Prevalence of asthma-like symptoms by ISAAC video questionnaire in Mozambican schoolchildren.

Abstract

The International Study of Asthma and Allergies in Childhood (ISAAC) video questionnaire was developed to overcome the language and cultural differences in the assessment of asthma-like symptoms.
27 schools were included in the Maputo Asthma and Allergies in childhood Study (MAPAAS) using ISAAC methods, and a video questionnaire (VQ) was administered to 1614 adolescents 13-14 years old of 20 schools located in urban, suburban and semi-rural areas of Maputo (Mozambique). Simultaneously, they also replied to the ISAAC written questionnaire (WQ).
According to the video questionnaire, the prevalence of current asthma was 11.9% (compared with 13.3% using the written questionnaire). Wheezing after exercise in the last year was reported by about 21%. Females reported more frequent wheezing after exercise than males (p < .001). The prevalence of nocturnal cough in the last year was 24.7%, and was more frequent in the suburban area (p < .001). "Severe attacks of asthma" was reported by 11.9% of the individuals. Teenagers instructed in the suburban schools reported more severe asthma-like symptoms than others (p < .05). There was a poor correlation between the WQ and the AVQ3.0 (kappa coefficients varied from 0.09 to 0.24). The lowest agreement was observed for the question regarding severe attacks of asthma. Agreement was better in terms of specificity than in terms of sensitivity.
In spite of the poor agreement between the written and the video questionnaires, the prevalence of asthma symptoms estimated using the video questionnaire confirms that asthma is an important public health problem in Maputo.

Full text

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Monaldi Arch Chest Dis
2006; 65: 4, 189-195
ORIGINAL ARTICLE
Prevalence of asthma-like symptoms
by ISAAC video questionnaire
in Mozambican schoolchildren
S. Mavale-Manuel1,2,3,4, O. Joaquim4, E. Nunes1,4, A. Pedro1,
S. Bandeira1, E. Eduardo1, C. Macome1, L. Almeida1, A. Cossa1,
J. Malichocho1, L. Maciel1, E. Constance4, S. Marques4, A. Tembe4,
J. de Blic5, I. Annesi-Maesano2,3
Introduction
Recent studies have reported a high prevalence
of asthma symptoms in the world, particularly
among children [1]. Asthma prevalence is variable
among the countries and it is suggested that the
variation may be due to differences in the diagnos-
tic criteria and study methods used. In epidemio-
logical studies, asthma has commonly been de-
fined in the following ways:
1) the self-reporting of asthma (with or without
the physician’s confirmation) or asthma-like
symptoms (wheeze, whistling, nocturnal
cough and exercise induced dyspnoea) [2]; and
2) the existence of bronchial hyperresponsiveness
as assessed by a challenge to special stimuli
(histamine, methacholine, cold air, exer-
cise…).
Indeed, there are potential problems associated
both with asthma-like symptoms arising from sub-
Keywords: Allergy, asthma, children, ISAAC, mozambique, video questionnaires.
1Maputo Central Hospital - Department of Paediatrics, Mozambique.
2INSERM, U707: EPAR, Paris, F-75012 France.
3Université Pierre et Marie Curie - Paris 6, UMR-S 707: EPAR Paris, F-75012 France.
4University Eduardo Mondlane, Faculty of Medicine, Maputo, Mozambique.
5Hôpital Necker Enfants-Malades Paris, France.
Correspondence: Isabella Annesi-Maesano; EPAR UMR-S 707 INSERM, Paris, France; EPAR UMR-S 707 UPMC, Paris 6,
Paris, France; Medical School St-Antoine, 27 rue Chaligny 75571 Paris CEDEX 12, France; e-mail: annesi@u707.jussieu.fr
ABSTRACT: Prevalence of asthma-like symptoms by
ISAAC video questionnaire in Mozambican schoolchildren.
