Box 1.

Identified themes and subthemes

Theme	Subthemes
Descriptions of GPs’ current use of QIRx	Examples of successful use
	‘Partial’ use of QIRx: risk scores as thresholds but without knowledge of subsequent risk reduction
	Internalised non-numerical ideas of the value of treatments
Discussion of the lack of use of QIRx	Awareness of a knowledge deficit
	An absence of accessible information in a context of information overload
	Low confidence in statistical terminology
	Competing drivers to clinical practice
Making decisions in the absence of QIRx	Working with non-numerical, internalised ‘knowledge fragments’
	Using knowledge of physiology and extremes of age or risk
	Using non-numerical heuristics
	Taking into account patients’ characteristics
	Employing qualitative communication styles to convey non-numerical estimates of risk
GPs’ attitudes and feelings about the use or non-use of QIRx	Positive expressions of the value of QIRx in current practice
	Relative contentment with not using QIRx for some
	Negative impact on patient care due to a lack of understanding of QIRx
	Negative emotions arising from challenges in this area
GPs’ views on possibly increasing the use of QIRx in the future	Imagined benefits of increasing the use of QIRx
	Anticipated barriers to increasing the use of QIRx