Chronic obstructive pulmonary disease: frequent past exacerbations, daily wheeze and bronchitic symptoms increased the risk of exacerbations.

Clinical bottom line (level 1b)

  1. More than half of patients who attend outpatient clinics with chronic obstructive pulmonary disease had between 3 and 8 exacerbations a year.
  2. Patients were at increased risk of exacerbations of chronic obstructive pulmonary disease if they had; frequent past exacerbations, daily wheeze or bronchitic symptoms.
  3. Patients with between 3 and 8 exacerbations in a year had a worse quality of life score than those with between 0 and 2 exacerbations.
Seemungal et al: American Journal of Respiratory Critical Care Medicine 1998; 157: 1418-1422
Expires November 2003

The study

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

Setting: Outpatients clinics, London

73 patients (aged mean 68 years, 74% male) chronic obstructive pulmonary disease with FEV1 <70% predicted for age and height; ß 2-agonist reversibility <15% or 200 ml

Excluded if
  • exacerbation within the previous 4 weeks
  • asthma
  • bronchiectasis
  • carcinoma of the bronchus
  • inability to complete diary cards




    • Backward logistic regression was used to adjust for confounding factors.

    96% followed for 1 year
    Outcomes studied:
  • number of patients with 0-2 exacerbations were diagnosed if the following patterns were experienced for two or more consecutive days: 2 or more of 3 major symptoms (increase in dyspnoea, sputum purulence and increased sputum volume); or any 1 major symptom together with any 1 of the following minor symptoms- increase in nasal discharge, wheeze, sore throat, cough or fever.
  • number of patients with 3-8 exacerbations

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    number of patients with 0-2 12 months 32/70 45.71%
    (34.04% to 57.38%)    		 2
    (2 to 3)
    number of patients with 3-8 exacerbations 12 months 38/70 54.29%
    (42.61% to 65.96%)    		 2
    (2 to 2)

    prognostic factor for
    number of patients with 3-8 exacerbations     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)    		 p-value
    frequent past exacerbations 12 months 38/70
    (54.29%)     		0.73
    (0.6 to 0.93)     		-12
    (-8 to -55)     		0.013
    daily wheeze 12 months 25/70
    (36.0%)     		1.34
    (1.1 to 5.7)     		14
    (2 to 45)     		0.042
    bronchitic symptoms 12 months 43/70
    (61.43%)     		1.56
    ( to )     		10
    (3 to 13)     		0.009

    • SGRQ scores (St. George's Respiratory Questionnaire) were determined by patients filling in questionnaires with emphasis on Symptom, Activity and Impact. Scores vary from 0 (no disability) to 100 (maximum disability).
    • Mean SGRQ score for patients with 0-2 exacerbations was 48.9.
    • Mean SGRQ score for patients with 3-8 exacerbations was 64.1.
    • There was a mean difference of -15.1 between the two groups (CI -22.3 to -7.80), in favour of the 0-2 group.

    Comments

    1. Confidence intervals for the odds ratios were not given in the text and neither was a control rate for past exacerbations. Figures were estimated using proportion of total as PEER and NNF.

    Citation

    1. Seemungal TAR, Donaldson GC, Paul EA, et al: Effect of exacerbation on quality of life in patients with chronic obstructive pulmonary disease. American Journal of Respiratory Critical Care Medicine 1998; 157: 1418-1422
    Search Terms: COPD, chronic obstructive pulmonary disease and prognosis in Medline
    Contributor: Clare Wotton and Musab Hayatli, November 1999
    Reviewer: Daniel Sontheimer

    Clinical Question.
    Patient COPD
    Intervention or Exposure acute exacerbations
    Comparison no exacerbations
    Outcome affect quality of life