| OBSERVATION DATE (BLOOD PRESSURE) | Data Element | |
| OBSERVATION DATE (BMI) | Data Element | |
| OBSERVATION DATE (DIABETES RELEVANT DIAGNOSIS) | Data Element | |
| OBSERVATION DATE (EYE EXAMINATION) | Data Element | |
| OBSERVATION DATE (FOOT EXAMINATION) | Data Element | |
| OBSERVATION DATE (HbA1c LEVEL) | Data Element | |
| OBSERVATION DATE (SERUM CHOLESTEROL LEVEL) | Data Element | |
| OBSERVATION DATE (SERUM CREATININE LEVEL) | Data Element | |
| OBSERVATION DATE (SMOKING STATUS) | Data Element | |
| OBSERVATION DATE (URINARY ALBUMIN LEVEL) | Data Element | |
| OBSERVATION MEASUREMENT VALIDATION | Class | |
| Obsessive Compulsive Disorder Inventory Questionnaire | Supporting Information | |
| OBSESSIVE COMPULSIVE DISORDER INVENTORY SCORE | Data Element | |
| OCCUPATION (CPA CARE COORDINATOR) | Data Element | |
| Occupational Psychologist | Supporting Information | To top |
| Occupational Therapist | Supporting Information | |
| OCCUPATION CODE | Data Element | |
| OCCUPATION CODE | Attribute | |
| OCCUPATION CODE (CLINICAL SECOND SPECIALTY) | Data Element | |
| OCCUPATION CODE (CLINICAL SPECIALTY) | Data Element | |
| OCCUPATION CODE DESCRIPTION | Data Element | |
| OCCUPATION CODE DESCRIPTION | Attribute | |
| OCCUPATION CODE TYPE | Class | |
| OCCUPIED BED DAYS | Data Element | |
| OCCUPIED BED DAYS NHS PATIENTS | Attribute | |
| OCCUPIED BED DAYS NON-NHS PATIENTS | Attribute | |
| OFFERED FOR ADMISSION DATE | Data Element | |
| OFFERED FOR ADMISSION DATE | Attribute | |
| OFFERED FOR ADMISSION DATE STATUS | Data Element | |
| OFFER OF ADMISSION | Class | To top |
| OFFER OF ADMISSION ACCEPTED DATE | Attribute | |
| OFFER OF ADMISSION ACCEPTED OR REFUSED | Attribute | |
| OFFER OF ADMISSION GROUP IDENTIFIER | Attribute | |
| OFFER OF ADMISSION MADE DATE | Attribute | |
| OFFER OF ADMISSION MADE TIME | Attribute | |
| OFFER OF ADMISSION VERBAL OR WRITTEN | Attribute | |
| Office for National Statistics | Supporting Information | |
| Ofsted | Supporting Information | |
| Old Version 3 ADMITTED PATIENT CARE CDS TYPE - BIRTH EPISODE (retired) | Data Set | |
| Old Version 3 ADMITTED PATIENT CARE CDS TYPE - DELIVERY EPISODE (retired) | Data Set | |
| Old Version 3 ADMITTED PATIENT CARE CDS TYPE - GENERAL EPISODE (retired) | Data Set | |
| OPCS Classification of Interventions and Procedures | Supporting Information | |
| Operating Department Practitioner | Supporting Information | |
| OPERATING THEATRE | Class | |
| OPERATING THEATRE CODE | Attribute | To top |
| OPERATING THEATRE DEDICATED TO DAY CASES | Attribute | |
| OPERATING THEATRE INTENDED SPECIALTY | Class | |
| OPERATING THEATRE NAME | Attribute | |
| OPERATING THEATRE OPERATIONAL PLAN | Class | |
| OPERATING THEATRE OPERATIONAL PLAN END DATE | Attribute | |
| OPERATING THEATRE OPERATIONAL PLAN START DATE | Attribute | |
| OPERATING THEATRES DEDICATED TO DAY CASES TOTAL | Data Element | |
