Table 1.

Proportion of missing data within the 61 studies with QoL outcomes

	Number of Studies
Proportion of missing data	No imputation	Imputation	Total
None	6	0	6
< 10%	16	5	21
11–20%	6	5	11
>20%	8	3	11
Unclear	6	6	12
Total	42	19	61