Table 1.
Descriptive characteristics of articles and unique studies included in the review
| Characteristic | Frequency (%)a |
|---|---|
| ARTICLES | (N = 73) |
| Study design | |
|
Clinical trial Trial registry record Guideline |
36 (49%) 19 (26%) 18 (25%) |
| Year of publication or registration | |
|
2011–2014 2015–2018 2019–2021 |
22 (30%) 28 (38%) 23 (32%) |
| Country of publicationb,c | |
|
Argentina Brazil China France Japan Korea Poland South Africa Spain Sweden The Netherlands United Kingdom United States (Not applicable for trial registry records, n = 19) |
1 (2%) 4 (7%) 1 (2%) 3 (6%) 3 (6%) 2 (4%) 1 (2%) 1 (2%) 2 (4%) 1 (2%) 4 (7%) 8 (15%) 23 (43%) |
| UNIQUE STUDIES | (N = 61) |
| Type of intervention | |
|
Enzyme replacement therapy Gene therapy Substrate reduction therapy Tumor necrosis factor alpha (TNF-α) inhibitor (Not applicable for guidelines, n = 18) |
29 (67%) 8 (19%) 5 (12%) 1 (2%) |
| MPS subtype | |
| MPS (General) | 3 (5%) |
| MPS I only | |
|
MPS I-H MPS I-H, I-HS MPS I-H, I-HS, I-S MPS II only |
5 (8%) 1 (2%) 1 (2%) 20 (33%) |
| MPS III only | |
| MPS IIIA | 6 (10%) |
| MPS IIIB | 3 (5%) |
| MPS IIIA-C | 2 (3%) |
| MPS IIIA-D | 2 (3%) |
| MPS IV only | |
| MPS IVA | 7 (11%) |
| MPS VI only | 5 (8%) |
| MPS VII only | 2 (3%) |
| Multiple subtypes | |
| MPS I-H, II | 1 (2%) |
| MPS I-H, I-HS, I-S, II, IVA, VI | 1 (2%) |
| MPS I-H, I-HS, I-S, II, VI | 1 (2%) |
| MPS II, III (unspecified) | 1 (2%) |
| Age of trial participantsd | |
|
Children (< 19 years) only Children and adults (majority children) (Not applicable for trial registry records and guidelines, N = 32) |
18 (62%) 11 (38%) |
| Sample size for completed trials (n = 29)d,e | |
| Median (Q1–Q3) | 12 (7–25) |
| Industry involvement and editorial independence in guideline developmentf | |
| Direct industry funding | |
|
Yes No |
13 (72%) 5 (28%) |
| Author affiliation with industry | |
|
Yes No |
5 (28%) 13 (72%) |
| Statement of editorial independence | |
|
Yes No |
6 (33%) 12 (67%) |
| Competing interests recorded/discussed | |
|
Recorded (none declared) Recorded Recorded and discussed |
3 (17%) 12 (67%) 3 (17%) |
MPS mucopolysaccharidosis
aFrequency and percentage unless otherwise specified. Percentages may not add to 100 due to rounding
bNot applicable to trial registry records. Percentages reported for those articles where this characteristic is applicable
cDetermined by country of corresponding author
dNot applicable to trial registry records and guidelines
eWhere there were multiple articles reporting on completed trials from the same study, only the sample size from the primary report was included
fNot appliable to clinical trials and trial registry records