Table 1.

Data extracted at stage two

Data extracted	Description
Study characteristics	Study aims
	Study design (categorised as experimental, observational, instrument development, model development)
	Setting in which the instrument was used
Instrument source	Name of instrument
	Source paper for the instrument as cited by the authors
Instrument purpose	Purpose for which the instrument was used (descriptive, predictive or diagnostic, outcome measure/evaluative)
Instrument format	Number of items
	Response scale (Likert, ipsative, etc.); response options
Instrument content and theoretical basis	Constructs and dimensions measured
	Definitions of the constructs; additional description of the content required to illustrate how the construct had been operationalized (e.g., sample items)
	Theoretical basis of the instrument and references cited for the theory