7
Validation of a new Brazilian version of the “Night Eating Questionnaire”
ORIGINAL ARTICLE
Validation of a new Brazilian version of the
“Night Eating Questionnaire”
Validação de uma nova versão brasileira do “Questionário alimentar Noturno”
Gleiciane Moreira Dantas1, Thisciane Ferreira Pinto1, Eanes Delgado Barros Pereira2, Renan Montenegro
Magalhães Júnior3, Veralice Meireles Sales de Bruin2, Pedro Felipe Carvalhedo de Bruin2
ABSTRACT
Objectives: The Night Eating questionnaire (NEQ) is regarded
as an important tool for the assessment of the severity of the
Night Eating Syndrome. The objective of this study was to
validate a new Brazilian Portuguese version of the NEQ that could
be easily applied to patients from the public health system. Methods:
In order to develop the Brazilian Portuguese version of the NEQ,
we adopted the following steps: (a) translation, (b) back-translation,
(c) comparison between translation and back-translation and (d)
pretest. Subsequently, intra and inter-observer reproducibility
were assessed in 37 patients from the Endocrinolgy Outpatient
Clinic at the University Hospital of the Federal University of
Ceará, Brazil. The reliability of the questionnaire was evaluated in 90
individuals from the same Institution. The construct validity of the
NEQ was assessed by correlations with clinical variables. Results:
This new translated and culturally adapted version showed excellent
internal consistency (alfa coefficient =0.87) and reproducibility
both intra-observer and inter-observer (individual item coefficients
ranging from 0.95 to 1.0 and 0.92 – 1.0, respectively). Conclusions:
These results indicate that this Brazilian Portuguese version of
the NEQ is a valid and reliable instrument for the assessment
of patients with nocturnal eating problems and is equivalent to its
original version. No major cultural adaptations were introduced to
the questionnaire during the validation process, despite significant
linguistic and cultural differences.
Keywords: adaptation, circadian rhythm, eating disorders, obesity,
questionnaires, sleep.
RESUMO
Objetivos: O Questionário Alimentar Noturno (QAN) é um
instrumento utilizado para avaliar a intensidade dos sintomas
alimentares noturnos e auxiliar na identificação de portadores da
Síndrome Alimentar Noturna. O objetivo do presente estudo foi
validar uma nova versão em português do QAN, culturalmente
adaptada para uso no Brasil. Métodos: Na elaboração da versão
em português, foram seguidas as seguintes etapas: tradução;
retrotradução para o inglês; revisão das traduções e pré-teste. Em
seguida, avaliou-se a reprodutibilidade intra e interobservador
num grupo de 37 pacientes do Hospital Universitário da Universidade Federal do Ceará, Brasil. Finalmente, a confiabilidade
e validade de construção do questionário foram avaliadas em 90
indivíduos obesos e não obesos, usuários da mesma instituição.
Resultados: A escala traduzida e adaptada apresentou excelente
consistência interna (coeficiente alfa de Cronbach = 0,87) e
reprodutibilidade intraobservador (coeficientes entre 0,95 e 1,0)
e interobservador (coeficientes entre 0,92 e 1,0). Escores mais
elevados foram observados entre os indivíduos obesos, comparados aos não obesos (p<0,01). Conclusões: O QAN, na sua presente versão em português, é um instrumento válido e confiável
para aplicação em pacientes brasileiros com sintomas alimentares
noturnos e é equivalente à versão atual em inglês. Nenhuma
modificação relevante foi necessária durante o processo de adaptação e validação, apesar das diferenças linguísticas e culturais com o
instrumento original.
Descritores: adaptação, obesidade, questionários, ritmo circadiano,
sono, transtornos da alimentação.
INTRODUCTION
Night Eating Syndrome (NES) is a common clinical
condition that affects about 1.5% of adults and may be
associated with impaired daytime performance, poor
quality of sleep and excess weight(1,2). NES is currently
characterized by night hyperphagia preceding the onset of
sleep; initial or midphase insomnia; nighttime awakenings,
usually without amnesia and accompanied by eating, and
morning anorexia(3).
NES should be differentiated from Sleep-Related
Eating Disorder, a syndrome in which the abnormal eating
behavior involves the ingestion of bizarre or atypical
foods after partial arousal with a reduced level of consciousness. In such cases, unlike patients with NES, episodes of food intake are usually described as involuntary
or “out of control” and occur with partial or complete
amnesia of the events(4).
