The algorithm uses Structured Query Language to identify AAA cases, controls, and excludes from the Electronic Medical Record. AAA cases were defined as meeting at least one of three criteria: had a AAA repair procedure (Case Type 1), had at least one vascular clinic encounter with a diagnosis of ruptured AAA (Case Type 2), or had at least two vascular clinic encounters with a diagnosis of unruptured AAA (Case Type 3). AAA controls must be neither excludes nor cases, had an encounter within the past 5 years, and never had a diagnosis of ICD9 code 441.3, 441.4, or 441.9 from any department. Patients were excluded if any exclusion diagnosis existed in the medical record, were younger than 40 or older than 89, were neither a Case Type 1 nor Case Type 2 and haven’t had an encounter within the past 5 years, or were not a case and had an ICD9 code diagnosis of 441.* at some point in the medical history.
Comments
Updates 2012-08-15
The Pseudocode and Flowchart files were updated today (2012-08-15). No substantive changes -- Content did not change.
Added notations on the excludes. Indicated where they occur on the flow chart.
Excludes have the following functions
Type 1: Remove known confounders, i.e., diagnoses that lead to generalize aorta/artery problems that can include AAA.
Type 2: Remove very old (HIPAA) and very young who will not be informative since the age-at -onset is 65 +/- 13 years.
Type 3a: Remove individuals who might be cases, but who have insufficient data to vaildate
Type 3b: Remove individuals who have had the suspicion of aortic aneurysm at any time so that they cannot contaminate the controls.
Questions
1. Missing ICD9 codes for coronary stenosis and unintentional weight loss. Can you please add these to the data dictionary?
2. At what timepoint do you want INRs (within how many ? days prior to an anticoagulaent or antiplatelet medication mention)?
Update 2012-09-24
1. Missing codes in revised data dictionary.
2. Removed the condition. Simply collect INR regardless.
Update 2012-09-24
1. Missing codes in revised data dictionary.
2. Removed the condition. Simply collect INR regardless.
Updated Data dictionary
1. Reordered the ICD-9 codes to match the order of static variables
2. Removed duplicate (HIV)
3. Added missing ICD-9 codes (see response to Jim Linneman above)
4. Removed pretreatment clause for INR in repeating lab values
Updated Data dictionary
1. Reordered the ICD-9 codes to match the order of static variables
2. Removed duplicate (HIV)
3. Added missing ICD-9 codes (see response to Jim Linneman above)
4. Removed pretreatment clause for INR in repeating lab values
Vascular Surgery in pseudocode and flowchart
It should be noted that vascular surgery can be replaced by whatever specialty treats some or all of the abdominal aortic aneurysm cases. At some sites that might be Interventional Radiology, at othe sites both. The Vascular Surgery should be treated as a placeholder for the collection of specialty clinics/service lines that treat AAA at the site.