Table 1 Inclusion and exclusion criteria

Population

• Adult (60 years or older) patients undergoing surgery for acute intra- or extracapsular hip fracture

• Adults under the age of 60 years

• Patients undergoing surgery for reasons other than intra- or extracapsular hip fractures

• Patients with hip fractures not related to an acute trauma

• Patients with pathological fractures

• Patients with periprosthetic fractures

Geography

• No limitation

• No limitation

Date of search

• Searches will go back to 1997

Interventions

• Early surgery for hip fracture. We will use the definition for “early” as defined by authors in the primary study.

• We will exclude studies that do not compare timing of surgery

Control interventions

• Delayed surgery for hip fracture. We will include all categories of “delayed” as defined by authors in the primary study.

• We will exclude studies that do not compare timing of surgery

Outcomes

• All-cause mortality

- Short term: at 1 month

- Medium term: at 6 months

- Long term: at 12 months

• Severe perioperative complications

- Pulmonary embolism

- Pneumonia

- Deep vein thrombosis

- Others

• Other perioperative complications

- Urinary tract infection

- Pressure ulcer

- Others

• Functional capacity

• Quality of life (e.g., assessed with SF36)

• Studies that do not include at least one of the outcomes listed under the inclusion criteria

Publication language

• English, German

• All other languages

Study design

• Original research

• Eligible study designs include:

- RCTs

- Prospective controlled cohort studies

• Case series

• Case reports

• Retrospective controlled cohort studies

• Case-control studies

• Studies without a control group

Publication type

Any publication reporting primary data

• Publications not reporting primary data

• Publications available as abstract only