NES was originally described more than 50 years
ago in patients with resistant obesity from a specialist
clinic(5). Subsequent studies have generally confirmed the
presence of a significant association between NES and
obesity. In subjects of normal weight, the prevalence
of NES was 0.4%; in contrast, the prevalence of the
disorder was between 6% and 14% for patients seeking
weight reduction treatment(6-8) and 27% in those referred
for bariatric surgery(9). Unfortunately, the data currently
available are insufficient to determine whether NES promotes weight gain and to what extent excess weight can
increase nocturnal food intake(4). The high prevalence of
NES has also been reported in elderly patients with type
2 diabetes (3.8%)(10), in patients with sleep apnea (8.6%)
(11)
and in psychiatric patients (12%), particularly those
presenting with substance abuse(9).
Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará – UFC – Fortaleza
(CE), Brasil.
2
Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal do Ceará – UFC – Fortaleza (CE), Brasil.
3
Departamento de Saúde Comunitária, Faculdade de Medicina, Universidade Federal do Ceará – UFC – Fortaleza (CE), Brasil.
Corresponding author: Pedro Felipe Carvalhedo de Bruin. Departamento de Medicina Clínica - Faculdade de Medicina - Universidade Federal do Ceará. Rua Prof.
Costa Mendes, 1608, 4o andar - Fortaleza (CE), Brazil - CEP 60430-140 - E-mail: [email protected]
Recceived: August 20, 2010; Accepted: August 30, 2011.
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One of the main features of NES is the delay in the
circadian rhythm of food intake. In normal subjects there
is a period of prolonged fasting during nocturnal sleep
that can last about 12 consecutive hours. During this entire
period, mechanisms related to circadian rhythms and sleep
operate together to promote the regulation of glucose
metabolism and appetite modulation. This is contrary to
what can be seen in fasting during sedentary wakefulness,
where glucose levels are gradually reduced(4). In subjects
with NES, a 90-minute delay has been described in the
circadian rhythm of ingestion of calories, carbohydrates
and fats, which is accompanied by a significant delay in
the rhythm of the regulatory hormones insulin and leptin.
There is also a delay in the rhythms of melatonin, cortisol,
prolactin and thyroid-stimulating hormone(1). It is speculated that these changes are due to the involvement of
three distinct neuroendocrine systems: the glucocorticoid
system, the melanocortin system and the serotonergic
system(12).
The Night Eating Questionnaire (NEQ) is an
instrument designed to assess the severity of symptoms
and to assist in identifying patients with NES(13). The
first version of the NEQ in English (unpublished),
contained nine items with four points each on a Likert
scale. The instrument assessed morning anorexia (two
items); nocturnal hyperphagia (one item), initial insomnia (one item); maintenance insomnia (one item); food
intake at night (one item) and mood (three items). With
the increase in knowledge concerning NES, the NEQ was
revised, and new items were included(14). Subsequently,
two updates were published(15,16). The current version of
the NEQ contains 14 items with five options each. The
five new questions were introduced to better address the
psychological aspects of the disorder, such as wishes and
feelings regarding control of night eating and binge eating
to get back to sleep(17).
A critical factor to be considered when using any
questionnaire is its suitability to the country where it will
be used and knowledge of its measurement properties
in that context (i.e., its reproducibility, reliability, validity
and sensitivity to changes). Briefly, reproducibility is a
measure of consistency of results when the questionnaire is repeated at different times (intra-observer reproducibility) or by different observers (interobserver
reproducibility). The intraclass correlation coefficient
is the most suitable for the determination of reproducibility, as it accounts for the variability due to observers,
patients, and random error in its calculation. Reliability
is measured by the Cronbach alpha coefficient, which
assesses the internal consistency of the questionnaire
components(18). The validity of an instrument is its ability
to measure what is intended to be measured. The main
types of validity to be considered when selecting a questionnaire are content, criterion and construction validity.
Content validity concerns the relevance of the questions
that compose the instrument, including understanding
and lack of ambiguity of the scale. Criterion validity refers
to the correlation of the scale with other measurements
of the disease considered the gold standard, which
8
eventually may not be available. Another way to measure
validity is to determine whether there are correlations with
other supposedly related variables. These correlations
derive theoretically from hypotheses that are based on the
concept that the variables being measured are associated(10).
Sensitivity to change is defined as the scale’s ability
to detect changes due to treatment or associated with
the history of the disease. This property is more important
when the measure has an evolving purpose and is of little
relevance to predictive or discriminative instruments.
A Portuguese version of the NEQ(19) was previously
published. For its construction, a translation, back translation,
correction, adaptation and validation of the semantic content were performed. A limitation of that study was the inclusion of individuals from Southern Brazil who had very
high education levels compared to the national average.
It is widely recognized that educational level influences
health and lifestyle outcomes assessed by self-reported
measures. Therefore, it is reasonable to assume that the
comprehension of questions and, consequently, the answers obtained may have been affected(20-23). Because
education level closely reflects the socio-economic situation, it is likely that the subjects studied belonged to a
more favorable socio-economic category than the general
Brazilian population and, therefore, were endowed with
greater cognitive ability and greater access to information
and health services(24).