S. Mavale-Manuel, O. Joaquim, E. Nunes, A. Pedro,
S. Bandeira, E. Eduardo, C. Macome, L. Almeida, A. Cossa,
J. Malichocho, L. Maciel, E. Constance, S. Marques,
A. Tembe, J. de Blic, I. Annesi-Maesano.
Background. The International Study of Asthma and
Allergies in Childhood (ISAAC) video questionnaire was
developed to overcome the language and cultural differ-
ences in the assessment of asthma-like symptoms.
Methods. 27 schools were included in the Maputo
Asthma and Allergies in childhood Study (MAPAAS) us-
ing ISAAC methods, and a video questionnaire (VQ) was
administered to 1614 adolescents 13-14 years old of 20
schools located in urban, suburban and semi-rural areas
of Maputo (Mozambique). Simultaneously, they also
replied to the ISAAC written questionnaire (WQ).
Results. According to the video questionnaire, the
prevalence of current asthma was 11.9% (compared with
13.3% using the written questionnaire). Wheezing after ex-
ercise in the last year was reported by about 21%. Females
reported more frequent wheezing after exercise than males
(p<.001). The prevalence of nocturnal cough in the last year
was 24.7%, and was more frequent in the suburban area
(p<.001). “Severe attacks of asthma” was reported by 11.9%
of the individuals. Teenagers instructed in the suburban
schools reported more severe asthma-like symptoms than
others (p<.05). There was a poor correlation between the
WQ and the AVQ3.0 (kappa coefficients varied from 0.09 to
0.24). The lowest agreement was observed for the question
regarding severe attacks of asthma. Agreement was better in
terms of specificity than in terms of sensitivity.
Conclusions. In spite of the poor agreement between
the written and the video questionnaires, the prevalence of
asthma symptoms estimated using the video questionnaire
confirms that asthma is an important public health prob-
lem in Maputo.
Monaldi Arch Chest Dis 2006; 65: 4, 189-195.

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S. MAVALE-MANUEL ET AL.
jective symptoms recognition and recall and with
the under diagnosis of asthma depending either on
the health care system or on age, sex and smoking
habits of the individuals. Furthermore, the afford-
ability of clinical tests like bronchial challenges
depends on the health systems or on resources. The
International Study of Asthma and Allergies in
Childhood (ISAAC) was intended to provide an
accurate assessment of asthma prevalence in chil-
dren from differing language and cultures [4]. The
ISAAC protocol for measuring asthma prevalence
and severity in 13-14 years old schoolchildren
comprises a self-completed written questionnaire
(WQ) based on self-reported asthma-like symp-
toms and a video questionnaire. In the ISAAC
phase I, English speaking countries have reported
a higher prevalence of asthma symptoms [5],
which was attributed also to a better understanding
of the word “wheezing” in English speaking indi-
viduals, as wheezing does not exist in all lan-
guages. The use of video constitutes an attempt to
overcome the translation problems associated with
the written questionnaire as population with differ-
ent cultural and language background may vary
widely in the interpretation of the same questions
[6]. Furthermore, it was suggested that each coun-
try needs to check the validity of both types of
questionnaire provided by ISAAC with its own lo-
cal data [7]. The aim of this study was to evaluate
the concordance between the written and video
questionnaire in Mozambican school children.
Methods
STUDY POPULATION
In the frame of the Maputo Asthma and Aller-
gies in childhood Study (MAPAAS), 21 primary
schools and 6 secondary schools were randomly se-
lected from a total of 126 schools registered in Ma-
puto by stratifying for geographic (urban, suburban
and semi-rural) location and inhabitant’s density so
that to be representative of the distribution of the
population of children and adolescents in Maputo.
Regarding this stratification, 10 were in the urban
area, 12 in the suburban area and 5 in the semi-rur-
al area. All schools but one were public. We select-
ed children by their actual age, regardless of the
grade within the school by selecting several grades.
The inclusion of the right class of age was made by
visiting each classroom in each school and request-
ing those who attained 13 years of age and at most
14 years 11 months to stand up. Those remaining
seated were requested to vacate the class. The oth-
ers were enrolled in this survey. Teenagers were in-
vited to complete a written questionnaire and in a
sub-sample to reply to a video questionnaire.
