Skip to main content

Table 2 Results of meta-regression analysis Duchenne Muscular Dystrophy (DMD) prevalence and birth prevalence

From: Global epidemiology of Duchenne muscular dystrophy: an updated systematic review and meta-analysis

Outcome Subgroup Study-level covariate(s) included into the meta-regression Heterogeneity assessment
Covariate(s) selected p-value* Cochran’s Q (df) p-value (Q test) I2 (%) Between-study variancee R2 (%)f
DMD prevalence Males only (15 studies) None (random-effects MA) 856.4531 (df = 14) < 0.0001 98.46% 0.4741
Continenta 0.2027 450.7452 (df = 12) < 0.0001 97.90% 0.3857 18.65%
Study year (begin) + Study duration 0.4195 632.8951 (df = 12) < 0.0001 97.89% 0.4227 10.84%
Study designc 0.6429 572.9228 (df = 12) < 0.0001 98.40% 0.4452 6.10%
DMD birth prevalence All (27 studies) None (random-effects MA) 82.0309 (df = 26) < 0.0001 89.79% 0.1646
Continentb 0.9308 74.7046 (df = 23) < 0.0001 88.90% 0.1619 1.64%
Study year (begin) + Study duration 0.0012 60.8329 (df = 23) < 0.0001 83.13% 0.0905 45.02%
Study designd 0.3189 78.8714 (df = 24) < 0.0001 87.51% 0.1483 9.90%
  1. MA Meta-analysis, I2 Measure of inconsistency, df Degrees of freedom referred to the Cochran’s Q test
  2. *P-values from omnibus Wald-type test of parameters (i.e. study-level covariates included into the model)
  3. aContinents were regrouped as follows: America North (US and Canada) (4 studies), Europe North/Centre/East (8 studies), Others (Asia East and Africa South) (3 studies)
  4. bContinents were regrouped as follows: America North (US and Canada) (4 studies), Asia East and Australia/New-Zealand (4 studies), Europe Centre/East/South (13 studies), Europe North (6 studies)
  5. cStudy designs were regrouped as follows: Observational cohort (3 studies), Retrospective cohort/chart-review/cross-sectional (9 studies), epidemiological survey (3 studies)
  6. dStudy designs were regrouped as follows: Cross-sectional (10 studies), Prospective cohort and survey (8 studies), Retrospective cohort/chart-review (9 studies)
  7. eTotal and residual between-study variance: the overall heterogeneity corresponds to the total between-study variance estimated from random-effects MA whereas the residual heterogeneity corresponds to between study-variance explained by the study-level covariates included into meta-regression model
  8. fR2 is the proportion of the overall heterogeneity (i.e. the total between-study variance) which is “explained” (i.e. reduced) by the effect of the included study-level covariate