processing-scripts > ADHD200 database - missing data and other queries
Jan 5, 2021  06:01 AM | Marietta Papadatou-Pastou - National and Kapodistrian University of Athens, Athens, Greece
ADHD200 database - missing data and other queries
Hello everyone,

We have some trouble with the ADHD200 database and we would really appreciate some help. I have downloaded the attached files and I would like to ask the following questions:

1. Is there an updated version of this database? According to the webpage it was last updated in 2016. One of the reasons why we are asking is that in a number of cells we find the word "pending". Importantly for site "2" the diagnosis is pending, not allowing us to understand which participants are ADHD and which are controls.

2. Do you have information on the means of assessing handedness in each site (e.g., writing hand, the Edinburgh Handedness Inventory, self-report, observation, etc.)?

3. With the term "handedness" do you refer to hand preference or hand skill?

4. For site "5" (= the New York University Child Study Center) the handedness values do not correspond to the key (i.e., 0,1,2), but are continuous. Could you let us know how to interpret these values? Are higher values closer to strong right-handedness or strong left-handedness? Does the value 999 denote a missing value?

5. Again for the data of site "5", a lot of participants seem to have comorbidities, but for a good number of participants the column on additional diagnosis is marked with "N/A". Can we ask why it is non applicable for those participants? This is important for our analysis, because comorbidity is an exclusion criterion.

6. For sites 6 and 8 all participants seem to be right-handed. Is it safe to assume that they were selected for right-handedness?

7. For site "3", we find that participant 2876903 has been allocated the value "3" for handedness, which does not correspond to the key. What would be the handedness of that participant?

8. For site "7" the first 88 participants (participant codes starting with 16) seem to be controls and only 9 participants (codes starting with 25) seem to be a mixture of controls and ADHD. Do these participants correspond to two different studies?

9. For site "8" we see the value "0" under the column DX (we assume it is for the diagnosis). Does this mean this site gave information for typically developing participants only?

10. An important point for us is whether participants were pre-selected to be right-handed (or preferred if so). This would be an exclusion criterion for our analysis. For example, for site "1", 241 out of 245 participants are right-handed, when we would expect 10% to be left-handed. For site "7" only 4 in 98 participants are left-handed.

11. Did all sites use a right vs. ambidextrous vs. left classification of handedness of just the sites where we found a mention of ambidextrous participants? (i.e. only study 3, where one ambidextrous participant is to be found).

I thank you in advance!!

Marietta Papadatou-Pastou
Assistant Professor in Neuropsychology
University of Athens