Asthma in South African adolescents: a time trend and risk factor analysis over two decades

Background South Africa has undergone major economic and health system changes, impacting the epidemiology of childhood asthma. This study aimed to investigate prevalence time trends of asthma in South African adolescents over two decades and to identify associated risk factors. Methods A cross-sect...

Full description

Bibliographic Details
Main Authors: Cynthia B. Baard, Zoe Franckling-Smith, Jacinta Munro, Lesley Workman, Heather J. Zar
Format: Article
Language:English
Published: European Respiratory Society 2021-04-01
Series:ERJ Open Research
Online Access:http://openres.ersjournals.com/content/7/2/00576-2020.full
id doaj-1e73420cb963460a852fe27fb4112d47
record_format Article
spelling doaj-1e73420cb963460a852fe27fb4112d472021-07-05T08:43:39ZengEuropean Respiratory SocietyERJ Open Research2312-05412021-04-017210.1183/23120541.00576-202000576-2020Asthma in South African adolescents: a time trend and risk factor analysis over two decadesCynthia B. Baard0Zoe Franckling-Smith1Jacinta Munro2Lesley Workman3Heather J. Zar4 University of Cape Town, Dept of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, and the SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa University of Cape Town, Dept of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, and the SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa University of Cape Town, Dept of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, and the SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa University of Cape Town, Dept of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, and the SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa University of Cape Town, Dept of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, and the SA-MRC Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa Background South Africa has undergone major economic and health system changes, impacting the epidemiology of childhood asthma. This study aimed to investigate prevalence time trends of asthma in South African adolescents over two decades and to identify associated risk factors. Methods A cross-sectional survey was conducted in 2017, in a randomised sample of 13–14-year-old Cape Town adolescents, using the standardised Global Asthma Network written, video and environmental questionnaires. Using time-trend analysis, the prevalence and severity of asthma were compared with data from the 2002 ISAAC phase III study. Environmental and social risk factors were analysed. Results A total of 3979 adolescents were included. The prevalence of lifetime and current asthma were 34.5% and 21.3%, respectively, on the self-report written questionnaire, similar to 2002 results. The prevalence of severe asthma in the previous 12 months increased, measured by wheeze limiting speech (7.8% to 11.8%), four or more attacks of wheezing (5.0% to 5.8%) or woken by wheeze on one or more nights per week (5.0% to 6.9%). The video questionnaire revealed increases in lifetime (16.9% to 22.5%), current (11.2% to 18.7%) and severe asthma (12.1% to 14.8%). Multivariate analysis showed associations between current asthma and smoking, female sex, pet exposure and higher socioeconomic status. Severe asthma was associated with smoking, pet exposure, outdoor pollution exposure and informal housing; 33% of those with severe or current asthma had been diagnosed. Conclusion The prevalence of asthma is high, with increasing rates of severe asthma in adolescents. Underdiagnosis is a major concern and reduction in exposure to environmental factors, particularly smoking, and improved socioeconomic development are needed.http://openres.ersjournals.com/content/7/2/00576-2020.full
collection DOAJ
language English
format Article
sources DOAJ
author Cynthia B. Baard
Zoe Franckling-Smith
Jacinta Munro
Lesley Workman
Heather J. Zar
spellingShingle Cynthia B. Baard
Zoe Franckling-Smith
Jacinta Munro
Lesley Workman
Heather J. Zar
Asthma in South African adolescents: a time trend and risk factor analysis over two decades
ERJ Open Research
author_facet Cynthia B. Baard
Zoe Franckling-Smith
Jacinta Munro
Lesley Workman
Heather J. Zar
author_sort Cynthia B. Baard
title Asthma in South African adolescents: a time trend and risk factor analysis over two decades
title_short Asthma in South African adolescents: a time trend and risk factor analysis over two decades
title_full Asthma in South African adolescents: a time trend and risk factor analysis over two decades
title_fullStr Asthma in South African adolescents: a time trend and risk factor analysis over two decades
title_full_unstemmed Asthma in South African adolescents: a time trend and risk factor analysis over two decades
title_sort asthma in south african adolescents: a time trend and risk factor analysis over two decades
publisher European Respiratory Society
series ERJ Open Research
issn 2312-0541
publishDate 2021-04-01
description Background South Africa has undergone major economic and health system changes, impacting the epidemiology of childhood asthma. This study aimed to investigate prevalence time trends of asthma in South African adolescents over two decades and to identify associated risk factors. Methods A cross-sectional survey was conducted in 2017, in a randomised sample of 13–14-year-old Cape Town adolescents, using the standardised Global Asthma Network written, video and environmental questionnaires. Using time-trend analysis, the prevalence and severity of asthma were compared with data from the 2002 ISAAC phase III study. Environmental and social risk factors were analysed. Results A total of 3979 adolescents were included. The prevalence of lifetime and current asthma were 34.5% and 21.3%, respectively, on the self-report written questionnaire, similar to 2002 results. The prevalence of severe asthma in the previous 12 months increased, measured by wheeze limiting speech (7.8% to 11.8%), four or more attacks of wheezing (5.0% to 5.8%) or woken by wheeze on one or more nights per week (5.0% to 6.9%). The video questionnaire revealed increases in lifetime (16.9% to 22.5%), current (11.2% to 18.7%) and severe asthma (12.1% to 14.8%). Multivariate analysis showed associations between current asthma and smoking, female sex, pet exposure and higher socioeconomic status. Severe asthma was associated with smoking, pet exposure, outdoor pollution exposure and informal housing; 33% of those with severe or current asthma had been diagnosed. Conclusion The prevalence of asthma is high, with increasing rates of severe asthma in adolescents. Underdiagnosis is a major concern and reduction in exposure to environmental factors, particularly smoking, and improved socioeconomic development are needed.
url http://openres.ersjournals.com/content/7/2/00576-2020.full
work_keys_str_mv AT cynthiabbaard asthmainsouthafricanadolescentsatimetrendandriskfactoranalysisovertwodecades
AT zoefrancklingsmith asthmainsouthafricanadolescentsatimetrendandriskfactoranalysisovertwodecades
AT jacintamunro asthmainsouthafricanadolescentsatimetrendandriskfactoranalysisovertwodecades
AT lesleyworkman asthmainsouthafricanadolescentsatimetrendandriskfactoranalysisovertwodecades
AT heatherjzar asthmainsouthafricanadolescentsatimetrendandriskfactoranalysisovertwodecades
_version_ 1721318712520212480