| Operating Theatre Session | Supporting Information | |
| OPERATING THEATRE SESSION TYPE | Attribute | |
| OPERATING THEATRE TOTAL | Data Element | |
| OPERATING THEATRE TYPE | Attribute | |
| OPERATION CANCELLATION | Attribute | |
| OPERATION CANCELLATION PATIENT CHOICE | Attribute | |
| OPERATION STATUS | Data Element | |
| OPERATION STATUS CODE | Data Element | To top |
| OPERATIVE PROCEDURE | Class | |
| OPERATIVE PROCEDURE INDICATOR | Attribute | |
| OPHTHALMIC MEDICAL PRACTITIONER | Class | |
| OPHTHALMIC MEDICAL PRACTITIONER END DATE | Attribute | |
| OPHTHALMIC MEDICAL PRACTITIONER START DATE | Attribute | |
| OPHTHALMIC QUALIFICATION COMMITTEE CODE | Attribute | |
| Ophthalmic Qualifications Committee | Supporting Information | |
| OPPORTUNISTIC SCREENING TYPE | Attribute | |
| Optical Headquarters | Supporting Information | |
| Optical Site | Supporting Information | |
| OPTICIAN PREMISES TYPE | Attribute | |
| OPTOMETRIST | Class | |
| ORAL HEALTH AGE GROUP | Attribute | |
| Oral Health Programme | Supporting Information | |
| Ordinarily Resident | Supporting Information | To top |
| ORGAN DONATION CONSENT | Class | |
| ORGAN DONATION TYPE | Attribute | |
| ORGAN IDENTIFIER | Attribute | |
| ORGANISATION | Class | |
| ORGANISATION ACTIVITY ROLE | Class | |
| ORGANISATION ACTIVITY ROLE CODE | Attribute | |
| ORGANISATION CODE | Attribute | |
| ORGANISATION CODE (CODE OF COMMISSIONER) | Data Element | |
| ORGANISATION CODE (CODE OF PROVIDER) | Data Element | |
| ORGANISATION CODE (EMPLOYER) | Data Element | |
| ORGANISATION CODE (LOCAL PATIENT IDENTIFIER (BABY)) | Data Element | |
| ORGANISATION CODE (LOCAL PATIENT IDENTIFIER (MOTHER)) | Data Element | |
| ORGANISATION CODE (LOCAL PATIENT IDENTIFIER) | Data Element | |
| ORGANISATION CODE (NHS HEALTH CHECK PROVIDER) | Data Element | |
| ORGANISATION CODE (OF REPORTING PATHOLOGY) | Data Element | To top |
| ORGANISATION CODE (ON PATHWAY) | Data Element | |
| ORGANISATION CODE (PATIENT PATHWAY IDENTIFIER ISSUER) | Data Element | |
| ORGANISATION CODE (PCT OF GP PRACTICE) | Data Element | |
| ORGANISATION CODE (PCT OF RESIDENCE (MOTHER)) | Data Element | |
| ORGANISATION CODE (PCT OF RESIDENCE) | Data Element | |
| ORGANISATION CODE (POSITION NON-NHS FUNDER) | Data Element | |
| ORGANISATION CODE (PRIMARY CARE TRUST FOR HPV VACCINE) | Data Element | |
| ORGANISATION CODE (PROVIDER AT RECORD CREATION) | Data Element | |
| ORGANISATION CODE (PROVIDER CONSULTANT UPGRADE) | Data Element | |
| ORGANISATION CODE (PROVIDER DECISION TO TREAT (CANCER)) | Data Element | |
| ORGANISATION CODE (PROVIDER FIRST CANCER SPECIALIST) | Data Element | |
| ORGANISATION CODE (PROVIDER FIRST DIAGNOSTIC TEST) | Data Element | |
| ORGANISATION CODE (PROVIDER FIRST SEEN) | Data Element | |
| ORGANISATION CODE (PROVIDER TREATMENT START DATE (CANCER)) | Data Element | |
| ORGANISATION CODE (RECEIVING) | Data Element | To top |
