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Table 2 Association between study factors and ADHD estimates

From: ADHD prevalence estimates in Italian children and adolescents: a methodological issue

Study factors Univariate analyses Multivariate analyses
  Estimated prevalence difference % 95% CI P Estimated prevalence difference % 95% CI P
Min Max Min Max
Diagnostic criteria (DSM-IV as reference)
Other criteria 1.65 1.23 2.07 < 0.0001 1.21 -11.53 9.11 0.7944
Geographical location (North, Center and South as reference)
 Northern Italy 2.17 1.53 2.81 < 0.0001 −1.39 -14.42 11.65 0.8123
 Central Italy −0.46 −1.15 0.23 0.1772 −8.91 -21.66 3.83 0.1454
 Southern Italy 0.58 −0.11 1.27 0.1134 −5.92 -18.35 6.52 0.3045
Case definition (clinician as reference)
 AND rule −0.12 −0.56 0.32 0.6161 −0.64 -12.21 10.93 0.9013
 Parent 0.96 0.32 1.60 0.0003 2.09 −9.81 14.00 0.6957
 Teacher 5.05 4.67 5.43 < 0.0001 12.88 4.28 21.48 0.0087
 Child 15.14 12.08 18.20 < 0.0001 26.01 9.96 42.07 0.0057
Origin of sample (population as reference)
 School 3.87 3.60 4.14 < 0.0001 4.41 −8.59 17.41 0.4569
 Family Pediatrician Practice 0.76 0.07 1.45 0.0051 7.75 -17.67 33.16 0.5022
Quality (RoB score ≥ 6 as reference)
 RoB score ≤ 5 1.45 1.14 1.76 < 0.0001 −5.34 -14.25 3.56 0.2038
Sample size (> 1000 participants as reference)
 ≤ 1000 participants 2.77 2.13 3.41 < 0.0001 4.21 −5.63 14.05 0.3528
Year of study publication (≥ 2006 as reference)
 < 2006 −0.03 −0.37 0.31 0.8688 −0.04 −9.62 9.55 0.9932
Intercept 15.44 −0.89 31.77 0.0609