| OACIS | Oil and Auto Cooperation for International Standards 
| Others |
| OACIS | Online Arizona Certification Information System
| Others |
| OACIS | Open Architecture Clinical Information System
| Others |
| OACIS | Optimizing Advanced Complex Illness Support
| Others |
| OACIS | Osaka Acute Coronary Insufficiency Study
| Others |
| OACIS | Outcomes After Critical Illness and Surgery
| Others |