Given these facts, a new Portuguese translation was
completed in the present study; this was followed by cultural adaptation, with content and construction validation,
and determination of reliability and reproducibility. We
use a more representative sample of public health system
users in an attempt to obtain a more appropriate instrument to be used widely in our country.
MATERIAL AND METHODS
Translation and cultural adaptation of the Night
Eating Questionnaire
The Portuguese translation of the instrument, followed by
cultural adaptation for application to Brazilian patients, was
based on the latest version of the English questionnaire,
which consists of 14 questions, each with five options. In this version of the NEQ, the following aspects
are addressed: morning anorexia (two questions); desires
and control over eating behavior after dinner and before
bed (two questions) and during nighttime awakenings (two
questions); percentage of food consumed after dinner
(one question); insomnia (one question); frequency of
night awakenings and food intake (three questions); mood
swings (two questions); and awareness of nocturnal episodes of food intake (one question)(16). For the translation,
the following steps were performed:
Initial Translation - Two independent translators, aware
of the objectives of the study, translated the English questionnaire into Portuguese. Then the two translations were
compared, and in cases of differences, modifications were
made by consensus.
Back translation - Two new translators, who were
not aware of the goals of the study and without prior
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Validation of a new Brazilian version of the “Night Eating Questionnaire”
knowledge of the questionnaire in English, performed
a back translation (from Portuguese into English). The
two English versions were then compared to the original
questionnaire.
Revision of translations - Researchers met and discussed all differences and discrepancies arising from the
questionnaire translation and back translation processes
and obtained a Portuguese version by consensus.
Evaluation of cultural equivalence - The Portuguese
version was administered to groups of six subjects who
were consecutively recruited among overweight and
obese patients who attended regular appointments at
the endocrinology clinic at the Walter Cantídio University Hospital of the Ceará Federal University (Hospital
Universitário Walter Cantídio / Universidade Federal do
Ceará - UFC). For each question, the patients were asked
to report whether they understood and to provide their
interpretation of the question. After administering the
questionnaires to the six individuals, the authors made
modifications as needed. A final version was obtained
after administering the questionnaire to 12 patients.
Measurement properties of the Night Eating
Questionnaire
Reproducibility - The reproducibility of the final version of the NEQ in Portuguese was measured by applying the questionnaire to overweight or obese patients who
consecutively attended regularly scheduled consultations
at the Endocrinology and Obesity Surgery Clinic of the
UFC Hospital. Patients of both genders, aged between 18
and 60 years, with a BMI above 25 were asked to participate in this stage of the study. We excluded patients
with serious comorbidities, including neoplasms, congestive heart failure, kidney failure or liver failure, amaurosis,
severe psychiatric disorders, history of alcohol or drug
abuse; patients using sedatives or hypnotics; women who
were pregnant or breastfeeding; patients who had previously undergone bariatric surgery; and patients who opted
out. The final sample consisted of 37 patients, 11 with
25≤BMI<30 and 26 with BMI≥30. They completed the
questionnaire in three distinct stages. On the first day, they
were interviewed separately by two investigators (observer
1 and 2) with an average interval of 30 minutes between
interviews to determine interobserver reproducibility. After one week, they were contacted by telephone and interviewed again by observer 1 (intra-observer assessment).
Reproducibility (intra- and interobserver) was calculated
using the intra- and inter-class correlation coefficients, respectively. All interviews were conducted in the morning.
Reliability - The reliability of the scale was determined
by Cronbach’s alpha coefficient, which measures the homogeneity of the components of the scale, i.e., the internal consistency of the 14 items that make up the final score of the
instrument. For this purpose, the scale was administered to
90 adult patients of both genders, with or without overweight
or obesity, with regular follow-up in the Endocrinology and
Obesity Surgery outpatient clinics of the UFC Hospital. Similar exclusion criteria to those described in the previous step
of reproducibility were adopted to evaluate reliability.
Validation - Content validity was determined, as
previously described, for the item of cultural equivalence.
Construct validity was determined through correlation
analysis between the NEQ score and BMI, which was
considered to be an associated variable; this was done concomitant with the reliability assessment.
The study followed international standards for research involving human subjects and was approved by
the UFC Committee on Research Ethics. All participants
signed informed consent forms.
Statistical analysis
Cronbach’s alpha was used to determine the reliability
of the NEQ. We used the inter- and intra-class correlation coefficients to analyze inter- and intra-observer
reproducibility, respectively. In comparing the obese and
non-obese groups, we used Student’s t-test to evaluate the
age, BMI and NEQ total score variables; Fisher’s test was
used to analyze the gender, NEQ≥ 25 and NEQ≥ 30 variables. For the analysis, we used SPSS version 16.0 (SPSS
Inc., Chicago, USA). Data are presented as the mean and
standard deviation (SD) or percentages when appropriate.
