Statins and MACE

In the AMI algorithm you require confirmed labs Troponin I >= 0.05 or CK-MB/CK ratio >3.0 for case confirmation. Also requiring No abnormal TnI/CKMB ratio labs for control confirmation. Our Troponin I labs report results in text format of "<0.1" or "<=0.1" or "0.3" ng/mL in roughly 70% of the records returned for our PMRP cohort. 

We have Troponin I labs as far back as December 1995 and they indicate "High" values based on the following timeframe:

High 0.6 ng/mL - Dec 1995 to Mar 5, 1998
High 0.3 ng/mL - Mar 6, 1998 to Mar 30, 2006
High 0.1 ng/mL - Mar 31, 2006 to Current

Question: I am unable to determine if "<=0.1" (text value) is >=0.05 (numeric), so can I just use our HIGH cut-offs based on the lab date and determine if a Troponin I lab result exceeds the HIGH cut-off (example: IF HIGH = 0.1 and result = "<=0.1" THEN not elevated)?

Statin exposure reads:
The number of days that the earliest statin prescription prior to the event (AMI/Revascularization)

I'm assuming this should be
The number of days from earliest prescription of (any) statin to the event (AMI/Revascularization).

Is that correct?   If not, please clarify your intent.

Also the way I am reading your control definition there will be no controls
*Statin prescribed
*No MACE found in problem list by NLP
*Matched to cases on MACE

These three seem to exclude everyone. If someone is on a statin and has no notes indicating prior MACE and then they have a MACE (so they can be matched to another case) aren't they then a case themselves?

What am I missing?

Can you clarify in the main case control logic, which CPTs are revascularization codes and which ones are specifically stent/angioplasty codes?

Hi again (I'm on a roll!)

For the case defintion NLP I see the list of terms for the controls, but I don't see which terms you want us to look for for AMI and which are for revascularization. The control list seems to have terms that are not apropos either such as chyper so I didin't want to assume.

Also:
In the dictionary
*There is no definition given for the 0/1/2/3 and 0/1/2/3/4 MACE variables
*For diabetes do you want type 1/2/others?
*Which HTN meds do you want for your HTN def?  If you asked me to define this I would grab ace inhibitors,  beta blockers, ccbs and a grab bag of Clonidine, methyldopa, hydrochlorothiazide, fursemide, bumetanide, hydralazine, labetalol, terazosin, doxazosin, prazosin, acetazolamide, losartan and spronolactone. 
*Smoking will also have a level of missing.
*We will not have aspirin use captured in any sort of reliable way since it is OTC.
*'Antiplatelet' is too broad for me.  What are these drugs and what 'types' do they fall into?
 

Questions:

1. Should we provide "all" eligible controls so that matching to cases can be done at VU?  Depending on control counts, you may be able to match 2:1, 3:1, 4:1. If so, would it make sense to change date fields to age fields so that you can match by age (i.e. age_first_mention_statin, age_event (for MACE events), and age_most_recent_statin)?

I believe you stated (in a recent email) that controls are required to have >=180 days of Statin exposure prior to their most recent visit.

2. Do controls need to be seen recently? If so, how recently? 

3. Are there any other age timepoints you would need for matching, such as age_at_most_recent_visit?

Thanks for all your answers!

Is the current data dictionary the final version, or is it still subject to change?

Please help me to understand following data dictionary variables

1. Mace type : Some patient qualifies for multiple type of MACE eg CABG and PTCA or AMI and CABG etc. Should their MACE type be marked as unknown or there is some priority like if MI and CABG then MACE type is AMI? Also I am assuming that if patient is deceased then MACE type will be Death and not MI/CABG/PTCA.

     2. How_event_recorded:  Values are 0-Code and 1-NLP: NLP is used for exclusion only so in which situation How_event_recorded=”y”? Also Mace exclusion NLP terms are same as case NLP terms.

 3.  AS per MACE algorithm  there should be 2 ICD dx within 5 days  window. I  would suggest if we could make site specific modification as follow

    a. For inpatient dx 5 days window not required but it should be Primary diagnosis for inpatient stay + elevated Troponin /CK MB lab within 5 days and Statin within 180 days  b. For outpatient dx 5 day window rule applies.  

      Else we will be dropping out some genuine cases. E.g. An MI patient has inpatient stay for 7 days.  In this situation we will not find 2 MI dx within 5 days. I agree with this modification.

Katie, 

Go ahead and send Mace_Status as a repeat variable.

Thanks,

Jacqueline

Hi again,

I have 7 patients that were prescribed two statin meds on the same day/time (not simply generic vs  trade name).  How should I report the type of statin in these cases?

Thanks!

-Katie

Include both separated by a comma.

Thanks, Jacqueline

Hello,

I have one last question regarding the medications in the data dictionary.  You have in the variable descriptions: "if the patient was using Asprin 180 days before the first event."  Does this mean within 180 days before the first event?  In which case, if the patient was on them, say 100 days before the first event, they would be flagged "yes" here.

Thanks!

-Katie

Katie,

we just requested the first mention of statin in EMR and the most recent statin mentioned 180 days prior to the event.

As to your example, yes, we still consider the patient as taking statin.