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Research Article
TheScientificWorldJOURNAL (2003) 3, 811–825
ISSN 1537-744X; DOI 10.1100/tsw.2003.60
*Corresponding author.
©2003 with author.
811
Lifestyle, Quality of Life, and Health
Søren Ventegodt
1,*
and Joav Merrick
2
1
The Quality of Life Research Center, Teglgårdstræde 4-8, DK-1452 Copenhagen K,
Denmark;
2
National Institute of Child Health and Human Development, Division of
Community Health, Zusman Child Development Center, Ben Gurion University, Beer-
Sheva and Office of the Medical Director, Division for Mental Retardation, Ministry of
Social Affairs, Jerusalem, Israel
E-mails: ventegodt@livskvalitet.org; jmerrick@internet-zahav.net
Received June 15, 2003; Revised July 2, 2003; Accepted July 4, 2003; Published August 22, 2003
This study was performed in order to investigate the connection between lifestyle,
quality of life, and health status by way of a questionnaire-based survey. The
questionnaire was mailed in February 1993 to 2,460 persons aged between 18 and
88, randomly selected from the CPR (Danish Central Register), and 7,222 persons
from the Copenhagen Perinatal Birth Cohort 1959–61.
A total of 1,501 persons between the ages of 18 and 88 years and 4,626
persons between the ages of 31 and 33 years returned the questionnaire
(response rates 61.0% and 64.1%, respectively). Variables investigated in this
study were: alcohol consumption, tobacco consumption, type of diet, amount of
exercise taken, quality of life, self-assessed health status, and number of medical
complaints from which respondent suffered. The results showed that health has a
stronger correlation to quality of life (r = 0.5, p < 0.0001) than it has to lifestyle (r =
0.2, p < 0.0001).
It is concluded that preventable diseases could be more effectively handled
through a concentrated effort to improve quality of life rather than through an
approach that focuses solely on the factors that are traditionally seen to reflect an
unhealthy lifestyle.
KEY WORDS: quality of life, QOL, lifestyle, smoking, alcohol, diet, exercise, health,
prevention, public health, Denmark
DOMAINS: child health and human development, behaviour, behavioural psychology,
social psychology, sociology, clinical medicine, medical care, nursing
Ventegodt and Merrick: Lifestyle, QOL, and Health TheScientificWorldJOURNAL (2003) 3, 811-825
INTRODUCTION
There is a general consensus that many of the diseases that plague the Western world (which are
not the result of external factors such as starvation, micro-organisms, infection, or genetic
defects) are lifestyle related and, as such, preventable through lifestyle changes. Thus, increasing
time and effort is being spent on developing public health strategies to promote “healthy”
lifestyles. However, it is not a simple task to identify and dispel the negative and unhealthy parts
of our modern lifestyle even with numerous behavioural factors that can be readily highlighted
harmful, like the use of alcohol, use of tobacco, the lack of regular exercise and a high fat, low
fibre diet.
However, there is more to Western culture and lifestyle than these factors, and if we focus
only on them we risk overlooking others. We refer to other large parts of our life, for instance, the
way we think about and perceive life (our life attitudes, our perception of reality, and our quality
of life) and the degree of happiness we experience through the different dimensions of our
existence. These factors or dimensions can now, to some degree, be isolated and examined[1,2].
The medical sociologist Aaron Antonovsky (1923–1994) from Ben Gurion University in Beer-
Sheva, who developed the salutogenic model of health and illness[3,4], discussed the dimension,
“sense of coherence,” that is closely related to the dimension of “life meaning” as perhaps the
deepest and most important dimension of quality of life[1,2,3,4]. Typically, the clinician or
researcher, when attempting to reveal a connection between health and a certain factor, sides with
only one of the possible dimensions stated above. A simple, one-dimensional hypothesis is then
postulated, for instance, that cholesterol is harmful to circulation. Cholesterol levels are then
measured, and manipulated, and ensuing changes to circulatory function monitored. The
subsequent result may show a significant though small connection which supports the initial
hypothesis, which in turn becomes the basis for implementing preventive measures, such as a
change of diet. The multifactorial dimension is therefore often overlooked.
The purpose of this presentation was to use the results of a cross-sectional survey examining
close to 10,000 Danes to show and compare the connections between lifestyle and health, and the
various dimensions of quality of life and health.
