Table 1

Data collection

	Variables	Source of Data
Main exposure variable	Timing of first contact with secondary healthcare services for diabetes management	Administration records
Cardiovascular risk factors	Smoking, hypertension, dyslipidaemia, obesity, high HbA1c	HIPE laboratory records
Comorbidities	PVD, history of minor LEA, chronic kidney disease, retinopathy, ischaemic heart disease	HIPE laboratory records
Sociodemographic risk factors	Age, gender, SES, marital status	Administration records

HbA1c, glycosylated haemoglobin HIPE, hospital in-patient enquiry; LEA, lower extremity amputation; PVD, peripheral vascular disease; SES, socio-economic status.