title: Six-Minute Walk Test Results Predict Risk of Hospitalization for Youths with Cystic Fibrosis: A 5-Year Follow-Up Study.
abstract: To evaluate the association of 6-minute walk test (6MWT) and other variables (anthropometry, chronic Pseudomonas aeroginosa colonization, pulmonary function, and respiratory muscle strength) with the risk of hospitalization for pulmonary exacerbation in children and adolescents with cystic fibrosis (CF).
  
  
  
  Cohort study that included patients with CF aged 6-18 years. All participants underwent spirometry, manovacuometry, and 6MWT during the 5-year follow-up. Anthropometric and clinical data were collected and the time to first hospitalization, total days of hospitalization, and antibiotic use during follow-up was recorded.
  
  
  
  A total of 26 patients with CF, mean age 10.2 ± 2.8 years, were included. The group had mild impairment of lung function with a significant decline in forced expiratory volume in 1 second (P = .019) over the 5 years. Respiratory muscle strength and 6MWT proved to be preserved, although maximum inspiratory pressure increased (P < .001) and maximum expiratory pressure and 6-minute walk distance (6MWD) remained stable. There were inverse associations of 6MWD in meters (r = -0.813, P < .001) and z score (r = -0.417, P = .015) with total days of hospitalization. Moreover, there was a reduction in the risk of a first hospitalization (Cox HR 0.32; P = .037) in patients with a greater 6MWD.
  
  
  
  We found an association between the 6MWT and the risk of hospitalization in children and adolescents with CF. Furthermore, functional capacity apparently does not follow the expected decline in pulmonary function over time, whereas inspiratory muscle strength increases with disease progression.
authors.affiliation: Centro Infant, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil; Graduate Program in Pediatrics and Child Health, PUCRS, Porto Alegre, Rio Grande do Sul, Brazil. Electronic address: mdonadio@pucrs.br.
authors.forename: Márcio V F
authors.initials: MV
authors.lastname: Donadio
authors.affiliation: Graduate Program in Pediatrics and Child Health, PUCRS, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: João P
authors.initials: JP
authors.lastname: Heinzmann-Filho
authors.affiliation: Graduate Program in Pediatrics and Child Health, PUCRS, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Vendrusculo
authors.affiliation: School of Physiotherapy, Universidade Veiga de Almeida (UVA), Rio de Janeiro, Brazil.
authors.forename: Patrícia X H
authors.initials: PXH
authors.lastname: Frasson
authors.affiliation: School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Paulo J C
authors.initials: PJC
authors.lastname: Marostica
mesh_terms: D000704:Analysis of Variance; D000886:Anthropometry; D002648:Child; D015331:Cohort Studies; D016001:Confidence Intervals; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology*; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012129:Respiratory Function Tests; D018570:Risk Assessment; D013997:Time Factors; D016138:Walking / Q000502:physiology*
keywords: disease progression; prognosis; respiratory function tests