METHODS
Population 1 (RH)
The Copenhagen Perinatal Birth Cohort 1959–61[5,6,7,8] is a prospective longitudinal perinatal
study that included all deliveries (over 20 weeks gestation, birthweight over 250 g) that took
place at the University Hospital (Rigshospitalet) in Copenhagen, Denmark during the period of
September 21, 1959 to December 21, 1961. The cohort consisted of 9,006 pregnant women, who
delivered 8,820 live born infants and 362 stillborn or late abortions over 250 g. 170 women gave
birth to twins, three to triplets, and the remainder were single births. The pregnant women were
contacted and examined before delivery as early in pregnancy as possible. In order to evaluate
and code the social, medical, and obstetrical information uniformly, all examinations were done
by the same physician[5]. He also examined all women after delivery and coded information
made by the women herself during pregnancy and also the information describing the events in
the delivery room[7].
The infants were examined by one of three pediatricians on the first and fifth days. Physical
and neurological examinations were conducted. Upon discharge the mothers received a
questionnaire related to child development during the first year, which they brought to the
hospital at the age of 1 year for a physical reexamination (a total of 8,425 children survived 28
days) [6,7,8]. Follow-up physical examinations took place at 3 and 6 years with developmental
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recording done by the mothers between examinations. At a later stage all school health records
were retrieved and coded by one physician[9]. More than 1,000 factors relating to pregnancy,
birth, and child development were collected on each child resulting in numerous scientific
publications over the last 40 years.
In 1993 a new follow-up study was performed and 7,222 of the surviving children were
identified (now aged between 31 and 33 years) and contacted with a nonanonymous
questionnaire[1]. A written reminder to nonresponders was sent a month later resulting in 4,626
usable responses (f = 2,489, m = 2,131) corresponding to a response rate of 64.1%. The response
rate for each individual question was typically a little lower. These 4,626 persons constitute
population 1.
Population 2(CPR)
Using the Danish National Register (CPR-register) 2,460 Danes between the ages of 18 and 88
years were chosen randomly and contacted with the same questionnaire[1]. Of the 2,460
contacted we received 1,501 responses, corresponding to a response rate of 61.0%.
The Questionnaire on Quality of Life
The questionnaire used in the study, “Questionnaire for the Self Evaluation of Quality of Life”
(SEQOL), contained 317 questions with 205 in an easy-to-answer multiple-choice format. The
questionnaire was divided into the following sections: social information, lifestyle, illness,
sexuality, self-perception, life perception, and eight series of questions measuring the quality of
life[13].
The development of the questionnaire and progression of the study was guided by the
following methodological demands for quantitative questionnaire-based quality of life
research[13]:
1. A clear definition of the quality of life.
2. A philosophy of life based on the definition of point 1.
3. A theory that has this philosophy as its framework by
a) deducing questions that are unambiguous, mutually exclusive, and together are
fully exhaustive, and by
b) establishing the relative weighting of each question.
4. A number of response options that might be given a quantitative interpretation on a
fraction scale.
5. Technical checks in terms of reproducibility, sensitivity, well-scaledness, etc.
6. The survey must be meaningful to both researchers, respondents, and those who use the
results.
7. An appreciation of the aesthetic dimension.
The present study followed these requirements[13] with the theoretical basis for quality of life
measurement based upon the integrative quality of life theory[13]. It organises eight individual
theories of quality of life into a spectrum ranging from subjective (self-evaluated) to objective
(externally evaluated) quality of life and spanning a core of theories that consider quality of life
as deriving from human nature or human existence itself (existential theories). These eight
theories or dimensions of life quality were operationalized into eight rating scales, then grouped
into three dimensions:
I. Subjective Dimensions
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1. Immediate, self-experienced well-being
2. Satisfaction with life
3. Happiness
II. Existential Dimensions
4. Needs fulfillment
5. Subjective experience of objective temporal domains (family, work, leisure)
6. Subjective experience of objective spatial domains (satisfaction with social relationships)
7. Expression of life’s potentials
III. Objective Dimension
8. Objective factors (income, employment, education, etc.)
Eighty-five of the questions in the questionnaire were used to measure quality of life along these
eight dimensions. A Likert-scale with five response options was symmetrically arranged around a
neutral midpoint. As an example, well-being was measured by the question, “How are you feeling
now?”, and the response options given were “very good,” “good,” “neither good nor poor,”
“poor,” and “very poor.” The central and precisely worded mid-point (neither good nor poor), the
response options symmetrically aligned up and down the scale (good, poor) and the use of the
same amplifier (very) all combine to suggest that the five points on the scale may be considered
equidistant.
