Please assess the completion status of the following clinical trial:

Trial Title: Patients With Chronic Obstructive Pulmonary Disease at Altitude - Effect of Nocturnal Oxygen on Breathing and Sleep

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* chronic obstructive pulmonary disease (COPD), GOLD grade 2-3~* residents at low altitude (\<800 m)~Exclusion Criteria:~* unstable condition, COPD exacerbation~* mild (GOLD 1) or very severe COPD (GOLD 4)~* requirement for oxygen therapy at low altitude residence~* hypoventilation~* pulmonary hypertension~* more than mild or unstable cardiovascular disease~* use of drugs that affect respiratory center drive~* internal, neurologic or psychiatric disease that interfere with protocol compliance including current heavy smoking (\>20 cigarettes per day), inability to perform 6 min walk test.~* previous intolerance to moderate altitude (\<2600m).~* exposure to altitudes \>1500m for \>2 days within the last 4 weeks before the study.~* pregnant or nursing patients

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 75 Years
- Healthy Volunteers: f

Study Arms:
- Oxygen (Type: ACTIVE_COMPARATOR): oxygen administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m
- Sham oxygen (Type: PLACEBO_COMPARATOR): Sham oxygen (room air) administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m

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