Efficacy of Alendronate for Preventing Collapse of Femoral Head in Adult Patients with Nontraumatic Osteonecrosis

Table 2

Methodological quality of included randomized controlled trials.

Study	Randomized adequately^a	Allocation concealed	Blinding^b	Balance in baseline	Advoiding selective reporting	Similar cofactors	Follow-up rate	Level of evidence^d
Chen et al. 2012 [13]	Yes	Yes	Double blinded	Yes	Yes	Yes	81%	1b
Lai et al. 2005 [14]	Unclear	No	No	Yes	Yes	Yes	100%	2b
Nishii et al. 2006 [15]	Unclear	No	No	Yes	Yes	Yes	88%	2b
Hsu et al. 2010 [31]	Yes	Yes	No	Yes	Yes	No^c	93%	2b
Wang et al. 2008 [32]	Yes	Yes	Double blinded	Yes	Yes	Yes	92%	1b

The trials which randomization schedules were explicitly described could get an “Yes”.
^bThe trials which placebo was adequately decribed how to blind both patients and investigators were considered as “Double Blinded”.
^cIn Hsu’s study, they compared alendronate + extracorporeal shock wave treatment + hyperbaric oxygen therapy versus extracorporeal shock wave treatment alone.
^dThe level of evidence was rated on basis of Oxford Centre for Evidence-based Medicine-Levels of Evidence (March 2009) [36].