If an underlying scale was selected ranging from 0 to 100%, from the worst imaginable to
the best imaginable quality of life, the five response options may be reasonably positioned at 10,
30, 50, 70, and 90%. In other words, if a respondent checks “good,” his or her well-being is
measured as 70%. In this manner, an approximated ratio scale was obtained, so that means could
be computed and compared.
A weighted mean for the eight quality of life dimensions was computed by subjective and
existential measures, respectively. The resulting overall measure was global (covers all aspects of
life, not merely health-related aspects) and generic (not disease-related or intended for a specific
category of patients).
Significance levels for the relationships between each variable and the measured quality
of life were computed for the continuous variable using classical correlation and a modified
regression[13], while in the case of the discrete variables, every group was tested individually
against the rest of the sample HO: µi = µnon-i (that is, the null hypothesis that the mean quality of
life for a particular group [for example, smokers]) was significantly different from the mean
quality of life for the rest of the population [for example, those that do not smoke]).
The questionnaire has been validated[1,2,10,11], and the measurement instruments (the
rating scales) proved to be valid and sensitive to the same degree as commonly recognised
international instruments. A 1-month and a 3-month test-retest for reproducibility showed
correlation coefficients for the eight instruments ranging from 0.6 to 0.9. A qualitative assessment
of the validity of the questionnaire was performed, in which 80% of the respondents indicated
that the questionnaire items expressed all dimensions relating to their quality of life, 17% were in
doubt, and 3% felt they did not express all dimensions, which was found to be acceptable.
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The Questionnaire on Health in SEQOL
The following questions on health were used in the questionnaire:
1. How do you rate your own physical health now?
physical mental
very good 1 1
good 2 2
neither good nor poor 3 3
poor 4 4
very poor 5 5
2. Do you have any of the following health problems now? (Please circle a number in each row)
No Yes, Yes,
some- a lot
what
pain/discomfort in shoulder or neck? 1 2 3
pain/discomfort in back or buttocks? 1 2 3
pain/discomfort in arms, hands, legs,
knees, hips, or joints? 1 2 3
headache? 1 2 3
a rapid heart beat? 1 2 3
nervousness, restlessness, or anxiety? 1 2 3
stress? 1 2 3
difficulty sleeping or insomnia? 1 2 3
melancholy, depression, or unhappiness? 1 2 3
tiredness? 1 2 3
stomach pain or stomachache? 1 2 3
indigestion, diarrhea, or constipation? 1 2 3
eczema, rash, or itching? 1 2 3
cold, head cold, or cough? 1 2 3
difficulty in breathing or breathlessness? 1 2 3
discomfort in the sexual organs (f)? 1 2 3
The Questionnaire on Lifestyle in SEQOL
The following questions were used in the questionnaire to assess lifestyle:
1. Your eating habits? (Please circle the lines that relate most closely to you)
1 I eat what I like
2 I think I have a healthy diet
3 I think I have an unhealthy diet
4 I have a low calorie diet because of my weight
5 I eat ready-prepared dishes/fast food at least once a week
6 I eat vegetarian food
7 Information campaigns influence my eating habits
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2. How many hours of exhausting exercise do you get a week? (Possibly during work)
1 0 hours
2 about 30 minutes
3 about 1 hour
4 about 2 hours
5 about 4 hours or more
3. How much alcohol did you drink in total last week (i.e., Monday,
Tuesday, Wednesday, and Thursday)?
Ordinary beer (number of pints): ____
Strong beer (number of pints) : ____
Red or white wine (number of glasses): ____
Dessert wine (number of glasses): ____
Spirits (number of drinks): ____
4. How much alcohol did you drink in total last weekend (i.e., Friday, Saturday, and Sunday
inclusive)?
