Quality of Life after Gastric Bypass Surgery: A Cross-Sectional Study

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1 Quality of Life after Gastric Bypass Surgery: A Cross-Sectional Study Maureen P. Dymek,* Daniel le Grange,* Kim Neven, and John Alverdy Abstract DYMEK, MAUREEN P., DANIEL LE GRANGE, KIM NEVEN, AND JOHN ALVERDY. Quality of life after gastric bypass surgery: a cross-sectional study. Obes Res. 2002;10: Objective: Numerous reports document significant weight loss after gastric bypass; however, there is little objective data on postsurgical changes in health-related quality of life (HRQL). Research Methods and Procedures: This study examined HRQL in four groups of patients: presurgery (T1), several weeks postsurgery (T2), 6 months postsurgery (T3), and 1 year postsurgery (T4). Subjects were given three HRQL measures: the short form 36 (SF-36), the Impact of Weight on Quality of Life-Lite Questionnaire (IWQOL-Lite), and the Bariatric Analysis and Reporting Outcome System (BAROS). Subjects also completed the Beck Depression Inventory (BDI) and the Rosenberg Self-Esteem Scale (RSE). Results: There were no significant differences among the groups on demographics or presurgical body mass index. Results showed significant differences between T1 and T2 on several SF-36 and IWQOL-Lite subscales, as well as the RSE and BDI. Significant differences were found on all measures between T2 and T3. Significant differences were found on all subscales of the IWQOL-Lite, but no subscales of the SF-36, the RSE, or the BDI between T3 and T4. Discussion: This study is the first to objectively document these differences in several objective measures of HRQL, depression, and self-esteem after gastric bypass in a large sample. It is notable that many differences are apparent within several weeks after surgery. Furthermore, results indicate that the IWQOL-Lite may be more sensitive than Received for review March 22, Accepted for publication in final form July 10, *Department of Psychiatry and Department of Surgery, The University of Chicago Hospitals, Chicago, Illinois. Address correspondence to Maureen Dymek, Ph.D., The University of Chicago, Department of Psychiatry, 5841 South Maryland Avenue, MC 3077, Chicago, IL mdymek@yoda.bsd.uchicago.edu Copyright 2002 NAASO the SF-36 to the changes of quality of life that gastric bypass patients report. Key words: clinically severe obesity, obesity surgery, short form 36, Impact of Weight on Quality of Life Questionnaire Introduction Clinically severe obesity, defined as weighing 100 pounds or 100% above one s ideal body weight, has increased dramatically over the last several decades, with recent estimates indicating that 3% of the U.S. adult population has this level of obesity (1,2). Clinically severe obesity is associated with an increased risk of morbidity and mortality from numerous related medical conditions such as coronary artery disease, diabetes, and certain types of cancer (3,4), and is associated with debilitating psychosocial consequences such as depression, low self-esteem, prejudice, and social bias. The costs to treat the medical comorbidities of clinically severe obesity in the United States have been estimated at 39.3 billion dollars per year (5); the costs of additional consequences of obesity, such as work absenteeism and decreased productivity are thought to be just as high. Unfortunately, the clinically severe obese typically respond poorly to traditional dietary and exercise weight-loss regimens, and when an initial response occurs, it is likely to be poorly maintained (6,7). Surgical interventions, such as gastric bypass (GBP), were developed as an alternative weight-loss method for the clinically severe obese, aimed at individuals whose weight-loss attempts have repeatedly failed and whose medical and psychosocial problems related to obesity are overwhelming. Whereas numerous studies show that GBP significantly reduces weight, there are shortcomings in the current understanding of the effect of GBP on health-related quality of life (HRQL) and psychosocial functioning after surgery. HRQL refers to the impact of health conditions on an individual s general life functioning. HRQL reflects the OBESITY RESEARCH Vol. 10 No. 11 November

