Authors

1 PhD Student of Biostatistics, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

2 Professor/MD PhD, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

3 Professor/MD, Psychiatry and Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran.

4 Associate Professor/MD, PhD, Traditional Medicine and History of Medical Sciences Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.

5 Professor/PhD, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

6 Associate Professor/PhD, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Abstract

Background
Attention-deficit/hyperactivity disorder (ADHD) is usually accompanied with other comorbidities that make treatment suboptimal and results in inadequate outcomes. Investigating the factors having an effect on improvement of ADHD can lead to better outcomes and a higher adherence to medication.
Materials and Methods
This historical cohort study was carried out on records of 6 to 13 year old patients with ADHD during the years 2008 to 2015 in the Children's Medical Center in Tehran, Iran. Baseline characteristics of patients such as gender, birth weight, the age of the first diagnosis, weight, severity of ADHD at the baseline, time duration of receiving the Methylphenidate, types of comorbidity, and dosage of Methylphenidate were extracted from hospital records. The Generalized Estimating Equation (GEE) was used to develop a multivariable model. This model is based on a stepwise procedure.
Results
One hundred and thirty-nine children (75.5% boys, mean age of 97.8±26.8 months) were assessed. Time duration of receiving Methylphenidate (OR=1.06; p< 0.001), severity of ADHD at the baseline (OR=0.94; p< 0.001), and dosage of Methylphenidate (OR=2.34; p< 0.001) had a significant relationship with improvement. In this study any relationship between improvement of ADHD and other factors was not found.
Conclusion
In this study, the clinical severity of ADHD at baseline, logarithm of dosage of Methylphenidate, and time duration of receiving the Methylphenidate were associated with improvement of ADHD.

Keywords