Quality of life

What is quality of life?

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Quality of life is an increasingly popular term, as shown by the substantial growth in the number of quality-of-life studies.  
Yet this term has not been accurately defined.

Interest in quality-of-life issues in children, adolescents and adults with congenital heart diseases has increased substantially, and has been stimulated by an overall interest in quality and outcomes. Quality-of-life studies contribute more than just mortality and morbidity data by considering physical, psychological and social problems as well.

Over the years, many patients with congenital heart disease have reported specific psychosocial, educational and behavioural challenges in addition to the medical problems that they face. They also report feelings of being different, social impediments because of physical restrictions, and problems obtaining employment and insurance. Although these barriers are assumed to affect the patients’ quality of life, they have decreased as medical treatment has improved.

Difficulties with definition

A range of definitions for quality of life exists in the published work. “The term ‘quality of life’ generates its own research conferences”, says paediatric cardiologist Henrik Holmstrøm at University Hospital Oslo, Norway. “Giving simple answers to questions on this topic is just not possible”, he adds. Several scientists have called for a consensus on definitions and measurement, whereas others accept that agreement will never be reached.

So what seems to be the problem? Historically, quality of life was measured as subjective health status. Consequently, some scientists use the term health-related quality of life, thus stressing the importance of health issues. They believe that although the common interpretation of quality of life is broad and covers issues such as social areas, surroundings, economy and satisfaction with health, the term health-related quality of life is narrower and includes mental and physical health and their consequences. Other research groups have concluded that quality of life should be defined and measured in terms of life satisfaction, because health is not the only factor.

Well-being, perceived health and health status are well used terms in definitions for quality of life. Others include happiness, content and satisfaction. One of the most well known and experienced researchers in this field, Philip Moons from Belgium, defines quality of life as “the degree of overall life satisfaction that is positively or negatively affected by people’s perception of certain aspects of life that are important to them, including matters both related and unrelated to health”. He is using a satisfaction-with-life approach and strongly disagrees that health status alone is a satisfactory measure.

Other sources, like the organisation Mental Health Norway, describe quality of life as “The experienced value of existence, from physical or psychological well-being to carrying out meaningful activities”. Well-being has both physical (health, diet, protection against pain and disease) and psychological (stress, worry, pleasure and other positive or negative emotional states) aspects.

Quality of life defies measurement

The term quality of life is often used generally in society, in politics, at an administrative level, in health care and in clinical settings as a measure of effective treatment and how well the individuals are treated. For physicians, quality of life, health status and functional status are often used interchangeably. While researchers disagree about what is really meant by the term, the amount of research escalates, and the significance of this research is growing in importance: decisions about what research or treatments to invest the most in are closely related to their effect on a patient's quality of life.

Unlike standard of living, quality of life is not a tangible notion, and therefore cannot be measured directly. Additionally, predicting the quality of life of an individual is impossible, since the combination of attributes leading one individual to be content is rarely the same for another. For many patients with chronic heart disease, exercise capacity in the laboratory is only weakly related to exercise capacity in daily life. Two patients with the same clinical criteria often have substantially different responses. Although physiological measures provide information to clinicians, they are of little interest to patients because they often correlate poorly with the areas in which patients are most interested and familiar: functional capacity and well-being.

How is quality of life measured?

Many people worldwide have tried to develop ways to measure quality of life. Most of the methods available are standardised questionnaires or test batteries to obtain information about patients' functioning or self-perceived health. Some measures consist of a single question that essentially asks "How is your quality of life?" This question could be asked in a simple or a sophisticated fashion, but either way it yields little information. More commonly, the questionnaires are made up of several items or questions, which might include mobility and self-care or depression, anxiety, and well-being. For some methods, the importance of each item is rated in relation to the others. However, usually items are equally weighted, which assumes that their value is equal.

The questionnaires are either administered by trained interviewers or are self-administered.