2 way that patient s perceive and react to their health status, and the effect their health has on other aspects of their lives, such as work, leisure activities, and social relationships. HRQL has recently received a greater emphasis in medical outcome studies because of its multidimensional assessment of well-being (8,9). HRQL is a particularly relevant construct in obesity and weight-loss research, because obesity has been shown to exert significant negative consequences on HRQL, which seem to resolve with adequate weight loss (10 13). Whereas the main objective of GBP surgery is to diminish the numerous consequences of obesity to improve health status and general psychosocial functioning, and to increase a patient s activity, engagement in life, and work productivity few studies have objectively examined these outcomes. With the increasing prevalence of clinically severe obesity and with GBP rapidly gaining popularity as an effective weight-loss method, this lack of research represents a significant shortcoming in the obesity literature. The current study assesses HRQL in clinically severely obese patients before and after gastric bypass surgery. In addition to assessments of weight and psychosocial functioning, we employ three measures of HRQL, the short form 36 (SF-36) (14), a generic measure designed for use with all medical populations; the Impact of Weight on Quality of Life-Lite Questionnaire (IWQOL-Lite) (15), designed specifically for obese populations; and the Moorehead-Ardelt Quality of Life Questionnaire of the Bariatric Analysis and Reporting Outcome System (BAROS) (16), developed specifically to assess HRQL after bariatric surgery. Research Methods and Procedures Study Design A controlled cross-sectional design was used in which a preoperative control group of clinically severe obese patients awaiting surgery (T1; n 80) was compared with three different groups of patients at three different postsurgical time-points: 2 to 4 weeks postsurgery (T2; n 60), 6 months postsurgery (T3; n 93), and 1 year postsurgery (T4; n 83). Subjects Subjects were recruited from the Center of Surgical Treatment of Obesity at The University of Chicago Hospitals between May 2000 and May All subjects underwent a multidisciplinary evaluation, including a history and physical examination by a surgeon, nutritional evaluation by a registered dietitian, and psychological evaluation by a clinical psychologist. Candidates approved for the surgery had a body mass index (BMI) 40 kg/m 2,oraBMI 35 kg/m 2 with significant obesity-associated medical conditions, and had minimal medical, dietary, or psychological contraindications for surgery. Patients were excluded from the study if they had previously undergone GBP surgery at another center. The presurgical (T1) group consisted of individuals who were accepted into the program and were scheduled and awaiting GBP surgery. The postsurgical (T2 to T4) groups consisted of patients who underwent Roux-en-Y gastric bypass surgery at The University of Chicago Hospitals (surgical technique described elsewhere) (17). Subjects in the T1 and T2 groups were recruited into the study during either their presurgical evaluation [T1; 100% (80/80) of subjects approached agreed to complete questionnaires] or a postsurgical follow-up appointment several weeks after surgery [T2; 91% (60/66) of subjects approached agreed to complete questionnaires], and completed the questionnaires during these clinic visits. Subjects in the T3 and T4 groups were recruited through either scheduled follow-up clinic visits or mass mailings, in which all patients without scheduled follow-up appointments were sent questionnaires to be completed either 6 months (T3) or 1 year (T4) after surgery. Seventy-eight percent (138/176) of our final N in the T3-T4 groups completed the questionnaires in clinic, and 98% (138/141) of subjects approached in the clinic agreed to complete questionnaires. Twenty-two percent (38/176) of our final N in the T3 and T4 groups completed the questionnaires through mail; 63% (38/60) of subjects contacted through mail completed questionnaires. There were no significant differences in demographics between those who did and did not agree to be in the study. Presurgical demographic and descriptive data of all four samples are presented in Table 1. Using ANOVA, there were no significant differences in presurgical age or BMI, excess weight [determined using the Hamwi (18) equation], or education between the groups. There were also no significant differences between the groups in sex or race using 