1. Error in Table 3
In the original article [1], there was a mistake in Table 3 as published. The units displayed for ferritin (mg/L) are incorrect, with µg/L being the correct unit for that parameter. Values for ferritin levels are correct, and only the units are affected by this typographic mistake. Interpretation of the results are not affected, since it was carried out with the correct values and units from the analysis. The corrected version of Table 3 appears below:
Table 3.
Zero-inflated Poisson regression models for the association between inattention, hyperactivity, and ADHD symptoms with ferritin levels (µg/L log scale) on a continuous scale and in tertiles.
| Tertile 1 [1.98, 20.92] (µg/L) | Tertile 2 (20.92, 38.79] (µg/L) | Tertile 3 (38.79, 216.5] (µg/L) | p for Trend ** | Continuous | ||
|---|---|---|---|---|---|---|
| Beta CI (95%) | Beta CI (95%) | Beta CI (95%) | Beta CI (95%) |
|||
| Inattention | ||||||
| Count model *1 | ||||||
| Male *** | 1 (Ref.) | −0.3 (−0.55, −0.05) | −0.37 (−0.6, −0.14) | 0.002 | −0.19 (−0.32, −0.07) | |
| Female *** | 1 (Ref.) | −0.11 (−0.64, 0.42) | 0.35 (−0.07, 0.77) | 0.066 | 0.09 (−0.13, 0.31) | |
| Zero-inflation model *2 | 1 (Ref.) | 0.19 (−0.24, 0.63) | 0.19 (−0.24, 0.63) | 0.488 | −0.04 (−0.26, 0.19) | |
| Hyperactivity | ||||||
| Count model *1 | 1 (Ref.) | −0.07 (−0.29, 0.16) | −0.11 (−0.33, 0.11) | 0.327 | −0.03 (−0.15, 0.09) | |
| Zero-inflation model *2 | 1 (Ref.) | 0.24 (−0.16, 0.64) | 0.17 (−0.23, 0.56) | 0.411 | 0.11 (−0.11, 0.32) | |
| ADHD | ||||||
| Count model *1 | 1 (Ref.) | −0.09 (−0.24, 0.06) | −0.09 (−0.23, 0.05) | 0.239 | −0.02 (−0.1, 0.05) | |
| Zero-inflation model *2 | 1 (Ref.) | 0.36 (0, 0.71) | 0.12 (−0.22, 0.47) | 0.515 | 0.13 (−0.06, 0.33) |
Models adjusted by cohort, smoking during pregnancy, alcohol intake during pregnancy, pre-pregnancy BMI, social class, sex and age of the child, living with mother/father, and weeks (week of sample collection). *1 Count model coefficients (Poisson with log link). *2 Zero-inflation model coefficients (binomial with logit link). ** p for the trend between tertiles. *** Model with interaction term between sex and ferritin. Significant associations (p < 0.05) are indicated in bold.
2. Error in Table 4
In the original article [1], there was a mistake in Table 4 as published. The units displayed for ferritin (mg/L) are incorrect, with µg/L being the correct unit for that parameter. Values for ferritin levels are correct, and only the units are affected by this typographic mistake. Interpretation of the results are not affected, since it was carried out with the correct values and units from the analysis. The corrected version of Table 4 appears below:
Table 4.
Zero-inflated Poisson regression models for the association between inattention, hyperactivity, and ADHD symptoms with ferritin levels (log scale).