The significance level was set at p<0.05.
RESULTS
Translation and cultural adaptation of the Night
Eating Questionnaire
The stages of translation and cultural adaptation of the
NEQ content are summarized in Table 1. The instrument
in its final version is presented in Table 2.
Evaluation of the reproducibility of the translated
and culturally adapted version of the Night Eating
Questionnaire
To assess the reproducibility of the new translated version
of the NEQ, we evaluated 37 patients (mean age (±SD)
of 45.0±11.0 years). Of the sample, 10 (27%) were male.
The educational level was determined in 35 patients and is
as follows: 64.9% finished elementary school, and 29.7%
finished high school. The NEQ score was 13.3±9.5 in patients who completed elementary school and 14.2±6.1 in
patients who completed high school with no significant
difference between groups (p=0.7). The intra- and interclass correlation coefficients were above 0.70 for all questions (Table 3).
Evaluation
of
reliability
and
construct
validity of the translated and culturally adapted
version of the Night Eating Questionnaire
To assess the reliability of the NEQ, 90 patients
were studied (ages ranging from 19 to 78 years
[mean age = 46.2 ± 11.5 years]). Of the sample, 26
were male (28.9%). The BMI ranged from 16.6 to
67.5, averaging 33.6 (± 9.2). The NEQ score ranged
from 1 to 44 points, averaging 11.4 (± 6.9) (Table 4).
Assessing the reliability of the NEQ using Cronbach’s
alpha showed an overall coefficient of 0.87. The alpha coefficient calculated for each item is presented
in Table 5.
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Table 1. Evaluation of semantic equivalence between the original instrument "Night Eating Questionnaire" in English, the translated and backtranslated versions and the final version in Portuguese.
Original version
Translated version
Back-translated version
Final version
1. How hungry are you usually in the 1. Como é geralmente sua fome 1. Are you usually hungry in the 1. Como geralmente é sua fome
morning?
pela manhã?
morning?
pela manhã?
2. When do you usually eat for the 2. Quando você se alimenta pela 2. What time do you have your 2. Quando você geralmente se
first time?
primeira vez?
first meal?
alimenta pela primeira vez?
3. Você tem um forte desejo
3. Do you have cravings or urges to 3. Você tem desejo ou necessidade 3. Do you feel like having snacks
ou uma necessidade de fazer
eat snacks after supper, but before de fazer lanches depois do jantar e after dinner or before going to
lanches no período após o janbedtime?
antes da hora de dormir?
bed?
tar até a hora de dormir?
4. How much control do you have 4. Que controle você tem sobre a 4. Are you able to control your 4. Que controle você tem sobre
over your eating between supper and sua fome entre o jantar e a hora de hunger between dinner and go- sua alimentação entre o jantar e
bedtime?
dormir?
ing to bed?
a hora de dormir?
5. Considerando toda a sua
5. Que quantidade da sua ingestão
5. How much of your daily food intake
5. How much of your daily food ingestão diária de alimentos,
diária de comida você consome dedo you consume after suppertime?
intake you have after dinner?
que quantidade você come depois do jantar?
pois do jantar?
6. Are you currently feeling blue or 6. Você geralmente se sente triste 6. Do you usually feel sad or de- 6. Você geralmente se sente
down in the dumps?
ou deprimido?
pressed?
triste ou na fossa?
7. When you are feeling blue, is your 7. Quando você está triste, seu hu- 7. When you are sad, your mood 7. Quando você está triste, seu
mood lower in the:
mor é mais baixo:
is usually down:
humor é mais baixo:
8. How often do you have trouble get- 8. Com que freqüência você tem di- 8. How often do you have 8. Com que freqüência você tem
ting to sleep?
ficuldade para dormir?
difficulties to sleep?
dificuldade para adormecer?
9. Com exceção de idas apenas ao
9. Other than only to use the
banheiro, com que freqüência você
bathroom, how often do you get up at
se levanta no meio da noite pelo
least once in the middle of the night?
menos uma vez?
9. Quantas vezes por semana
9. Except for going to the
você se levanta no meio da
bathroom, how often do you
noite, sem contar às vezes em
wake up at least once in the midque você vai somente ao bandle of the night?
heiro?
10. Você tem desejo ou necessi10. Do you have cravings or urges to 10. Você tem desejo ou necessidade 10. Do you feel like eating when
dade de comer quando acorda
eat snacks when you wake up at night? de comer quando acorda à noite?
you wake up at night?
à noite?
11. Do you need to eat in order to
11. When you wake up at night, 11. Você precisa comer para
11. Você precisa comer para voltar a
get back to sleep when you awake at
do you need to eat to go back voltar a dormir quando acorda
dormir quando acorda à noite?
night?
sleeping?
à noite?
