Abstract
Dixon, Stephanie N., et al. “MyTEMP: Statistical Analysis Plan of a Registry-Based, Cluster-Randomized Clinical Trial.” Canadian journal of kidney health and disease 8 (2021): 20543581211041182.
In the published version of the above article, there are three corrections or updates the authors want to make as stated below:
1)
The published statistical plan stated: Finally, we will examine four definitions of intradialytic hypotension using the same blood pressure data as the key secondary outcome at the cluster level. We will examine the center’s proportion of patients (weighted by the dialysis center size) whose (1) systolic blood pressure dropped from ≥ 90 mm Hg before dialysis to < 90 mm Hg during dialysis; (2) nadir intradialytic systolic blood pressure was ≥ 25% lower than their pre-dialysis level or whose systolic blood pressure dropped from ≥ 90 mm Hg before dialysis to < 90 mm Hg during dialysis; (3) nadir intradialytic systolic blood pressure was ≥ 25% lower than their pre-dialysis level; and (4) nadir intradialytic systolic blood pressure was ≥ 35 mm Hg lower than their pre-dialysis level.
However, it should have stated: Finally, we will examine five definitions of intradialytic hypotension using the same blood pressure data as the key secondary outcome at the cluster level. We will examine the center’s proportion of patients whose (1) nadir systolic blood pressure is < 90 mmHg anytime during a dialysis session when the value before the session was ≥ 90 mmHg, or drop in systolic blood pressure ≥ 30 mmHg anytime during the session from value before session; (2) systolic blood pressure dropped from ≥ 90 mm Hg before dialysis to < 90 mm Hg during dialysis; (3) nadir intradialytic systolic blood pressure was ≥ 25% lower than their pre-dialysis level or whose systolic blood pressure dropped from ≥ 90 mm Hg before dialysis to < 90 mm Hg during dialysis; (4) nadir intradialytic systolic blood pressure was ≥ 25% lower than their pre-dialysis level; and (5) nadir intradialytic systolic blood pressure was ≥ 35 mm Hg lower than their pre-dialysis level.”
2) The published statistical plan stated: All analyses described in this document will be conducted after the trial ends and when the data covering the trial period are available at ICES. We expect to complete the analysis when the data covering the trial period are released from the Office of the Registrar General Database (ORGD) (updated releases from this database occur every 2-3 years).
Update: All analyses described in the statistical analysis plan will be conducted after the trial ends and when the data covering the trial period are available at ICES. We expect to complete the analysis in 2022.
3) The published statistical plan stated: Data on cause of death will be obtained from the ORGD, which uses a modified version of Becker’s groupings based on International Classification of Diseases 10th Revision (ICD-10) coding.
Update: Data on cardiovascular-related causes of death will primarily be captured using the following definition: (a) in-hospital (or emergency department) death with a cardiovascular disease diagnosis in the primary/most responsible diagnosis position or (b) out-of-hospital death (including death in an emergency department) without documentation of cancer in the 365 days before and including the date of death and without documentation of trauma in the 30 days before and including the date of death.2 A death in the emergency department with a cardiovascular event as the primary diagnosis will be defined as “in-hospital” cardiovascular-related death, regardless of whether they had cancer or trauma code.
Justification: We were recently notified of unanticipated delays in the linkage of the Office of the Register General deaths database at ICES, which will now take several more years to cover the entire trial period. As a result, we will use an alternate method of ascertaining cardiovascular-related deaths, validated by Lix et al.2 (2021).
1. Dixon S, Sontrop J, Al-Jaishi A, et al. MyTEMP: Statistical Analysis Plan of a Registry-Based, Cluster-Randomized Clinical Trial. Can J kidney Heal Dis. 2021;8:205435812110411. doi:10.1177/20543581211041182
2. Lix LM, Sobhan S, St-Jean A, et al. Validity of an algorithm to identify cardiovascular deaths from administrative health records: a multi-database population-based cohort study. BMC Health Serv Res. 2021;21(1). doi:10.1186/S12913-021-06762-0