Table 1 Assessment of risks to bias in non-randomised studies
Study | Were eligibility criteria explicit? | Was sample source/selection described? | Were patients assembled at same time? | Was a method of diagnosis stated?‡ | Were clinical details described? | Was individual patient data reported? | Was outcome assessment blinded? | Was blinding method adequately described? | Was follow up time stated?Φ | Were withdrawals stated? | Were reasons for withdrawal stated? |
|---|---|---|---|---|---|---|---|---|---|---|---|
Barkan 2005[24] | Y | N | CT | N | Y | N | N | NA | Y | Y | Y |
Jorgensen 2005[19] | Y | Y | CT | N | Y | N | N | NA | Y | Y | Y |
Feenstra 2005[18] | Y | N | CT | N | Y | N | N | NA | Y | N | NA |
Van der Lely 2001[8] | Y | N | N | N | Y | N | N | NA | Y | Y | Y |
Sesmilo 2002[9] | Y | N | CT | Y | Y | N | N | NA | Y | Y | Y |
Fairfield 2002[10] | N | N | CT | N | Y | N | N | NA | Y | N | NA |
Parkinson 2002[22] | N | N | CT | N | Y | Y†| N | NA | N | N | NA |
Parkinson 2003a[15] | Y | N | CT | N | Y | N | N | NA | N | N | NA |
Parkinson 2003b[23] | N | N | CT | N | Y | Y†| N | NA | Y | N | NA |
Parkinson 2004[14] | N | N | CT | N | N | Y†| N | NA | N | N | NA |
Jehle 2005[17] | N | N | CT | N | Y | Y | N | NA | Y | Y | Y |
Paisley 2006[13] | N | N | CT | N | Y | Y | N | NA | N | N | N |
Biering 2006[11] | CT | Y | NA | N | N | Y a | N | NA | N | Y | Y |
Colao 2006[16] | Y | Y | Y | Y | Y | Y | N | NA | Y | Y | Y |
Pivonello 2007[20] | Y | N | CT | Y | Y | Y | Y | Y | Y | Y | N |
Schreiber 2007[21] | N | Y | N | N | Y | N | N | NA | Y | Y | N‡‡ |
Parkinson 2007[12] | Y | N | CT | N | Y | Y | Y | N | N | N | NA |