Prostate cancer screening in primary care: Doctors’ perspectives on prostate-specific antigen (PSA) screening of asymptomatic men in Australia and the United Kingdom

Abstract

Screening for prostate cancer is a highly debated public health issue. The evidence base is contested, the prostate-specific antigen (PSA) test as a screening technology is limited, no medical body recommends a population screening program for prostate cancer screening, local authorities differ in the advice they offer on the value of PSA screening in clinical care, and the substantial harms associated with PSA screening are well documented. Decisions about PSA screening most commonly occur in consultation with a general practitioner (GP). This qualitative study was designed to explain how GPs understand, reason about, and use the PSA test to screen men for prostate cancer risk in primary care. Australia and the United Kingdom draw on the same evidence base for prostate cancer screening yet have notably different rates of PSA screening; they are the two locations of this research study. In this thesis I report on GP perspectives on PSA screening. Methods: This is an empirical study using grounded theory methodology. Data were generated from in-depth interviews with GPs in Australia and the United Kingdom, who make decisions about using or not using the PSA test as a screening tool. Analysis was developed through transcript coding and detailed memo writing, using constant comparison to develop insight and connections between concepts. The overall aim of the study was to gain an in-depth understanding of how and why clinicians use the PSA test to screen for prostate cancer in primary care. Main findings: This grounded theory study found that for Australian GPs on the frontline, decision making about PSA screening is extremely difficult and complex. There was extensive variation in the clinicians’ accounts of their screening behaviour. Different motivations (values and goals) of GPs, context of the clinic and specific clinical interactions, opportunity to trust, and responses to uncertainty, were central explanations for varied practice. GPs intuitively and/or explicitly drew from multiple, potentially 3 conflicting, types of knowledge (including that from the research evidence) - developed over time – to guide their screening decisions. The study included UK GPs as a comparison case to examine the place of past and present screening policy, and healthcare system structure and organisation in influencing and incentivising particular ways of practicing. The UK experience demonstrates that Australian screening practices are not inevitable – things can be done differently. Some Australian clinicians in this study experienced significant emotional and cognitive burden, as a result of making screening decisions under challenging conditions. The empirical chapters of the thesis focus on four key issues: managing the potential for overdiagnosis, responding to uncertainty, practice and policy context, and communicating about PSA screening. The Discussion chapter draws these findings together into a new explanatory model of GPs’ decision making about PSA screening. Conclusion: This research provides an in-depth comparative analysis of important drivers of prostate cancer screening reported from the perspective of GPs in two locations with diverse screening rates. The model produced provides an explanation of the complex and varied process of PSA screening in the two jurisdictions. Policy continues to evolve and attract substantial debate in this field in Australia. Given that past attempts to intervene in PSA screening practice in Australia seem to have had limited effect, a new approach that better reflects the complexity of this issue, including the range of drivers of current practice, seems warranted. These findings offer useful empirical guidance for future policy and practice, grounded in the experiences of clinicians.