Study design and patient selection
This retrospective study was approved by the Quality Improvement
Assessment Board (QIAB) at MD Anderson Cancer Center. We initially
identified all 12-lead ECGs performed between November
23rd, 2019 and January 31st, 2020.
Based on the available ECGs, we included inpatients with a newly signed
or verified order for a QTc-prolonging medication, and at least two
12-lead ECG readings: A baseline ECG in sinus rhythm within three days
before the QTc-prolonging medication was signed or verified, and a
follow-up ECG any time after, up to a maximum of eleven days (i.e.,
within a fourteen-day time period from the baseline ECG reading). We
excluded patients with a pacemaker or with a QRS complex greater than
120 ms. We targeted a sample size of 100 patients and discontinued our
ECG screening when we reached this goal.