12. Quando você acorda no meio 12. When you wake up in the 12. Quando você acorda
da noite, com que freqüência você middle of the night, how often no meio da noite, com que
come?
do you eat?
freqüência você lancha?
12. When you get up in the middle of
the night, how often do you snack?
13. When you snack in the middle of 13. Quando você faz um lanche no 13. If you have snacks in the 13. Quando você faz um lanche
the night, how aware are you of your meio da noite, você tem consciência middle of the night are you no meio da noite, você tem
eating?
de que comeu?
aware of your hunger?
consciência de que comeu?
14. How much control do you have 14. Que controle você tem sobre a 14. Do you have control of your 14. Que controle você tem
over your eating while you are up at sua alimentação quando está acor- hunger when you stay awake at sobre a sua alimentação quannight?
dado à noite?
night?
do está acordado à noite?
15. How long have your current 15. Há quanto tempo você tem tido
15. Há quanto tempo você
15. How long have you had diffidifficulties with night eating been go- dificuldades com a alimentação dutem tido dificuldades com a
culties in eating during the night?
ing on?
rante a noite?
alimentação durante a noite?
Table 2. Portuguese version, translated and culturally adapted, of the Night Eating Questionnaire.
1. Como é geralmente sua fome pela manhã?
Nenhuma (0)
Pouca (1)
Alguma (2)
Moderada (3)
Muita (4)
2. Quando você geralmente se alimenta pela primeira vez?
Antes das 9.00 (0)
Entre 9.01 até 12.00 (1)
Entre 12.01 até 3.00 (2)
Entre 3.01 até 6.00 (3)
Às 6.01 ou mais tarde (4)
3. Você tem um forte desejo ou uma necessidade de fazer lanches no período após o jantar até a hora de dormir?
Nunca (0)
Um pouco (1)
Às vezes (2)
Muito (3)
Bastante (4)
4. Que controle você tem sobre sua alimentação entre o jantar e a hora de dormir?
Nenhum (0)
Pouco (1)
Algum (2)
Muito (3)
Total (4)
5. Considerando toda a sua ingestão diária de alimentos, que quantidade você come depois do jantar?
Nada (0)
Menos da metade (1)
Metade (2)
Mais da metade (3)
Quase tudo (4)
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Validation of a new Brazilian version of the “Night Eating Questionnaire”
6. Você geralmente se sente triste ou na fossa?
Nunca (0)
Um pouco (1)
Ás vezes (2)
Muito (3)
Extremamente (4)
7. Quando você está triste, seu humor é mais baixo:
No início da manhã (0)
No fim da manhã (1)
À tarde (2)
No início da noite (3)
No fim da noite (4)
_____ Assinale aqui, caso seu humor não varie durante o dia.
8. Com que freqüência você tem dificuldade para adormecer?
Nunca (0)
Às vezes (1)
Metade das vezes (2)
Geralmente (3)
Sempre (4)
9. Quantas vezes por semana você se levanta no meio da noite, sem contar às vezes em que você vai somente ao banheiro?
Nunca (0)
*********
Menos de uma vez por semana (1)
Cerca de uma vez por semana (2)
Se você marcou “0” na questão 9, por favor, pare aqui
Mais de uma vez por semana (3)
Toda noite (4)
*********
10. Você tem desejo ou necessidade de comer quando acorda à noite?
Nunca (0)
Um pouco (1)
Às vezes (2)
Muito (3)
Extremamente (4)
11. Você precisa comer para voltar a dormir quando acorda à noite?
Nunca (0)
Um pouco (1)
Às vezes (2)
Muito (3)
Extremamente (4)
12. Quando você acorda no meio da noite, com que freqüência você lancha?
Nunca (0)
*********
Às vezes (1)
Metade das vezes (2)
Geralmente (3)
Se você marcou “0” na questão 12, por favor, passe à questão 15
Sempre (4)
*********
13. Quando você faz um lanche no meio da noite, você tem consciência de que comeu?
Nunca (0)
Um pouco (1)
Às vezes (2)
Muito (3)
Completamente (4)
14. Que controle você tem sobre a sua alimentação quando está acordado à noite?
Nenhum (0)
Um pouco (1)
Algum (2)
Muito (3) - Completamente (4)
15. Há quanto tempo você tem tido dificuldades com a alimentação durante a noite?
_______ Meses - _______ Anos
Table 3. Reproductibility coefficient of do QAN by question (n=37).
