Asthma: increased risk of asthma death or readmission following hospital admission.

Clinical bottom line (level 3b)

  1. Patients who were admitted to hospital with asthma were at increased risk of being readmitted with asthma (NNH = 4 at 12 months) , or dying from asthma (NNH = 150 at 12 months) in the next 12 months.
Crane et al: International Journal of Epidemiology 1992; 21 (4): 737-744
Expires November 2002

The study

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

Setting: acute hospital, New Zealand, 1981-7

528 patients (aged range 5 to 45 years, ?% male) admitted with asthma
Cases: 265 patients (% male, mean age ): 39 patients who died from asthma within the 12 months after admission; 226 readmitted with asthma within the next 12 months
Controls: 263 patients (% male, mean age ): admitted with asthma who did not re attend

Factors studied:
  • death or readmission from asthma


    • Factors summarised:
  • admission in last year
  • admission in last year


    • Logistic regression was used to adjust for confounding factors.

    Outcomes studied:
  • death from asthma
  • readmission for asthma

    • The evidence

    Patient expected event rate for death from asthma: 0.1%
    risk factor for
    death from asthma     		adjusted OR
    (95% CI)    		 NNH
    (95% CI)
    admission in last year 7.8
    (1.0 to 76.8)     		150
    (14 to inf)

    Patient expected event rate for readmission for asthma: 30%
    risk factor for
    readmission for asthma     		adjusted OR
    (95% CI)    		 NNH
    (95% CI)
    admission in last year 3.0
    (1.0 to 9.3)     		4
    (2 to inf)

    Comments

    1. The death rate and readmission rates were estimated.
    2. We have to reevaluate markers of risk of asthma death or readmission and evaluate the efficacy the recent treatment strategy.

    Citation

    1. Crane J, Pearce N, Burgess C, et al: Markers of risk of asthma death or readmission in the 12 months following a hospital admission for asthma. International Journal of Epidemiology 1992; 21 (4): 737-744
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Mitsuhiro Kamei

    Clinical Question.
    Patient asthma
    Intervention or Exposure admission in last year
    Outcome death, readmission