The population is ageing and surgery is becoming more common as the treatment of choice for many diseases and conditions in older people. Although mortality rates are low for many operations, older patients are at increased risk of complications and may have poor outcomes including longer hospital stays and discharge to sub-acute care or aged care facilities.The aim of this thesis was to describe the occurrence of non-disease specific complications, known as geriatric syndromes, in older patients admitted to surgical wards, and to explore the association of 'frailty' and other key risk factors with geriatric syndromes and discharge outcomes in order to identify high risk groups who might benefit from interventions designed to prevent these complications and improve discharge outcomes.The specific aims were to:1. Describe the occurrence of geriatric syndromes in older surgical ward patients (with the exception of hip fracture or cardiothoracic patients) 2. Investigate the association between key risk factors for geriatric syndromes and discharge outcomes (acute length of stay and discharge destination) in older surgical ward patients.A literature review of the occurrence of geriatric syndromes in the broader surgical population cared for in usual care wards is presented in Chapter 2(1).The occurrence of geriatric syndromes in older patients admitted under two surgical subspecialty units is presented in Chapter 3 (2). In this retrospective cohort study of 112 patients aged 65, admitted under the urology or vascular surgical units of Royal Brisbane and Women's Hospital for three days or more, we found that geriatric syndromes occurred in 32 % of patients. We examined the association of pre-existing impairment in activities of daily living (a unidimensional marker of frailty), mode of admission (elective versus non-elective), extent of surgery (non-operative, minor, major) and surgical sub-specialty unit with ≥1 geriatric syndromes. In multivariable analysis, nonelective admission, major surgery and pre-existing impairment in activities of daily living increased the likelihood of geriatric syndromes. No significant association was seen in the adjusted model with surgical unit, age or comorbidity score.In Chapter 4, we describe the prevalence of frailty and the occurrence of geriatric syndromes in older vascular surgical ward patients and more precisely examine the association of pre-existing II patient factors (frailty and comorbidities), illness severity, surgical severity and mode of admission with ≥1 geriatric syndromes, acute length of stay and discharge destination from the vascular surgical unit. In a prospective cohort study of 110 patients admitted to the vascular surgical unit of Royal Brisbane and Women's Hospital for three days or more, we found that 39% of participants were frail and 36% developed ≥1 geriatric syndromes. In multivariable analysis, this study found multiple risk factors for geriatric syndromes; frailty and non-elective admission were important predictors for both geriatric syndrom...