Intra-observer
Interobserver
Q1
1.00 (0.0)*
1.00 (0.0)**
Q2
1.00 (0.0)*
1.00 (0.0)**
Q3
*
1.00 (0.0)
0.99 (0.0)**
Q4
0.96 (0.0)*
0.94 (0.1)**
Q5
*
0.95 (0.1)
0.92 (0.1)**
Q6
1.00 (0.0)*
0.99 (0.0)**
Q7
*
1.00 (0.0)
1.00 (0.0)**
Q8
0.97 (0.0)*
0.94 (0.1)**
Q9
1.00 (0.0)
1.00 (0.0)**
Q10
*
0.99 (0.0)
0.98 (0.1)**
Q11
1.00 (0.0)*
1.00 (0.0)**
Q12
*
1.00 (0.0)
1.00 (0.0)**
Q13
1.00 (0.0)*
1.00 (0.0)**
Q14
1.00 (0.0)
Intraclass correlation coefficient.
**
Interclass correlation coefficient.
1.00 (0.0)**
*
*
*
Table 4. Age, body mass índex and score of Questionário Alimentar
Noturno (n=90).
RANGE
MEAN
SD
Age
19.0 – 78.0
46.2
+11.5
BMI
16.6 – 67.5
33.6
+9.2
QAN
1 – 44
11.4
+6.9
BMI: Body Mass Index; QAN: Questionário Alimentar Noturno;
SD: standard deviation.
To assess construct validity, the 90 selected patients
were divided into two groups: non-obese (BMI<30) and
obese (BMI≥30). The non-obese group consisted of 41
subjects, 13 of whom were male (31.7%), who had a mean
BMI of 26.6 (±2.6). The mean NEQ score of the nonobese group was 8.6 (±3.8) points. The obese group consisted of 49 individuals, 13 of whom were males (26.5%),
who had a mean BMI of 39.5 (±8.6). The mean NEQ
score in the obese group was 13.73 (±7.91). The mean age
of the non-obese group was 49.4 (±11.9) years, and the
mean age of the obese group was 43.5 (±10.5) years, with
a significant difference between groups (p<0.01). In the
obese group, using an NEQ threshold of 25, 4 patients
were considered positive and 45 patients were considered
negative. When the threshold was 30, 2 patients were considered positive and 47 were considered negative. We observed a statistically significant difference between groups
with and without obesity related to the NEQ (p<0.01)
(Table 6).
DISCUSSION
In this study, a new Portuguese translation and cultural
adaptation of the NEQ was performed with the purpose
of using it on the Brazilian population. We also studied
the properties of the questionnaire with respect to its
reproducibility, reliability and validity. The final translated
version of the questionnaire showed excellent measurement properties.
The need to translate and adapt health measurement scales for use in another language than the original
is widely recognized. This option is preferable to building
a new questionnaire, as it allows for comparisons between
the data obtained in studies from many countries and multinational research projects. It is well known that the scales
should not only be linguistically translated, but must also
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Dantas GM, Pinto TF, Pereira EDB, Júnior RMM, de Bruin VMS, de Bruin PFC
12
Table 5. Cronbach’s alpha coefficien for each question of Questionário Alimentar Noturno (n=90).
Questions
Alpha valeu
1. Como é geralmente sua fome pela manhã?
0.837
2. Quando você geralmente se alimenta pela primeira vez?
0.828
3. Você tem um forte desejo ou uma necessidade de fazer lanches no período após o jantar até a hora de dormir?
0.813
4. Que controle você tem sobre sua alimentação entre o jantar e a hora de dormir?
0.820
5. Considerando toda a sua ingestão diária de alimentos, que quantidade você come depois do jantar?
0.817
6. Você geralmente se sente triste ou na fossa?
0.820
7. Quando você está triste, seu humor é mais baixo?
0.860
8. Com que freqüência você tem dificuldade para adormecer?
0.824
9. Quantas vezes por semana você se levanta no meio da noite, sem contar às vezes em que você vai somente ao banheiro?
0.803
10. Você tem desejo ou necessidade de comer quando acorda à noite?
0.800
11. Você precisa comer para voltar a dormir quando acorda à noite?
0.805
12. Quando você acorda no meio da noite, com que freqüência você lancha?
0.805
13. Quando você faz um lanche no meio da noite, você tem consciência de que comeu?
0.790
14. Que controle você tem sobre a sua alimentação quando está acordado à noite?
0.816
Table 6. General characteristics and evaluation by Questionário Alimentar Noturno according with obesity (90).
Non-obese
Obese
p
(IMC<30)
(IMC≥30)
Age
49.4 ± 11.9
43.5 ± 10.5
0.01*
Gender (M/F)
13/28
13/36
0.64**
QAN
8.6 ± 3.8
13.7 ± 7.9
< 0.01*
QAN ≥ 25 (Yes/No)
0/41
4/45
0.12**
QAN ≥ 30 (Yes/No)
0/41
2/47
0.49**
**
Student’s t test; Fisher’s test; QAN: Questionário Alimentar Noturno;
BMI: Body Mass Index.
