Please assess the completion status of the following clinical trial:

Trial Title: Effect of Noninvasive Ventilation on Lung Function in Amyotrophic Lateral Sclerosis

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: SUPPORTIVE_CARE
- Time Perspective: None
- Masking: SINGLE
- Phase: None
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* clinical diagnosis of amyotrophic lateral sclerosis~* clinical indication to start noninvasive ventilation (forced vital capacity \< 50% predicted or signs/symptoms of respiratory insufficiency)~* age 18 to 80 years old~Exclusion Criteria:~* prior institution of NIPPV~* inability to safely use NIPPV~* indications for tracheostomy assisted ventilation because of inability to clear secretions from the airway~* inability or unwillingness to perform pulmonary function testing~* presence of advanced dementia.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 80 Years
- Healthy Volunteers: f

Study Arms:
- High-level ventilation (Type: ACTIVE_COMPARATOR): Each subject will spend 2 hours receiving high-level noninvasive ventilation.
- Low-level ventilation (Type: ACTIVE_COMPARATOR): Each subject will receive 2 hours of low-level noninvasive positive pressure ventilation.

Based on this trial design, predict the completion outcome and termination type (if applicable).