QUESTIONNAIRES
Written questionnaire
The ISAAC written questionnaires (WQ) was
presented to students in the Portuguese version.
The WQ includes questions on wheezing and
cough symptoms, previous diagnostics of asthma,
and questions on rhinitis and eczema. The written
questionnaire on asthma comprises 5 questions
that correspond to the 5 sequences depicted in the
video questionnaire. The questions on asthma-like
symptoms are:
1) Have you had wheezing or whistling in the
chest in the last 12 months?
2) In the last 12 months, you chest sounded
wheezy during or after exercise?
3) In the last 12 months, how often, on average
has your sleep been disturbed due to wheezing?
(Never woken with wheezing/ less than one
night per week / one or more nights per week).
4) In the last 12 months, have you had a dry
cough at night, apart from a cold or chest in-
fection?
5) In the last 12 months, has wheezing ever been
severe enough to limit you speech to only one
or too words at time between breaths?
Video questionnaire
The International Version of the ISAAC video
questionnaire (AVQ 3.0) was used. The interna-
tional version was developed to make the exercise
sequence more universally applicable, by showing
running rather than indoor aerobic exercise, and al-
so to provide ethnic diversity amongst the subjects
in the video. The video contains five short se-
quences of asthma symptoms and signs. The first
sequence shows a young person seated with clear-
ly audible wheezing, but without breathlessness
and no evidence of airway obstruction. Four fur-
ther sequences shown in the video are:
1) exercise-induced wheezing;
2) walking at night with wheezing;
3) nocturnal coughing; and
4) a final sequence showing a severe attack of
asthma.
Each sequence is followed by three questions
asking the respondent if their breathing has ever been
like the person’s in the video, if “yes” in the last 12
months?” and if “yes” again in the last month?”. The
field researcher read the questions, and teenagers
were asked to mark down whether they themselves
had experienced such symptoms using a one-page
printed answers sheet. The video questionnaire took
about 7 minutes to be administered, and the term
“asthma” was not mentioned during this time.
STUDY DESIGN
After completing the written questionnaire, the
children themselves were shown the video and an-
swered questions at the time. In accordance with
the ISAAC methodology, after the completion of
the WQ, this was collected by members of the staff
and, when the logistic conditions allowed it, ado-
lescents were invited to answer the AVQ3.0.
STATISTICAL ANALYSIS
The Kappa index [8] was used to find the de-
gree of agreement between the ISAAC AVQ3.0
and WQ on asthma symptoms in the last 12
months. Simultaneously the agreement was com-

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ASTHMA ALLERGIES ISAAC CHILDREN MAPUTO MOZAMBIQUE
puted as the ratio of the number of concordant re-
sponses to the total of the population. The data was
entered using Microsoft Office Access 2000 and
analyzed with STATA Intercooled version 8.2
(StataCorp 4905 Lakeway Drive College Station,
Texas 77845 USA).
ETHICAL CONSIDERATIONS
Permission to conduct the study was obtained
from the Bio-ethics committee in Mozambique,
the Department of Schools Education, school Prin-
cipals, the parents of the children and all partici-
pants gave a verbal consent to participate.
Results
Socio-demographic characteristics
SCHOOLS
27 schools participated in ISAAC WQ and 20
schools in both WQ and AVQ 3.0 (77.7%). Con-
trarily as expected, urban schools had fair partici-
pation in video questionnaire (75%). The highest
school participation rate in AVQ3.0 was observed
in the suburban area (90%). Semi-rural areas pre-
sent the lowest participation in AVQ3.0 (table 1).
ADOLESCENTS
2630 children completed the WQ. The video
and written questionnaire was administrated to
1614 children (61%). Of a total of 1614 adoles-
cents, 743 (46%) were male and 871 (54%) fe-
male.