Over the years, the measurement of quality of life has taken on a more individual approach. The use of individual-based methods overcomes the problem of predetermined questions, which assume that each person’s quality of life is affected by the same determinants and that different aspects of life are equally important for everyone. The individual approach represents a paradigm shift in the measurement of quality of life, according to Philip Moons. “A comparison of quality-of-life measures derived from healthy people (controls) with those from patients with congenital heart disease suggested that both groups basically perceive the same issues to be important. This finding provides crucial information for health-care professionals to improve their understanding of the consequences of heart defects on patients' quality of life”, Moons says.

Family first, not money

Moons’ research has detected 12 important factors contributing to the quality of life of adult patients with congenital heart diseases. Most patients identified general issues, such as family, job or education, friends, and health to be important determinants. The relative importance was highest for family, then health, friends, and future. “Quality-of-life research often focuses on health-related quality of life. Patients' health is consistently identified as an important determinant. However, only 59% of patients with congenital heart disease identified health as an important determinant of quality of life. Moreover, a fairly equal number of patients and healthy controls identified health as important. By focusing on health-related quality of life, investigators substantially overestimate the effect of health-related factors and seriously undervalue the effect of non-medical determinants”, Philip Moons explains.  One significant difference between patients with congenital heart disease and healthy people in this study was that financial means and material well-being was an important determinant in twice as many controls as patients. “Patients with congenital heart disease rated material aspects in proper perspective”, Moons says.

Better quality of life

Several studies have been done to find out more about quality of life and congenital heart disease. Most of these studies focus on adolescent and adults because of the methodological challenges of measuring quality of life for children.
Philip Moons and his colleagues have investigated whether the severity of congenital heart disease is associated with quality of life and the perceived health of adult patients. After checking and cross-checking all possible factors, they noted no link between the two. Earlier studies have shown that patients with Fallot’s tetralogy rated their quality of life higher than did patients with atrial septal defect, even though Fallot’s tetralogy is considered a more severe diagnosis. Another study noted that subjectively perceived health status was fairly even in patients with four different diagnoses.

Moons’ study concluded that the overall quality of life of adults with congenital heart disease was good, in fact even better than that for the average population.

The severity of the heart defect only has a determinist effect when it is measured in terms of poor functional status. In Moons’ study, and in others, health status is perceived to be significantly lower by cyanotic patients than by others.

In all studies, severity is measured not only by the heart defect itself or patients’ functional status, but also in terms of the number of surgical procedures. “Patients’ assessment of their quality of life relates more to functional status than to the initial diagnosis”, concludes Philip Moons.

The role of neurodevelopment

Gil Wernovsky, from The Cardiac Center at The Children’s Hospital of Philadelphia and the University of Pennsylvania, has shown that the quality of life for children with congenital heart disease is not as good as it could be, and he calls for new approaches. His experience is that the neurodevelopmental burden of disease for many children and their families is much more substantial than is the daily effect of their disease. He says: “Many families of teenagers with complex congenital heart disease and significant learning or behavioural problems openly ask me why they were not informed of these potential problems when their child was born. It is of little comfort when I explain that when their child was born in the late 1980s and early 1990s, there were simply not enough school-aged survivors to know the true effect of congenital heart disease and its management on long-term quality of life”. However, more knowledge is now available. Wernovsky believes that factors in the intensive-care unit should be investigated as rigorously as have those in the operating room. “We need to be more critical of our current strategies as being right. We could find that our practices and established techniques might be all wrong”, he bluntly concludes.


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Moons P, Marquet K, Budts W, De Geest S. Validity, reliability and responsiveness of the "Schedule for the Evaluation of Individual Quality of Life – Direct Weighting" (SEIQoL-DW) in congenital heart disease, www.hqlo.com/content/2/1/27, accessed 5/11/2008.

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Moons P, et al. Health status, functional abilities and quality of life following the mustard or senning operation, Ann Thorac Surg 2004; 77: 1359–65;

Wernovsky G. Improving neurologic and quality-of-life outcomes in children with congential heart desease: past, present and future, J Thorac Cardiovasc Surg 2008; 135: 347–54.

