PG cohort:  Inclusion criteria  Consent given and inclusion in PRÄP-GO Patient capable of giving consent or existing legal guardian in the case of patients not capable of giving consent  Exclusion criteria  - None  NFC cohort:  Inclusion criteria  Patient capable of giving consent or existing legal guardian in the case of patients not capable of giving consent Age ≥ 70 years Elective surgery planned Expected anesthesia duration> 60 min No frailty syndrome (0 positive out of 5 standardized parameters) according to the physical frailty phenotype (Fried et al., 2001)  Exclusion criteria  Severe cardiac or pulmonary disease (NYHA IV, Gold IV) Intracranial interventions Moribund patients (palliative situation) Patients with a neuropsychiatric clinical picture or severe hearing and / or visual acuity impairment (not compensated by visual or hearing aids), which limit the performance of the neurocognitive tests Insufficient language skills Participation in another interventional rehabilitation study or a study according to the German Drug Law or the medical Device Law that has not been approved by the study leader (Exception: parallel participation in adjuvant therapy study).  NO cohort:  Inclusion criteria  - Age ≥ 70 years  No elective surgery planned No surgery within 6 months prior to study enrollment  Exclusion criteria - See NFC cohort  GB cohort:  Inclusion criterion  - Doctor, nurse or therapist from the cooperation partners of PRAEP-GO who were involved in the project  Exclusion criterion  - Language barrier  Relatives:  Inclusion criteria  Member of a patient in the PRÄP-GO cohort Age ≥ 18 years  Exclusion criterion  - Language barrier