Key Points
- To evaluate the relationship between vascular risk factors, especially smoking and hypertension, and the risk of aneurysmal subarachnoid haemorrhage.
- Conducted a case-control study comparing 141 consecutively admitted patients with subarachnoid haemorrhage against age- and sex-matched general practice controls in Lisbon.
- Evaluated the prevalence and independent associations of vascular risk factors including smoking, hypertension, diabetes, and hyperlipidaemia.
- Hypertension was 8.3 times more frequent (95% CI 4.6–16.7) and smoking was 4.0 times more frequent (95% CI 2.0–8.6) in cases compared to controls, whereas diabetes and hyperlipidaemia showed no difference.
- Smoking remained independently associated with subarachnoid haemorrhage after adjusting for hypertension in both hypertensive participants (OR = 10.5, 95% CI 1.9–56.4) and normotensive participants (OR = 3.7, 95% CI 1.6–10.1).
Structured PICO
Are smoking and hypertension associated with an increased risk of aneurysmal subarachnoid haemorrhage?
PPopulation141 consecutively admitted patients with subarachnoid haemorrhage and age- and sex-matched control subjects registered with a general practitioner in a western suburb of Lisbon
IInterventionSmoking and hypertension (risk factor exposure)
CComparatorAbsence of smoking and hypertension (control group without subarachnoid haemorrhage)
OOutcomeAneurysmal subarachnoid haemorrhagehard clinical
Smoking and hypertension are strong, independent risk factors for aneurysmal subarachnoid haemorrhage.