Tight K Pilot Study - Data Codebook

Permanent identifier

https://doi.org/10.17037/DATA.00002415

Description

Data associated with a pilot and feasibility study of the maintenance of serum potassium levels ≥ 3.6 mEq/L vs ≥ 4.5 mEq/L after isolated elective coronary artery bypass grafting, and the incidence of new-onset atrial fibrillation. Data was collected from patients scheduled to undergo a heart operation called Coronary Artery Bypass Graft Surgery (CABG) at two NHS hospitals in London.

Data access

Anonymised data may be requested for use in further research, in accordance with the research ethical approvals. Please state the variable names that you wish to access (from the list below) when submitting data requests.

No access will be provided to personally identifiable information analysed by the study.

Codebook

Data variables are held in three tables:

  1. Tight K demographics follow-up data
  2. Tight K Potassium serum measurement data
  3. Tight K Potassium supplements data

These are linked using an ID number associated with each patient. ID numbers used in this dataset have been randomly assigned and are unrelated to other patient identifier systems.

1. Tight K demographics follow-up data

Variable Name Variable Label Answer Label Answer Code Variable Type
identifier Patient ID number (anonymised) Open ended   String
day_rand randomised days (number elapsed days from start) Open ended   Numeric
rand_6m Randomised within 6 months of first randomisation     Numeric
    No 0  
    Yes 1  
group Randomised group     Numeric
    Tight 0  
    Relaxed 1  
age Age (years) Open ended   Numeric
gender Gender     Numeric
    Female 0  
    Male 1  
ethnicity Ethnicity Open ended   String
surg_yn Was CABG surgery performed?     long
    No 0  
    Yes 1  
day_surgery Day that CABG surgery performed (number elapsed days from start) Open ended   Numeric
fup_day28 Patient followed up at 28 days     Numeric
    No 0  
    Yes 1  
day_fu Day of follow-up (number elapsed days from start) Open ended   Numeric
reason_no_day28 Reason not followed up at 28 days Open ended   String
day_withdraw Day of withdrawal (number elapsed days from start) Open ended   Numeric
withdrew Patient withdrawals Open ended   String
withdrew_detail Detail of withdrawal provided by site Open ended   String
new_af New-onset AF up to 5 days post-surgery     Numeric
    No 0  
    Yes 1  
other_af All other arrhythmia up to 5 days post-surgery     Numeric
    No 0  
    Yes 1  
cc_stay Critical care length of stay (days) Open ended   Numeric
hosp_stay Hospital length of stay (days) Open ended   Numeric
eq5d_day28 EQ-5D-5L at 28 day follow up Open ended   Numeric
holter_disruption Disruption to Holter monitor data     Numeric
    No 0  
    Yes 1  

2. Tight K Potassium serum measurement data

Variable Name Variable Label Answer Label Answer Code Variable Type
identifier Patient ID number (anonymised) Open ended   String
period Period     Numeric
    Period 1 1  
    Period 2 2  
    Period 3 3  
    Period 4 4  
    Period 5 5  
k_value K+ value (mmol/L) Open ended   double
group Randomised group     long
    Tight 0  
    Relaxed 1  

3. Tight K Potassium supplements data

Variable Name Variable Label Answer Label Answer Code Variable Type
identifier Patient ID number (anonymised) Open ended   Numeric
period Period that K+ measurement was taken     Numeric
    Period 1 1  
    Period 2 2  
    Period 3 3  
    Period 4 4  
    Period 5 5  
time Time that K+ measurement was taken HH:MM   Numeric
k_value K+ level (mmol/L) Open ended   double
k_given Was K+ supplemented?     Numeric
    No 0  
    Yes 1  
num_k_given Total number of times K+ supplemented per patient Open ended   Numeric
k_supp_viol_row K+ supplementation violation (per row)     Numeric
    No 0  
    Yes 1  
k_supp_viol_pat K+ supplementation violation (per patient)     Numeric
    No 0  
    Yes 1  
group Randomised group     Numeric
    Tight 0  
    Relaxed 1