The timed walk test as a measure of severity and survival in idiopathic pulmonary fibrosis.
Idiopathic pulmonary fibrosis (IPF) is a relentlessly progressive disease with a median survival of approximately 3 yrs. Measurements of airflow and lung volumes at rest are generally used to monitor the clinical course in this disorder. This study was designed to determine if a modified version of the 6-min walk test, called the timed walk test, accurately characterises disease severity and survival in IPF. The study population consisted of 28 patients with well-characterised progressive IPF. The timed walk test and concurrent measures of disease severity were assessed at baseline. Participants were prospectively followed for > or =4 yrs to determine the relationship between parameters of the timed walk test and survival. There were strong correlations between the end-exercise saturation and walk-velocity parameters of the timed walk test and diffusing capacity, and arterial oxygen tension at rest. In univariate Cox proportional-hazards models, end-exercise saturation, change in saturation with exercise, walk distance and walk velocity were associated with survival. In unadjusted logistic regression models, odds of death at 2 yrs were associated with the same parameters. In conclusion, the timed walk test relates to disease severity and long-term outcome in progressive idiopathic pulmonary fibrosis.
Hallstrand
T S
TS
Dept of Medicine, Division of Pulmonary and Critical care Medicine, University of Washington, Seattle, WA 98195-6522, USA.
Boitano
L J
LJ
Johnson
W C
WC
Spada
C A
CA
Hayes
J G
JG
Raghu
G
G
D000368:Aged; D000704:Analysis of Variance; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010100:Oxygen / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000401:mortality*; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D012307:Risk Factors; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016019:Survival Analysis; D016138:Walking
D010100:Oxygen