Preusser 1994.

Study characteristics
Methods	Study design: RCT Study grouping: parallel‐group
Participants	Baseline characteristics IMT N (randomized/analyzed): /12 Loss to follow‐up or excluded: 1 Age, mean (SD) in years: 68/10 Gender (M/F): 6/6 Control/sham N (randomized/analyzed): /8 Loss to follow‐up or excluded: 1 Age, mean (SD) in years: 62/17 Gender (M/F): 1/7 Overall N (randomized/analyzed): 22/20 Loss to follow‐up or excluded: 2 Gender (M/F): 7/13 COPD stage (GOLD): severe to very severe Included criteria The presence of COPD as defined by the ATS  Willingness to participate in a 3‐month inspiratory muscle training protocol Excluded criteria Uncontrolled cardiac disease, diabetes, hypertension, musculoskeletal, and neuromuscular diseases
Interventions	Intervention characteristics IMT: consisted of supervised sessions, 3 days/week for 12 weeks, using Threshold IMT device at 52% of PImax. The training duration ranged from 5 min in week 1 to 18 min in week 12 Control/sham: this group received a similar IMT protocol and trained at 22% of PImax
Outcomes	Functional exercise capacity: 12MWD Respiratory muscle strength: PImax (FRC) Respiratory muscle endurance: Respiratory muscle endurance pressure (Pthmax) Notes: "After quietly breathing through an unloaded system for 2 min, the threshold load began at ‐4 cm H2O pressure and increased by ‐2 cm after every fifth breath (every 15 s) until the subject either signalled to stop the test or was unable to match respiratory rate, duty cycle and flow rate during three of the five breaths for that pressure load. The maximal threshold load successfully completed during the ramp test was recorded"
Identification	Sponsorship source: supported by grant F31 NR06378, National Center for Nursing Research; a grant from the American Nurses Foundation; and the Epsilon Chapter of Sigma Theta Tau Country: USA Author's name: Barbara A. Preusser Institution: College of Nursing, The Ohio State University, and the Department of Pulmonary Medicine, The Ohio State University Hospitals, Columbus Address: University of Utah College of Nursing, 25 South Medical Drive, Salt Lake City 84112
Notes