Ordinary beer (number of pints): ____
Strong beer (number of pints) : ____
Red or white wine (number of glasses): ____
Dessert wine (number of glasses): ____
Spirits (number of drinks): ____
5. Was the past week typical of your normal level of alcohol consumption?
1 yes
2 no, more than typical
3 no, less than typical
6. Do you smoke?
1 Yes, daily
2 Yes, now and then
3 No, I stopped less than a year ago
4 No, I stopped more than a year ago
5 No, I have never smoked
7. If yes, how much do you smoke on average?
Number of cigarettes daily ____
Number of cheroots daily ____
Number of cigars daily ____
Amount of smoking tobacco (grams) ____
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RESULTS
Health against Lifestyle
For both populations 1 and 2 we found only a very modest connection between health — in all
dimensions — and lifestyle. We conducted two analyses: a classical correlation analysis (Table 1)
and a regression analysis (Table 2) termed “weighted linear regression”, which compensated for
the number of respondents in the different groups[1].
From the tables we see that where we have significant results only a very small connection
between lifestyle and health existed.
TABLE 1
Pearson Correlation (r, p) between Lifestyle Factors and Health
Self-Evaluated Physical Health Self-Evaluated Mental Health Satisfaction with Health
CPR RH CPR RH CPR RH
(r) (p) (r) (p) (r) (p) (r) (p) (r) (p) (r) (p)
Alcohol
consumption 0.0496 0.0884 0.0124 0.4537 -0.0172 0.5671 -0.3730 0.0261 0.0389 0.1825 0.0158 0.3370
Smoking -0.0604 0.0205 0.0799 0.0001 -0.0311 0.2461 0.0746 0.0001 -0.0524 0.0446 -0.0970 0.0001
Exercise 0.1209 0.0001 0.1495 0.0001 0.0589 0.0284 0.0926 0.0001 0.0898 0.0014 0.1225 0.0001
Diet*
(Healthy/unhealthy)
-0.0046 0.8632 0.0459 0.0020 0.0153 0.0586 0.0343 0.0226 0.0108 0.6835 0.0279 0.0596
Health/unhealthy
lifestyle
0.0886 0.0006 0.1433 0.0001 0.0641 0163 0.1241 0.0001 0.0778 0.0028 0.1309 0.0001 0.
Number of Complaints Overall Health Status
CPR RH CPR RH
(r) (p) (r) (p) (r) (p) (r) (p)
Alcohol
consumption 0.0658 0.0230 0.0513 0.0019 0.0315 0.2981 0.0068 0.6934
Smoking -0.1177 0.0001 -0.1815 0.0001 -0.0740 0.0061 -0.1189 0.0001
Exercise 0.0751 0.0040 0.1054 0.0001 0.1124 0.0001 0.1489 0.0001
Diet*
(Healthy/unhealthy) 0.0315 0.2310 0.0405 0.0062 0.0290 0.2899 0.0557 0.0003
Health/unhealthy
lifestyle
0.0823 0.0021 0.1503 0.0001 0.1073 0.0001 0.1684 0.0001
* Healthy diet was determined by the following factors: fat/low fat, fast-food/not fast-food, vegetarian/not vegetarian, and self evaluated as healthy /
unhealthy by the respondent.
CPR = Sample randomly drawn from the Danish Central Persons Register.
RH= Sample taken from Rigshospitalet (The Copenhagen Perinatal Birth Coh t 1959-61 at University Hospital) or
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TABLE 2
Connection between Lifestyle and Health Expressed through Weighted Linear Regression (a, p)
Self-Evaluated Physical Health Self-Evaluated Mental Health Satisfaction with Health
CPR RH CPR RH CPR RH
(a) (p) (a) (p) (a) (p) (a) (p) (a) (p) (a) (p)
Alcohol
consumption
-2.7 ±9.7 -11.1 ±5.0 -2.9 ±9.3 -12.1 ±5.8 -8.7 ±9.1 -7.4 ±5.1
Smoking
-13.9 ±10.3 -20.1 ±10.5 -4.0 ±10.6 -10.7 ±11.5 -6.1 ±9.7 -11.4 ±10.5
Exercise
7.5 ±3.5 10.0 ±1.9 3.7 ±3.6 6.8 ±2.2 5.0 ±3.4 8.4 ±2.0
Diet**
(Healthy/unhealthy)
6.1 ±7.6 5.1 ±5.1 7.4 ±8.2 3.9 ±5.7 4.0 ±7.7 7.5 ±5.1
Health/unhealthy
lifestyle
13.8 ±8.6 18.8 4.9 12.5 ±8.8 18.0 ±5.4 12.7 ±8.1 15.7 ±4.9
Number of Complaints Overall Health Status
CPR RH CPR RH
(a) (p) (a) (p) (a) (p) (a) (p)
Alcohol
Consumption
1.2 ±5.6 6.2 ±3.5 -5.4 ±6.6 -8.9 ±3.8
Smoking
-5.2 ±6.3 -16.3 ±6.9 -9.6 ±7.3 -14.0 ±7.5
Exercise
2.8 ±2.1 5.0 ±1.3 4.8 ±2.4 7.2 ±1.4
Diet**
(Healthy/unhealthy)
1.6 ±4.9 2.4 ±3.4 4.0 ±5.7 5.2 ±3.7
Health/unhealthy
Lifestyle
7.7 ±5.0 11.9 ±5.8 11.9 ±5.8 15.3 ±3.6
**a is the difference in health between the highest and lowest quality of life group as a percentage of the average health for all groups. p = ±1.96 ×
SE{a}.
