RT Journal Article
SR Electronic
T1 Quadriceps strength predicts mortality in patients with moderate to severe chronic obstructive pulmonary disease
JF Thorax
JO Thorax
FD BMJ Publishing Group Ltd and British Thoracic Society
SP 115
OP 120
DO 10.1136/thx.2006.062026
VO 62
IS 2
A1 Elisabeth B Swallow
A1 Diana Reyes
A1 Nicholas S Hopkinson
A1 William D-C Man
A1 Raphaël Porcher
A1 Edward J Cetti
A1 Alastair J Moore
A1 John Moxham
A1 Michael I Polkey
YR 2007
UL http://thorax.bmj.com/content/62/2/115.abstract
AB Background: Prognosis in chronic obstructive pulmonary disease (COPD) is poorly predicted by indices of air flow obstruction, because other factors that reflect the systemic nature of the disease also influence prognosis. Objective: To test the hypothesis that a reduction in quadriceps maximal voluntary contraction force (QMVC) is a useful predictor of mortality in patients with COPD. Methods: A mortality questionnaire was sent to the primary care physician of 184 patients with COPD who had undergone quadriceps strength measurement over the past 5 years. QMVC was expressed as a percentage of the patient’s body mass index. The end point measured was death or lung transplantation, and median (range) follow-up was 38 (1–54) months. Results: Data were obtained for 162 patients (108 men and 54 women) with a mean (SD) percentage of forced expiratory volume in 1 s (FEV1) predicted of 35.6 (16.2), giving a response rate of 88%. Transplant-free survival of the cohort was 93.5% at 1 year and 87.1% at 2 years. Cox regression models showed that the mortality risk increased with increasing age and with reducing QMVC. Only age (HR 1.72 (95% CI 1.14 to 2.6); p = 0.01) and QMVC (HR 0.91 (95% CI 0.83 to 0.99); p = 0.036) continued to be significant predictors of mortality when controlled for other variables in the multivariate analysis. Conclusion: QMVC is simple and provides more powerful prognostic information on COPD than that provided by age, body mass index and forced expiratory volume in 1 s.