| Tertile 1 [1.98, 20.92] (µg/L) | Tertile 2 (20.92, 38.79] (µg/L) | Tertile 3 (38.79, 216.5] (µg/L) | p for Trend ** | Continuous | ||
|---|---|---|---|---|---|---|
| Beta CI (95%) | Beta CI (95%) | Beta CI (95%) | Beta CI (95%) | |||
| stratified by Sex | ||||||
| Inattention | ||||||
| Boys | Count model *1 | 1 (Ref.) | −0.32 (−0.57, −0.06) | −0.4 (−0.63, −0.16) | 0.001 | −0.21 (−0.34, −0.08) |
| Zero-inflation model *2 | 1 (Ref.) | 0.09 (−0.46, 0.63) | −0.27 (−0.8, 0.25) | 0.270 | −0.14 (−0.43, 0.15) | |
| Girls | Count model *1 | 1 (Ref.) | 0.04 (−0.61, 0.69) | 0.58 (0.02, 1.13) | 0.012 | 0.15 (−0.09, 0.39) |
| Zero-inflation model *2 | 1 (Ref.) | 0.37 (−0.36, 1.09) | −0.32 (−1.13, 0.49) | 0.311 | −0.38 (−1.17, 0.42) | |
| Hyperactivity | ||||||
| Boys | Count model *1 | 1 (Ref.) | −0.09 (−0.37, 0.19) | −0.16 (−0.44, 0.11) | 0.244 | −0.03 (−0.18, 0.12) |
| Zero-inflation model *2 | 1 (Ref.) | 0.16 (−0.37, 0.68) | 0 (−0.52, 0.51) | 0.981 | −0.03 (−0.32, 0.25) | |
| Girls | Count model *1 | 1 (Ref.) | −0.02 (−0.44, 0.39) | −0.07 (−0.49, 0.35) | 0.727 | −0.1 (−0.33, 0.13) |
| Zero-inflation model *2 | 1 (Ref.) | 0.41 (−0.22, 1.04) | 0.48 (−0.16, 1.12) | 0.143 | 0.34 (−0.02, 0.7) | |
| ADHD | ||||||
| Boys | Count model *1 | 1 (Ref.) | −0.14 (−0.32, 0.03) | −0.22 (−0.39, −0.06) | 0.008 | −0.07 (−0.16, 0.02) |
| Zero-inflation model *2 | 1 (Ref.) | 0.25 (−0.23, 0.73) | −0.05 (−0.52, 0.41) | 0.778 | −0.02 (−0.27, 0.24) | |
| Girls | Count model *1 | 1 (Ref.) | 0.02 (−0.31, 0.34) | 0.17 (−0.13, 0.47) | 0.237 | 0.02 (−0.14, 0.19) |
| Zero-inflation model *2 | 1 (Ref.) | 0.6 (0.05, 1.16) | 0.49 (−0.05, 1.04) | 0.077 | 0.39 (0.08, 0.69) | |
| Stratified by Cohort | ||||||
| Inattention | ||||||
| Gipuzkoa | Count model *1 | 1 (Ref.) | −0.18 (−0.82, 0.47) | 0.18 (−0.35, 0.71) | 0.410 | 0.22 (−0.04, 0.48) |
| Zero-inflation model *2 | 1 (Ref.) | 0.8 (−0.15, 1.75) | 0.05 (−0.82, 0.91) | 0.873 | 0.16 (−0.31, 0.63) | |
| Sabadell | Count model *1 | 1 (Ref.) | −0.35 (−0.72, 0.03) | −0.22 (−0.55, 0.1) | 0.116 | −0.16 (−0.31, 0) |
| Zero-inflation model *2 | 1 (Ref.) | 0.38 (−0.29, 1.05) | 0.03 (−0.6, 0.66) | 0.887 | −0.03 (−0.36, 0.3) | |
| Valencia | Count model *1 | 1 (Ref.) | −0.24 (−0.64, 0.15) | −0.39 (−0.76, −0.02) | 0.043 | −0.29 (−0.51, −0.06) |
| Zero-inflation model *2 | 1 (Ref.) | −0.44 (−1.22, 0.35) | −0.6 (−1.35, 0.14) | 0.123 | −0.27 (−0.71, 0.18) | |
| Hyperactivity | ||||||
| Gipuzkoa | Count model *1 | 1 (Ref.) | −0.07 (−0.77, 0.62) | 0.06 (−0.67, 0.78) | 0.932 | 0.23 (−0.11, 0.57) |
| Zero-inflation model *2 | 1 (Ref.) | 0.65 (−0.3, 1.6) | −0.1 (−1, 0.8) | 0.838 | 0.1 (−0.4, 0.59) | |