*
be culturally adapted to maintain the validity of the content in different populations with different lifestyles. Any
changes resulting from this adaptation may alter the psychometric properties of the instrument. Therefore, it is
highly recommended that preservation of the measuring
properties of the new version be verified after the translation and adaptation process. Thus, the new instrument
should retain the characteristics of the questions, as well
as their relationship with the scale, internal consistency,
and response capacity.
The NEQ was designed as a measure of severity for symptoms related to NES in the USA(13,17). In this
study, in addition to the process of translation and back
translation of the instrument, we conducted a semantic
and cultural equivalence evaluation because without this
step, the adaptation of this instrument loses in terms of
its overall meaning. The Brazilian scale showed excellent
internal consistency, with an alpha coefficient slightly below 0.9. It is believed that an alpha coefficient greater than
0.9 may suggest the presence of redundant items, while
that below 0.7 may reflect low internal consistency(25,26).
The translated version also showed excellent intra- and
inter-observer reproducibility. A theoretical hypothesis
was drawn and correlations were constructed to measure
construct validity. This hypothesis was based on works
from international literature showing that patients with a
high BMI often present with NES symptoms as assessed
by the NEQ(5,9,27). We note that in this translated version
(Questionário Alimentar Noturno - QAN), the NEQ was
in fact positively correlated with BMI, i.e., the greater the
degree of obesity was, the greater the nocturnal eating
disorder.
During cultural adaptation, the NEQ was applied
to adult users of the Unified Health System, which will
supposedly be the main targets of future applications of
the instrument, thus allowing better representativeness in
the study. Stratification by education was also performed,
although the differences in NEQ scores were not statistically significant.
The frequency of patients who were evaluated
by NEQ who presented with NES characteristics in the
obese population of this study was 8.2% and 4.1%, respectively, when using a threshold score greater than or
equal to 25 and a threshold greater than or equal to 30.
Previous studies have reported rates of approximately
1.5% in the general population(1), 9% to 14% in obesity
clinics(7,8) and 9% to 42% among candidates for bariatric
surgery(28,29). The frequency found in this study for the
threshold ≥25 is thus similar to that previously reported
in obesity clinics(7,8).
If we compare this with the other previously published Portuguese version of the NEQ, we can see significant discrepancies in items 3, 9 and 13, and less pronounced
differences in items 5, 7 and 12. In the other items, the sentences can be considered very similar. It is likely that the
differences mentioned contribute to the increased internal
consistency and better understandability of the questions
in this study compared to the previous one. Although the
previous version in Portuguese has shown reasonable internal consistency, there was better psychometric equivalence
when the item assessing mood swings during the day was removed, with alpha coefficient increasing from 0.78 to 0.82.
In this version, the measure of internal consistency proved
to be higher (Cronbach’s alpha = 0.87), and no significant
change compared to the original scale was necessary. It is
also important to emphasize that in the present study, the
sample utilized had an educational level closer to the target
audience of interest for questionnaire administration.
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Validation of a new Brazilian version of the “Night Eating Questionnaire”
In summary, this translated and culturally adapted
version of the NEQ proved to be suitable for application
even in individuals with a low educational level. New studies on the applicability of NEQ using samples stratified
by education level, income level and social class should be
conducted to further evaluate this instrument with more
precision.
REFERENCES
1. Rand CS, Macgregor AM, Stunkard AJ. The night eating syndrome
in the general population and among post operative obesity surgery
patient. Int J Eat Disord. 1997; 22:65-69.
2. Striegel-Moore RH, Dohm FA, Hook JM, Schreiber GB, Crawford
PB, Daniels SR. Night eating syndrome in young adult women:
prevalence and correlates. Int J Eat Disord. 2005; 37:200-206.
3. O’Reardon JP , Ringel BL, Dinges DF, Allison KC, Rogers NL,
Martino NS et al. Circadian Eating and Sleeping Patterns in the
Night Eating Syndrome. Obesity Res. 2004; 12(11):1789-1796.
4. Howell MJ, Schenk CH, Crow SJ. A review of nighttime eating
disorders. Sleep Med Rev. 2009; 13(1):23-34.
5. Stunkard AJ, Grace WJ, Wolf HG. The night-eating syndrome:
A pattern of food intake among certain obese patients. Am J
Med. 1955; 19(1):78−86.
6. Birketvedt GS, Florholmen J, Sundsfjord J, Osterud B, Dinges D,
Bilker W et al. Behavioral and neuroendocrine characteristics of the
night-eating syndrome. JAMA. 1999; 282(7):657-63.
7. Gluck M, Geliebter A, Satov T. Night eating syndrome is associated
with depression, low self-esteem, reduced daytime hunger, and less
weight loss in obese outpatients. Obesity Res. 2001; 9(4): 264-267.
