Association of time of day at stroke onset with functional outcomes after reperfusion therapy in acute ischaemic stroke: a retrospective cohort study in China
In brief
Night-onset strokes face roughly 45% higher risk of disability after reperfusion
In a Chinese cohort of 712 patients treated with thrombolysis or thrombectomy, strokes that began between 6 pm and 6 am were about one-and-a-half times more likely to have an unfavorable three-month functional outcome than day-onset strokes. The effect was strongest for events occurring between 10 pm and 2 am, suggesting timing may influence recovery and warrants further study.
- Journal
- BMJ open (Q1)
- Published
- 18 September 2026
- Study design
- Prospective / inception cohort
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Yiqing Wang, Shenghao Fan, Shicun Huang, Man Lu, Yi Yang, Haifeng Lu, et al.
- PMID
- 42760078
- DOI
- 10.1136/bmjopen-2026-119656
Why clinicians should know about it
- Picked for Neurology (clinical) (paper of the day, 21 September 2026): Night‑onset stroke linked to poorer outcomes after reperfusion therapy
Abstract
OBJECTIVES: To investigate the association between the time of day of stroke onset and functional outcomes among patients with acute ischaemic stroke who received reperfusion therapy. DESIGN: Retrospective cohort study. SETTING: Patients with acute ischaemic stroke who received reperfusion therapy (intravenous thrombolysis or combined endovascular therapy) between October 2018 and March 2022 in China were included. PARTICIPANTS: A total of 712 patients with acute ischaemic stroke receiving reperfusion therapy were included. Patients were categorised into two groups (day-onset (06:00-18:00) and night-onset (18:00-06:00)) and into six groups by 4-hour intervals. OUTCOME MEASURES: The primary outcome was the 3-month functional status, evaluated using the modified Rankin Scale, with scores of 0-2 classified as favourable and scores of 3-6 as unfavourable outcomes. Propensity score matching (PSM), inverse probability of treatment weighting (IPTW) and overlap weighting (OW) were used for analyses. RESULTS: 148 out of 286 patients (51.7%) in the night-onset group and 182 out of 426 patients (42.7%) in the day-onset group experienced unfavourable outcomes at 3 months. Night-onset stroke was associated with a significantly higher risk of unfavourable outcome compared with day-onset stroke (OR 1.44 (95% CI 1.06 to 1.94), p=0.018). This association remained significant after adjustment using PSM (OR 1.45 (95% CI 1.01 to 2.08), p=0.044), and was further confirmed in analyses using IPTW (OR 1.42 (95% CI 1.02 to 1.96), p=0.036), OW (OR 1.42 (95% CI 1.03 to 1.96), p=0.032) and multivariable adjustment (adjusted OR 1.55 (95% CI 1.07 to 2.22), p=0.019). Night-onset stroke during 22:00-02:00 (adjusted OR 2.44 (95% CI 1.34 to 4.43), p=0.003) was significantly associated with a higher likelihood of unfavourable outcome in adjusted analysis. CONCLUSIONS: Night-onset stroke was associated with poorer functional outcomes at 3 months among patients receiving reperfusion therapy. Further multicentre prospective studies are warranted to validate these findings. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry Identifier: ChiCTR2500101844.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.