2. Assessments All subjects completed the following questionnaires, designed to assess health-related quality of life, depression, and self-esteem. SF-36 (14) is a 36-item self-report survey containing eight subscales designed to assess general HRQL. These subscales are described in more detail in Table 2. On the SF-36, higher scores indicate better quality of life. IWQOL-Lite (15) is a 31-item self-report survey developed to assess HRQL in obese populations. In addition to a total score, the IWQOL-Lite generates five subscale scores, which are described in more detail in Table 2. On the IWQOL-Lite, higher scores indicate poorer quality of life. The Beck Depression Inventory (19) (BDI) is a standard self-report questionnaire consisting of 21 multiple-choice items designed to assess the presence and severity of depressive symptomatology. On the BDI, higher scores indicate more severe depression OBESITY RESEARCH Vol. 10 No. 11 November 2002

3 Table 1. Presurgical demographic and descriptive data across groups T1 T2 T3 T4 Presurgery (n 80) 2 to 4 Weeks post (n 60) 6 Months post (n 93) 1 Year post (n 83) Age (years SD) F 1.1; p 0.34 Education (years SD) F 1.3; p 0.29 BMI (kg/m 2 SD) F 2.4; p 0.07 Excess weight (kg SD) F 2.5; p 0.06 Gender 80% female 76% female 73% female 81% female 2 1.4; p 0.70 Race ; p 0.09 Caucasian 62.5% 69% 73% 76% African American 22.5% 22% 20% 20% Hispanic 15% 9% 6% 4% BMI, body mass index. The Rosenberg Self-Esteem Scale (20) (RSE) is a widely used self-report instrument consisting of 10 items that measure overall self-esteem. On the RSE, higher scores indicate poorer self-esteem. In addition to the above measures, all subjects in the postsurgical groups were assessed with the following outcome measure. BAROS (16) is a quantitative measure used to measure the outcome of bariatric surgery. The BAROS consists of standardized clinician ratings of surgical complications, postsurgical weight loss and medical changes, and a brief, patient-rated measure of quality of life. The BAROS generates subscale scores for weight, medical comorbidities, and quality of life, and a total outcome score of surgical success, ranging from 0 (failure) to 9 (excellent). Data Analysis 2 s and ANOVAs were conducted to test for group differences on presurgical BMI and demographic characteristics. For BMI, BDI, and RSE, separate one-way ANOVAs were conducted to assess differences among groups. On statistical significance of each ANOVA, Tukey s honest significant difference post hoc tests were conducted between T1 and T2, T2 and T3, and T3 and T4 to determine the specific time periods of significant difference. For BAROS measures and all HRQL measures, two separate omnibus multivariate ANOVAs (MANOVAs) were conducted (one using all BAROS variables and one using HRQL variables). For these variables, MANOVAs were chosen over conducting numerous ANOVAs to reduce experiment-wise error rate, given the theoretical overlap of the HRQL variables and the BAROS variables. On statistical significance of each MANOVA, Tukey s honest significant difference post hoc tests were conducted on all HRQL subscales between T1 and T2, T2 and T3, and T3 and T4, and on BAROS variables between T2 and T3 and T3 and T4 (because BAROS measures outcome, it is not given at T1) to determine the specific periods of significant difference. Results Weight, BMI, and BAROS Table 3 presents BMI and weight loss variables for the groups. One-way ANOVA demonstrated a significant difference in BMI across the four time-points (F(3,309) 63.3, p 0.000). As displayed in Table 4, post hoc tests demonstrated significant differences in BMI between T2 and T3 and T3 and T4, but not T1 and T2. Table 3 also presents BAROS outcome data for the three postsurgical groups. MANOVA revealed a significant difference between the groups on the BAROS subscales (F(8,428) 46.6, p 0.000). As shown in Table 4, post hoc tests demonstrated significant differences between T2 and T3 and T3 and T4 on each BAROS variable and the BAROS total score. To guard against type 1 error, percent of excess weight lost was not statistically analyzed, but is presented in Table 3 for descriptive purposes. Depression and Self-Esteem Table 3 displays the BDI (higher scores indicate greater depressive symptomotology) and RSE (higher scores indicate poorer self esteem) scores across the four groups. Two one-way ANOVAs revealed significant differences between the groups on the BDI (F(3,309) 49.0, p 0.000) and RSE (F(3,307) 25.9, p 0.000). As shown in Table 4, post hoc tests demonstrated significant differences on the BDI between T1 and T2 and T2 and T3, but not T3 and T4. OBESITY RESEARCH Vol. 10 No. 11 November

