Stroke: Infection within one week was a weak risk factor for cerebrovascular ischaemia.

Clinical bottom line (level 3b)

  1. About 24% of patients with cerebrovascular ischaemia had a recent infection.
  2. Risk factors for cerebrovascular ischaemia were; infection within one week before, hypertension, diabetes mellitus, current smoker, coronary artery disease and previous stroke or TIA.
Grau et al: Stroke 1995; 26: 373-379
Expires December 2002

The study

Case-control study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: emergency unit of neurology department of a university hospital, Germany

394 patients (aged range 22 to 80 years; mean 63, 58% male) persistent or transient cerebral ischaemia or controls

Excluded if
  • cerebral haemorrhage
  • uncertainty about diagnosis


    • Cases: 197 patients (63% male, mean age 58): persistent or transient cerebral ischaemia
    Controls: 197 patients (% male, mean age ): age, sex and area of residence matched controls

    Factors studied:
  • cerebrovascular ischaemia


    • Factors summarised:
  • infection within 1 week in men
  • infection within 1 week
  • previous stroke or TIA
  • diabetes mellitus
  • coronary heart disease
  • current smoker
  • hypertension


    • Logistic regression analysis was used to adjust for confounding factors.

    Outcomes studied:
  • cerebrovascular ischaemia

    • The evidence

    Patient expected event rate for cerebrovascular ischaemia: 2.00%
    risk factor for
    cerebrovascular ischaemia     		adjusted OR
    (95% CI)    		 NNH
    (95% CI)
    infection within 1 week in men 5.20
    (1.60 to 16.8)     		13
    (4 to 86)
    infection within 1 week 4.60
    (1.90 to 11.3)     		15
    (6 to 58)
    previous stroke or TIA 4.60
    (2.00 to 10.3)     		15
    (7 to 52)
    diabetes mellitus 3.40
    (1.70 to 6.80)     		22
    (10 to 74)
    coronary heart disease 2.20
    (1.20 to 4.20)     		44
    (17 to 256)
    current smoker 1.90
    (1.02 to 3.60)     		58
    (21 to 2552)
    hypertension 1.70
    (1.04 to 2.90)     		74
    (28 to 1277)

    Comments

    1. The lack of effect across gender makes the finding of infection as a risk very uncertain, and should be considered only as a preliminary hypothesis.
    2. What this study adds to previous studies is that infection may be a risk factor in stroke in older people. Previous studies have shown hypertension etc as risk factors and have shown infection as a risk factor in the young.

    Citation

    1. Grau AJ, Buggle F, Heindl S, et al: Recent infection as a risk factor for cerebrovascular ischemia. Stroke 1995; 26: 373-379
    Contributor: Clare Wotton and Musab Hayatli, December 1999
    Reviewer: Kev Hopayian

    Clinical Question.
    Patient acute cerebrovascular ischaemia
    Intervention or Exposure recent infection
    Comparison no recent infection
    Outcome risk factor