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Amoah AS, McLean E, Price AJ, Amberbir A, Crampin AC. Factors associated with self-reported diagnosed asthma in urban and rural Malawi: Observations from a population-based study of non-communicable diseases. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002952. [PMID: 38990860 PMCID: PMC11239063 DOI: 10.1371/journal.pgph.0002952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 06/05/2024] [Indexed: 07/13/2024]
Abstract
The growing burden of asthma in low- and middle-income countries has been linked to urbanisation and lifestyle changes. However, this burden has not been well characterised in adults. Therefore, we investigated the prevalence of self-reported diagnosed asthma and associated factors in urban and rural adults in Malawi, Southern Africa. Within a cross-sectional population-based survey to determine the burden and risk factors for non-communicable diseases (NCDs) in the city of Lilongwe and rural Karonga district, we collected information on self-reported previously diagnosed asthma and asthma-related symptoms using an interviewer-led questionnaire. Other data collected included: demographic characteristics, socioeconomic status indicators, NCD comorbidities, environmental exposures, and anthropometric measurements. We used multivariable logistic regression models to explore factors associated with self-reported asthma adjusting for variables associated with the outcome in univariable analysis. Findings were corrected for multiple comparisons using the Bonferroni method. We analysed data from 30,483 adult participants (54.6% urban,45.4% rural and 61.9% female). A prior asthma diagnosis was reported in 5.1% of urban and 4.5% of rural participants. In urban females, being obese (>30 kg/m2) compared to normal weight (18.5-24.9 kg/m2) was associated with greater odds of asthma (OR = 1.59, 95% CI [1.26-2.01], p<0.001), after adjusting for confounders. We observed associations between previously diagnosed heart disease and asthma in female participants which remained significant in rural females after Bonferroni correction (OR = 2.30,95%CI [1.32-4.02], p = 0.003). Among rural males, current smokers had reduced odds of diagnosed asthma (OR = 0.46,95%CI [0.27-0.79], p = 0.004) compared to those who had never smoked. In Malawi the prevalence of self-reported diagnosed asthma was greatest in females and urban dwellers. Notably, our findings indicate relationships between excess body weight as well as comorbidities and diagnosed asthma in females. Future investigations using longitudinally collected data and clinical measurements of asthma are needed to better understand these associations.
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Affiliation(s)
- Abena S. Amoah
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi
| | - Estelle McLean
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi
| | - Alison J. Price
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi
| | | | - Amelia C. Crampin
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi
- School of Health and Wellbeing, University of Glasgow, Glasgow, United Kingdom
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Njoroge MW, Mjojo P, Chirwa C, Rylance S, Nightingale R, Gordon SB, Mortimer K, Burney P, Balmes J, Rylance J, Obasi A, Niessen LW, Devereux G. Changing lung function and associated health-related quality-of-life: A five-year cohort study of Malawian adults. EClinicalMedicine 2021; 41:101166. [PMID: 34712931 PMCID: PMC8529201 DOI: 10.1016/j.eclinm.2021.101166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND In Sub-Saharan Africa cross-sectional studies report a high prevalence of abnormal lung function indicative of chronic respiratory disease. The natural history and health impact of this abnormal lung function in low-and middle-income countries is largely unknown. METHODS A cohort of 1481 adults representative of rural Chikwawa in Malawi were recruited in 2014 and followed-up in 2019. Respiratory symptoms and health-related quality of life (HRQoL) were quantified. Lung function was measured by spirometry. FINDINGS 1232 (83%) adults participated; spirometry was available for 1082 (73%). Mean (SD) age 49.5 (17.0) years, 278(23%) had ever smoked, and 724 (59%) were women. Forced expiratory volume in one second (FEV1) declined by 53.4 ml/year (95% CI: 49.0, 57.8) and forced vital capacity (FVC) by 45.2 ml/year (95% CI: 39.2, 50.5) . Chronic airflow obstruction increased from 9.5% (7.6, 11.6%) in 2014 to 17.5% (15.3, 19.9%) in 2019. There was no change in diagnosed asthma or in spirometry consistent with asthma or restriction. Rate of FEV1 decline was not associated with diagnosed Chronic obstructive pulmonary disease (COPD), asthma, or spirometry consistent with asthma, COPD, or restriction. HRQoL was adversely associated with respiratory symptoms (dyspnoea, wheeze, cough), previous tuberculosis, declining FEV1 and spirometry consistent with asthma or restriction. These differences exceeded the minimally important difference. INTERPRETATION In this cohort, the increasing prevalence of COPD is associated with the high rate of FEV1 decline and lung function deficits present before recruitment. Respiratory symptoms and sub-optimal lung function are independently associated with reduced HRQoL.
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Affiliation(s)
- Martin W. Njoroge
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
- Corresponding author at: Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
| | - Patrick Mjojo
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
| | | | - Sarah Rylance
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
| | - Rebecca Nightingale
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Stephen B. Gordon
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
| | - Kevin Mortimer
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Liverpool University Hospital NHS Foundation Trust, Liverpool, UK
| | - Peter Burney
- National Heart and Lung Institute, Imperial College, London, UK
| | - John Balmes
- University of California, San Francisco, United States of America
- University of California, Berkeley, United States of America
| | - Jamie Rylance
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
| | - Angela Obasi
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Louis W. Niessen
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- John Hopkins Bloomberg School of Public Health, Baltimore, United States of America
| | - Graham Devereux
- Department of Clinical Sciences and International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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