Hoppenstein 2005.

Methods	RCT Institutional review board–approved and written informed consent was obtained before patient inclusion into the study
Participants	Sixty ASA physical status I, II, and III geriatric patients at least 60 years of age, undergoing surgical fixation of the neck of femur Patients with known haemoglobinopathy, as well as those with a clinical history of cerebrovascular or carotid artery disease, were excluded from the study.
Interventions	Treatment group: spinal anaesthesia performed with the patient in the lateral decubitus position and 4 mg isobaric bupivacaine plus 25 mcg of fentanyl via a 25‐gauge pencil‐point needle (n = 30) Control group: General anaesthesia with thiopental, fentanyl, nitrous oxide, isoflurane and vecuronium (n = 30)
Outcomes	Length of surgery
Notes	Presence/absence of thromboprophylaxis not mentioned
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Patients were allocated via computer‐generated randomization schedule to one of two treatment groups
Allocation concealment (selection bias)	Low risk	Randomized after enrolment
Blinding of participants and personnel (performance bias) All outcomes	High risk	"open label study"
Blinding of outcome assessment (detection bias) All outcomes	High risk	"open label study"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	No conversion to general anaesthesia
Other bias	Low risk	Groups well balanced