Doering 2000.

Methods	Randomised parallel group trial.
Participants	100 participants undergoing total hip replacement. Intervention group: 21 women, 25 men (mean age 59 years, SD 11); control group: 17 women, 37 men (mean age 60 years, SD 9). Inclusion criteria: aged ≥ 18 years, osteoarthritis of the hip. Exclusion criteria: previous hip surgery, co‐morbidity associated with severe pain, scheduled elective hip replacement, co‐morbidity that might alter cortisol and catecholamine excretion, psychiatric co‐morbidity. Location: Innsbruck, Austria.
Interventions	Intervention group (n = 46) shown a 12‐minute video in the presence of an investigator the night before surgery; film contained procedural information (pre‐ and postoperative), behavioural instructions and information about a participant's likely sensory experiences. Control group (n = 54) received preoperative information delivered by a surgeon and anaesthetist, and routine information sheets.
Outcomes	Anxiety (Spielberger State‐Trait Anxiety Inventory (20‐80 points) higher score represented greater anxiety); depression (von Zerssen Depression Scale; scoring system not reported); days to mobilisation (standing and climbing stairs); length of hospital stay; pain (100‐mm VAS, and postoperative analgesics); blood pressure; cortisol excretion. Participants were assessed preoperatively and 2 days postoperatively.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Patients... were randomly assigned to the preparation or control group." Comment: randomisation was performed by means of chance numbers (personal communication)
Allocation concealment (selection bias)	Unclear risk	Comment: allocation concealment not described.
Blinding (performance bias and detection bias) Self‐reported outcomes	High risk	Comment: No description of any attempt to blind participants; participants likely to be aware of group allocation and this may have influenced participants' responses to the anxiety questionnaire.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Quote: "Physicians of the Departments of Orthopedics and Anesthesia were blind to the assignment of patients to groups." Comment: for measures of mobility and use of analgesics outcome assessment was blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: there does not appear to be any withdrawals (e.g. cortisol data were complete) but missing values are not explicitly reported.
Selective reporting (reporting bias)	Unclear risk	Comment: data for all continuous outcomes were presented as mean values without measures of variation in figure format; however, trialists provided means and SDs on request. All outcomes listed in the methods were reported in the results, but without the trial protocol, it is unclear whether any other outcomes were measured but not reported based on the results.
Other bias	Low risk	Comment: no other sources of bias identified.