Paediatric diagnostic test utilisation in primary care: an analysis of variation using quantitative and qualitative approaches

Thesis

This thesis aimed to examine the landscape of diagnostic tests for children in primary care. My hypothesis was that substantial variation exists in how general practitioners (GPs) request tests for children, as this area entails a high level of diagnostic uncertainty. Unwarranted variation has harmful consequences; it exacerbates health inequities and strains health resources. My thesis, therefore, aimed to quantify and explore variation in paediatric test use and identify the potential drivers of variation.

First, laboratory test use in Oxfordshire was analysed from 2005 to 2019, to establish the role of paediatric diagnostic tests in general practice compared with other settings. In the subsequent study, paediatric test use was investigated in general practice using data from the Clinical Practice Research Datalink from 2007 to 2019. Tests that increased by the greatest margin and were subject to the highest between-practice variability were identified as tests that are potentially overused and warrant further investigation. Following this, semi-structured interviews were undertaken with 18 GPs and 2 GP trainees to explore their perspectives on requesting tests for children and identify some perceived drivers of variation. Finally, diagnostic guidelines for common paediatric conditions were examined, to determine whether the quality of guidelines and the quality of evidence underpinning diagnostic test recommendations could be driving variation in testing practices.

This thesis presents the first comprehensive study of paediatric test use and variation in primary care. It highlights the scarcity of evidence for diagnostic tests in children, despite their increasing use in general practice. The variability of test use that was observed between practices reflects inconsistency in guidelines and practice. In the final chapter, a research strategy to develop paediatric test indicators is proposed; these indicators seek to identify inappropriate testing and improve the quality of diagnostic services delivered to children.

Authors: Thomas, ET

• DOI: 10.5287/ora-eyzpqby7r
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: primary health care; public health; child health; epidemiology; diagnostic tests; clinical practice guidelines; general practice; qualitative research; paediatrics
• Subjects: Pediatrics; Epidemiology; Primary Health Care; Diagnostic tests