Table 1

Secondary endpoints and associated outcomes

Secondary objectives	Secondary outcomes
To evaluate the effect of perioperative melatonin administration on: Duration of postoperative delirium incidence Need for postoperative sedative or antipsychotic drugs administration Need for postoperative physical restrain prescription Incidence of postoperative falls Length of hospital stay Day 10 postoperative (or end of hospital stay if shorter) cognitive performance Day 30 postoperative mortality Day 30 postoperative functional status and quality of life To assess the total cost, the cost-effectiveness and the cost utility of perioperative melatonin administration. To assess the safety of perioperative melatonin administration.	Number of days CAM positive Incidence of postoperative sedative or antipsychotic drugs administration from D1 to D10 (or end of hospital stay if shorter) Incidence of postoperative physical restrain prescription from D1 to D10 (or end of hospital stay if shorter) Incidence of postoperative falls from D1 to D10 (or end of hospital stay if shorter) Mini Mental State Examination at D10 postoperative (or end of hospital stay if shorter) Duration of hospital stay D30 postoperative mortality D30 postoperative patient autonomy evaluated by the Katz Index of activities of daily living D30 postoperative quality of life and QALYs evaluated by EQ5D5L questionnaire; 30days QALYs are the utility weights for the 30-day periodx30/365 Total hospital costs at D30 calculated as the cumulative costs of all admissions (inpatient and outpatient, home care, rehabilitation) over a 30 days period Incremental cost effectiveness and cost utility ratios Occurrence of side effects

Secondary objectives

Secondary outcomes

To evaluate the effect of perioperative melatonin administration on:
- Duration of postoperative delirium incidence
- Need for postoperative sedative or antipsychotic drugs administration
- Need for postoperative physical restrain prescription
- Incidence of postoperative falls
- Length of hospital stay
- Day 10 postoperative (or end of hospital stay if shorter) cognitive performance
- Day 30 postoperative mortality
- Day 30 postoperative functional status and quality of life
To assess the total cost, the cost-effectiveness and the cost utility of perioperative melatonin administration.
To assess the safety of perioperative melatonin administration.

Number of days CAM positive
Incidence of postoperative sedative or antipsychotic drugs administration from D1 to D10 (or end of hospital stay if shorter)
Incidence of postoperative physical restrain prescription from D1 to D10 (or end of hospital stay if shorter)
Incidence of postoperative falls from D1 to D10 (or end of hospital stay if shorter)
Mini Mental State Examination at D10 postoperative (or end of hospital stay if shorter)
Duration of hospital stay
D30 postoperative mortality
D30 postoperative patient autonomy evaluated by the Katz Index of activities of daily living
D30 postoperative quality of life and QALYs evaluated by EQ5D5L questionnaire; 30days QALYs are the utility weights for the 30-day periodx30/365
Total hospital costs at D30 calculated as the cumulative costs of all admissions (inpatient and outpatient, home care, rehabilitation) over a 30 days period
Incremental cost effectiveness and cost utility ratios
Occurrence of side effects

CAM, Confusion Assessment Method; QALYs, quality-adjusted life year.