4 Table 2. SF-36 and IWQOL-LITE subscales Subscale SF-36 Physical functioning Role physical Bodily pain General health Vitality Social functioning Role emotional Mental health IWQOL-Lite Physical functioning Self-esteem Sexual life Public distress Work Description Ten items measuring limitations in performance of various physical activities, ranging from vigorous activities to simple self-care functions. Four items which measure functionality in work and other daily activities as a result of physical health. Two items which measure degree of pain and pain-related functional limitations. Five items which measure an individual s appraisal of their overall health. Four items which measure energy level. Two items which measure health related limitations in social functioning. Three items which measure functionality in work and other daily activities as a result of emotional health. Five items which measure the presence and degree of depression and anxiety. Eleven items measuring the impact of weight on various physical activities, ranging from self-care to mild exertion. Seven items measuring the impact of weight on self-consciousness and negative self-evaluation. Four items measuring the impact of weight on sexual desire, performance, and enjoyment. Five items measuring the impact of weight on social and public activities. Four items measuring the impact of weight on work performance and promotion. SF-36, short form 36; IWQOL-LITE, Impact of Weight on Quality of Life-Lite Questionnaire. Post hoc tests demonstrated significant differences on the RSE between T1 and T2 and T2 and T3, but not T3 and T4. Using a BDI cut-off score of 10 19, subjects were divided into two groups: depressed and nondepressed. Using this criteria, 71% (57/80) of subjects in the T1 group were grouped into the depressed category; likewise, 44% (26/ 60) of subjects in T2, 13% (12/93) of subjects in T3, and 15% (12/83) of subjects in T4 were grouped in the depressed category. Three separate 2 tests were then conducted between T1 and T2, T2 and T3, and T3 and T4, to examine differences in depression status across the groups. Results showed significant differences between T1 and T2 [ 2 (1) 7.7, p 0.006] and T2 and T3 [ 2 (1) 15.1p 0.001], but not between T3 and T4 [ 2 (1) 0.1, p 0.73]. Quality of Life Table 5 displays the SF-36 subscale scores across the four groups (higher scores indicate higher functioning). MANOVA revealed a significant difference between the groups on the HRQL subscales (F(42,843) 11.1, p 0.000). As shown in Table 6, post hoc tests demonstrated significant differences between T1 and T2 on the General Health, Vitality, and Mental Health subscales of the SF-36, and the Physical Functioning subscale of the IWQOL-Lite. A marginally significant difference (p 0.08) was revealed on the IWQOL-Lite total score between T1 and T2. Post hoc tests demonstrated significant differences between T2 and T3 on all of the subscales of the SF-36 and the IWQOL- Lite, as well as the IWQOL-Lite total score. Post hoc tests demonstrated significant differences between T3 and T4 on the Physical Functioning, Self-Esteem, Public Distress subscales and the total score of the IWQOL-Lite, but on no subscales of the SF-36. A marginally significant difference (p 0.07) was revealed on the IWQOL-Lite Sexual Life subscale between T3 and T4. Discussion Course of Change in HRQL after GBP The results of these cross-sectional analyses reveal significant differences over the time periods assessed in BMI, depression, self-esteem, and numerous HRQL variables. Whereas change over time was not tested directly because of our cross-sectional design, it is likely that the differences 1138 OBESITY RESEARCH Vol. 10 No. 11 November 2002

