Table 3.

Approaches to missing data, by year, number of follow‐ups, and extent of missing data (n = 47)

	Primary analysis method						Reported a sensitivity analysis
	CCA		MI		Other		Yes		No
	n	%	n	%	n	%	n	%	n	%
Publication year
2013 (n = 13)	6	46	3	23	4	31	5	38	8	62
2014 (n = 15)	9	60	1	7	5	33	6	40	9	60
2015 (n = 19)	5	26	10	53	4	21	11	58	8	42
Number of follow‐up assessmentsa
1 (n = 10)	7	70	1	10	2	20	3	30	7	70
≥2 (n = 36)	13	36	13	36	10	28	18	50	18	50
Proportion of complete casesb
<50% (n = 15)	4	27	6	40	5	33	8	53	7	47
50–75% (n = 18)	10	56	4	22	4	22	9	50	9	50
75%–95% (n = 14)	6	43	4	29	4	29	5	36	9	64
Information missingc
Similar (n = 22)	13	59	6	27	3	14	10	45	12	55
More cost missing (n = 3)	1	33	2	67	0	0	2	67	1	33
More effect missing (n = 10)	4	40	2	20	4	40	6	60	4	40

Note. % = row percentages. CCA = complete‐case analysis; MI = multiple imputation.

^aExcluding one study with continuous follow‐up (n = 46).

^bFor the five studies with less than 5% of incomplete cases, four used CCA and one an ad hoc hybrid method for their primary analysis. One of the five studies conducted a sensitivity analysis to missing data.

^cExcluding 12 studies where this was unclear (n = 35).