Question	Judgement	Criteria
1: Were uninterpretable or intermediate test results reported?	Yes	The number or proportion of uninterpretable or intermediate test results is reported.
	No	Uninterpretable or intermediate test results arose but the number or proportion is not reported.
	Unclear	It is not possible to tell whether or not there were any uninterpretable or intermediate test results.
2: Were structural brain images available for comparison?	Yes	Structural brain images taken within 6 months of the DAT images were available to aid interpretation.
	No	No structural brain images (± 6 months) were available to aid image interpretation.
	Unclear	Insufficient information to make a judgement.
3: Was the method of image reconstruction consistent throughout the study?	Yes	The method of image reconstruction is stated and was the same for all participants in the study.
	No	The method of image reconstruction varied within the study.
	Unclear	Insufficient information to make a judgement.
4: Had test operators had appropriate training?	Yes	DAT image interpreters were fully qualified or certified nuclear medicine specialists with prior experience of the technique.
	No	DAT image interpreters lacked this training or experience.
	Unclear	Insufficient information to make a judgement.
5: Were data on observer variation in DAT image interpretation reported and within an acceptable range?	Yes	Data on intra‐ and inter‐observer variation in DAT image interpretation are reported and agreement is good (kappa > 0.6).
	No	Observer variation is not reported or agreement was poor (kappa < 0.6).
	Unclear	It is not clear whether observer variation was measured.