Understanding the impact of age and the role of geriatric assessments in treatment decision-making for older adults with cancer

Abstract

Treatment decision-making is complex for older adults with cancer given the heterogeneity in health and potential presence of age-related vulnerabilities. Personalised care guided by geriatric assessments (GAs) can reduce the risk of under- or over-treatment. However, use of GAs and assessment of geriatric domains more broadly is low in Australian clinical practice. This thesis aimed to synthesise the current international evidence associated with GAs for cancer patients, explore Australian cancer healthcare professionals (HCPs), older cancer patients and their carers’ experiences and views of treatment decision-making for older adults with cancer and finally, quantitatively evaluate the relative importance oncologists’ place on patient and clinical characteristics when weighing up treatment decisions. Study 1 involved an umbrella review which identified inconsistencies in GA definition and lack of implementation focussed reviews. Study 2 involved semi-structured qualitative interviews with Australian HCPs (n=29), older adults with cancer (n=19), and carers (n=9). HCP themes included(1)Who do we consider older? Chronological vs. functional age,(2)Clinical management of older adults-theory vs. practice,(3)Is there value in geriatric assessments?,(4)Factors that impact GA implementation and an overarching theme(5)Treatment decision-making for older adults with cancer. Patient and carer themes included(1)Impact of age in decision-making: assumptions and discussions,(2)Factors that influenced patient treatment decisions and,(3)Cancer and ageing-related supports. Study 3 used a discrete choice experiment (DCE) methodology. Oncologists (n=44) placed highest relative importance on survival whilst age had the lowest relative importance and was not a statistically significant influence in decision-making. Overall, this thesis provides critical insight into the role of age in treatment decision-making and considerations for implementation of GAs for older adults with cancer.