** Healthy diet was determined by the following factors: fat/low fat, fast-food/not fast-food, vegetarian/not vegetarian, and self evaluated as healthy /
unhealthy by the respondent.
CPR = Sample randomly drawn from the Danish Central Persons Register.
RH= Sample taken from Rigshospitalet (The Copenhagen Perinatal Birth Cohort 1959-61 at University Hospital)
Health against Quality of Life
Using the same regression and correlation tests as above, we found large and significant
connections between the dimensions of health and quality of life, both in the CPR study and in
the cohort (see Tables 3 and 4).
The analysis showed a large and clear connection between quality of life and health.
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TABLE 3
Pearson Correlation (r,p) between Health and Quality of Life
Self-Evaluated Physical Health Self-Evaluated Mental Health Satisfaction with Health
CPR RH CPR RH CPR RH
(r) (p) (r) (p) (r) (p) (r) (p) (r) (p) (r) (p)
Well-being
0.5020 0.0001 0.4687 0.0001 0.6595 0.0001 0.7052 0.0001 0.5230 0.0001 0.4699 0.0001
Life satisfaction
0.3812 0.0001 0.3667 0.0001 0.6217 0.0001 0.6531 0.0001 0.4369 0.0001 0.3971 0.0001
Happiness
0.2785 0.0001 0.3034 0.0001 0.5162 0.0001 0.5753 0.0001 0.3579 0.0001 0.3322 0.0001
Fulfillment of needs
(approx. Maslow)
0.2457 0.0001 0.3185 0.0001 0.4888 0.0001 0.5155 0.0001 0.2838 0.0001 0.3117 0.0001
Temporal domains*
0.2886 0.0001 0.3454 0.0001 0.5263 0.0001 0.5451 0.0001 0.3206 0.0001 0.3647 0.0001
Spatial domains**
0.3023 0.0001 0.3530 0.0001 0.4560 0.0001 0.4643 0.0001 0.4048 0.0001 0.4378 0.0001
Expression of life’s
potential***
0.2274 0.0001 0.2400 0.0001 0.3264 0.0001 0.4062 0.0001 0.2337 0.0001 0.2457 0.0001
Objective factors
0.1745 0.0001 0.1910 0.0001 0.2142 0.0001 0.2907 0.0001 0.1714 0.0001 0.1892 0.0001
Overall QL 0.3749
0.0001 0.3722 0.0001 0.5232 0.0001 0.5903 0.0001 0.4175 0.0001 0.3899 0.0001
Number of Complaints Overall Health Status
CPR RH CPR RH
(r) (p) (r) (p) (r) (p) (r) (p)
Well-being
0.4513 0.0001 0.4710 0.0001 0.6815 0.0001 0.6830 0.0001
Life satisfaction
0.3876 0.0001 0.4182 0.0001 0.5800 0.0001 0.5855 0.0001
Happiness
0.2775 0.0001 0.3469 0.0001 0.4634 0.0001 0.4991 0.0001
Fulfillment of needs
(approx. Maslow)
0.2749 0.0001 0.3240 0.0001 0.4191 0.0001 0.4736 0.0001
Temporal domains*
0.0307 0.0001 0.3485 0.0001 0.4722 0.0001 0.5162 0.0001
Spatial domains**
0.2848 0.0001 0.3158 0.0001 0.4694 0.0001 0.5065 0.0001
Expression of life’s
potential***
0.1927 0.0001 0.2106 0.0001 0.3170 0.0001 0.3479 0.0001
Objective factors
0.2197 0.0001 0.2480 0.0001 0.2275 0.0001 0.2843 0.0001
Overall QL
0.3621 0.0001 0.3988 0.0001 0.5235 0.0001 0.5588 0.0001
*Family, work, and leisure time.
