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Table 9 Risk factors and potential confounding variables

From: Risk factors for foot ulceration in adults with end-stage renal disease on dialysis: study protocol for a prospective observational cohort study

Continuous variables

Categorical variables

Participant characteristics

Participant characteristics

 • Age

 • Male sex

 • Body mass index

 • Current smoker

Health-related quality of life (SF-36v2®)

 • Living alone

 • Physical Component Score


 • Mental Component Score

 • Diabetes mellitus


 • Retinopathy

 • Duration of diabetes

 • Peripheral neuropathy

Dialysis-related variables

 • Peripheral arterial disease

 • Duration of dialysis

 • Arterial calcification

Laboratory blood tests

 • Hypertension

 • C-reactive protein

 • Dyslipidaemia

 • Serum albumin

 • Ischaemic heart disease

 • Total calcium

 • Congestive cardiac failure

 • Serum phosphate

 • Cerebrovascular disease

 • Parathyroid hormone

 • Osteoarthritis

 • Glycated haemoglobin (HbA1c)

 • Inflammatory arthritis

 • Haemoglobin

Lower extremity complications


 • Previous foot ulceration

 • Peak plantar pressures

 • Current foot ulcer present at baseline

 • Previous lower extremity amputation


 • Reduced range of motion of the 1st metatarsophalangeal joint

 • Foot deformity

 • Inappropriate/ill-fitting footwear

 • Skin pathology

 • Nail pathology

 • Poor foot health care behaviours

 • Regular podiatry attendance

  1. Potential confounding variables that will be considered in the regression models are boldface