Evidence map›Paper›PMID 41412617›Full record

ArticleBMJ open2025

Association between weather, air quality and asthma-related emergency department visits: a retrospective time-series study in Singapore.

Ming Ren Toh, Xingdi Wen, Gerald Xuan Zhong Ng, Adam Quek Rop Fun, Puan Youxin, Liesel Fong, Jun Tian Wu, Marcus Ong, David Bruce Matchar, Ngiap Chuan Tan and 4 more

Abstract read
In one paragraph

Article in BMJ open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

14 authors.

Ming Ren TohDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore toh.mingren@gmail.com.ORCID http://orcid.org/0000-0002-7019-9743
Xingdi WenNanyang Technological University, Singapore.
Gerald Xuan Zhong NgDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore.
Adam Quek Rop FunHealth Services Research, Duke-NUS Medical School, Singapore.
Puan YouxinDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore.
Liesel FongDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore.
Jun Tian WuHealth Services Research, Duke-NUS Medical School, Singapore.
Marcus OngHSSR, Duke-NUS Medical School, Singapore.
David Bruce MatcharDepartment of Internal Medicine, Duke University, Durham, North Carolina, USA.ORCID http://orcid.org/0000-0003-3020-2108
Ngiap Chuan TanSingHealth Polyclinics, Singapore.ORCID http://orcid.org/0000-0002-5946-1149
Chian Min LooDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore.
Aziz SheikhNuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Mariko Siyue KohDepartment of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore.
Shao Wei LamHealth Services Research, Duke-NUS Medical School, Singapore.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesTo evaluate the association between asthma-related emergency department (ED) visits and weather, air quality, monsoons, haze and cultural festivals in Singapore.

designRetrospective cohort study.

settingA public healthcare cluster that covers 20% of the nation's adult asthma population.

participants2617 adult patients accounting for 5337 asthma ED visits between 2016 and 2024. PRIMARY AND SECONDARY OUTCOME MEASURES: Temperature, rainfall, wet bulb temperature (WBT), wind speed and Pollution Standards Index (PSI) were correlated with asthma ED counts at 0-7 day lags. Associations between ED visits and monsoons, transboundary haze and cultural festivals were evaluated using one-way analysis of variance. Weekly seasonal ARIMA models with exogenous regressors were fitted, incorporating PSI as a covariate and adjusting for demographic, clinical and socioeconomic factors.

resultsAsthma ED visits were positively correlated with PSI (lag 0: r=0.142; 95% CI 0.107 to 0.178) and inversely correlated with rainfall (lag 3: r=-0.062; 95% CI -0.099 to -0.026) and WBT (lag 1: r=-0.067; 95% CI -0.104 to -0.031). Wind speed (lag 2: r=-0.049; 95% CI -0.086 to -0.013) and ambient temperature (lag 6: r=-0.045; 95% CI -0.081 to -0.008) showed weaker inverse associations. Mean PSI was higher during haze (82.67 vs 51.46, p<0.001) and festival periods (53.42 vs 51.57, p=0.001). Mean ED visits fell across successive haze events (2.60 in 2016, 2.36 in 2019, 1.46 in 2023) but peaked during the Northeast monsoons despite lower PSI, indicating weather influences beyond ambient pollution.

conclusionsPSI-ED association peaked on the same day of exposure but was no longer significant after adjusting for demographic and clinical factors. Pollution-linked festivals, transboundary haze and the Northeast monsoon were associated with increased asthma ED visits.

Indexed as

Air PollutionAsthmaEmergency Service, HospitalWeatherAdultAgedEmergency Room VisitsFemaleHumansMaleMiddle AgedRetrospective StudiesSeasonsSingaporeYoung AdultAsthmaClimate ChangePREVENTIVE MEDICINE

Identifiers

PMID41412617
PMCPMC12716579

What Socratic holds

Textmetadata
LicenceCC BY-NC
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.