Prevalence of asthma-like symptoms
The global prevalence of current asthma ac-
cording to AVQ3.0 was 11.9% compared to 13.3%
in the case of current wheeze (wheezing in the last
12 months) according to WQ. In the schools of ur-
ban, suburban and semi rural area, the prevalence
of video current wheeze is similar (table 2). Stu-
dents of suburban area reported more frequently
Table 1. - Distribution and location of schools
Location of schools Written questionnaire
(number of schools)
Video questionnaire
(number of schools)
Rate of video participation
(%)
Urban
Suburban
Semi-rural
Total
12
10
5
27
9
9
2
75
90
40
7420
Table 2. - Prevalence of video questionnaire asthma-like symptoms by location of schools
Urban SuburbanRural Total
Freq% Freq% Freq% Freq%P
Population
419 25.9 104664.8 149 9.21614100
Asthma-life symptoms
Wheezing (while at rest)
Ever
In last year
One or more per month
Wheezing after exercise
Ever
In last year
One or more per month
Waking with wheeze
Ever
In last year
One or more per month
Waking with cough
Ever
In last year
One or more per month
Severe attack of asthma
Ever
In last year
One or more per month
85
47
35
20.3
11.2
8.4
234
129
133
22.4
12.3
12.7
29
17
19.5
11.4
6.0
348
193
177
21.6
11.9
10.9
NS
NS
<.059
162
103
86
38.7
24.6
20.5
365
207
243
34.9
19.8
23.2
46
27
25
30.9
18.1
16.8
573
337
354
35.5
20.9
21.9
NS
NS
NS
80
40
36
19.1
9.6
8.6
172
102
97
16.4
9.8
9.3
25
18
16.8
12.1
5.4
277
160
141
17.1
9.9
8.7
NS
NS
<.0018
170
95
74
40.6
22.7
17.7
492
283
274
47.0
27.1
26.2
43
21
17
28.9
14.1
11.4
705
399
365
43.7
24.7
22.6
<.001
<.01
<.001
74
38
25
17.7
9.1
5.6
239
133
140
22.9
12.3
13.4
30
22
18
20.1
14.8
12.1
343
193
183
21.3
11.9
11.3
NS
NS
<.001

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192
S. MAVALE-MANUEL ET AL.
waking with cough ever and in the last year (table 2).
The prevalence of wheezing after exercise in the
last year was about 21%, and there was no location
difference (table 2). The prevalence of nocturnal
cough in the last year was 24.7%. The prevalence
of current waking with wheeze was 9.9%, without
any significant location difference (table 2).
Female schoolchildren reported significantly
more frequent wheezing after exercise (p<.001)
(table 3). No other differences were observed
among sexes.
Severity of asthma
Severe attacks of asthma were reported by
11.9% of the individuals (table 2). Teenagers in-
structed in the suburban schools reported severe
asthma-like symptoms significantly more severe
regardless wheezing while at rest, waking with
wheeze, waking with cough and clearly severe at-
tack of asthma one or more time per month (table
2). Female adolescents reported significantly more
severe attacks of asthma than male (table 3).
Agreement between WQ and AVQ3.0
Agreement between responses to the 5 corre-
sponding questions “wheezing at rest, nocturnal
wheezing, exercise wheezing, night cough and se-
vere wheezing” in the AVQ3.0 and WQ respec-
tively were moderate and weak, although statisti-
cally significant at the level of 0.05, with Kappa
indices varying from 0.09 to 0.24. Severe wheez-
ing yielded the weakest correlation (table 4).