5 Table 3. Weight, depression, self-esteem and BAROS data across groups T1 T2 T3 T4 Presurgery 2 to 4 Weeks post 6 Months post 1 Year post F p BMI, kg/m 2 (SD) 51.7 (8.0) 50.5 (7.8)* 40.6 (8.3) 37.0 (7.7) % excess weight lost 9.7 (4.2) 44.1 (11.4) 57.7 (14.5) BDI, score (SD) 17.8 (10.5) 11.9 (8.8)* 6.0 (5.4) 5.4 (4.4) RSE, score (SD) 22.8 (7.0) 19.9 (5.7)* 16.3 (5.0) 16.1 (5.0) BAROS, score (SD) Weight 0.02 (0.1)* 1.3 (0.5) 1.8 (0.7) Medical 0.04 (0.2)* 2.3 (0.6) 2.5 (0.6) QOL 0.09 (1.0)* 1.9 (0.8) 2.0 (0.7) Total 0.08 (1.2)* 5.3 (1.5) 6.2 (1.3) * Post hoc tests revealed significant differences on these measures between T2 and T3. Post hoc tests revealed significant differences on these measures between T3 and T4. Post hoc tests revealed significant differences on these measures between T1 and T2. BAROS total score of 1 failure, 1to3 fair, 3to5 good, 5to7 very good, 7to9 excellent (16). BAROS, Bariatric Analysis and Reporting Outcome System; BMI, body mass index; BDE, Beck Depression Inventory; RSE, Rosenberg Self-Esteem Scale; QOL, quality of life. measured reflect change over time postsurgically. Thus, it is reasonable to infer that the first year after GBP represents a period of major life changes. We were quite surprised to observe such noteworthy differences in HRQL relatively soon after surgery. By 2 to 4 weeks postsurgery, significant differences were evident in subject s appraisal of their overall health (SF-36 General Health), depression (BDI, SF-36 Mental Health), and selfesteem (RSE), when compared with the presurgical group. Whereas these findings corroborate earlier pilot research (17), we were nevertheless surprised to see significant differences in energy level (SF-36 Vitality) and physical functioning (IWQOL-Lite Physical Function) so rapidly after surgery. Given the temporal proximity of this time-point to such a major invasive surgery, we expected to see energy and physical functioning diminished at T2. Whereas it is Table 4. Tukey honest significant difference (D T ) and p values on weight, depression, and self-esteem, and surgical outcome T1/T2 T2/T3 T3/T4 Presurgery/2 Weeks post D T (p) 2 to 4 Weeks post D T (p) 6 Months/1 Year post D T (p) BMI, kg/m 2 (SD) 1.30 (0.79) 9.82 (0.001) 3.61 (0.01) BDI, score (SD) 5.89 (0.001) 5.90 (0.001).63 (0.94) RSE, score (SD) 2.93 (0.02) 3.61 (0.001).24 (0.99) BAROS, score (SD) Weight 1.26 (0.001) 0.54 (0.001) Medical 2.25 (0.001) 0.20 (0.04) QOL 1.78 (0.001) 0.17 (0.33) Total 5.19 (0.001) 0.97 (0.001) BMI, body mass index; BDI, Beck Depression Inventory; RSE, Rosenberg Self-Esteem Scale; BAROS, Bariatric Analysis and Reporting Outcome System; QOL, quality of life. OBESITY RESEARCH Vol. 10 No. 11 November

6 Table 5. HRQL subscale means (and SDs in parentheses) across groups T1 T2 T3 T4 Presurgery 2 to 4 Weeks post 6 Months post 1 Year post Norm comparison (Ref. 14) SF-36 Physical functioning 38.0 (22.4) 39.5 (22.7)* 74.3 (23.8) 80.7 (21.8) 85.2 (23.3) Role physical 32.2 (35.5) 27.8 (37.8)* 79.3 (37.3) 83.8 (32.6) 81.0 (34.0) Bodily pain 41.3 (21.7) 42.2 (23.9)* 67.5 (20.6) 68.0 (21.4) 75.2 (23.7) General health 34.5 (22.2) 56.2 (18.3)* 68.8 (18.8) 73.7 (16.7) 72.0 (20.3) Vitality 29.3 (19.6) 40.6 (21.7)* 65.1 (19.4) 68.9 (16.6) 60.9 (21.0) Social functioning 49.2 (27.7) 48.8 (30.5)* 85.1 (20.5) 85.5 (19.6) 83.3 (22.7) Role emotional 53.3 (42.3) 50.3 (45.4)* 83.7 (34.1) 87.7 (28.8) 81.3 (33.1) Mental health 57.9 (20.1) 66.8 (18.5)* 81.3 (13.5) 78.2 (14.5) 74.7 (18.1) IWQOL-LITE Physical functioning 44.5 (8.1) 38.9 (10.0)* 23.1 (9.7) 18.5 (7.4) Self-esteem 26.4 (7.1) 25.3 (7.3) 16.6 (7.0) 13.9 (6.5) Sexual life 12.7 (5.1) 11.7 (5.0)* 8.1 (4.2) 6.5 (3.1) Public distress 18.6 (4.4) 17.0 (5.2)* 11.8 (5.9) 8.5 (3.8) Work 11.9 (4.5) 10.7 (3.8)* 7.1 (3.2) 6.1 (2.7) Total (22.5) (25.1)* 66.5 (25.7) 53.5 (20.6) * Post hoc tests revealed significant differences on these measures between T2 and T3. Post hoc tests revealed significant differences on these measures between T1 and T2. Lower scores denote better functioning. Post hoc tests revealed significant differences on these measures between T3 and T4. Post hoc tests revealed a marginally significant difference on this measures between T1 and T2. Post hoc tests revealed a marginally significant difference on this measures between T3 and T4. HRQL, health-related quality of life; SF-36, short form 36; IWQOL-LITE, Impact of Weight on Quality of Life-Lite Questionnaire. possible that these scores could have been somewhat inflated by patients feeling more optimistic about their health and life functioning, this explanation is unlikely, as HRQL subscales were not globally inflated at this time-point. Thus, it is likely that patients notice real improvements in these areas soon after surgery. This finding is notable, because the difference in scores is not only