Adult ; Age Factors ; Aged ; Aged, 80 and over ; Amputation ; economics ; Cerebrovascular Disorders ; epidemiology ; Cohort Studies ; Comorbidity ; Conservative Treatment ; Costs and Cost Analysis ; Diabetes Mellitus ; economics ; Diabetic Foot ; economics ; epidemiology ; therapy ; Female ; Foot Deformities, Acquired ; economics ; epidemiology ; therapy ; Foot Injuries ; economics ; epidemiology ; therapy ; Health Care Costs ; Hospitalization ; economics ; Humans ; Hypertension ; epidemiology ; Joint Diseases ; economics ; epidemiology ; therapy ; Length of Stay ; economics ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Ischemia ; epidemiology ; Peripheral Vascular Diseases ; epidemiology ; Retrospective Studies ; Singapore ; epidemiology ; Wound Infection ; economics ; epidemiology ; therapy ; Young Adult