Medical and Psychological Predictors of Bariatric Surgery Completion
Valentina Ivezaj¹, Karen K. Saules¹, & David Mahony2
Eastern Michigan University, Ypsilanti, MI¹
Greenville Hospital System, Greenville, SC2
Results Continued
Introduction
Results Continued
Bariatric surgery (BS) is a clinically- and cost-effective
procedure for moderate to severe obesity (Picot et al., 2009).
Despite strong evidence of favorable outcomes, however, it is
estimated that only about 0.6% of those who are medically
eligible have undergone BS (Encinosa et al., 2005). Although the
literature clearly indicates that most eligible patients do not
undergo BS, research is lacking as to why some patients followthrough with BS while others do not. The goal of the current
study was to develop models to predict how psychosocial
factors influence BS completion using the PsyBari-II (Mahony,
2010).
Seventeen PsyBari-II items were significantly associated with BS followthrough. Factor analysis of these items yielded six factors with eigen
values greater than 1.0, accounting for 58.68% of the variance.
Method
A sample of 480 bariatric candidates approved for BS completed
the PsyBari-II, a psychological test designed for bariatric presurgical screening. The measure covers a host of demographic,
psychosocial, weight, medical, and substance use history
variables, followed by 115 validated items that cover surgical
motivation, emotional eating, anger, binge eating, obesityrelated depression, weight-related physical impairment, weightrelated social impairment, substance use, and surgical anxiety.
In September 2010, medical records and the BOLD database
were used to determine which of these patients completed
surgery within one year of their approval for BS.
Results
Participants were predominantly female (71.9%) and White
(69.9%), with a mean BMI (±SD) of 47.97 (±7.94) and mean age
(±SD) of 40.87 (±11.2). Sixty-nine percent actually followedthrough with BS, with 63% having gastric bypass, 35.8% having
the band procedure, and 1.2% having another form of BS. BS
follow-through did not differ by gender or race. Medical/weight
history and PsyBari-II items were analyzed separately. At the
bivariate level, obesity onset and number of different weight
loss programs were significantly (p<.05) associated with BS
follow-through. In a simultaneous logistic regression model,
both obesity onset in childhood (OR=1.61) and increased
number of weight loss programs tried (OR=1.05) significantly
increased the likelihood of BS follow-through.
Contact: vivezaj@emich.edu
Figure 1: Mean Factor Item Scores as a Function of
Surgery Completion Status
Table 1: Principal Components Analysis with Varimax Rotation of Items
that were Significantly Related to Surgery Follow-Through
Factor 1: Weight Concerns
When I think about my weight, I get mad at myself.
I feel guilty after I eat too much.
My eating gets out of control.
I am bitterly disappointed with my weight.
I think about dieting.
I worry that I will gain more weight if I don’t have bariatric surgery.
Factor 2: Health Concerns
I worry about my health.
I worry that I will die at a young age if I don’t have surgery.
I can’t go places that have too many stairs.
Factor 3: Confidence in Medical Care
My doctors take my complaints seriously.
I am satisfied with the medical care I receive
Factor 4: Psychiatric/Trauma History
In the past, things were so bad that I thought about suicide.
In the past, I was treated in a psychiatric hospital.
I don’t talk about it but I was the victim of sexual abuse/attack.
Factor 5: Post-Surgical Compliance
Losing weight will be easy after the surgery.
I spend time planning meals.
Factor 6: Surgical Fear
I’m so worried about the surgery that I might not do it.
p<.05
Loading
0.83
0.74
0.63
0.62
0.54
0.45
p<.05
p<.05
p<.05
0.74
0.70
0.58
0.87
0.87
0.73
0.66
0.64
0.76
-0.68
0.89
At the bivariate level, five factors were significantly associated with BS
completion. These five factors were entered into a simultaneous logistic
regression model to identify the strongest predictors, which were weight
concerns, psychiatric trauma history, post-surgical compliance, and
surgical fear. See Figure 1 for a visual depiction of factor means as a
function of BS status.
Discussion
Results indicate that almost one third of BS candidates who
were approved for surgery did not follow through with having
BS. Given the costs, time, and resources associated with BS
assessments, future research should explore why some BS
candidates do not follow-through with BS, ultimately impacting
the cost-effectiveness of pre-bariatric screening.
Childhood obesity onset and increased number of different
weight loss programs tried were related to BS completion.
Based on the PsyBari-II items, greater weight concerns, less
psychiatric trauma history, expected post-surgical compliance,
and less surgical fears were also associated with BS completion.
Findings suggest that relatively few questions in circumscribed
domains predict BS follow-through. In future research, PsyBari-II
data may also shed light on which factors best predict postsurgical outcomes.
Presented at the 2011 Annual Meeting of the Society of Behavioral Medicine