TRENDS IN HOSPITALIZATION RATES FROM ASTHMA IN CHILDREN AND ADOLESCENTS IN POLAND

1
TRENDS IN HOSPITALIZATION RATES FROM ASTHMA
IN CHILDREN AND ADOLESCENTS IN POLAND

• Krystyna Szafraniec1, Wieslaw Jedrychowski1,
  Bogdan Wojtyniak2 and Pawel Gorynski2
• 1Chair of Epidemiology and Preventive Medicine,
  Jagiellonian University, Krakow, Poland
• 2 Department of Medical Statistics, National
  Institute of Hygiene, Warsaw, Poland

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Background

• Asthma is considered as an allergic inflammation
  of airways, which causes bronchial obstruction.
• Nowadays, asthma is one of the common chronic
  disease in industrialised countries and its
  prevalence has increased worldwide over the last
  thirty years.
• Its prevalence varies markedly across the
  regions, possible risk factors have been
  identified that may explain the differences in
  asthma prevalence across countries or its rising
  trends.

3
Background
Of the already recognized risk factors for asthma
the strongest are a parental history of asthma
and occurrence of other atopic diseases such as
hay fever and eczema. The environmental factors
include indoor allergens, environmental tobacco
smoke, and possible changes in housing, diet and
life style. There has been long debate about the
possible role of ambient air pollution as a cause
of increase in asthma. The evidence relating air
pollution to asthmatic symptoms is still weak and
inconsistent.
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Background
Though geographical trends of asthma in the world
are clearly variable, numerous countries,
independently of their economic status, have
confirmed increasing prevalence of childhood
asthma.
The increase began in the 1970s and the range of
increase doubled at least.
Changes in prevalence of asthma ever diagnosed in
children and young adults
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Aims of the study

• To assess the time trends in hospitalization
  rates from asthma in children and adolescents
  below 19 years of age for the last 15 years in
  Poland
• Analyse geographical variation in
  hospitalization from asthma within the country

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Material and Methods

• Data from individual hospital records were used
  to recognize the cause of hospitalization
• Morbidity ratios in 5-year age groups from
  asthma for years 1986-1999 were calculated
• Linear regression method was applied to examine
  trends over time

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Results
Hospitalization rates from asthma in children and
adolescents below 19 years of age showed a
consistent rising trends. In the period 1984-1996
the rates doubled for both genders.

• Time trends were highly linear (plt0.001,
  R20.94).
• Hospitalization rates estimated by the
  regression analysis were 1.6-times higher for
  boys than girls.
• Mean annual increase was 12.2 for boys and
  10.6 for girls.

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Results
Trends in hospitalization rates due to childhood
asthma by age groups

• The most steep increase occurred in the children
  under 4 years of age (annually 20.3 for boys
  and 18.9 for girls).
• In the age groups 5-9 yrs and 10-14 yrs mean
  annual gender-related increase range from 10.5 -
  14.1.

Girls Boys
Girls Boys
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Results
Trends in hospitalization rates due to childhood
asthma by age groups

• The slowest increase was in the oldest age group
  (3.7 annually), however, linear trend in this
  group was statistically significant (plt0.001).
• Only in the oldest age group the differences in
  the rates were not gender-related.

Girls Boys
Girls Boys
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Results
Geographical distribution of hospitalization
rates due to asthma in 1999 by provinces was
significantly variable compared with the average
country rate.
The highest overall rates in the northern part of
Poland were observed. They were almost twice as
high as the average country rate of 145/100
000. This trend remained stable for all age
groups except for the children 14-19. The lowest
hospitalization rates, representing 60-75 of
country average were noted for the north-west
provinces.
Hosp. rate / 100 000
161 - 290 121 - 160 90 - 120 missing
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Summary

• The results show that hospitalization rates for
  children with asthma in Poland reflect linear
  increase over the last several years.
• The tendency was typical for the youngest age
  groups.
• Though hospitalization rates were significantly
  lower in girls than boys for each age group, the
  time trends in both groups increased similarly.
• The geographical variability of the
  hospitalization rates due to asthma in Poland is
  not compatible with the hygienic hypothesis of
  asthma and allergic diseases.