statistically significant, but it also represents a clinically significant difference in functioning. Our results indicate that the time period between several weeks postsurgery and 6 months postsurgery was unequivocally the period of greatest difference. Statistically and clinically significant differences were present on all measures assessed. To our knowledge, only several studies to date have examined psychosocial changes 6 months after surgery in GBP (17,21). The present findings are consistent with these studies, which revealed considerable changes in mood, self-image, eating behavior, and HRQL within 6 months after surgery (17,21). The differences between 6 months and 1 year postsurgery seemed to level off as measured by the SF-36, BDI, and RSE. However, significant differences in physical functioning, self-esteem, sexual life, and public distress were shown between the groups on the IWQOL-Lite. This finding suggests that as weight loss begins to taper, HRQL differences may not be evident on a generic HRQL measure, but are evident on an obesity-specific HRQL measure. This finding confirms that disease-specific measures, particularly the obesity-specific IWQOL-Lite, are more sensitive to change in obese populations and weight loss than generic measures. It is noteworthy to point out that improvements in BMI, depression, self-esteem, and HRQL do not seem to parallel each other in a linear fashion in this population. Significant differences were evident between T1 and T2 on depression, self-esteem, and some SF-36 subscales, but not in BMI. At T2, patient s had lost an average of 9.7% of excess body weight, and while this is a considerable weight loss, it is important to note that T2 patients BMIs were not significantly different from those at T1 (50.5 kg/m 2 at T2 vs kg/m 2 at T1), suggesting a mechanism other than weight may be involved in the HRQL differences between T1 and T2. This finding is at variance with other studies (10,13), 1140 OBESITY RESEARCH Vol. 10 No. 11 November 2002

7 Table 6. Tukey honest significant difference (D T ) and p values on HRQL subscales across groups T1/T2 T2/T3 T3/T4 Presurgery/2 Weeks post D T (p <) 2 to 4 Weeks post D T (p <) 6 Months/1 Year post D T (p <) SF-36 Physical functioning 0.88 (0.99) (0.001) 6.36 (0.24) Role physical 5.61 (0.83) (0.001) 3.76 (0.90) Bodily pain 1.03 (0.99) (0.001) 0.41 (0.99) General health (0.001) (0.002) 4.99 (0.29) Vitality (0.005) (0.001) 3.67 (0.58) Social functioning 0.92 (0.99) 35.9 (0.001) (1.0) Role emotional 2.94 (0.97) (0.001) 5.25 (0.78) Mental health 8.61 (0.02) (0.001) 2.81 (0.67) IWQOL-LITE* Physical functioning 5.52 (0.003) (0.001) 4.53 (0.003) Self-esteem 1.14 (0.80) 8.74 (0.001) (0.21) Sexual life 1.12 (0.50) 3.38 (0.001) 1.61 (0.07) Public distress 1.50 (0.33) 5.28 (0.001) 3.41 (0.001) Work 1.07 (0.35) 3.64 (0.001) 1.09 (0.17) Total (0.08) (0.001) (0.001) * Lower scores denote better functioning. HRQL, health-related quality of life; SF-36, short form 36; IWQOL-LITE, Impact of Weight on Quality of Life-Lite Questionnaire. which show significant correlations between weight loss and changes in HRQL. However, the design of the present study made it impossible to analyze this finding specifically. This needs to be assessed further in longitudinal studies. HRQL Outcome after GBP The current study is one of the first to present overall surgical outcome scores using the BAROS. Our results indicate that there are significant differences on all subscales of the BAROS between T2 and T3 and T3 and T4. Furthermore, as soon as 6 months after surgery, patients experience significant improvements in weight loss, medical comorbidities, and quality of life, which place them in the very good outcome group as defined by the BAROS. It is also noteworthy that 6 months after surgery, patients report normal levels of HRQL and psychosocial functioning. Both the T3 and T4 groups showed levels of HRQL functioning similar to normal-weight, healthy comparison groups as measured by the SF-36 [see Table 4; SF-36 control scores adapted from Ware et al. (14)]. Similarly, within 6 months after surgery, patients report levels of depression on the BDI considered to be within normal limits (e.g., a total score under 10) (16). Implications, Limitations, and Future Directions The present research has important implications for the presurgical and follow-up care of the GBP patient. Whereas all of these