Table 1.

Summary statistics on reporting of visit irregularity, predictors of visit times, and methods of analysis

Outcomes of Interest	N (out of 44)	%
Study design
Prospective	10	23
Retrospective	31	70
Unclear	3	7
Clearly defined end of study
Yes	34	77
No	10	23
Comparison of those with and without full follow-up among studies with a clearly defined end of follow-up	(out of 34)
Yes	5	15
No	24	71
Not Applicable (all participants had full follow-up)	5	15
Method of analysis
Linear or logistic regression	8	18
Gaussian process regression	1	2
Repeated measures	11	25
Mixed model or generalized mixed model	20	45
GEE	3	7
IIW-GEE	1	2
Reported summary statistics on
Number of visits per patient	25	57
Gaps between visits per patient	3	7
Follow-up time per patient	25	57
Predictors of visit time assessed
Yes	2	5
No	41	93
Unclear	1	2
Was there a need to account for informative visit times?
Yes	6	14
of which
Analysis specifically designed to check for informativeness	1 (out of 6)	18
Informativeness inferred by reviewers	5 (out of 6)	82
Unclear	38	86
Method used to account for informative visit times for studies with sufficient reporting of an identifiable need	(out of 6)
Yes	1	19
No	5	81