Primary Care (incident)

In the Clinical Practice Research Datalink (CPRD, primary care data) we ascertained AAA cases by searching for Read terms related to an abdominal aortic aneurism diagnosis or evidence of endovascular/transluminal procedures related to the emergency repair of an aneurysmal segment of the aorta.

Read code	Read term	CALIBER category
G71..00	Aortic aneurysm	Abdominal aortic aneurysm
G713.00	Abdominal aortic aneurysm which has ruptured	Abdominal aortic aneurysm
G713.11	Ruptured abdominal aortic aneurysm	Abdominal aortic aneurysm
G713000	Ruptured suprarenal aortic aneurysm	Abdominal aortic aneurysm
G714.00	Abdominal aortic aneurysm without mention of rupture	Abdominal aortic aneurysm
G714.11	AAA - Abdominal aortic aneurysm without mention of rupture	Abdominal aortic aneurysm
G714000	Juxtarenal aortic aneurysm	Abdominal aortic aneurysm
G715.00	Ruptured aortic aneurysm NOS	Abdominal aortic aneurysm
G715000	Thoracoabdominal aortic aneurysm, ruptured	Abdominal aortic aneurysm
G716.00	Aortic aneurysm without mention of rupture NOS	Abdominal aortic aneurysm
G716000	Thoracoabdominal aortic aneurysm, without mention of rupture	Abdominal aortic aneurysm
G718.00	Leaking abdominal aortic aneurysm	Abdominal aortic aneurysm
G71z.00	Aortic aneurysm NOS	Abdominal aortic aneurysm

Emergency repair of aneurysmal segment

Read code	Read term	CALIBER category
7A11000	Emerg repl aneurysm bifurc aorta by anast aorta to fem art	Emergency AAA repair
7A11200	Emerg repl aneurysm bifurc aorta by anast aorta to iliac a	Emergency AAA repair
7A11211	Y graft of abdominal Aortic aneurysm (emergency)	Emergency AAA repair
7A13.00	Emergency replacement of aneurysmal segment of aorta	Emergency AAA repair
7A13.11	Emergency repair of aortic aneurysm	Emergency AAA repair
7A13300	Emerg replace aneurysm infrarenal aorta by anast aorta/aorta	Emergency AAA repair
7A13400	Emerg replace aneurysm abdom aorta by anast aorta/aorta NEC	Emergency AAA repair
7A13411	Tube graft abdominal Aortic aneurysm (emergency)	Emergency AAA repair
7A13y00	Emergency replacement of aneurysmal segment of aorta OS	Emergency AAA repair
7A13z00	Emergency replacement of aneurysmal segment of aorta NOS	Emergency AAA repair

Read terms are hierarhically organized in top-level chapters i.e. chapter G....00 is related to Circulatory System Diseases and sub-headings i.e. heading G2...00 is related to Hypertensive Heart Disease while G3...00 is related to Ischaemic Heart Disease.

Secondary Care (incident and prevalent)

In Hospital Episode Statistics (HES, hospital admission data) we used ICD-10 terms (see below) for AAA diagnosis when marked as the primary diagnosis i.e. the main condition treated or investigated during the relevant episode of healthcare. We used the date of admission to hospital as the date of the event. We additionally searched for OPCS-4 terms indicating the emergency repair of an aneurysmal segment of the aorta.

ICD-10 code	ICD-10 term	CALIBER category
I713	Abdominal aortic aneurysm, ruptured	Abdominal aortic aneurysm
I714	Abdominal aortic aneurysm, without mention of rupture	Abdominal aortic aneurysm
I715	Thoracoabdominal aortic aneurysm, ruptured	Abdominal aortic aneurysm
I716	Thoracoabdominal aortic aneurysm, without mention of rupture	Abdominal aortic aneurysm
I718	Aortic aneurysm of unspecified site, ruptured	Abdominal aortic aneurysm
I719	Aortic aneurysm of unspecified site, without mention of rupture	Abdominal aortic aneurysm

