Quality of Life Measurement Postbariatric Surgery

Background

The World Health Organization (WHO) describes quality of life (QOL) as a “broad multidimensional concept that usually includes subjective evaluations of both positive and negative aspects of life.” ¹ Health-related quality of life measurement (HRQOL) is a multidimensional concept that focuses on the perception of health and the impact of health on lifestyle, and can be measured for both an individual and the community. HRQOL measurement for an individual incorporates the individual's perception of their current health status, health risks, environmental risk factors, socioeconomic status, and functional status, and is inclusive of both mental and physical health. In measuring community-based HRQOL, the focus is on population health and how communities interact with and are interacted upon by their environments, public health policies, socioeconomic status, culture, and social determinants of health. The presence and severity of chronic disease adversely impacts the QOL for both individuals and communities. Chronic disease is commonly defined as an illness that occurs and progresses over time leading to premature death, illness, or disability, and can adversely affect quality of life years (QALYs). ²

Having reached epidemic proportions in the United States, obesity has become a chronic disease that serves as the genesis for other life-limiting medical comorbidities. The prevalence of obesity continues to increase in all populations and age groups. According to the National Center for Health Statistics (2012), 35.7% of adults (more than 78 million) and 16.9% of children and adolescents (12.5 million) were obese in 2009–2010. ³ Most chronic diseases such as hypertension, diabetes, and asthma are primarily medically managed. As with all chronic disease, the impact of the disease upon the individual and the effectiveness of medical interventions to reduce disability and early death are measured by QOL outcomes. ⁴ The management of chronic obesity includes not only dietary and behavioral or lifestyle changes but also surgical management. ² Bariatric surgery has emerged as one of the treatments of choice and one of the most effective treatments for improving QOL and limiting death and disability. ⁵

Outcomes measurement in the postsurgical bariatric patient routinely includes QOL metrics. Measuring QOL in the postbariatric surgery patient is essential in determining the efficacy of treatment for patients, providers, as well as governmental and other regulatory agencies and payors. ⁶ Most QOL measurement tools include assessment of multiple domains or dimensions of health, activities of daily living, and medical and functional status as well as psychosocial aspects. For this reason, QOL metrics are often long, time consuming, and complex in both administration to the patient, perception of time spent completing the assessment by the patient, and in interpretation and scoring by the clinician. QOL measurement tools vary and can be self-administered, telephonically administered, or administered in an interview format on a one-on-one basis. The newest trend in assessing QOL measurement is Internet based and therefore can be accessed remotely by the bariatric patient and the clinician or program. Accessing QOL measurement tools via the Internet provides for convenient use of the tool, conservation of resources, and quick access to outcomes scoring, and facilitates assuring confidentiality for the participating patient. It is important to note that almost all clinically tested and validated QOL tools are trademarked, and therefore access fees and permission for use are usually required.

Since the early 1980s, the exploration of the use and development of bariatric-related QOL measurement instruments has increased, though few address the postbariatric surgery patient specifically. Many of the instruments developed to measure QOL originally used either the Medical Outcomes Study Short Form, also known as the “SF-36,” or the Impact of Weight on Quality of Life (IWQOL) assessments as the baseline for the creation of a tool to measure postbariatric surgery QOL specifically.^7,8 This article provides a brief overview of the existing instruments used to assess QOL in the postbariatric surgical patient that have demonstrated adequate reliability and validity. This article also offers suggestions for other more comprehensive validated QOL measurement tools that can be used in this specific patient population.

The Bariatric Analysis and Reporting Outcomes System

The first QOL instrument developed to address postsurgical-related QOL specifically was the Bariatric Analysis and Reporting Outcomes System (BAROS) in 1997.^9,10 The BAROS is a short one-page tool that measures percentage of excess weight loss and changes in medical conditions, and assesses the domains of self-esteem, social and sexual interaction, work, and physical ability. ¹⁰ The BAROS tool is unique in that it uses a simple picture-type scale to measure the psychosocial functions for QOL. It is the only tool that assesses weight loss, improvement in comorbid conditions, development of complications, need for reoperations, and changes in QOL.^9,11

The Gastrointestinal Quality of Life Index

The Gastrointestinal Quality of Life Index (GIQLI) tool was developed primarily to focus on the postsurgical GI tract, its function, and post-bypass condition. The tool also assesses for GI symptomatology and function, along with some limited assessment of physical and mental well-being. It does not, however, specifically address QOL as perceived by the postoperative bariatric surgery patient. The Bariatric Quality of Life Index (BQL) is the current standard for QOL measurement used by many bariatric surgical programs. The BQL was developed as a shorter alternative tool to the GIQLI to measure QOL specifically as it relates to weight-related comorbidities and surgery-related gastrointestinal symptoms. ¹² The BQL is a short one-page, two-part questionnaire that is administered pre- and postsurgery. Part one assesses postsurgical GI symptoms and symptom management as well as medications. Part two assesses QOL components of weight, exercise, psychosocial issues, functionality, and self-esteem. The BQL has demonstrated both internal validity (Cronbach's α=0.898) and construct validity.

The World Health Organization Quality of Life

In the mid-1990s, the WHO ¹ identified a need to create an outcome measure that was both statistically reliable and able to demonstrate external validity “cross-culturally” to meet the needs of people from diverse cultures, languages, and belief systems to measure individual perceptions of QOL. The result was the WHOQOL-100. The first version of this instrument took several years to develop, pilot, and test. The final instrument that eventually developed after exhaustive testing includes 100 questions and addresses 25 domains. The WHOQOL-100 developed into one of the most comprehensive culturally valid and reliable QOL assessments available. The WHO group recognized that the comprehensive nature of the tool also served as a disadvantage in regards to the length of time it takes to complete the survey as well as score it. Thus, the need was identified for a shorter instrument and alternative, disease-specific QOL measurement tools. The tool that was developed is the WHOQOL-BREF.^1,13 Both the WHOQOL-100 and the WHOQOL-BREF demonstrate internal reliability and construct validity. As chronic obesity is not solely limited to any specific culture, race, geographic region, or nationality, use of a culturally based QOL tool in the postbariatric surgical patient is an appropriate tool to consider depending upon the patient or patient population identified.

The Sickness Impact Profile

The Sickness Impact Profile (SIP) is a 136-item QOL tool that uses 12 individual factors or categories to assess two domains: physical and psychosocial.^7,14 This tool takes an estimated 30 minutes to complete, and focuses on the effects of health and healthcare services on QOL. It can be interviewer or self-administered, and answers are based on a simple “yes” or “no” format. The SIP is behaviorally based on patient self-report of perceptions and impact of illness-related dysfunction in the activities of daily living. The SIP assessment has demonstrated internal reliability; in construct validity testing, it exceeded established Activities of Daily Living assessment in reproducibility.

Conclusion

Surgical outcomes are generally measured and driven by length of stay, absence of surgical complications, volumes, and cost. ⁷ In considering the overall impact of surgical intervention on chronic obesity and the mitigation of associated morbidity and mortality risks, it seems most appropriate that postsurgical intervention outcomes measurement focus more on QOL after surgery once weight loss has begun. It is important to note that it can be said the true measurement of value for the bariatric surgical patient is the absence of pain, reduction in symptoms, the return of autonomy in self-care and performing activities of daily living, improved acceptance in society or reduction of isolation from society, the absence of depression, and increased overall participation in and satisfaction with life. The benefits of health and recovery from bariatric surgery as treatment for chronic obesity are best measured using a comprehensive QOL instrument that can be administered at both pre- and postsurgical intervals to show trends and measure changes in QOL for the bariatric patient over time.