Asthma: increased risk of death if non-compliant or previous life-threatening attacks.

Clinical bottom line (level 3b)

  1. Patients in the community were at increased risk of dying from asthma if they had:
    • one or more life-threatening asthma attacks
    • one or more previous respiratory arrests
    • non-compliance with treatment
  2. Patients attending hospital were at increased risk of dying from asthma if they had:
    • one or more life-threatening asthma attacks
    • psychosocial problems
Rea et al: Thorax 1986; 41: 833-839
Expires November 2002

The study

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

Setting: Auckland region, New Zealand over two years

127 patients (aged mean 33 years, 57% male) asthma

Excluded if
  • >60 years old


    • Cases: 44 patients (57% male, mean age 33): died from asthma
    Controls: 83 patients (57% male, mean age 33): with asthma, matched for age ( ± 5 years), sex, race, date of hospital admission. community controls- 44 patients with asthma matched for age, sex, race


    Multivariate regression analysis performed on risk factors.

    Outcomes studied:
  • community death from asthma
  • death from asthma in patients attending hospital

    • The evidence

    Patient expected event rate for community death from asthma: 0.0057%
    risk factor for
    community death from asthma     		adjusted RR
    (95% CI)    		 NNH
    (95% CI)
    non-compliance with treatment inf
    (5.2 to inf)     		inf
    (4200 to inf)
    1 or more life-threatening asthma attack inf
    (4.9 to inf)     		inf
    (4500 to inf)
    1 or more previous respiratory arrests inf
    (1.4 to inf)     		inf
    (44000 to inf)
    1 or more hospital admission with asthma in last year 16
    (2.6 to 666)     		1200
    (27 to 12000)
    1 or more attendance to an emergency department with asthma in last year 8.5
    (2.0 to 76)     		2300
    (240 to 18000)
    3 or more categories of asthma drug prescribed in last year 3.0
    (1.0 to 11)     		8800
    (1900 to 440000)
    pulmonary function not measured by GP within last year 2.7
    (1.1 to 7.6)     		10000
    (2700 to 180000)

    Patient expected event rate for death from asthma in patients attending hospital: 0.1%
    risk factor for
    death from asthma in patients attending hospital     		adjusted RR
    (95% CI)    		 NNH
    (95% CI)
    1 or more life threatening asthma attacks 3.8
    (1.2 to 16)     		360
    (70 to 5000)
    psychosocial problems 3.5
    (1.0 to 14)     		400
    (80 to 250000)

    Comments

    1. The main message of this study is structural. Patients who use emergency departments as main health resource require special medical attention. Hospital or primary care follow up should be offered according to the best available resources.
    2. No information on death rate in patients attending hospital with asthma was given. Estimated at 0.1%.

    Citation

    1. Rea HH, Scragg R, Jackson R, et al: A case-control study of deaths from asthma. Thorax 1986; 41: 833-839
    Search Terms: acute asthma in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Santiago Alvarez Montero

    Clinical Question.
    Patient asthma
    Intervention or Exposure risk factors
    Outcome death