Hi,
I am a researcher at Imperial College London trying to model the progression of Alzheimer?s Disease and AddNeuroMed is one of the studies that I am particularly interested in as the time between visits is relatively small (~3 months) compared to other studies of the sort.
I have a quick question about the time between visits which arose while trying to simultaneously understand the **(1)** ?Basic variables? and **(2)** ?Conclusion_Diagnos_Sum? (Data -> Clinical -> Summary variables) tables on the Synapse portal.
The number of visits seems to match between the two data tables however I am getting confused with the 3-month intervals (the column names in (2)) and the Age at Visit column in (1).
For example, Entity_ID=**LNDADC034** has 9 visits (baseline -> 24 months in (2)) however their age at baseline in ?basic variables? is 80 and their age at visit 9 as 85 which implies that there was approximately 5 years between visits.
Would you be able to point out a mistake that I am making in my interpretation of the tables? If not, would you be able to advise on whether I should assume that all visits are 3 months apart as per (3) or if I should rely on the differences between Age at Visit as per (1).
Thank you in advance for your time.
Kind regards,
Kevin
Created by Kevin McRae-McKee kevinmcraemckee Hello,
My question is close to the subject of this topic,
For temporal data in syn3796525, Months are indicated as "Month 03, Month 06, Month 09, Month 12, Month 15, Month 18, Month 21, Month 27, Month 24". However, in data description, it's said that Visits were done every 3 months for the first year, and then every year.
Should I trust the data description or the Months as described in the files ?
Kindest Regards,
Luc Dear @Mette,
I hope you are well.
I was just wondering if you have had a chance to contact the data provider on our query.
We hope to hear from you soon.
Thank you so much.
Kindest regards,
Mei Mei Dear @Mette,
I hope this message finds you well.
I am writing to follow up on my colleague's (Kevin McRae-McKee) query on Time of Visit, as per threads above. We would truly appreciate your response and look forward to hearing back as soon as possible as this issue encompasses a major and critical part of our study. We hope that you will be able to help us seek an answer or if not kindly point us to someone who could address the query.
Thank you and we look forward to your advice in anticipation.
Kindest regards,
Mei Mei Dear @Mette
I was wondering if you had heard back from the data provider regarding my query directly above.
Apologies for pressing the issue - we just know that once we can fully understand the structure of the visits, AddNeuroMed will contribute immensely to our analysis.
Thanks again for you help,
Kevin Dear @Mette,
Thank you for your response. The visit numbers make a lot more sense now that I am not trying to link the two tables that I previously mentioned.
However, I do have another follow-up query as there still seem to be sizable number of ages that don't match.
Based on your response above, I have assumed that the "Visit" variable from the "Basic Variables" table is coded such that visits (1 through 10) represent chronological visits (baseline, 3 months, 6 months, 9 months, 12 months, 24 months, ..., 72 months) respectively.
This makes sense for some people in the sense that by their 12-month visit they have aged by 1 year, at their 24-month visit by 2 years, etc.
However, there exist some people that seem to be a year older at every visit.
For example, **Entity_ID=LNDCTL012**'s first 5 visits they age 5 years such that at visit 1 (assumed to be baseline) they are 82y/o, at visit 2 (assumed to be 3 months) they are 83y/o, at visit 3 (assumed to be 6 months) they are 84y/o, etc.
Is it possible that while some people followed the protocol of visits every 3 months for year and then annually after that, others simply had annual visits and these visits were labelled in the same way (i.e. 1,2,...)?
If this is correct, is there a way to distinguish between the two types of people/cohorts? Or, alternatively, are there precise visit dates that we can have access to? That might solve the problem in one go.
I cannot think of another explanation for the discrepancy in age changes. Please let me know if I am being thick and am forgetting something obvious and apologies if so.
Thanks again for your help - it is really appreciated.
Kind regards,
Kevin The visits were as stated here: https://www.synapse.org/#!Synapse:syn2790911/wiki/235387
ie, follow ups every 3 months for the first year and annually following that. The ages in the basic variables matched that, but the Diagnosis_Sum file is confusing and we will remove it. Thank you for pointing that out Dear @kevinmcraemckee. My apologies for the slow reply on this. I see the issue you are referring to, but will haver to contact the data provider for clarification. I will let you know as soon as I hear back
Best,
Mette Synapse ID (Basic Variables): syn4984917
Synapse ID (Conclusion_Diagnos_Sum): syn4012998