RESULTS
In this study 815 children were studied. Male to female ratio was 1.38
(male-57.9%, female -42.1%). Age wise distribution showed that 28.22%
of children were in 5-8yrs age group, 33.12 % children in 9-11yrs age
group and 38.65% children in 12-15 yrs. age group. 368 children were
from Marathi medium (45.15 %) and 447 were from English medium schools
(54.85 %).(Table-1).Overall Prevalence of asthma in our study was 6.13
%. Prevalence of asthma in age group of 5-8yrs (6.96%) was more than
that in age group 9-11 yrs. (6.29%) and in age group 12-15 yrs.
(5.39%). This difference was not statistically significant. In this
study, overall male predominance was observed in the children with
asthma. Prevalence of asthma in male children was 6.36%. Prevalence of
asthma in female children was 5.83 %. In age group 5-8 yrs. 7.6%
female had asthma as compared to 6.52% males. In age group 9-11 yrs.
and 12-15 yrs. male predominance was observed (6.53% vs 5.83% and
6.0% vs 5.83% ) respectively .(table-2). Out of 62 children labelled
as probable asthmatics, 50 children were diagnosed as asthmatic after
clinical evaluation. Out of 50 children, 30 were male and20 were female.
Family history of asthma and allergic diseases was present in 30 (60%),
either asthma or allergic diseases in 17 (34%), and no family history
of either in 3 (6%). Family history of asthma is an important
predisposing factor in asthmatic children. In our study, 11.05% (90 out
of 815) of cohort had family history of asthma, while 62% (31 out of
50) of asthmatic children had positive family history. This difference
was statistically highly significant (X^2 = 175.9, p<
0.0001) (Table-3). More number of children with decrease PEFR had family
history of asthma. 58.06% (18/31) of children with family history of
asthma had decreased PEFR as compared to 52.6 % (10/19) children
without family history of asthma. This difference was statistically not
significant (p: 0.70).(Table-4).In children with decreased PEFR it was
found that 64.3% had positive family history of Asthma, 35.7% had no
such history. Family history of other allergic diseases besides asthma
also has significant association with prevalence of asthma. In this
study 7.36% (60/815) of children had positive family history of
allergic diseases. 56 % (28/50) of asthmatics had history of allergic
disease in their family except asthma. This was highly significant (
p< 0.005). (table-3)In children who do not have family history
of allergic diseases 57.1% (16/28) had decreased PEFR. While in
children who do not have family history of allergic disease 54.5 %
(12/22) had decreased PEFR. (P: 0.85).Of asthmatic children 58% had
history of atopic diseases. 56% of these had decrease in PEFR. In this
study 8.05% (36 out of 447) of English medium students suffered from
asthma as compared to 3.8% (14 out of368) of students studying in
Marathi medium. This was significant(p<0.05) (table-1).
Decrease in PEFR was seen in 58.3% of English medium students as
compared to 50% in Marathi medium students(p> 0.05).
DISCUSSION
Asthma is chronic childhood disease with increasing prevalence over past
decades. Environmental factors and genetic factors are contributing for
the same. Pune is one of the most rapidly growing cities of India. In
Pune, prevalence reported in 2004 by ISAAC phase 3 was 2.9%. While a
study by Maria Cheraghi et. al. in 2009 and 2012 showed a prevalence of
5.4% and 6.7% respectively. (4).There was an increase in the
prevalence of asthma by 130%in a decade. These were questionnaire based
studies, where diagnosis of probable asthma was done by analysis of
response sent by parents. The diagnosis was not confirmed by clinical
examination. Prevalence of Asthma in present study was 6.13% .In our
study, prevalence of asthma in age group 5-8 yrs. was 6.96%, in age
group 9-11 yrs. was 6.29% and in age group 12-15 yrs. was 5.39%. A
similar age wise prevalence of asthma of 7% among 6-7 yrs. old and 6.3
% amongst 13-14 yrs. olds was reported from Pune .(4).An Iranian study
by HadiBazzazi et al found prevalence of 7% in children aged 12-13 yrs.
(6).As compared to 2012 Pune study, there was no increase in prevalence
of asthma in our study. Unlike previous study,we had taken a detailed
history and done examination and investigations of 62 probable
asthmatics diagnosed by the questionnaire. We excluded 12 probable
asthmatics as on examination we could not confirm the diagnosis of
asthma in them .In spite of excluding 12 probable asthmatics from 62
probable asthmatics the prevalence of asthma in this study was 6.13%
.We found male predominance in asthmatics. Prevalence of asthma in males
was 6.36% and females were 5.83%. Male to female ratio was 1:1.5 .Most
of the studies have reported male predominance in prevalence of asthma.
(7,8,9).Jain et.al. considered that to
increase bronchial responsiveness in males. (10).S. K. Chhabra reported
prevalence of 12% in males as compared to 11.2% in females.
(8).Similarly Renata Gontijo et. al .reported prevalence of 8.1% and
6.1% respectively in males and females. (11).In our study 11.5% of
children in cohort of 815 had family history of asthma. While in
asthmatic group 62% children had family history of asthma. This
correlation was highly significant (p< 0.0001). Similar strong
relationship between family history of asthma and asthma has been
reported previously. (8,10).First detailed study for asthma inheritance
was conducted by Cook and Vander Veer in year 1916 . They came to
conclusion that familial association was due to genetic component.
(7,12). In this study we found strong association between family history
of allergic diseases and asthma. 7.36 % of 815 children had family
history of allergic disorder, while 56% of asthmatic had family history
of allergic disorders. Anzhela V. Glushkovaet .al.found that family
history of allergic disease had highly significant association with
prevalence of asthma in children. (13). Hadi Bazzaziet. al. that 30.2%
of asthmatic children had family history of allergic disorders with
strong association between family history of allergic disorders and
asthma. (6)PEFR was performed at the time of confirmation of diagnosis.
This was a baseline PEFR irrespective of the clinical symptoms. Hence
the difference in PEFR value was not significant in children with
predisposing factor and children without them.Out of 28 children with
family history of allergic disorders 57.1 % had decreased PEFR as
compared to 42.9% of children with no family history of allergic
disorders. 58.06% of children with family history of asthma had
decrease in PEFR as compared to 41.9% of children In children who do
not have family history of ashtma. We discovered that children who had
both family history of asthma and family history of allergic disease had
higher incidence of low PEFR as compared to those who had either or
none. This may indicate higher chance of asthma being triggered by minor
triggers in these children. Prevalence of asthma was 8.05% in students
of English medium school, and was 3.8% in students of Marathi medium
school. Children from
Marathi medium were from lower socioeconomic class as they were from
government school and were from an area away from the city. Students
from English medium were from a private school located in the crowded
area of city. Dr Strachan’s theory that children in larger families were
exposed to more infection , resulting in healthier immune system that
were less likely to mistake harmless substances for allergen . A similar
difference of 7.3%and 5.8 % in private and public schools respectively
was reported by Maria Cheraghi et.al.
(4).They stated that this was because students of private schools were
from higher socioeconomic class as compared to public schools catering
to lower socioeconomic class.The strength of this study was that after
screening using ISAAC, probable asthmatics were examined and
investigated. Children not confirming to diagnosis of asthma were not
included. PEFR was performed in all asthmatic children, which was not
the feature of other studies. Doing study in two schools was the
limitation.