**Self, others, world.
***Personal relations to all known persons, self, and surrounding world.
CPR = Sample randomly drawn from the Danish Central Persons Register.
RH= Sample taken from Rigshospitalet (The Copenhagen Perinatal Birth Cohort 1959-61 at University Hospital)
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TABLE 4
The Connection between Quality of Life and Health Expressed through Weighted Linear
Regression (a, p)
Self-Evaluated Physical Health Self-Evaluated Mental Health Satisfaction with Health
CPR RH CPR RH CPR RH
(a)* (p) (a) (p) (a) (p) (a) (p) (a) (p) (a) (p)
Well-being
60.8 ±10.3 57.4 ±6.1 0.6595 ±10.5 94.7 ±5.4 58.0 ±9.9 59.4 ±6.1
Life satisfaction
37.2 ±10.5 48.1 ±5.5 80.3 ±9.4 83.7 ±4.9 51.2 ±10.4 49.2 ±5.4
Happiness
39.1 ±14.4 44.5 ±6.9 87.4 ±12.8 95.9 ±6.5 49.8 ±13.6 45.9 ±6.8
Fulfillment of needs
(approx. Maslow)
24.3 ±8.7 50.4 ±14.9 64.1 ±8.1 68.3 ±15.6 28.6 ±8.4 39.4 ±14.8
Temporal domains
27.9 ±11.1 60.6 ±14.9 66.7 ±10.5 87.2 ±14.3 43.5 ±10.6 71.9 ±14.7
Spatial domains**
25.2 ±16.4 42.1 ±5.6 73.5 ±15.8 64.9 ±5.7 58.5 ±15.3 56.9 ±5.4
Expression of life’s potential†
25.4 ±9.6 25.3 ±7.2 32.6 ±10.2 42.8 ±8.0 28.6 ±9.2 25.5 ±7.3
Objective factors
22.7 ±16.6 36.7 ±11.9 17.1 ±19.0 51.2 ±12.6 18.3 ±16.3 37.1 ±12.0
Overall QL
50.7 ±7.6 46.7 ±4.8 7 ±7.9 78.0 ±4.5 55.9 ±7.6 47.8 ±4.8 1.7
Number of Complaints Overall Health Status
CPR RH CPR RH
(a) (p) (a) (p) (a) (p) (a) (p)
Well-being
39.9 ±6.3 48.9 ±4.0 0.7 ±6.2 62.7 ±3.6
Life satisfaction
31.0 ±6.0 42.1 ±3.6 48.0 ±6.3 53.6 ±3.5
Happiness
38.6 ±8.0 44.5 ±4.5 53.4 ±8.9 56.1 ±4.6
Fulfillment of needs
(approx. Maslow)
24.1 ±5.3 45.3 ±9.9 34.2 ±5.7 53.5 ±10.6
Temporal domains*
30.6 ±6.8 36.7 ±9.9 41.3 ±7.1 62.4 ±9.6
Spatial domains**
27.3 ±9.9 28.0 ±3.9 44.5 ±10.3 47.0 ±3.9
Expression of life’s
potential†
12.9 ±5.6 11.8 ±5.1 22.0 ±6.7 22.5 ±5.4
Objective factors
10.9 ±9.7 21.6 ±7.6 15.9 ±11.1 35.6 ±8.2
Overall QL
27.7 ±4.8 36.4 ±3.2 47.2 ±5.0 50.3 ±3.2
a is the difference in health between the highest and lowest quality of life group as a percentage of the average health for all groups. p = ±1.96 × SE{a}.
*Family, work, and leisure time.
**Self, others, world.
†Personal relations to all known persons, self, and surrounding world.
CPR = Sample randomly drawn from the Danish Central Persons Register.
RH= Sample taken from Rigshospitalet (The Copenhagen Perinatal Birth Cohort 1959-61 at University Hospital)
Quality of Life against Lifestyle
To illustrate the above findings it may be worth having a look at the connections between health,
quality of life and lifestyle (see Figure 1, Figure 2, and Figure 3). The important question is, What
is the underlying factor responsible for determining the quality of life? Is it a simple and quite
trivial connection to health status? Or, alternatively, is quality of life determined by numerous
factors over which people have great influence. Is it reasonable to suggest that those with deep
insight and knowledge about life can live their life in such a way that they thrive and maintain
their health, while those who lack knowledge about life live in such a way that quality of life is
not experienced and they become more susceptible to illness?
