have a distinct postsurgical complication that needs to be identified during the presurgical evaluation.
The PsyBari was designed to be able to predict which patients would develop postsurgical psychosocial problems. An intriguing look into its predictive abilities came with the most recent publication. This study focused on the patients who disclosed a history of sexual abuse. A logistical regression found that for women, a history of physical abuse and suicidal ideation predicted sexual abuse status correctly 82 percent of the time. While for men, a history of psychological problems, psychiatric medications, psychiatric hospitalization, and suicidal ideation predicted sexual abuse status correctly 94 percent of the time. These results are intriguing because although the PsyBari was not designed to predict a patient’s sexual abuse status, it seems to do this well. Future studies will focus an clarifying the PsyBari’s ability to predict specific postsurgical psychosocial problems.
Unique Psychometric Concerns
The results of the validation studies have furthered our knowledge about bariatric surgery patients and helped to identify distinct subgroups. They also identified psychometric parameters that are unique to bariatric surgery patients. By interviewing patients about their experiences when taking the test and conducting missing data analyses and factor analyses, several psychometric concerns have emerged. One of the initial concerns is the length of time it takes to complete the PsyBari. Patients become increasingly restless if the test takes longer than 30 minutes. In fact, when using longer tests, or a combination of tests, patients often respond to items randomly (in order to complete the test faster) or they simply refuse to complete all of the items. Because of this, the PsyBari is calibrated to take approximately 30 minutes to complete although overall completion time ranges from 15 to 60 minutes.
Another concern is the wording of the items. Patients have difficulties with negatively worded or double-negative items (e.g., I have never been in a psychiatric hospital). When queried on their responses, patients report being confused about the wording and often leave the item blank or put an incorrect response. Patients also complain about items that seem to have no relevance to weight or bariatric surgery. For example, when asked if they are depressed, they will often respond no and complain that this is an intrusive question. But when asked if they are depressed about their weight, they are more willing to respond yes. Due to these constraints, the test items are all written simply, directly, and when possible, they relate to the topic of weight, eating habits, or bariatric surgery. This does leave the test vulnerable to social desirability response styles, which will be clarified in future studies.
With the results of these and future validation studies, the PsyBari can achieve its ultimate goal of accurately identifying distinct contraindications for bariatric surgery for each patient. The test will be able to determine which patients are at risk for specific postsurgical psychological, behavioral, interpersonal, and medical adherence problems. This includes determining which patients are unlikely to go through with surgery and which ones will experience significant weight regain.
1. Surgical Review Corporation. http://www.surgicalreview.org. Accessed September 3, 2010
2. National Institutes of Health Consensus Development Conference Panel: Gastrointestinal Surgery for Severe Obesity. Ann Intern Med. 1991;115: 956–961.
3. Fabricatore AN, Crerand CE, Wadden TA, et al. How do mental health professionals evaluate candidates for bariatric surgery? Survey results. Obes Surg. 2006;16(5):567–573.
4. Chen EY, McCloskey MS, Doyle P, et al. Body mass index as a predictor of 1 year outcome in gastric bypass surgery. Obes Surg. 2006;19:1240–1242.
5. Bauchowitz AU, Gonder-Frederick LA, Olbrisch ME, et al. Psychosocial evaluation of bariatric surgery candidates: A survey of present practices. Psycho Med. 2005;67:825–832.
6. The PsyBari. A psychological evaluation for bariatric surgery candidates. www.psybari.com. Accessed September 3, 2010
7. Guthrie HM. The nature of food cravings following weight-loss surgery. Dissertation thesis. University of Leeds, Leeds, Unitd Kingdom. 2008.
8. Mahony D. Psychological assessments of bariatric surgery patients. Development, reliability, and exploratory factor analysis of the PsyBari. Obes Surg. 2010 Mar 20. [Epub ahead of print]
9 Mahony D. Psychological gender differences in bariatric surgery candidates. Obes Surg. 2008;18(5):607–610.
10 Mahony D. Assessing sexual abuse/attack histories with bariatric surgery patients. J Child Sex Abus. In press.
11 Omalu BI, Ives DG, Buhari AM, et al. Death rates and causes of death after bariatric surgery for Pennsylvania residents, 1995–2004. Arch Surg. 2007;142(10):923–929.