Sickle cell disease: nearly a third of patients had acute chest syndrome within 2 years.

Clinical bottom line (level 1b)

  1. Nearly a third of patients with sickle cell disease had acute chest syndrome within 2 years.
  2. SS patients were at an increased risk of acute chest syndrome if they:
    • were young at study entry
    • had a low Hb F level
    • had a low degree of anaemia
    • had a high white cell count
  3. SC patients were at an increased risk of acute chest syndrome if they had a high white cell count.
Castro et al: Blood 1994; 84 (2): 643-649
Expires June 2003

The study

Prospective cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: multicentre, USA

3751 patients (aged ?, ?% male) sickle cell disease

Factors studied:
  • acute chest syndrome




    • Multivariate analysis was used to adjust for confounding factors.

    ?100% followed for 2 years
    Outcomes studied:
  • acute chest syndrome developed a new infiltrate on chest x-ray and/or had a perfusion defect demonstrable on a lung radioisotope scan

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    acute chest syndrome 2 years 1085/3751 28.9%
    (27.5% to 30.4%)

    • SS patients were at increased risk of acute chest syndrome if they:
      • were young at study entry, p<0.0001
      • had a low Hb F level , p<0.0001
      • had a low degree of anaemia, p<0.0001
      • had a high white cell count, p<0.005
    • SC patients were at increased risk of acute chest syndrome if they had a high white cell count (p-value not given).

    Comments

    1. No odds ratios were given, and the number of cases of acute chest syndrome were not given for each subset of sickle cell disease.
    2. There were a small number of SC patients, so other prognostic factors may have been missed.

    Citation

    1. Castro O, Brambilla DJ, Thorington B, et al: The acute chest syndrome in sickle cell disease: incidence and risk factors. Blood 1994; 84 (2): 643-649
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer:

    Clinical Question.
    Patient sickle cell disease
    Intervention or Exposure prevalence and prognostic factors
    Outcome acute chest syndrome