Table 3. - Prevalence of asthma-like symptoms by gender
Male FemaleAll
Freq%Freq% Freq%
Population
74346 87154p 1614100
Asthma symptoms
Wheezing (while at rest)
Ever
In last year
One or more per month
Wheezing after exercise
Ever
In last year
One or more per month
Waking with wheeze
Ever
In last year
One or more per month
Waking with cough
Ever
In last year
One or more per month
Severe attack of asthma
Ever
In last year
One or more per month
154
81
71
20.7
10.9
9.6
194
112
106
22.3
12.9
12.2
NS
NS
NS
348
193
177
21.6
11.9
11.0
236
131
147
31.8
17.6
19.8
337
206
207
38.7
23.7
23.8
<.05
<.05
.05
573
337
354
35.5
20.9
21.9
140
81
66
18.8
10.9
8.9
137
79
77
15.7
9.1
8.8
NS
NS
NS
277
160
143
17.2
9.9
8.9
317
173
160
42.7
23.3
21.5
388
226
205
44.6
26.0
23.6
NS
NS
NS
705
399
365
43.7
24.7
22.6
141
77
71
19.0
10.3
9.6
202
116
112
23.2
13.3
12.9
<.05
.0680
<.05
343
193
183
21.3
12.0
11.3
Table 4. - Agreement between written and video questionnaires
written Questionnaire
video Questionnaire
Yes
Yes
n
Yes
No
n
No
Yes
n
No
No
n
Agreement (%)
Kappa P-value
%%%%
1. Wheeze at rest
2. Exercise wheeze
3. Night wheeze
4. Night cough
5. Severe wheeze
65
75
50
(4)
(4.6)
(3.1)
(6.7)
(1.1)
134
73
106
145
50
(8.3)
(4.5)
(6.5)
(8.9)
(3.1)
128
262
110
291
174
(7.9)
(16.2)
(6.8)
(18)
(10.7)
1287
1204
1348
1070 (66.2)
1371
(79.7)
(74.6)
(83.5)
83.7
79.4
86.6
72.9
86.0
0.24
0.21
0.24
0.17
0.09
<.001
<.0001
<.001
<.0001
<.0001
108
19 (84.9)
P <0.005 indicating significant agreement.

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ASTHMA ALLERGIES ISAAC CHILDREN MAPUTO MOZAMBIQUE
Agreement was better in terms of specificity than
in terms of sensitivity. The lowest Kappa values
were found in the rural zone (table 5).
Discussion
The prevalence of current asthma is 13.3% us-
ing ISAAC written and 11.9% using ISAAC video
questionnaire. To our knowledge, this is the first
study which compares these two types of ques-
tionnaires in African Portuguese speaking coun-
tries.
Although Portuguese is the official language in
Mozambique, there are several traditional lan-
guages. Maputo, the capital, is an urbanised town
and there are miscellaneous of cultures, the pre-
dominant traditional language is Ronga and Xan-
gana. For this survey, we used the Portuguese
translation of ISAAC written questionnaire and the
international version of video questionnaire
AVQ3.0. We did not include tests for bronchial hy-
per-responsiveness due to their high costs.
Only 61% of eligible adolescents have an-
swered the video questionnaire. One of the causes
is due to limitation of material supply (television
and video). Sometimes AVQ3.0 was administrated
one or two days after WQ and in this case we lost
some children. Conversely, video questionnaires
were not easily administered in all schools due to
local logistical conditions such as absence of elec-
tricity. During the WQ, we observed that the ma-
jority of children did not understand well the trans-
lated terms of wheezing in Portuguese “Pieira, as-
sobios no peito ou chios”. Thai’s study shows that
most asthmatic children as well as controls used
terms to describe wheeze different from the ones
chosen by medical personnel [9]. In addition, some
studies suggest that to arrive at the correct preva-
Table 5. - Agreement between written and video questionnaires by zones
Table. 6. - The ISAAC written questions on asthma and their corresponding 5 sequences in the video questionnaire
Written questionnaireVideo questionnaire
1. Have you had wheezing or whistling in the chest in the last 12 months?
2. In the last 12 months, you chest sounded wheezy during or after exercise?
3. In the last 12 months, how often, on average has your sleep been disturbed
due to wheezing? (Never woken with wheezing/ less than one night per week
/ one or more nights per week);
4. In the last 12 months, have you had a dry cough at night, apart from a cold
or chest infection?
5. In the last 12 months, has wheezing ever been severe enough to limit you
speech to only one or too words at time between breaths?
Moderate wheezing at rest
Wheezing after exercise
Waking at night with wheezing
Waking at night with cough
Severe attack of asthma with wheezing
and breathlessness at rest