University of Oulu

Mäkikyrö, Elina M. S., Jaakkola, Maritta S., Jaakkola, Jouni J. K. Subtypes of asthma based on asthma control and severity : a latent class analysis. Respir Res 2017, 18:24

Subtypes of asthma based on asthma control and severity : a latent class analysis

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Author: Mäkikyrö, Elina M. S.1,2; Jaakkola, Maritta S.1,2; Jaakkola, Jouni J. K.1,2
Organizations: 1Center for Environmental and Respiratory Health Research (CERH), University of Oulu
2Medical Research Center Oulu (MRC Oulu)
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.5 MB)
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Language: English
Published: Springer Nature, 2017
Publish Date: 2017-04-21


Background: Asthma subtyping is a complex new field of study. Usually both etiological and outcome factors of asthma have been used simultaneously for subtyping thus making the interpretation of the results difficult. Identification of subtypes of asthma based on questionnaire data only will be useful for both treatment of asthma and for research. Our objective was to identify asthma subtypes that capture both asthma control and severity based on easily accessible variables.

Methods: We applied latent class analysis for the 1995 adult asthmatics, 692 men and 1303 women, of the Northern Finnish Asthma Study (NoFAS). The classifying variables included use of asthma medication within the last 12 months, St. George’s Respiratory Questionnaire score, and asthma-related healthcare use within the last 12 months. Covariates adjusted for included COPD, allergic rhinitis/allergic eczema, BMI, age and sex. All information was based on self-administered questionnaires.

Results: We identified four subtypes for women: Controlled, mild asthma (41% of participants); Partly controlled, moderate asthma (24%); Uncontrolled asthma, unknown severity (26%), and Uncontrolled, severe asthma (9%). For men we identified three subtypes: Controlled, mild asthma (31%); Poorly controlled asthma, unknown severity (53%); and Partly controlled, severe asthma (17%). For almost 96% of the subjects this subtyping was accurate. The covariates fitted in the model were based on clinical judgment and were good predictors of class membership.

Conclusions: Our results show that it is possible to form meaningful and accurate asthma subtypes based on questionnaire data, and that separate classification should be applied for men and women.

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Series: Respiratory research
ISSN: 1465-9921
ISSN-E: 1465-993X
ISSN-L: 1465-9921
Volume: 18
Article number: 24
DOI: 10.1186/s12931-017-0508-y
Type of Publication: A1 Journal article – refereed
Field of Science: 3142 Public health care science, environmental and occupational health
Funding: This work was funded by grants from the Emil Aaltonen Foundation, the Research Foundation of the Pulmonary diseases, The Väinö and Laina Kivi Foundation, and the Finnish Anti-Tuberculosis Association.
Dataset Reference: The data is stored in the facilities of the Center for Environmental and Respiratory Health Research. Due to the nature of the data set (data collected from the rosters of the The Social Insurance Institution of Finland) we are not allowed to publish online the data set or its’ parts.
Copyright information: © The Author(s). 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.