Table 1.

Characteristics of included studies (n = 52)

	n	%
	Median	(IQR)
General characteristics
Publication year
2013	14	27
2014	15	29
2015	23	44
CEA time frame
0–11 months	22	42
12 months	19	37
≥24 months	11	21
Follow‐up design
Continuous (time to event)	4	8
One follow‐up assessment	11	21
Repeated assessments	37	71
Effectiveness measure
QALY	42	81
Binary	6	12
Clinical scale score	3	6
Time to recovery	1	2
Missing data
Report exact number of complete cases	20	38
Proportion of complete casesa	0.63	(0.47–0.81)
Proportion complete effectiveness data (n = 47)	0.73	(0.55–0.86)
Proportion complete cost data (n = 40)	0.79	(0.67–0.92)
Differs between costs and effectivenessb
Yes, more cost data missing	3	6
Yes, more effect data missing	10	19
No	22	42
No missing (<5%)	5	10
Unclear	12	23
Differs between armsc
Yes	10	19
No	32	62
No missing (<5%)	5	10
Unclear	5	10

Note. IQR = interquartile range; QALY = quality‐adjusted life year.

^aProportion of trial participants with complete cost‐effectiveness data. An upper bound was used if exact number not reported.

^bMore than 5% difference in the proportion of participants with complete cost or effectiveness data.

^cMore than 5% difference in the proportion of complete cases between arms.