Ronette L. Kolotkin

Defining clinically meaningful change in health-related quality of life

This article reviews current approaches to defining clinically meaningful change in health-related quality of life (HRQOL) and provides guidelines for their use. Definitions of clinically meaningful change are discussed. Two broad methods for identifying clinically meaningful change are contrasted: anchor-based methods and distribution-based methods. Anchor-based methods include cross-sectional approaches and longitudinal approaches. Distribution-based methods include those based on statistical significance, sample variability, and measurement precision. Anchor-based and distribution-based methods have advantages and limitations, and neither seems to be superior to the other. An integrated system for defining clinically meaningful change is recommended that combines anchor-based and distribution-based methods. We propose a new terminology for describing meaningful change derived from anchor-based and distribution-based methods.

Quality of life and obesity

Interest in the quality of life of patients with different diseases continues to grow. Recent years have witnessed a dramatic rise in the prevalence of obesity worldwide, stimulating interest in the health and quality of life consequences of this phenomenon. The body of research on the quality of life of obese individuals has grown to a point that a review of this literature is warranted. Numerous studies have demonstrated that obese persons experience significant impairments in quality of life as a result of their obesity, with greater impairments associated with greater degrees of obesity. Weight loss has been shown to improve quality of life in obese persons undergoing a variety of treatments. Further research is needed to clarify whether quality of life differs among subsets of obese persons. Until recently, there has been little standardization of quality of life measures in obesity. The SF‐36 has been used in a number of studies of obese persons. Several obesity‐specific instruments have also been developed and have shown great promise. The quality of life of obese individuals is an important issue that should be included in weight management treatment and research.

Psychometric evaluation of the impact of weight on quality of life-lite questionnaire (IWQOL-lite) in a community sample.

The short form of impact of weight on quality of life (IWQOL)-Lite is a 31-item, self-report, obesity-specific measure of health-related quality of life (HRQOL) that consists of a total score and scores on each of five scales – physical function, self-esteem, sexual life, public distress, and work – and that exhibits strong psychometric properties. This study was undertaken in order to assess test–retest reliability and discriminant validity in a heterogeneous sample of individuals not in treatment. Individuals were recruited from the community to complete questionnaires that included the IWQOL-Lite, SF-36, Rosenberg self-esteem (RSE) scale, Marlowe–Crowne social desirability scale, global ratings of quality of life, and sexual functioning and public distress ratings. Persons currently enrolled in weight loss programs or with a body mass index (BMI) of less than 18.5 were dropped from the analyses, leaving 341 females and 153 males for analysis, with an average BMI of 27.4. For test–retest reliability, 112 participants completed the IWQOL-Lite again. ANOVA revealed significant main effects for BMI for all IWQOL-Lite scales and total score. Females showed greater impairment than males on all scales except public distress. Internal consistency ranged from 0.816 to 0.944 for IWQOL-Lite scales and was 0.958 for total score. Test–retest reliability ranged from 0.814 to 0.877 for scales and was 0.937 for total score. Internal consistency and test–retest results for overweight/obese subjects were similar to those obtained for the total sample. There was strong evidence for convergent and discriminant validity of the IWQOL-Lite in overweight/obese subjects. As in previous studies conducted on treatment-seeking obese persons, the IWQOL-Lite appears to be a reliable and valid measure of obesity-specific quality of life in overweight/obese persons not seeking treatment.

Effect of Roux-en-Y Gastric Bypass Surgery on the Sex Steroids and Quality of Life in Obese Men

