Table 1

Research questions using the PICOT/PECOT format as applicable

Research questions (RQs)PopulationExposureComparator (non-exposure)OutcomesTime
RQ1Adults ≥18 years of age undergoing any type of non-cardiac surgery (excluding cranial surgery)PICOT format not applicable for the first RQ (overall prognosis question, that is, no comparator, no exposure)Changes in cognitive performance after surgery compared with a preoperative baseline, as assessed through cognitive and/or neuropsychological assessmentsAny length of follow-up beyond 1 month*
RQ2Adults ≥18 years of ageUndergoing any type of non-cardiac surgery (excluding cranial surgery), including: general surgery, urological and gynaecological surgery, orthopaedic surgery (including spine surgery), thoracic surgery and vascular surgeryNot undergoing surgeryChanges in cognitive performance over time compared with a baseline, as assessed through longitudinal cognitive and/or neuropsychological assessments. For the patients exposed, will be postoperative changes compared with a preoperative baselineAny length of follow-up beyond 1 month*
RQ3Adults ≥18 years of age undergoing any type of non-cardiac surgery (excluding cranial surgery)Experiencing changes in cognitive performance after surgery compared with a preoperative baseline, as assessed through cognitive and/or neuropsychological assessmentsNot experiencing changes in cognitive performance after surgery compared with a preoperative baseline, as assessed through cognitive and/or neuropsychological assessmentsFunction/ability/disability (independence in basic and/or instrumental activities of daily living, employment)

  • physical performance

  • frailty

  • falls

  • quality of life

  • subjective complaints/concerns regarding cognition and/or function

  • caregiver burden

Any length of follow-up beyond 1 month*

  • *We will not make any a priori eligibility restrictions to the timing of assessment of cognitive changes. However, in the summary and analyses of the retrieved studies, we will make a distinction across studies based on their adherence to the recommended timeline for the definition of postoperative neurocognitive disorder, that is, between 1 month and 1 year after surgery.

  • PICOT/PECOT, Population, Intervention/Exposure, Comparator, Outcomes, Time.