Emergency repair of aneurysmal segment

OPCS-4 code	OPCS-4 term	CALIBER category
L18	Emergency replacement of aneurysmal segment of aorta	AAA procedure
L181	Emergency replacement of aneurysmal segment of ascending aorta by anastomosis of aorta to aorta	AAA procedure
L182	Emergency replacement of aneurysmal segment of thoracic aorta by anastomosis of aorta to aorta NEC	AAA procedure
L183	Emergency replacement of aneurysmal segment of suprarenal abdominal aorta by anastomosis of aorta to aorta	AAA procedure
L184	Emergency replacement of aneurysmal segment of infrarenal abdominal aorta by anastomosis of aorta to aorta	AAA procedure
L185	Emergency replacement of aneurysmal segment of abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L186	Emergency replacement of aneurysmal bifurcation of aorta by anastomosis of aorta to iliac artery	AAA procedure
L188	Other specified emergency replacement of aneurysmal segment of aorta	AAA procedure
L189	Unspecified emergency replacement of aneurysmal segment of aorta	AAA procedure
L19	Other replacement of aneurysmal segment of aorta	AAA procedure
L191	Replacement of aneurysmal segment of ascending aorta by anastomosis of aorta to aorta NEC	AAA procedure
L192	Replacement of aneurysmal segment of thoracic aorta by anastomosis of aorta to aorta NEC	AAA procedure
L193	Replacement of aneurysmal segment of suprarenal abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L194	Replacement of aneurysmal segment of infrarenal abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L195	Replacement of aneurysmal segment of abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L196	Replacement of aneurysmal bifurcation of aorta by anastomosis of aorta to iliac artery NEC	AAA procedure
L198	Other specified other replacement of aneurysmal segment of aorta	AAA procedure
L199	Unspecified other replacement of aneurysmal segment of aorta	AAA procedure
L20	Other emergency bypass of segment of aorta	AAA procedure
L201	Emergency bypass of segment of ascending aorta by anastomosis of aorta to aorta NEC	AAA procedure
L202	Emergency bypass of segment of thoracic aorta by anastomosis of aorta to aorta NEC	AAA procedure
L203	Emergency bypass of segment of suprarenal abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L204	Emergency bypass of segment of infrarenal abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L205	Emergency bypass of segment of abdominal aorta by anastomosis of aorta to aorta NEC	AAA procedure
L206	Emergency bypass of bifurcation of aorta by anastomosis of aorta to iliac artery NEC	AAA procedure
L208	Other specified other emergency bypass of segment of aorta	AAA procedure
L209	Unspecified other emergency bypass of segment of aorta	AAA procedure
L254	Operations on aneurysm of aorta NEC	AAA procedure
L27	Transluminal insertion of stent graft for aneurysmal segment of aorta	AAA procedure
L271	Endovascular insertion of stent graft for infrarenal abdominal aortic aneurysm	AAA procedure
L272	Endovascular insertion of stent graft for suprarenal aortic aneurysm	AAA procedure
L273	Endovascular insertion of stent graft for thoracic aortic aneurysm	AAA procedure
L274	Endovascular insertion of stent graft for aortic dissection in any position	AAA procedure
L275	Endovascular insertion of stent graft for aortic aneurysm of bifurcation NEC	AAA procedure
L276	Endovascular insertion of stent graft for aorto-uniiliac aneurysm	AAA procedure
L278	Other specified transluminal insertion of stent graft for aneurysmal segment of aorta	AAA procedure
L279	Unspecified transluminal insertion of stent graft for aneurysmal segment of aorta	AAA procedure
L28	Transluminal operations on aneurysmal segment of aorta	AAA procedure
L281	Endovascular insertion of stent for infrarenal abdominal aortic aneurysm	AAA procedure
L282	Endovascular insertion of stent for suprarenal aortic aneurysm	AAA procedure
L283	Endovascular insertion of stent for thoracic aortic aneurysm	AAA procedure
L284	Endovascular insertion of stent for aortic dissection in any position	AAA procedure
L285	Endovascular insertion of stent for aortic aneurysm of bifurcation NEC	AAA procedure
L286	Endovascular insertion of stent for aorto-uniiliac aneurysm	AAA procedure
L288	Other specified transluminal operations on aneurysmal segment of aorta	AAA procedure
L289	Unspecified transluminal operations on aneurysmal segment of aorta	AAA procedure

In mortality data, we used ICD-9 and ICD-10 terms (see below) located at the underlying cause of death position:

ICD-10 code	ICD-10 term	CALIBER category
I713	Abdominal aortic aneurysm, ruptured	Abdominal aortic aneurysm
I714	Abdominal aortic aneurysm, without mention of rupture	Abdominal aortic aneurysm
I715	Thoracoabdominal aortic aneurysm, ruptured	Abdominal aortic aneurysm
I716	Thoracoabdominal aortic aneurysm, without mention of rupture	Abdominal aortic aneurysm
I718	Aortic aneurysm of unspecified site, ruptured	Abdominal aortic aneurysm
I719	Aortic aneurysm of unspecified site, without mention of rupture	Abdominal aortic aneurysm

ICD-9 code	ICD-9 term	CALIBER category
4413	Aortic aneurysm and dissection ; Abdominal aneurysm, ruptured	Abdominal aortic aneurysm
4414	Aortic aneurysm and dissection ; Abdominal aneurysm without mention of rupture	Abdominal aortic aneurysm
4415	Aortic aneurysm and dissection ; Aortic aneurysm of unspecified site, ruptured	Abdominal aortic aneurysm
4416	Aortic aneurysm and dissection ; Thoracoabdominal aneurysm, ruptured	Abdominal aortic aneurysm
4417	Aortic aneurysm and dissection ; Thoracoabdominal aneurysm, without mention of rupture	Abdominal aortic aneurysm
4419	Aortic aneurysm and dissection ; Aortic aneurysm of unspecified site without mention of rupture	Abdominal aortic aneurysm

Combining evidence across sources to define and date phenotypes

Primary care 
1. Diagnosis of AAA during a consultation
2. Performance of emergency AAA repair procedure recording during a consultation

Secondary care 
1. Diagnosis of AAA as the primary diagnosis of any hospitalization
2. Performance of emergency AAA repair procedure recorded

Mortality 
1. Leaking or ruptured AAA as underlying cause of death 
2. AAA without leak or rupture as underlying cause of death

• Prognosis
• Aetiology

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