| ORGANISATION CODE (REQUESTED BY) | Data Element | |
| ORGANISATION CODE (RESPONSIBLE PCT) | Data Element | |
| ORGANISATION CODE (STOP SMOKING SERVICE PROVIDER) | Data Element | |
| ORGANISATION CODE TYPE | Data Element | |
| ORGANISATION CODE TYPE (BABY) | Data Element | |
| ORGANISATION CODE TYPE (MOTHER) | Data Element | |
| ORGANISATION CODE TYPE CDS COPY RECIPIENT | Data Element | |
| ORGANISATION CODE TYPE CDS PRIME RECIPIENT | Data Element | |
| ORGANISATION CODE TYPE CDS SENDER IDENTITY | Data Element | |
| ORGANISATION COMMENT | Attribute | |
| Organisation Data Service | Supporting Information | |
| Organisation Data Service Default Codes | Supporting Information | |
| ORGANISATION DEPARTMENT | Class | |
| ORGANISATION DEPARTMENT CODE | Attribute | |
| ORGANISATION DEPARTMENT TYPE | Attribute | To top |
| Organisation Diagram Overview | Supporting Information | |
| ORGANISATION END DATE | Attribute | |
| ORGANISATION NAME | Attribute | |
| ORGANISATION NAME | Data Element | |
| ORGANISATION NAME (EMPLOYER) | Data Element | |
| ORGANISATION NAME (PROFESSIONAL REGISTRATION BODY) | Data Element | |
| ORGANISATION NAME (RECEIVING) | Data Element | |
| ORGANISATION NAME (REFERRING) | Data Element | |
| ORGANISATION REGISTERED TYPE | Attribute | |
| ORGANISATION REGISTRATION | Class | |
| ORGANISATION REGISTRATION DATE | Attribute | |
| ORGANISATION REGISTRATION SERVICE | Class | |
| ORGANISATION REGISTRATION USER | Class | |
| ORGANISATION RELATIONSHIP | Class | |
| ORGANISATION RELATIONSHIP TYPE | Attribute | To top |
| ORGANISATION REPORTING PERIOD | Class | |
| Organisations Introduction | Supporting Information | |
| ORGANISATION SITE | Class | |
| ORGANISATION SITE BED AVAILABILITY | Class | |
| ORGANISATION SITE BED AVAILABILITY END DATE | Attribute | |
| ORGANISATION SITE BED AVAILABILITY START DATE | Attribute | |
| ORGANISATION SITE BED OCCUPANCY | Class | |
| ORGANISATION SITE BED OCCUPANCY END DATE | Attribute | |
| ORGANISATION SITE BED OCCUPANCY START DATE | Attribute | |
| ORGANISATION SITE CLASSIFICATION | Attribute | |
| ORGANISATION SITE CODE | Attribute | |
| ORGANISATION SITE END DATE | Attribute | |
| ORGANISATION SITE NAME | Attribute | |
| ORGANISATION SITE START DATE | Attribute | |
| ORGANISATION SITE TREATMENT CENTRE | Attribute | To top |
| ORGANISATION SITE TYPE | Attribute | |
| Organisations Menu | Supporting Information | |
| ORGANISATION START DATE | Attribute | |
| ORGANISATION TYPE | Attribute | |
| ORGANISATION TYPE (EMPLOYER) | Data Element | |
| ORGAN SUPPORT MAXIMUM | Data Element | |
| ORGAN SYSTEM SUPPORTED | Attribute | |
| ORIGIN | Attribute | |
| ORIGINAL DECIDED TO ADMIT DATE | Attribute | |
| ORIGINAL DECIDED TO ADMIT DATE | Data Element | |
| ORIGINAL DECIDED TO ADMIT DATE STATUS | Data Element | |
| ORIGINAL REFERRAL REQUEST RECEIVED DATE | Data Element | |
| ORIGINAL REFERRAL REQUEST RECEIVED DATE | Attribute | |
