Table 1.

Follow-up, nature, and presence of standardisation in selected studies

Ref.	Number of patients lost to follow up (5)	Nature of study	Standardisation for comorbidities
Chu et al[12]	17 (6.9)	Prospective	Standardised
Larrson et al[7]	0	Prospective	Not standardised
Schleiffer et al[23]	0	Prospective	Standardised
Faglia et al[20]	0	Prospective	Standardised
Van Damme et al[13]	0	Prospective	Standardised
Goldner et al[5]	NS	Prospective	Standardised
Morbach et al[16]	0	Prospective	Standardised
Ghanassia et al[8]	5 (5)	Prospective	Standardised
Skoutas et al[10]	0	Prospective	Standardised
Adler et al[24]	155 (2)	Prospective	Standardised
Ohsawa et al[25]	0	Prospective	Standardised
Izumi et al[9]	N/A	Retrospective	Standardised
Murdoch et al[6]	N/A	Retrospective	Standardised
Uzzaman et al[26]	N/A	Retrospective	Standardised
Acar et al[11]	N/A	Retrospective	Standardised
Nerone et al[17]	N/A	Retrospective	Standardised
Aulivola et al[27]	N/A	Retrospective	Not standardised
Jeyaraman et al[18]	N/A	Retrospective	Standardised
Jeyaraman et al[21]	N/A	Retrospective	Standardised
Thorud et al[15]	N/A	Meta-analyses	Standardised
Albers et al[28]	N/A	Meta-analyses	Standardised
Borkosky et al[14]	N/A	Systematic Review	Standardised

NS: Not specified; N/A: Not applicable.