The SAFE (SGRQ score, air-flow limitation and exercise tolerance) Index: a new composite score for the stratification of severity in chronic obstructive pulmonary disease
- Mohd Shah Azarisman1,
- Mohd Anshar Fauzi2,
- Mohd Perdaus Ahmad Faizal3,
- Zaharim Azami4,
- Abdul Manap Roslina5,
- Harun Roslan6
- 1Department of Medicine, International Islamic University Malaysia
- 2Department of Medicine, Universiti Kebangsaan Malaysia
- 3Department of Medicine, Universiti Kebangsaan Malaysia
- 4Universiti Kebangsaan Malaysia
- 5Department of Medicine, Universiti Kebangsaan Malaysia
- 6Department of Medicine, Universiti Kebangsaan Malaysia
- Correspondence to: Assistant Professor Dr Mohd Shah Azarisman Department of Medicine, International Islamic University Malaysia, Jalan Hospital Campus, 25150 Kuantan, Pahang, Malaysia; risman1973{at}hotmail.com
- Received 15 August 2006
- Accepted 8 February 2007
Abstract
Background: This study was proposed to develop a composite of outcome measures using forced expiratory volume percentage of predicted, exercise capacity and quality of life scores for assessment of chronic obstructive pulmonary disease (COPD) severity.
Materials and methods: Eighty-six patients with COPD were enrolled into a prospective, observational study at the respiratory outpatient clinic, National University Hospital Malaysia (Hospital Universiti Kebangsaan Malaysia - HUKM), Kuala Lumpur.
Results: Our study found modest correlation between the forced expiratory volume in 1 s (FEV1), 6 min walk distance and the SGRQ scores with mean (SD) values of 0.97 (0.56) litres/s, 322 (87) m and 43.7 (23.6)%, respectively. K-Means cluster analysis identified four distinct clusters which reached statistical significance which was refined to develop a new cumulative staging system. The SAFE Index score correlated with the number of exacerbations in 2 years (r = 0.497, p<0.001).
Conclusion: We have developed the SGRQ, Air-Flow limitation and Exercise tolerance Index (SAFE Index) for the stratification of severity in COPD. This index incorporates the SGRQ score, the FEV1 % predicted and the 6 min walk distance. The SAFE Index is moderately correlated with the number of disease exacerbations.
- ANOVA, analysis of variance
- COPD, chronic obstructive pulmonary disease
- FEV1, forced expiratory volume in 1 s
- FEV1%Pred, percentage of predicted FEV1
- FVC, forced vital capacity
- GOLD, Global Initiative for Chronic Obstructive Lung Disease
- HRQOL, Health-Related Quality of Life Questionnaire
- QOL, quality of life
- SGRQ, St George’s Respiratory Questionnaire
Footnotes
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Funding was provided by the Fundamental Research Fund, National, University Malaysia – UKM.
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Conflict of interest: none stated
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The abstract was accepted for a poster presentation at the 11th Congress of the Asian Pacific Society of Respirology (APSR) held in Kyoto, Japan, 19–22 November 2006







