Table 1

Summary characteristics of the 39 included studies

Studies with published results
Studies in progress
Study diffusion
 Registry database only8(20) 0(0)8(61)
 Journals31(79) 26(100)5(38)
  Specialist medical journals16(51) 15(58)1(3)
  Paediatric and adolescent medical journals12(39) 10(38)2(5)
  General medical journals3(10) 1(4)2(5)
Eligible diseases
 Unique32(82) 23(88)9(69)
 Set of conditions7(18) 3(12)4(31)
Time of intervention1  
 Before the last paediatric consultation26(68) 17(65)9(69)
 Between the last paediatric and the first adult consultation11(29) 9(35)2(15)
 After the first adult consultation1(3) 0(0)1(8)
Data collection of interventional group1  
 Retrospective14(36) 13(50)1(8)
 Prospective25(64) 13(50)11(85)
Number of comparison groups by study
 0 (precomparison/postcomparison in a single group)9(23) 7(27)2(15)
 125(64) 16(61)9(69)
 >15(13) 3(11)2(15)
Type of comparison group (n=30)*
 Historical group11(37) 10(38)1(9)
 Randomised group9(30) 1(4)8(73)
 Non-participants group5(17) 5(19)0(0)
 Contemporary data from another service/center/care setting5(17) 3(11)2(18)
 Non-randomised parallel group1(3) 0(0)1(9)
 Mixed data of historical cohort and non-participants group1(3) 1(4)0(0)
Blinding strategy2(5) 0(0)2(15)
Control in randomised studies (n=9)
 Usual care6(67) 1(4)5(62)
 Other intervention3(33) 0(0)3(38)
Size of intervention group or recruitment target (studies in progress)41(11–215)42(11–215)33(14–105)
Number of outcomes4(1–12)3(1–7)6(1–12)
Time of last data collection after transfer (months)12(3–96)312(3–96)12(3–24)
  • *The fact that the sum of comparison is higher than total number of studies is explained by the possibility for studies to have more than one comparison group.

  • NR, not reported.