Angiogram Study – Data Dictionary

All variables are coded as integers or ISO dates (YYYY-MM-DD). No free text is stored.

Convention: 9 = Not applicable / Unknown across the entire dataset.

Study_ID

Auto-assigned sequential integer starting at 1. Primary key.

DOB

Date of birth. Format: YYYY-MM-DD (ISO 8601).

Sex

Code	Meaning
1	Male
2	Female

Procedure_Date

Date the diagnostic angiogram was performed. Format: YYYY-MM-DD.

Age_at_Procedure

Auto-calculated integer: years between DOB and Procedure_Date.

Setting

Code	Meaning
0	Outpatient
1	Inpatient

Rules driven by Setting:

If Outpatient (0): Troponin_Positive is set to 9 (N/A). NSTEMI is not available as an Indication_Type. OP_Referral_Route is asked.
If Inpatient (1): Troponin_Positive must be 0 or 1. OP_Referral_Route / Non_Invasive_Test fields are set to 9 (N/A).

Troponin_Positive

Code	Meaning
0	No
1	Yes
9	N/A (auto-set when Setting = 0 Outpatient)

OP_Referral_Route (Outpatient only)

Code	Meaning
1	Direct referral
2	After non-invasive testing
9	N/A (auto-set when Setting = 1 Inpatient)

If After non-invasive testing (2): Non_Invasive_Test_Type and Non_Invasive_Test_Result are asked.
If Direct (1) or Inpatient: both test fields are set to 9.

Non_Invasive_Test_Type (OP + after testing)

Code	Meaning
1	CTCA
2	DSE (Dobutamine Stress Echo)
3	Exercise Echo
4	MPS (Myocardial Perfusion Scan)
9	N/A (Inpatient, or direct OP referral)

Non_Invasive_Test_Result (OP + after testing)

Code	Meaning
1	Positive / Abnormal
2	Negative / Normal
3	Equivocal / Inconclusive
9	N/A (Inpatient, or direct OP referral)

Indication_Type

Code	Meaning
1	Stable chest pain
2	NSTEMI (Inpatient only)
3	Unstable angina
4	Heart failure / LV dysfunction assessment
5	Pre-operative / valve procedural work-up
6	Cardiomyopathy assessment
7	Other

NSTEMI (2) is not available when Setting = 0 (Outpatient).

Hypertension

Code	Meaning
0	No
1	Yes
9	Unknown

Diabetes

Code	Meaning
0	No
1	Yes
9	Unknown

Hyperlipidaemia

Code	Meaning
0	No
1	Yes
9	Unknown

Smoking_Status

Code	Meaning
0	Never smoker
1	Ex-smoker
2	Current smoker
9	Unknown

Family_Hx_Premature_CAD

Code	Meaning
0	No
1	Yes
9	Unknown

Hx_CAD

Prior history of coronary artery disease (MI, PCI, or CABG).

Code	Meaning
0	No
1	Yes
9	Unknown

Angio_Outcome

Code	Meaning
0	Normal (<50% stenosis)
1	Non-obstructive (50–69% stenosis)
2	Obstructive (≥70% stenosis, or LM ≥50%)

Management_Strategy

Code	Meaning
1	Medical therapy only
2	PCI referral
3	CABG referral
4	Further cardiac investigation required
5	Diagnostic only / no change in management

If PCI referral (2): PCI_Outcome is asked.
Otherwise PCI_Outcome is set to 9 (N/A).

PCI_Outcome (PCI referral only)

Code	Meaning
1	Stented
2	Not stented (PCI done, no stent placed)
3	Not done
9	N/A (Management_Strategy ≠ 2)

Coding Convention Summary

Code	Meaning	Used In
9	Not applicable / Unknown	All conditional & yes/no/unknown fields
0	No (or Outpatient, or Normal)	Binary fields, Setting, Angio_Outcome
1	Yes (or first option)	All coded fields
2+	Additional categories	See individual field tables above

No cell in the dataset is ever empty. Every field always contains a coded integer or an ISO date.

Conditional Logic Summary

Condition	Fields affected	Action
Setting = 0 (OP)	Troponin_Positive	Auto-set to `9`
Setting = 0 (OP)	Indication_Type	NSTEMI (2) hidden
Setting = 1 (IP)	OP_Referral_Route, Non_Invasive_Test_Type, Non_Invasive_Test_Result	Auto-set to `9`
OP_Referral_Route = 1 (Direct)	Non_Invasive_Test_Type, Non_Invasive_Test_Result	Auto-set to `9`
Management_Strategy ≠ 2	PCI_Outcome	Auto-set to `9`