title: Fixed-altitude stair-climbing test replacing the conventional symptom-limited test. A pilot study.
abstract: BACKGROUND
  The objective of this study was to investigate whether a patient's maximum capacity is comparable in 2 different stair-climbing tests, allowing the simplest to be used in clinical practice.
  
  
  METHODS
  Prospective, observational study of repeated measures on 33 consecutive patients scheduled for lung resection. Stair-climbing tests were: the standard test (climb to 27 m) and the alternative fixed-altitude test (climb to 12 m). In both cases, heart rate and oxygen saturation were monitored before and after the test. The power output of stair-climbing for each test (Watt1 for the standard and Watt2 for the fixed-altitude test) was calculated using the following equation: Power (watt)=weight (kg)*9.8*height (m)/time (sec). Concordance between tests was evaluated using a regression model and the residuals were plotted against Watt1. Finally, power output values were analyzed using a Bland-Altman plot.
  
  
  RESULTS
  Twenty-one male and 12 female patients (mean age 63.2±11.2) completed both tests. Only 12 patients finished the standard test, while all finished the fixed-altitude test. Mean power output values were Watt1: 184.1±65 and Watt2: 214.5±75.1. The coefficient of determination (R(2)) in the linear regression was 0.67. No fixed bias was detected after plotting the residuals. The Bland-Altman plot showed that 32 out of 33 values were within 2 standard deviations of the differences between methods.
  
  
  CONCLUSIONS
  The results of this study show a reasonable level of concordance between both stair-climbing tests. The standard test can be replaced by the fixed-altitude test up to 12 m.
authors.affiliation: Servicio de Cirugía Torácica, Complejo Asistencial Universitario de Salamanca, Salamanca, España. Electronic address: nuria.novoa@usal.es.
authors.forename: Nuria M
authors.initials: NM
authors.lastname: Novoa
authors.affiliation: Servicio de Cirugía Torácica, Complejo Asistencial Universitario de Salamanca, Salamanca, España.
authors.forename: María
authors.initials: M
authors.lastname: Rodríguez
authors.affiliation: Servicio de Cirugía Torácica, Complejo Asistencial Universitario de Salamanca, Salamanca, España.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Gómez
authors.affiliation: Servicio de Cirugía Torácica, Complejo Asistencial Universitario de Salamanca, Salamanca, España.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Jiménez
authors.affiliation: Servicio de Cirugía Torácica, Complejo Asistencial Universitario de Salamanca, Salamanca, España.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Varela
mesh_terms: D000368:Aged; D015992:Body Mass Index; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010865:Pilot Projects; D011013:Pneumonectomy; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D013147:Spirometry; D013312:Stress, Physiological
chemical_list: D010100:Oxygen
keywords: Capacidad de ejercicio; Evaluación preoperatoria; Exercise capacity; Lung resection; Preoperative evaluation; Prueba de subir escaleras; Resección pulmonar; Stair-climbing test