Of course this cannot be determined conclusively through a cross-sectional survey, and we
continue the work prospectively. But the cross-sectional survey showed a strong connection
between our quality of life and our personal relations — with partner, friends and work
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colleagues — and only a modest connection with objective factors such as annual income and
level of education[12,13].
Lifestyle against health status
40
45
50
55
60
65
70
75
80
85
very healthy healthy neither nor unhealthy very unhealthy
Lifestyle classification
Overall health status rating (0 - 100)
CPR Group
University Hospital Cohort (RH)
Figure 1. Lifestyle against health status. The statistical co-variation is about 10% in both studies. This is a far weaker
co-variation than is seen between quality of life and health (figure 2), suggesting that global QOL is the most important
factor of the two for preventing disease and improving public health.
Quality of life against health status
40
45
50
55
60
65
70
75
80
85
very good good neither good nor poor poor
Quality of life classification
Overall health status rting (0 - 100)
CPR Group
University Hospital Cohort (RH)
Figure 2. Global quality of life against health status. The statistical co-variation is about 40% in both studies. This is a
far stronger co-variation than is seen between lifestyle and health (Figure 1), and between quality of life and lifestyle
(Figure 3), suggesting that global QOL is the most important factor for preventing disease and improving health.
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Quality of life against lifestyle
40
45
50
55
60
65
70
75
80
85
very healthy healthy neither healthy nor
unhealth
unhealthy very unhealthy
Lifestyle classification
Overall quality of life rating (0 - 100)
CPR Group
University Hospital Cohort (RH)
Figure 3: Global quality of life against lifestyle. The statistical co-variation is 5-10% in the two studies. This is a far weaker co-
variation than is seen between quality of life and health (Figure 2). Taken together with the week connection between lifestyle and
health status (Figure 1) the results suggests that lifestyle is only weakly connected to QOL and health. To improve QOL and health
more than a change in lifestyle seems to be needed.
DISCUSSION
The presented data seem to suggest that lifestyle factors have a much smaller connection with
health than normally assumed in the medical world. On the other hand, quality of life, more
specifically the self-evaluated experience of life, showed a very strong connection with self-
evaluated health.
Numerous clinical trials have found links between lifestyle factors and health status, but
perhaps the connection is an indirect one. Perhaps lifestyle is just an indicator of quality of life
and it is quality of life that is the major determinant of health. When we controlled for quality of
life we found, in general, no connection between a healthy/unhealthy lifestyle and self-evaluated
health[13].
It has been demonstrated in the literature that psychotherapy treatments, in which the patient
focuses on emotions and personal relationships, have positive effects on quality of life and
survival[14,15,16], and that radical changes in life behaviours and attitudes can be beneficial to
recovery[14]. There is also evidence to suggest that, in general populations, general well-being is
positively related to life expectancy[17,18].
In view of these studies and our own results, it maybe reasonable to try and improve health
by attempting to directly improve quality of life rather than just changing a particular aspect of
someone’s lifestyle, such as diet or exercise, as is often advised by physicians.
If a strong causal link between quality of life and health could be clearly demonstrated, it
could perhaps be more effective for public health strategists to look at motivating populations to
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identify and improve the aspects of their lives with which they may be unhappy, such as their jobs
or relationships.
By developing our understanding of the link between quality of life and health, greater steps
may be made toward health maintenance and improvement. Seemingly, we lack a structured
science that can integrate the concepts of quality of life, experience and consciousness into
medical theory and clinical practice.
The lifestyle questionnaire is not validated. This is because of the objectivity of the data
collected and the general agreement about the involved factors as the most important ones, and
therefore we have not found validation necessary. A more severe problem with this study is that
we measured health and QOL in very much the same way, while we measured lifestyle
differently. This is a necessity, because the first two mentioned are subjective data, while the third
consists of objective data. Health can be measured objectively in many dimensions such as lung
capacity, physical strength, number of medical diagnosis or use of medication, but to measure
global health subjective judgment is mandatory, either from a doctor or from the person himself.
We believe that the data collected directly from the patient are the most valid. We have done our
best to select reliable data and strongly believe that the presented correllations are not an artefact.
