Development and validation of a score assessing the risk of severe asthma in primary care

Abstract

Objective

To develop and validate the Asthma Severity-Health Search (AS-HScore), predicting severe asthma risk in Italian primary care. According to the current asthma treatment guidelines, the AS-HScore intended to serve as a clinical decision support system (CDSS) for General Practitioners (GPs).

Methods

Using the Health Search Database (HSD), a cohort of 32,917 asthma-diagnosed patients between 2013 and 2021 was identified. The AS-HScore was developed using multivariable Cox regression in a two-part cohort: development and validation. Candidate determinants were estimated and linearly combined to form the score; its predictive accuracy was evaluated in the validation sub-cohort.

Results

AS-HScore performance in the validation cohort revealed a 73% area under the curve (i.e. discrimination power) and a 22% pseudo-R² (explained variation). Calibration slope of 1.07 indicated strong calibration without rejecting the equivalence hypothesis (p = 0.157). Estimating a mean 10% (SD: 6.8%) 1-year risk of severe asthma, GPs might be provided with risk thresholds for patient categorization.

Conclusion

The AS-HScore emerges as an accurate tool predicting severe asthma risk in the Italian primary care. It therefore shows promising application to enhance asthma care by early identification of severe cases. Implementing a score-based CDSS for Italian GPs holds potential for significantly improving asthma management and patients’ outcomes.

Keywords:

• Severe asthma
• risk assessment
• primary care

Transaprency

Declaration of funding

This article was supported by Astrazeneca. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit it for publication.

Declaration of financial/other relationships

FL, EM and IC provided consultations in protocol preparation for epidemiological studies and data analyses for Astrazeneca, GSK and Chiesi. CC and MU provided clinical consultances for Astrazeneca, GSK and Chiesi. IC is an employee at Genomedics SRL. AP and MG are employees at Astrazeneca. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

FL and IC conceived and designed the research and performed data analyses and drafted the manuscript. AP, MG, MU and CC drafted and critically revised the manuscript. All authors approved the final version before submission.

Acknowledgements

Authors would to thank Serena Pecchioli, MSc, and Elisa Bianchini, MSc, PhD, who provided support for the preparation of the analyses plan and execution of statistical analyses. We would like to acknowledge the network of general practitioners belonging to the Health Search Network.

Data availability statement

No individual patient-level data will be shared.

Ethics statement

This study followed the principles of the Declaration of Helsinki and compliant with the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Disagnosis (TRIPOD) statements. The study protocol was approved by the Scientific Committee of the Italian College of General Practitioners and Primary Care.