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Joined Mar 2019
Joined Mar 2019

Hi Mike,

I am looking for understanding better the variables COPD and asthma in the SHHS.

1/ On COPD for say the first visit there is: variable "copd15": Doctor of Medicine (MD) said participant had chronic obstructive pulmonary disease (COPD)? variable "crbron15": Doctor of Medicine (MD) said participant had chronic bronchitis? variable "emphys15": Doctor of Medicine (MD) said participant had emphysema? It is my understanding that emphysema or chronic bronchitis are two types of COPD, yet the COPD variable has only n=62 positive test when emphysema has n=132 and chronic bronchitis has n=315. How is it possible?

2/ Asthma: There are two potentially interesting variables for asthma. My interest is to know if the patient has asthma at the time of the PSG whether SHHS1 or SHHS2. For that purpose I wonder which of these two variables might be the best proxy? hi201e: e. Do you still have asthma? asthma15: Doctor of Medicine (MD) said participant had asthma?

3/ On both COPD and asthma How much time spam between the CPOD/asthma examination and the PSG recording? Is it in the order of days, months, years? For "asthma15" is it the answer to a questionnaire filled just before SHHS2?

4/ Diagnosis modality How were COPD and asthma diagnosed? Is it documented somewhere? What does it mean "Doctor of Medicine (MD) said participant had chronic obstructive pulmonary disease (COPD)?"? Does it relates to a specific test made for diagnosing COPD by the doctor who then reports COPD for the patient?

Thank you, Joachim

Dear Mark/Stephanie,

Regarding the AF labels provided in the SHHS variables. There seems to be three options available as part of the SHHS:

1/ AFIB: atrial fibrillation or flutter Visit 1 and visit 2 Minnesota (MN) code 8-3-1 or 8-3-2. Data derived from standard resting 12-lead electrocardiogram (ECG) with the participant supine. Records were interpreted and Minnesota (MN) codes were provided by clinical cardiologist

2/ AFIB Prevalent At the first visit Variable created as part of the analysis for Tung et al. 2017 (PMID: 28668820). Prevalent AF was defined by any of the following: a positive response to the question 'Has a doctor ever told you that you have or had atrial fibrillation'; AF identified on resting 12-lead ECG at the baseline SHHS exam; or if the parent study identified AF documented in the medical record before the SHHS baseline exam.

3/ AFIB incident After SHHS visit 1 Variable created as part of the analysis for Tung et al. 2017 (PMID: 28668820). Incident AF was considered present if AF was identified on a 12-lead ECG obtained at the second SHHS exam or was adjudicated by the parent cohorts at any time between the baseline PSG and the final follow-up date for AF ascertainment of June 30, 2006.

For variable 2 and 3 the paper from Tung et al. is referenced. For the first variable there is no reference. In addition, there are important differences in the number of cases between the variables. For example in AFIB there are 80 individuals classified as AF during the second visit whereas in AFIBincident there are 332 cases of AF at visit 2.

Do you have some more information/comments/explanation on how to understand the difference between these variables and which one is the most accurate diagnosis of AF during visit 1 and during visit 2?

Many thanks, Joachim