Another critique could be raised against our scientific design, as we have chosen not to use the
most advanced, but instead the simplest possible solutions all the way through the study in order
not to get lost in the complex scenario; we use the motto, “the most simple questionnaire, the
most simple strategies for statistical analysis.” The statistical analysis could have been done much
more elegantly using partial or even nonlinear regression, but we were convinced that the
conclusion would have been very much the same, just wrought with all the uncertainty that
inevitably comes from the use of advanced statistical procedures.
Even if more elaborated studies in the future show that we are wrong in our conclusion, it
can never be harmful to encourage people to focus on improving their QOL and their human
relations in general. We believe the good life can be lived when we feel good about ourselves and
other people, and when we really enjoy the work we do.
CONCLUSION AND QUESTIONS FOR FURTHER RESEARCH
The three most important things we learned from this study are:
• It seemed extremely important to be sharp about the concepts in use.
• We must discriminate between the concept of health itself — the state of body and mind
including emotional and spiritual dimensions, the concept of lifestyle in medicine
normally defined as health-related behaviour, and the concept of global QOL first the
experience of life itself or, in a broader philosophical sense, the state of our existence as a
whole.
• When we measure these three very different dimensions and look at weight of the
statistical connections, it appears that the dimension of most importance for health is not
lifestyle, but rather QOL. QOL and self-assessed physical and mental health are strongly
correlated, while lifestyle is not strongly correlated to either QOL or health.
We therefore must encourage everybody involved with public health issues to be sharp and
precise about their concepts, to include the concept of global QOL in the research, and to focus
on improving QOL in the population, in order to improve the general public health.
Much more research is needed, and the most important question for further research seems
to be how do we improve QOL in the aspects most relevant for health? We must also ask if we
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can actually use QOL as preventative or even curative medicine, in society as a whole, in the
work place, and in the medical clinic [19].
ACKNOWLEDGEMENTS
This paper reported results from the Danish Quality of Life Population Survey, the planning and
execution of which would not have been possible without the aid of Dorte Loldrup Poulsen,
Jørgen Hilden and Bengt Zachau-Christiansen. Funds were received from eleven Danish
Foundations, including The 1991 Pharmacy, the Goodwill, the JL, E. Danielsens & Wife’s,
Emmerick Meyer’s, the Frimodt-Heineken, the Family Hede Nielsen’s, Petrus Andersen’s, C.P.
Frederiksen’s and the Wedell-Wedellsborgs Foundations, and IMK Almene Fond. The research is
approved by the Copenhagen Ethical Committee under numbers (KF) V 100.1762/90 and (KF)
01-502/93.
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825
This article should be referenced as follows:
Ventegodt, S. and Merrick, J. (2003) Lifestyle, quality of life and health. TheScientificWorldJOURNAL 3, 811–825.
Handling Editor:
Hatim A. Omar, Associate Editor for Child Health and Human Development — a domain of
TheScientificWorldJOURNAL.
BIOSKETCH
Søren Ventegodt, MD, is the director of the the Quality of Life Research Center in Copenhagen, Denmark. He is also
responsible for a research clinic for holistic medicine in Copenhagen and used as a popular speaker throughout
Scandinavia. He has published numerous scientific and popular articles and a number of books on holistic medicine,
quality of life, and quality of working life. His most important scientific contributions are the comprehensive SEQOL
questionnaire, the very short QoL5 questionnaire, the integrated QOL theory, the holistic process theory, the life
mission theory, and the Danish Quality of Life Research Survey, 1991–94 in cooperation with the University Hospital
of Copenhagen and the late pediatric professor Bengt Zachau-Christiansen. Website: www.livskvalitet.org/
Joav Merrick, MD, DMSc, is professor of child health and human development affiliated with the Zusman Child
Development Center and Division of Community Health at the Ben Gurion University, Beer-Sheva, Israel and
presently the medical director of the Division for Mental Retardation, Ministry of Social Affairs, Jerusalem and the
director of the National Institute of Child Health and Human Development. He has authored and edited numerous
publications in the fields of child and human development, rehabilitation, intellectual disability, disability, health,
welfare, abuse, advocacy and prevention. Dr. Merrick received the Peter Sabroe Child Award for outstanding work on
behalf of Danish Children in 1985 and the International LEGO-Prize (“The Children’s Nobel Prize”) for an
extraordinary contribution toward improvement in child welfare and well-being in 1987. Website:
www.nichd–
israel.com