CONTEXT The effect of bariatric surgery on the reproductive function of obese men is not entirely elucidated. OBJECTIVE The aim of the study was to define the effect of Roux-En-Y gastric bypass surgery on the reproductive hormones and sexual function in obese men. DESIGN AND SETTING The cohort was followed for 2 yr at a clinical research center. PATIENTS Sixty-four severely obese men (22 who had gastric bypass surgery and 42 controls) participated in the study. INTERVENTION(S) Anthropometrics [weight, body mass index (BMI), and percentage body fat] and reproductive hormones were measured. The sexual quality of life was assessed using the Impact of Weight on the Quality Of Life-Lite questionnaire. MAIN OUTCOME MEASURE(S) Reproductive hormones and sexual quality of life were measured. RESULTS The mean age was 48.9 +/- 1.2 yr. At baseline, mean weight was 333.0 +/- 7.1 lb, BMI was 46.2 +/- 0.9 kg/m(2), and total testosterone was 339.9 +/- 21.32 ng/dl. BMI correlated positively with estradiol and negatively with total and free testosterone. Indices of dissatisfaction with sexual quality of life correlated positively with measures of obesity. Difficult sexual performance and low sexual desire correlated negatively with free and total testosterone (r = -0.273, P = 0.038; and r = -0.267, P = 0.042, respectively). After 2 yr, the gastric bypass surgery group had a significant decrease in BMI (-16.6 +/- 1.2 vs. -0.46 +/- 0.51 kg/m(2)) and estradiol (-8.1 +/- 2.4 vs. 1.6 +/- 1.4 pg/ml) and had an increase in total testosterone (310.8 +/- 47.6 vs. 14.2 +/- 15.3 ng/dl) and free testosterone (45.2 +/- 5.1 vs. -0.4 +/- 3.0 pg/ml). Sexual quality of life was improved after gastric bypass surgery. CONCLUSION Hormonal alterations and diminished sexual quality of life among obese men are related to degree of obesity, and both are improved after gastric bypass surgery.

Obesity and Sexual Quality of Life

Objectives: Reduced sexual quality of life is a frequently reported yet rarely studied consequence of obesity. The objectives of this study were to 1) examine the prevalence of sexual quality‐of‐life difficulties in obese individuals and 2) investigate the association between sexual quality of life and BMI class, sex, and obesity treatment—seeking status.

Assessing Weight‐Related Quality of Life in Adolescents

Objective: The development of a new weight‐related measure to assess quality of life in adolescents [Impact of Weight on Quality of Life (IWQOL)‐Kids] is described.

Randomized, double-blind, placebo-controlled trial of orlistat for weight loss in adolescents.

OBJECTIVE To evaluate the efficacy of orlistat to enhance weight loss in obese adolescents. METHODS The study was a 6-month randomized, double-blind, placebo-controlled trial to compare the effects of orlistat (120 mg orally 3 times a day) and placebo on reduction of body mass index (BMI). Forty adolescents between 14 and 18 years of age with a mean BMI of 40 kg/m2 entered the protocol between December 2002 and February 2003. Study subjects stayed overnight in the General Clinical Research Center, during which dietary records were reviewed and lifestyle recommendations were given. The study participants received either orlistat (120 mg orally 3 times a day) or placebo and were assessed monthly for 6 months. At 0, 3, and 6 months, fasting laboratory tests were performed. The primary end point was the change in BMI from baseline to 6 months. Secondary outcomes included changes in weight, lean body mass, and results of blood chemistry studies. RESULTS No statistically significant difference was noted between the 2 study groups for decrease in BMI from baseline to 6 months (P = 0.39). The decrease in BMI within the orlistat group (-1.3 +/- 1.6 kg/m2; P = 0.04) and within the placebo group (-0.8 +/- 3.0 kg/m2; P = 0.02), however, was statistically significant. Laboratory measurements did not differ between the 2 groups. In comparison with the placebo group, the orlistat group had increased adverse events, primarily gastrointestinal symptoms and findings. CONCLUSION In this study of obese adolescents, orlistat did not significantly reduce BMI in comparison with placebo at 6 months.