8. Stunkard AJ, Berkowitz R, Wadden T, Tanrikut C, Reiss E, Young
L. Binge eating disorder and the night eating syndrome. Int J Obes
Relat Metab. 1996; 20(7): 1– 6.
9. Lundgren JD, Allison KC, Crow S, O’Reardon JP, Berg KC, Galbraith J, et al. Prevalence of the night eating syndrome in a psychiatric population. Am J Psychiatr. 2006; 163(1):156−158.
10.Allison KC, Crow SJ, Reeves RR, West DS, Foreyt JP, Dilillo VG, et
al. Binge eating disorder and night eating syndrome in adults with
type 2 diabetes. Obesity. 2007; 15(5):1287-93.
11.Olbrich K, Muhlhans B, Allison KC, Hahn EG, Schahin SP,
de Zwaan M. Night eating, binge eating and related features in
patients with obstructive sleep apnea syndrome. Eur Eat Disord
Ver. 2009; 17:120–127.
12.Stunkard AJ, Allison KC, Lundgren JD, O’Reardon JP. A
biobehavioural model of the night eating syndrome. Obes
Rev. 2009; 10(Suppl. 2):69–77.
13.Boseck JJ , Scott G. E, Allison KC, Crosby RD, Mitchell JE, Zwaan
M. The application of ecological momentary assessment to the
study of night eating. Int J of Eat Disord. 2007; 40(3):271−276.
14.Wadden TA, Foster GD. Weight and lifestyle inventory. Philadelphia:
University of Pennsylvania. 2001.
15.Marshal HM, Allison KC, OReardon JP . Night eating syndrome
among nonobese perso. Int J Eat Dis. 2004; 35(3):217-222.
16.
Wadden TA, Foster GD. Weight and lifestyle inventory.
Obesity. 2006; 14(5):99-118.
17.Allison KC, Lundgren JD, O’Reardon JP, Martino NS, Sarwer DB,
Wadden TA, et al . The Night Eating Questionnare (NEQ): Psychometric properties of a measure of severity of Night Eating Syndrome. Eat Behav. 2008; 9(1):62-72.
18.Streiner DL & Norman GR. - Reliability. In: Streiner, DL. &
Norman, GR. - Health Measurement Scales. A Pratical Guide to their
Development and Use. 2 ed., Oxford Medical Publications. 1995.
19.Harb ABC, Caumo W, Hidalgo MPL. Tradução e adaptação da
versão brasileira do Night Eating Questionnaire. Cad. Saúde
Pública. 2008; 24(6):1368-1376.
20.
Byrne B. The general/academic self-concept nomological
network: a review of construct validation research. Rev Educ
Res. 1984; 54(1):427-56.
21.Chor D, Faerstein E, Melo Alves MG, Lopes CS. How reproducible
is self-reported information on exposure to smoking, drinking, and
dietary patterns? Evidence among Brazilian adults in the Pro-Saude
Study. São Paulo. Med J. 2003; 121(2):63-6.
22.Grassi-Oliveira R, Stein LM, Pezzi JC. Translation and content
validation of the Childhood Trauma Questionnaire into Portuguese
language. Rev Saúde Pública. 2006; 40(2): 249-55.
23.
Reichenheim ME, Moraes CL, Hasselmann MH. Semantic
equivalence of the Portuguese version of the Abuse Assessment
Screen tool used for the screening of violence against pregnant
women. Rev Saúde Pública. 2000; 34(6):610-6.
24.Monteiro CA, Conde WL, Castro IRR. A tendência cambiante
da relação entre escolaridade e risco de obesidade no Brasil
(1975-1997). Cad Saúde Pública. 2003; 19(1):67-75.
25.Cortina JM. What is coeficient alpha? An examination of theory
and applications. J Appl Psychol. 1993; 78(1):98-104.
26.Pedroso RS, Oliveira MS, Moraes JFD. Tradução, adaptação e
validação da versão brasileira da escala Marijuana Expectancy
Questionnaire. Cad Saúde Pública. 2007; 23 (1):63-73.
27.Aronoff N, Geleibter A, Hashim SA, Zammit G. The relationship
between daytime and nighttime intake in an obese nighteater. Obes
Res. 1994; 2(2):145-51.
28.Allison KC, Wadden TA, Sarwer DB, Fabricatore AN, Crerand
CE, Gibbons LM, et al. Night eating syndrome and binge eating
disorder among persons seeking bariatric surgery: prevalence and
related features. Obesity. 2006; 14(S 2):77S−82S.
29.Hsu LKG, Betancourt S, Sullivan, SP. Eating disturbances before
and after vertical banded gastroplasty: a pilot study. Int J of Eat
Disord. 1996; 19(1):23−34.
Sleep Sci. 2012;5(1):7-13
65 - Validation of a new Brazilian version of the Night Eating Questionnaire.indd 13
25/05/2012 19:00:36