. 2019 Nov 14;9(11):e031144. doi: 10.1136/bmjopen-2019-031144

Table 2.

Definitions of baseline demographics and risk factors

Variable or risk factor	Definition
Sex	Male/female
Age	18–50 years
Ethnicity	Caucasian Black Hispanic Asian Aboriginal Maori Pacific Islander Other
Prior stroke or TIA	Stroke prior to the index stroke is defined according to the same criteria as the index stroke; a rapidly evolving focal neurological deficit, without positive phenomena such as twitches, jerks or myoclonus, with no other than vascular cause, with symptoms persisting for more than 24 hours.⁹ Stroke will be further divided into intracerebral haemorrhage and ischaemic stroke based on neuroimaging. Haemorrhagic transformation of an ischaemic stroke will be classified as an ischaemic stroke. TIA is defined as a history of an episode of focal cerebral dysfunction lasting <24 hours without evidence of corresponding ischaemic lesion in earlier or present imaging studies.
Hypertension	A history of hypertension was defined as its presence either in the patients’ medical history, or when identified during admission for the index event after the acute phase within the first month after stroke. Hypertension was defined as the use of antihypertensive medication and/or systolic blood pressure of 140 mm Hg or greater and/or diastolic blood pressure of 90 mm Hg or greater.
DM	A history of DM was defined as its presence either in the patients’ medical history, or when identified during admission for the index event. Diabetes was defined as the use of diabetic medication and/or a fasting (defined as no caloric intake for at least 8 hours) plasma glucose >7 mmol/L and/or 2 h PG ≥11.1 mmol/L during OGTT and/or HbA1C≥6.5% (48 mmol/mol) and/or symptoms of hyperglycaemia or hyperglycaemic crisis and a random glucose >11.1 mmol/L.²⁰
Dyslipidaemia	A history of dyslipidaemia was defined as its presence either in the patients’ medical history, or when identified during admission for the index event. Dyslipidaemia was defined as use of statins and/or cholesterol level ≥5.0 mmol/L (193 mg/dL) and/or low-density lipoprotein level ≥3.0 mmol/L (116 mg/dL) and/or high-density lipoprotein level <1.0 mmol/L (39 mg/dL) and/or triglyceride level ≥1.7 mmol/L (150 mg/dL).
AF	A history of AF (chronic/paroxysmal) was defined as its presence either in the patients’ medical history, or when identified during admission for the index event. Atrial fibrillation will be defined as diagnosis based on ECG findings.
PFO	A presence of PFO was defined based on documentation in medical records, or when identified during hospitalisation for the index event. PFO will be defined as PFO with or without atrial septum aneurysm, as identified on TTE or TEE with or without contrast.
CAD	CAD included myocardial infarction and/or angina pectoris. A history of myocardial infarction or angina pectoris was defined as its presence either in the patients’ medical history, or when identified during admission for the index event.
Heart failure	A history of heart failure was defined as its presence either in the patients’ medical history, or when identified during admission for the index event. Heart failure was defined as ejection fraction <55%, reported on echocardiogram.
PAD	A history of PAD was defined as its presence either in the patients’ medical history, or when identified during admission for the index event.
Obesity	Obesity was defined as a body mass index greater than 30 kg/m², measured during admission for the index event or when reported by the patient.
Migraine	A history of migraine was defined as its presence either in the patients’ medical history or when identified during hospitalisation for the index event. Migraine was defined according to the International Headache Society criteria.²¹
Hormone replacement therapy	Use of oral or non-oral hormone replacement therapy at admission for the index event.
Oral contraceptives	Use of oral contraceptive pills at time of stroke onset.
Recent or acute infection	Signs or laboratory findings indicative of infection at admission or reported symptoms of any infectious disease during the month prior to stroke, or as concluded by institution of cohort.
Ever smoking	Any current or former smoker.
Heavy drinking	Heavy drinking was defined as the consumption of more than 21 units a week for men and 14 units a week for women, identified at admission for the index event.
Illicit recent drug use	Within the month prior to stroke.
Family history of stroke	History of ischaemic/haemorrhagic stroke or TIA in a first-degree relative.
Index stroke related to pregnancy	No Yes, pregnant at time of stroke Yes, stroke <6 weeks postpartum Yes, stroke <1 year after pregnancy
Pregnancy-related complications during any pregnancy	Gestational diabetes Hypertension Pre-eclampsia HELLP syndrome

AF, atrial fibrillation; CAD, coronary artery disease; DM, diabetes mellitus; HbA1c, glycosylated haemoglobin, type A1c; OGTT, oral glucose tolerance test;PAD, peripheral artery disease; PFO, patent foramen ovale;2 h PG, 2 hours post glucose; HELLP syndrome, haemolysis elevated liver enzymes and low platelets syndrome; TEE, transoesophageal echocardiogram;TIA, transient ischaemic attack; TTE, transthoracic echocardiogram.