Aspect | Specification | Number of studies (%) |
---|---|---|
Methods to identify attributesa | Characteristics vaccine, disease | 2 (4.8) |
Expert consultation | 19 (45.2) | |
Literature review | 33 (78.6) | |
Previous DCE | 4 (9.5) | |
Qualitative research | 28 (66.7) | |
Theories vaccine decision-making | 1 (2.4) | |
Vaccination policy | 1 (2.4) | |
Not reported | 1 (2.4) | |
Choice structure | Binary | 3 (7.1) |
Multinomial | 39 (92.9) | |
Methods to create choice sets, of multinomial studies (n = 39)a | D-efficiency | 3 (7.7) |
D-efficiency using software | 11 (28.2) | |
Fold-over | 3 (7.7) | |
Random | 3 (7.7) | |
Random using software | 1 (2.6) | |
Other software | 5 (12.8) | |
Not reported | 13 (33.3) | |
Format of choice question, of multinomial studies (n = 39)b | Forced choice | 4 (10.3) |
Forced choice, followed by opt-out | 12 (30.8) | |
Unforced choice with opt-out | 18 (46.2) | |
Unforced choice with opt-out, followed by forced choice | 2 (5.1) | |
Unclear | 3 (7.7) | |
Number of choice tasks | < 10 | 17 (40.5) |
10–15 | 10 (23.8) | |
> 15 | 10 (23.8) | |
Not reported | 5 (11.9) |