noted differences are in a positive direction, they represent such considerable changes from presurgical functioning that they have the potential to impart significant stress on a patient. Many GBP candidates have been obese for most of their lives and have psychologically adapted to the numerous physical, emotional, and social consequences of obesity. Thus, it may be somewhat challenging for patients to become accustomed to these changes postsurgically. The surgical team should communicate the likelihood of such significant change in many life areas after surgery, so that patients can prepare accordingly. To our knowledge, this is the first study of GBP that has employed three objective, reliable, and well-validated HRQL measures. The measures chosen offer an extensive analysis of HRQL; by employing the SF-36, comparisons to other medical populations are possible, and through use of the IWQOL-Lite and the BAROS, obesity-specific and surgery-specific QOL are examined. A limitation of this study is the cross-sectional design. However, all groups were equated on presurgical variables, which suggests that the differences between the groups were indeed because of the OBESITY RESEARCH Vol. 10 No. 11 November

8 different surgical time frames, rather than error or cohort effects. An additional limitation of the study is the relatively short postsurgical time frame assessed. Future studies should employ a longer postsurgical period using a longitudinal design. Acknowledgments No outside funding/support was received for this study. We gratefully acknowledge the contributions of Ronnette Kolotkin, Ph.D. and Ross Crosby, Ph.D. on an earlier draft of this article. References 1. Centers for Disease Control and Prevention. Update: prevalence of overweight among children, adolescents and adults United States MMWR Morb Mortal Wkly Rep. 1997;46: Van Italie TB. Prevalence of obesity. Endocrinol Metab Clin North Am. 1996;25: Kopelman PG. Obesity as a medical problem. Nature. 2000; 404: Pi-Sunyer FX. Medical hazards of obesity. Ann Int Med. 1993;119: Colditz GA. Economic costs of obesity. Am J Clin Nut Supplement. 1992;55:503S 7S. 6. Stunkard AJ, Stinnett JL, Smoller JW. Psychological and social aspects of the surgical treatment of obesity. Am J Psychiat. 1986;143: Wadden TA. The treatment of obesity: an overview. In: Stunkard AJ, Wadden T (eds). Obesity: Theory and Therapy, 2nd ed., New York: Raven Press; 1993, pp Kolotkin R, Meter K, Williams GR. Quality of life and obesity. Obes Rev. 2001;2: Guyatt GH, Feeny DH, Patrick DL. Measuring health related quality of life. Ann Intern Med. 1993;118: Fontaine KR, Barofsky I, Andersen RE, et al. Impact of weight loss on health-related quality of life. Qual Life Res. 1999;8: Kolotkin RL, Crosby RD, Williams GR, Hartley GG, Nicol S. The relationship between health related quality of life and weight loss. Obes Res. 2001;9: Rippe JM, Price JM, Hess SA, et al. Improved psychological well being, quality of life, and health practices in moderately overweight women participating in a 12-week structured weight loss program. Obes Res. 1998;6: Samsa GP, Kolotkin RL, Williams GR, Nguyen MH, Mendel CM. Effects of moderate weight loss on health related quality of life: an analysis of combined data from 4 randomized trials of sibutramine vs placebo. Am J Manag Care. 2001;7: Ware J, Snow K, Kosinski M, et al. SF-36 Health Survey: Manual and Interpretation Guide. Lincoln, RI: Quality Metric; Kolotkin RL, Crosby RD, Kosloski KD, Williams GR. Development of a brief measure to assess quality of life in obesity. Obes Res. 2001;9: Oria HE, Moorehead MK. Bariatric analysis and reporting outcome system. Obes Surg. 1998;9: Dymek M, Le Grange D, Neven K, Alverdy J. Quality of life and psychosocial adjustment in patients after Roux-en-Y gastric bypass: a brief report. Obes Surg. 2001;11: Hamwi G. Changing dietary concepts. In: Danowski TS (ed). Diabetes Mellitus: Diagnosis and Treatment. New York: American Diabetes Association; Beck AT, Steer R. Manual for the Beck Depression Inventory. San Antonio, TX: Psychological Corp.; Rosenberg M. Society and the Adolescent Self Image. Princeton, NJ: Princeton University Press; Waters GS, Pories WJ, Swanson MS, Meelheim HD, Flickinger EG, May H. Long term studies of mental health after the Greenville gastric bypass operation for morbid obesity. Am J Surg. 1991;161: OBESITY RESEARCH Vol. 10 No. 11 November 2002