Sheehan KJ, et al. - Researchers analyzed data from observational studies searched from MEDLINE, Embase, CINAHL, PEDRO, OpenGrey and ClinicalTrials.gov in order to identify immutable and modifiable prognostic factors of functional outcomes and their proposed mechanism after hip fracture surgery. Among operated adults with mean age of 65 years and older, one modifiable and one immutable prognostic factor for functional outcomes after hip fracture surgery was identified. Overall, 25 prognostic factors were identified. Anaemia and cognition were assigned a weak evidence level. Frailty was proposed as the mechanism for the link between anaemia and functional outcome. For the link between cognition and functional outcome, the proposed mechanisms included medication management, perceived potential, complications and time to mobility.