Explaining variations in test ordering in primary care: protocol for a realist review

Abstract

IntroductionStudies have demonstrated the existence of significant variation in test-ordering patterns in both primary and secondary care, for a wide variety of tests and across many health systems. Inconsistent practice could be explained by differing degrees of underuse and overuse of tests for diagnosis or monitoring. Underuse of appropriate tests may result in delayed or missed diagnoses; overuse may be an early step that can trigger a cascade of unnecessary intervention, as well as being a source of harm in itself.Methods and analysisThis realist review will seek to improve our understanding of how and why variation in laboratory test ordering comes about. A realist review is a theory-driven systematic review informed by a realist philosophy of science, seeking to produce useful theory that explains observed outcomes, in terms of relationships between important contexts and generative mechanisms.An initial explanatory theory will be developed in consultation with a stakeholder group and this ‘programme theory’ will be tested and refined against available secondary evidence, gathered via an iterative and purposive search process. This data will be analysed and synthesised according to realist principles, to produce a refined ‘programme theory’, explaining the contexts in which primary care doctors fail to order ‘necessary’ tests and/or order ‘unnecessary’ tests, and the mechanisms underlying these decisions.Ethics and disseminationEthical approval is not required for this review. A complete and transparent report will be produced in line with the RAMESES standards. The theory developed will be used to inform recommendations for the development of interventions designed to minimise ‘inappropriate’ testing. Our dissemination strategy will be informed by our stakeholders. A variety of outputs will be tailored to ensure relevance to policy-makers, primary care and pathology practitioners, and patients.Prospero registration numberCRD42018091986

Determinants of Medical Practice Variation Among Primary Care Physicians: Protocol for a Three Phase Study

“…In more general terms we will be not able to deduce what physician is practicing “good” medicine—the one who sends patients to a lot of tests or the one who sends few. Yet, because MPVs have been previously shown to be associated with poorer health outcomes [ 14 , 17 - 19 , 21 ], we believe that focusing on the measurement and dissection of the variation itself can contribute to the development of the approaches to reduce the MPV.…”

“…Major attempts to prevent the overuse of health services (HSs) include the British Medical Journal series Too Much Medicine [ 12 ], established in 2002, and Choosing Wisely campaigns [ 13 ], established in 2012. Increasing interest in this area is also reflected by the growing number of books, literature, and articles in the mainstream media [ 14 ].…”

“…While MPV is based on a relative comparison between providers ( Figure 1 ), overuse and underuse definitions call for a comparison between the individual provider practice and standard of care (absolute comparison) based on a “gold standard” or guideline recommendations [ 16 , 17 ]. Both overuse and underuse (eg, patients not receiving optimal care and resources used inefficiently) have negative consequences [ 14 ] and can contribute to MPV [ 15 ]. MPV is associated with poorer health outcomes, increased costs, disparities in care, and burden on medical systems [ 14 , 17 - 21 ].…”

“…Both overuse and underuse (eg, patients not receiving optimal care and resources used inefficiently) have negative consequences [ 14 ] and can contribute to MPV [ 15 ]. MPV is associated with poorer health outcomes, increased costs, disparities in care, and burden on medical systems [ 14 , 17 - 21 ]. Adopting the policy aimed to reduce variation is a central theme of quality management that has begun with industrial production and was recently adopted in medicine practice [ 19 , 22 , 23 ].…”

Efficiency over thoroughness in laboratory testing decision making in primary care: findings from a realist review

“…The methods for this review are described in detail in the published protocol. (25) The review was conducted according to Pawson's five steps, (26) outlined briefly in Table 1 below and in detail in Table S1. Review processes adhered to the RAMESES quality(27) and reporting(28) standards throughout.…”