Please assess the completion status of the following clinical trial:

Trial Title: Safety and Effectiveness of Apixaban in Very Elderly Patients With Non-valvular Atrial Fibrillation (NVAF) Compared to Warfarin Using Administrative Claims Data

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: COHORT
- Primary Purpose: None
- Time Perspective: RETROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~* Patients must meet all the following inclusion criteria to be eligible for inclusion in the study.~  1. Diagnosed with Atrial fibrillation (AF) anytime in the baseline period or on the index date, also have definitive diagnosis of AF anytime in the baseline period, on the index date, or post-index period.~ 2. Prescribed apixaban or warfarin on or after the day of AF diagnosis. The first observed prescription will be used to identify the patient's index date and treatment cohort~ 3. No use of the any Oral anticoagulants (OAC)s during the baseline period (the 180 days before the index date)~ 4. Age of 18 years or older on the index date.~ 5. Index date is at age 80 or older~Exclusion Criteria:~* Patients meeting any of the following criteria will not be included in the study:~  1. Having a diagnosis of valvular atrial fibrillation, post-operative atrial fibrillation, rheumatic atrial fibrillation or mechanical-valvular atrial fibrillation during the baseline and post-index period~ 2. Having a cardiac surgery procedure record during the baseline period~ 3. Having a joint replacement procedure record during the baseline period~ 4. Having a procedure of prosthetic heart valve during the baseline period~ 5. Having a diagnosis of venous thromboembolism during the baseline period~ 6. Female patients with pregnancy during the follow-up period~ 7. Patients prescribed off-label doses of OACs (per Japanese package insert of each OAC) or patients treated with OAC but in off-label or contraindicated manners.

- Gender: ALL
- Minimum Age: 80 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Warfarin cohort (Reference) (Type: None): Patients with NVAF treated with warfarin
- Apixaban cohort (Type: None): Patients with NVAF treated with apixaban

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