Table 4.

Assessment of the risk of bias of the retrospective GENEPSI study.

Bias	GENEPSI Study [25]
Confounding (allocation bias)	Low:
	“Patient data were retrospectively pooled from three psychiatric clinics in Madrid (see author affiliations) that had been using the Neuropharmagen test”
	Balanced distribution regarding baseline severity (CGI-S), age, sex, substance abuse and concomitant diseases
	“Genetic testing could also result in increased placebo effect. In order to avoid these confounder effects, we sought to perform this retrospective study exclusively in patients who had been genotyped, rather than comparing patients who received pharmacogenetic testing to patients treated as usual.”
Selection of participants (Inception bias)	Low:
	Baseline visit established as the one in which the saliva sample from the patient was collected
	Follow-up visit established 12-weeks after the baseline visit
Misclassification of interventions (misclassification bias)	Moderate:
	Intervention status well defined, although determined retrospectively
Deviations from intended interventions (performance bias)	Low:
	Retrospective assignment of intervention. No differences between groups in the care provided
Missing data (attrition bias)	Low:
	Patients lost to follow-up were evenly distributed
Measurement of outcomes (detection bias)	Moderate:
	CGI-S recorded in the clinical history by the treating clinician prior to retrospective study protocol definition
Selective reporting (outcome reporting bias)	Low:
	Prespecified outcomes were reported