A standardized measurement instrument was recommended for evaluating operator experience in complex healthcare interventions

•This study identifies, appraises, and recommends a standard measure to assess operators' experience in studies of surgical innovation.•Robust methodology was applied.•Supplemental validation used semistructured interviews with multinational and multidisciplinary professionals.•The SURG-TLX is preliminarily recommended because it was found to be most relevant, comprehensive, and comprehensible.•Routine use of a validated, standard measure to assess operators' experience supports efficient and transparent evaluation of complex interventions involving surgical innovation.