The aims of this study are to know if subjects at-risk were aware of their 50% risk for Familial Amyloidotic Polyneuropathy (FAP); to know the value of the subjective risk; to understand the association between sociodemographic characteristics and risk perception, and between the risk status and the subjective perception of risk. 174 subjects 50% at-risk for FAP were tested. 52.9% subjects at-risk were aware of their 50% risk condition. The mean value of the subjective risk was higher and closer to 50% when the subjects were aware of their 50% risk condition. Education was associated to a higher awareness of being at 50% risk. It seems that information on previous knowledge before performing the genetic counselling increases the subjective risk.
Los objetivos de este estudio son saber si los sujetos en riesgo eran conscientes de su riesgo del 50% para la polineuropatía amiloide familiar (PAF); conocer el valor del riesgo subjetivo; y comprender la asociación entre las características sociodemográficas y la percepción del riesgo y entre el riesgo real y la percepción subjetiva del riesgo. Se examinaron 174 sujetos con riesgo de PAF del 50%. 52,9% de los sujetos en riesgo eran conscientes de su condición de riesgo del 50%. El valor medio del riesgo subjetivo fue mayor y más cercano al 50% cuando los sujetos eran conscientes de su condición de riesgo del 50%. La educación se asoció a una mayor conciencia de estar al 50% de riesgo. Parece que la información sobre los conocimientos previos antes de realizar el asesoramiento genético aumenta el riesgo subjetivo.
Risk perception is understood as the ability of a subject to discern a certain amount of risk, while risk tolerance refers to a person’s capacity to accept a certain amount of risk (
Risk perception has become increasingly important in the last years, receiving particular attention for its influence on the attitudes and decisions of subjects and social groups regarding the acceptance of various modern technologies and activities, such as nuclear energy and gene technology (
As a consequence of the growth of knowledge and of an increasing number of genetic tests, genetic counseling can be offered to more and more subjects, couples and families (
Familial Amyloidotic Polyneuropathy (FAP) is a progressive neurodegenerative disease, inherited as an autosomal dominant trait (
A protocol of genetic counselling and psychosocial evaluation and support, before and after pre-symptomatic testing (PST), is thought to be important to a healthy adjustment to the test results (
According to
It is extremely important to realise what is the psychological meaning of being at 50% risk for FAP. This risk influences the entire life of the subject at-risk for this specific disease. Although the risk to develop the disease decreases gradually with age, at-risk subjects for FAP are never entirely sure that they have escaped the disease. In fact, the variable age of onset is an additional source of uncertainty (
The aims of the study are mainly four (i) to estimate how many subjects at-risk are aware of their 50% risk condition; (ii) to estimate the subjective risk of subjects at-risk; (iii) to verify if there is any association between the sociodemographic characteristics of the subjects and their risk perception; and (iv) to clarify the association between the risk status and the subjective perception of risk.
The considered hypothesis are two: (i) subjects at-risk who perform the PST, already aware of their 50% risk condition, will estimate their risk closer to 50% than the subjects at-risk who are not aware of their risk status, and (ii) subjects at-risk who undergo the PST, aware of their 50% risk, will estimate their risk lower than the subjects at-risk who are not aware of their risk status.
174 subjects at-risk, presenting a genetic risk of 50% for FAP, were studied. Subjects at-risk with a genetic risk of 50% are the subjects who descend from a progenitor, or had at least one brother with a molecular diagnosis of carrier. These subjects were asymptomatic, aged equal or older than 18 years and they had not been yet tested for the disease. The definition of 18 years as the minimum age to participate in this study is related with ethical and legal problems arising when persons ask for genetic testing for persons younger than 18 years. Exceptionally, young people aged 17 are accepted if they become 18 during the genetic counselling process. All the subjects at-risk were registered in the genetic counselling programme of the Center for Predictive and Preventive Genetics (CGPP), in order to know their genetic status, and have accepted to participate in the present study.
The studied sample included 104 (60%) women and 70 (40%) men. The age ranged between 17 and 66 years, with a mean age of 27.40 (
The
study was based on a protocol designed and conceived by the authors to study
the awareness, knowledge, and attitudes of Portuguese people concerning the
genetic testing for inherited progressive neurodegenerative late onset diseases.
All individuals have attended consultations for genetic counselling in the
Center for Preventive and Predictive Genetics, Institute for Molecular and Cell
Biology, in order to know their genetic risk for the disease or to know the
risk to transmit the disease. This study’s protocol is applied immediately
before the first counselling protocol session. One of the protocol’s issues
concerns risk perception. The subjective perception of this risk was assessed
with a closed question and a task: subjects at-risk were encouraged to choose
between two options - whether they were aware or not of their risk condition
and then they had to estimate their subjective risk by marking a cross in a
line that starts begging with a 0% risk and ends at a 100% risk, with major
tick marks every 10% (
From a total number of 174 (100%) subjects at-risk for FAP, 159 (91%) answered whether they were or not informed about their risk, until the moment they were being questioned about it. The remaining 15 (9%) subjects at-risk did not understand the question and, for that reason, their answer was not taken into account. Among the 159 subjects that answered about their awareness of the risk, 92 (53%) were aware of their 50% condition of genetic risk, and 67 (39%) were not.
The value of the subjective risk is higher (51%) and closer to 50% when the subjects are aware of their 50% risk condition, than when they were not (45%). There are significant statistical differences regarding the subjective risk, between the subjects that were aware of their 50% risk condition and those who were not [
Analyzing
The difference between the
subjective value of the risk for FAP cannot be considered statistically
significant regarding gender, nationality, and education (women, foreign
citizen, and more educated people present the highest values). On the contrary,
significantly different values are found regarding age, since older subjects
tend to choose a higher value of subjective risk (
The first hypothesis, based on the idea that subjects at-risk, who perform the PST aware of their 50% risk condition, will estimate their risk closer to 50% than the subjects at-risk who are not aware of their risk status, has been confirmed. In fact, the subjective risk is closer to 50% (52%) when the subjects are aware of their 50% risk than when they are not (45%) and the difference is significant. It means that the knowledge of the real risk condition (50%) influences the subjective perception of the risk when compared with the risk perception of those subjects who did not know their real risk condition previously to performing the PST: the knowledge of the objective risk takes subjects to perceive risk closer to the value of the objective risk. This may happen because previous knowledge is usually supported by trained professionals. And, although the communication of the risk may have been misunderstood by the subjects at-risk -because it was not properly contextualized or explained, which can lead to overestimation or underestimation of the risk, according to
The second hypothesis, based on the idea that subjects at-risk who perform the PST aware of their 50% risk condition will estimate a lower risk than the subjects at-risk who are not aware of their risk status, has not been proved. On the contrary, the subjects at-risk conscious of their 50% objective risk estimated a higher risk value than those who were not aware of the objective risk value.
Subjects who were aware of their 50% risk condition had more education than the subjects who were not aware. More educated subjects have a significant amount of previous information regarding the objective risk than those with less education. This is in agreement with the statements of
Older subjects tend to choose a higher value of subjective risk than younger ones. Perhaps it might be stated that older people have less risk tolerance, when considering what
In conclusion, subjects who present a higher subjective risk value are the ones aware of their objective risk value (50%), the most educated individuals and the elderly, that is, the more informed and more experienced subjects. The way in which people approach and evaluate risks is, in fact, influenced by other people (
Knowledge of risk perception in
people at-risk for a hereditary neurodegenerative disease such as FAP allows
psychologists to offer appropriate counselling to patients about the potential
distress they might feel. Moreover, and as
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000 (5). Informed consent was obtained from all patients for their inclusion in the study.
Research article.