Health outcomes of gastric bypass patients compared to nonsurgical, nonintervened severely obese

Favorable health outcomes at 2 years postbariatric surgery have been reported. With exception of the Swedish Obesity Subjects (SOS) study, these studies have been surgical case series, comparison of surgery types, or surgery patients compared to subjects enrolled in planned nonsurgical intervention. This study measured gastric bypass effectiveness when compared to two separate severely obese groups not participating in designed weight‐loss intervention. Three groups of severely obese subjects (N = 1,156, BMI ≥ 35 kg/m2) were studied: gastric bypass subjects (n = 420), subjects seeking gastric bypass but did not have surgery (n = 415), and population‐based subjects not seeking surgery (n = 321). Participants were studied at baseline and 2 years. Quantitative outcome measures as well as prevalence, incidence, and resolution rates of categorical health outcome variables were determined. All quantitative variables (BMI, blood pressure, lipids, diabetes‐related variables, resting metabolic rate (RMR), sleep apnea, and health‐related quality of life) improved significantly in the gastric bypass group compared with each comparative group (all P < 0.0001, except for diastolic blood pressure and the short form (SF‐36) health survey mental component score at P < 0.01). Diabetes, dyslipidemia, and hypertension resolved much more frequently in the gastric bypass group than in the comparative groups (all P < 0.001). In the surgical group, beneficial changes of almost all quantitative variables correlated significantly with the decrease in BMI. We conclude that Roux‐en‐Y gastric bypass surgery when compared to severely obese groups not enrolled in planned weight‐loss intervention was highly effective for weight loss, improved health‐related quality of life, and resolution of major obesity‐associated complications measured at 2 years.

Health-related Quality of life in patients seeking gastric bypass surgery vs non-treatment-seeking controls

Background: Previous research has found that health-related quality of life (HRQOL) differs among obese individuals depending on treatment-seeking status, with greater impairments found in obese individuals seeking treatments of greatest intensity. The goals of this study were to determine: 1) if there are differences in obesity-specific HRQOL between seekers of gastric bypass surgery and non-treatment-seeking controls; and, 2) if the presence and number of co-morbid conditions impacts on HRQOL. Methods: Participants were 339 surgical cases (mean age 42.9, mean BMI 47.7, 85.5% women) and 87 controls (mean age 48.8, mean BMI 43.5, 71.3% women). Obesity-specific HRQOL was assessed using the Impact of Weight on Quality of Life-Lite (IWQOL-Lite). Subjects were given a detailed medical history to determine the presence of co-morbid conditions. Results: After controlling for BMI, age, and gender, obesity-specific HRQOL was significantly more impaired (P<.001) in the surgery-seeking group than in the control group on all 5 scales and total score of the IWQOL-Lite. For total score, physical function and sexual life, there was increasing impairment with increasing number of co-morbid conditions. Treatment-seeking status, BMI, gender, and the presence of depression accounted for most of the variance in IWQOL-Lite total score. Conclusions: Persons seeking gastric bypass expe rience poorer HRQOL than non-treatment-seeking individuals after controlling for BMI, age, and gender. The presence of co-morbid conditions contributes to some aspects of HRQOL impairment.

Six-year changes in health-related quality of life in gastric bypass patients versus obese comparison groups

BACKGROUND Few studies have evaluated the long-term outcomes of bariatric surgery patients in relation to obese individuals not participating in weight loss interventions. Our objective was to evaluate the 6-year changes in health-related quality of life (HRQOL) in gastric bypass (GB) patients versus 2 obese groups not undergoing surgical weight loss. The study setting was a bariatric surgery practice. METHODS A total of 323 GB patients were compared with 257 individuals who sought but did not undergo gastric bypass and 272 population-based obese individuals using weight-specific (impact of weight on quality of life-lite) and general (medical outcomes study short-form 36 health survey) HRQOL questionnaires at baseline and 2 and 6 years later. RESULTS At 6 years, compared with the controls, the GB group exhibited significant improvements in all domains of weight-specific and most domains of general HRQOL (i.e., all physical and some mental/psychosocial). The 6-year percentage of excess weight loss correlated significantly with improvements in both weight-specific and physical HRQOL. The HRQOL scores were fairly stable from 2 to 6 years for the GB group, with small decreases in HRQOL corresponding to some weight regain. CONCLUSIONS GB patients demonstrated significant improvements in most aspects of HRQOL at 6 years compared with 2 nonsurgical obese groups. Despite some weight regain and small decreases in HRQOL from 2 to 6 years postoperatively, the HRQOL was relatively stable. These results support the effectiveness of weight loss achieved with gastric bypass surgery for improving and maintaining long-term HRQOL.