| Orthodontic Therapist | Supporting Information | |
| Orthoptist | Supporting Information | To top |
| Orthotist | Supporting Information | |
| Osteopath | Supporting Information | |
| Other Appointment | Supporting Information | |
| OTHER CARE PROFESSIONAL | Class | |
| OTHER PERSON OBSERVATION | Class | |
| OTHER REFERRALS | Data Element | |
| OTHER REFERRER CODE | Attribute | |
| OUTCOME AT 4 WEEK FOLLOW-UP | Attribute | |
| OUTCOME AT 52 WEEK FOLLOW-UP (retired) | Attribute | |
| OUTCOME OF ATTENDANCE | Attribute | |
| OUTCOME OF ATTENDANCE | Data Element | |
| OUTCOME OF ATTENDANCE CODE | Data Element | |
| Out-Patient Appointment | Supporting Information | |
| Out-Patient Appointment Consultant | Supporting Information | |
| Out-Patient Appointment Non-Consultant | Supporting Information | To top |
| OUT-PATIENT ATTENDANCE CDS TYPE (retired) | Data Set | |
| Out-Patient Attendance Consultant | Supporting Information | |
| OUT-PATIENT ATTENDANCE CONSULTANT (MENTAL HEALTH) | Data Element | |
| Out-Patient Clinic | Supporting Information | |
| OUT-PATIENT CLINIC REFERRING INDICATOR | Attribute | |
| OUT-PATIENT DID NOT ATTENDS (MENTAL HEALTH) | Data Element | |
| Out-Patient Effective Waiting Time Calculation | Supporting Information | |
| OUT-PATIENT EFFECTIVE WAITS | Data Element | |
| OUT-PATIENT FIRST APPOINTMENTS DID NOT ATTEND | Data Element | |
| OUT-PATIENT FIRST APPOINTMENTS FIRST ATTENDANCES SEEN | Data Element | |
| Out-Patient Flows Data Set | Data Set | |
| Out-Patient Flows Data Set Overview | Supporting Information | |
| OUT-PATIENT FOLLOW-UP APPOINTMENTS ATTENDANCES SEEN | Data Element | |
| OUT-PATIENT FOLLOW-UP APPOINTMENTS DID NOT ATTEND | Data Element | |
| OUT-PATIENT REFERRAL INDICATOR | Attribute | To top |
| Out-Patient Stocks Data Set | Data Set | |
| Out-Patient Stocks Data Set Overview | Supporting Information | |
| OUT-PATIENTS WAITING | Data Element | |
| Out-Patient Waiting List | Supporting Information | |
| OUT-PATIENT WAITING TIME BAND | Data Element | |
| Output Area | Supporting Information | |
| OVERSEAS SURGICAL TEAM MEMBER | Attribute | |
| OVERSEAS SURGICAL TEAM MEMBER | Data Element | |
| Overseas Visitor | Supporting Information | |
| Overseas Visitor Chargeable Category | Supporting Information | |
| OVERSEAS VISITOR EXEMPT CATEGORY | Attribute | |
| OVERSEAS VISITOR QUOTA NUMBER | Attribute | |
| OVERSEAS VISITOR REFERRAL PRODUCED | Attribute | |
| OVERSEAS VISITORS STATUS CLASSIFICATION | Attribute | |
| OVERSEAS VISITORS STATUS CLASSIFICATION | Data Element | To top |
| OVERSEAS VISITOR STATUS | Class | |
| OVERSEAS VISITOR STATUS END DATE | Attribute | |
| OVERSEAS VISITOR STATUS START DATE | Attribute | |
| Overseas Visitor Treatment Portal | Supporting Information | |
| OVERSEAS VISITOR TREATMENT PREARRANGED | Attribute | |
| OVERSEAS VISITOR UK ARRIVAL DATE | Attribute | |
| OXYGEN SERVICE SUPPLIER INDICATOR | Attribute | |