Wikipedia: Quality of life: en.wikipedia.org/wiki/Quality_of_life, accessed 6/11/2008

Author(s): Marit Haugdahl
Reviewed by: Prof. Philip Moons
Last updated: 2008-09-22

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Comments on this article

06.03.2009 | Edward Callus, Italy
The relationship between disease severity and health related quality of life or emotional functioning in adults with congenital heart disease population has already been investigated in various studies (1-5) and in most of them no association was found. The weak negative association between the severity of congenital heart disease and perceived health (3) in these patients indicates that denial, achievement motivation and a low knowledge of one’s condition could be moderators between disease severity and quality of life, as also outlined in some studies (2,4,5). Overestimation of the severity of their condition may lead to unnecessary distress. Underestimation of the disease can lead to non-compliance or (risky) behaviour which might negatively influence the health status. Both over- and underestimation of disease severity may negatively influence the health related quality of life. Therefore, it is important to verify if the patients have an accurate idea of their condition and to provide psycho-educational interventions to improve their knowledge when necessary.

1) Chessa, M., De Rosa, G., Pardeo, M., Negura, G. D., Butera, G., Feslova, V., et al. (2005). Illness understanding in adults with congenital heart disease. Ital Heart J, 6(11), 895-899.
2) Kovacs, A. H., Sears, S. F., & Saidi, A. S. (2005). Biopsychosocial experiences of adults with congenital heart disease: review of the literature. Am Heart J, 150(2), 193-201.
3) Moons, P., Van Deyk, K., De Geest, S., Gewillig, M., & Budts, W. (2005). Is the severity of congenital heart disease associated with the quality of life and perceived health of adult patients? Heart, 91(9), 1193-1198.
4) Utens, E. M., Verhulst, F. C., Erdman, R. A., Meijboom, F. J., Duivenvoorden, H. J., Bos, E., et al. (1994). Psychosocial functioning of young adults after surgical correction for congenital heart disease in childhood: a follow-up study. J Psychosom Res, 38(7), 745-758.
5) van Rijen, E. H., Utens, E. M., Roos-Hesselink, J. W., Meijboom, F. J., van Domburg, R. T., Roelandt, J. R., et al. (2003). Psychosocial functioning of the adult with congenital heart disease: a 20-33 years follow-up. Eur Heart J, 24(7), 673-683.
13.01.2011 | ANA RUBILAR, CHILE
Yo me llamo Ana Rubilar Varela, soy Enfermera especialista en paciente critico cardiovascular, trabajo en el Instituto Nacional de Tórax, santiago de Chile. Yo soy portadora de una Cardiopatia congenita: Malformación de Ebstien (Fui operada a los 14 años, actualmente tengo 25). Estoy haciendo una investigación acerca de la Calidad de vida en los pacientes adultos portadores de cardiopatias congenitas atendidos en el hospital donde trabajo, con el fin de determinar como influye su problema de salud en la vida diaria, en lo laboral, en lo emocional, en sus relaciones de pareja, etc. y encontré este articulo que me toca profundamente por la relación que tengo con el tema, tanto en "carne propia" como por mi profesion. y creo que, estudiar la calidad de vida con estos enfermos, es muy relevante para mejorarla, para ayudar a sus familias, para tener reciliencia en esta sociedad altamente competitiva y preocupada de "las apariencias".
04.03.2013 | Victor Varela, Colombia
Ana hoy 4 de MArzo de 2013 me encuentro con este artículo que me ha tocado tambien debido a que tengo una hija de 17 años con CC unico ventriculo y estenosis pulmonar, siempre he querido compartir con personas como usted el tema ya que desde el punto de vista médico a ellos poco les importa "la calidad de vida de los pacientes" me gustaría tener contacto directo ya que he desarrollado toda una experiencia al rededor del caso de mi hija, tanto que muchos médicos se sorprenden de que ella con su complejidad cardiaca pueda vivir de la manera como lo hace, para resumirles mi hija es una persona feliz. Mis correos son: varelaleon@hotmail.com y vivacapacitacion@gmail.com