| Sabadell | Count model *1 | 1 (Ref.) | −0.25 (−0.6, 0.11) | −0.31 (−0.64, 0.02) | 0.053 | −0.12 (−0.28, 0.03) |
| Zero-inflation model *2 | 1 (Ref.) | 0.24 (−0.36, 0.85) | −0.09 (−0.69, 0.51) | 0.814 | −0.04 (−0.35, 0.27) | |
| Valencia | Count model *1 | 1 (Ref.) | 0.06 (−0.36, 0.48) | 0.06 (−0.36, 0.48) | 0.904 | 0.01 (−0.25, 0.27) |
| Zero-inflation model *2 | 1 (Ref.) | −0.02 (−0.87, 0.82) | 0.59 (−0.17, 1.36) | 0.070 | 0.4 (−0.03, 0.82) | |
| ADHD | ||||||
| Gipuzkoa | Count model *1 | 1 (Ref.) | −0.06 (−0.48, 0.36) | 0.37 (−0.01, 0.74) | 0.045 | 0.33 (0.14, 0.53) |
| Zero-inflation model *2 | 1 (Ref.) | 0.85 (0.06, 1.63) | 0.27 (−0.48, 1.02) | 0.412 | 0.28 (−0.13, 0.69) | |
| Sabadell | Count model *1 | 1 (Ref.) | −0.29 (−0.53, −0.06) | −0.28 (−0.5, −0.07) | 0.005 | −0.1 (−0.21, 0) |
| Zero-inflation model *2 | 1 (Ref.) | 0.39 (−0.14, 0.92) | 0.03 (−0.49, 0.55) | 0.857 | 0.08 (−0.19, 0.35) | |
| Valencia | Count model *1 | 1 (Ref.) | 0.09 (−0.16, 0.35) | −0.11 (−0.35, 0.14) | 0.244 | −0.07 (−0.21, 0.08) |
| Zero-inflation model *2 | 1 (Ref.) | −0.04 (−0.68, 0.6) | 0.07 (−0.55, 0.69) | 0.788 | 0.12 (−0.24, 0.49) | |
Models adjusted by cohort, smoking during pregnancy, alcohol intake during pregnancy, pre-pregnancy BMI, social class, sex and age of the child, living with mother/father, and weeks (week of sample collection). For Gipuzkoa and Sabadell, models do not include the variable “lives with mother/father”. *1 Count model coefficients (Poisson with log link). *2 Zero-inflation model coefficients (binomial with logit link). ** p for the trend between tertiles. Significant associations (p < 0.05) are indicated in bold.
3. Text Correction
In the original article, the units mentioned in the abstract regarding ferritin levels were also incorrect. Hence, we corrected Abstract lines 8–10: “Comparing ferritin level by tertile, significant differences were observed between the first tertile (1.98, 20.92) and the second (20.92, 38.79) and third (38.79, 216.5) (µg/L) tertiles”.
The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. The original article has been updated.
Footnotes
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Reference
- 1.Santa-Marina L., Lertxundi N., Andiarena A., Irizar A., Sunyer J., Molinuevo A., Llop S., Julvez J., Beneito A., Ibarluzea J., et al. Maternal Ferritin Levels during Pregnancy and ADHD Symptoms in 4-Year-Old Children: Results from the INMA–INfancia y Medio Ambiente (Environment and Childhood) Prospective Birth Cohort Study. Int. J. Environ. Res. Public Health. 2020;17:7704. doi: 10.3390/ijerph17217704. [DOI] [PMC free article] [PubMed] [Google Scholar]