Abstract
Background
Evidence on risk factors for a complicated course of lower respiratory tract infections (LRTIs) in primary care remains limited and often consensus based. While socioeconomic status (SES) and migration background have been linked to complicated LRTIs in population-based studies, their predictive value in primary care remains unclear. Consequently, these factors are not incorporated within current guidelines, which may contribute to health inequalities. Therefore, we aimed to evaluate the added value of SES and migration background as predictive factors of a complicated course of LRTIs in primary care.
Methods
Routine care data from Dutch general practices participating in the Extramural LUMC Academic Network database (Leiden-The Hague-Zoetermeer region) from 2014 to 2023, excluding COVID-19 years, was linked to sociodemographic and hospital claims data from Statistic Netherlands. Adults presenting with LRTI complaints were included (n = 145,445). Multivariable logistic regression models were constructed to predict 30-day hospitalisation or death following LRTI. Models included conventional risk factors with SES and migration background subsequently added.
Results
In this study we show that after adjusting for conventional clinical factors, SES is a strong predictor of a complicated course of LRTI, whereas migration background is not. Patients in the lowest SES category have an adjusted odds ratio of 1.46 (95%CI: 1.31 – 1.62) for a complicated course compared to the highest.
Conclusions
SES is a strong predictor of a complicated course of LRTI in primary care, even after adjusting for conventional risk factors. The incorporation of SES into clinical decision tools and guidelines has the potential to enhance risk-stratification of patients with LRTI in daily practice of primary care, thereby supporting more equitable care.
Plain language summary
Lower respiratory tract infections, such as pneumonia, are common and sometimes lead to hospitalisation or death in severe cases. Currently, general practitioners use age and health conditions to assess risk, but social factors like socioeconomic status (SES) and migration background are not considered. This may lead to unequal differences in health outcomes. We analysed data from adults in Dutch general practices to see if these social factors improve predictions of severe outcomes within 30 days. We found that SES is an important predictor, even after accounting for other risk factors, while migration background had no significant effect. These findings suggest that including SES in future prediction tools and guidelines could help achieve a more equitable identification of patients at increased risk.
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Data availability
The data that support the findings of this study may be obtained from a third party and cannot be shared publicly due to the current Dutch legislation for data protection of Statistics Netherlands data. Data is stored by Statistic Netherlands. Under certain conditions, the dataset and additional microdata are accessible for statistical and scientific research and must be directly requested from Statistics Netherlands (microdata@cbs.nl). Source data for Fig. 1 and Fig. 2 are provided in Supplementary Data 1.
Code availability
All code required to reproduce the results of this study are disclosed through a repository on GitHub: https://github.com/elan-dcc/VanDokkum2648. All analyses were performed in Stata (Stata Corp 2023. Stata Statistical Software: Release 18. College Station, Texas, USA: Stata Corp LLC).
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Acknowledgements
The study was not funded by a specific grant from any funding agency in the public, commercial or not-for-profit sectors.
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All authors contributed equally to the conceptualisation of the study. Study design and methodology: HB CvN EDvD SlC. Literature search: EDvD and NK with contributions from HB and CvN. Data curation and data analysis: EDvD and NK with substantial contributions from HB and SlC. Data interpretation: EDvD, NK, HB and CvN with substantial contributions from all authors. Visualisation of results: EDvD, NK, HB and CvN with contributions of all authors. EDvD wrote the first draft of the manuscript with inputs from NK, HB, and CvN. All authors reviewed and revised drafts of the manuscript and approved the final version. EDvD, NK, and HB have full access to and have verified all the study data provided for the analysis.
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van Dokkum, E.D., Kraaijenbrink, N., Le Cessie, S. et al. Socioeconomic status and migration background as predictors of complicated lower respiratory tract infections in primary care. Commun Med (2026). https://doi.org/10.1038/s43856-026-01542-5
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DOI: https://doi.org/10.1038/s43856-026-01542-5
