Table 1.

Inclusion and exclusion criteria

Treatment	Inclusion/Exclusion Criteria
Metal on metal hip resurfacing	A minimum of two years follow-up was applied; Studies not reporting the specified outcomes (ref. table 2) such as laboratory only studies were excluded.
Watchful waiting	Observational data of people receiving WW with a follow-up of greater than five years were included
Total hip replacement	RCTs or systematic reviews of RCTs with a minimum of five years follow-up of different methods of THR and systematic reviews of such trials