Performance of AKI occurrence classification by several models using SCr and 1/SCr.

<p>(a) precision, (b) recall, and (c) F-measure. LIN: linear regression, RID: ridge regression, LAS: lasso, LAR: least-angle regression (LARS), SGD: stochastic gradient descent, RAF: random forest, and MRS: multivariate adaptive regression splines (MARS).</p

Definitions and time windows for serum creatinine (SCr) measurements used for detecting and staging AKI.

<p>Circles represent SCr measurements of a single patient taken at time points <i>t</i>₁, ⋯, <i>t</i>₁₃. Double-headed arrows represent time windows. The first window is centered around the registration date of a patient, and used to obtain SCr_<i>a</i>. The second and third windows are positioned next to each other such that the current date is located between them, and they are used for obtaining recent SCr, and staging AKI, respectively. See text for more details on SCr_<i>a</i>, SCr_<i>b</i>, and baseline SCr.</p

Window-based data creation.

<p>Blue, vertical arrows represent serum creatinine (SCr) measurements, and grey, vertical arrows in a dashed line represent oral chemotherapeutics. There are other temporal data that are also included as temporal features, but we omit them for simplicity’s sake. <i>t</i>₁, ⋯, <i>t</i>₈ represent the times when SCr values are measured. The highlighted blue arrow at <i>t</i>₅ indicates the current SCr. The double-headed arrows represent windows: the windows to the left of time <i>t</i>₅ are to summarize the temporal data before the current time <i>t</i>₅, and the window to the right of time <i>t</i>₅ is to capture the target value.</p

Performance of serum creatinine (SCr) regression by several models using SCr and 1/SCr.

<p>(a) mean squared error, and (b) mean absolute error. LIN: linear regression, RID: ridge regression, LAS: lasso, LAR: least-angle regression (LARS), SGD: stochastic gradient descent, RAF: random forest, and MRS: multivariate adaptive regression splines (MARS).</p

Distribution of patients by cancer type.

<p>Distribution of patients by cancer type.</p

Performance of AKI stage classification by several models trained with the full data and subsets.

<p>(a) precision, (b) recall, and (c) F-measure. I1: an interval between 2004/1/1 and 2007/11/31, I2: an interval between 2007/12/1 and 2011/10/31, and I3: an interval between 2011/11/1 and 2015/9/30. LIN: linear regression, RID: ridge regression, LAS: lasso, LAR: least-angle regression (LARS), SGD: stochastic gradient descent, RAF: random forest, and MRS: multivariate adaptive regression splines (MARS).</p

Missing rate of non-temporal variables.

<p>Missing rate of non-temporal variables.</p

Performance of serum creatinine (SCr) regression by several models trained with the full data and subsets.

<p>(a) mean squared error, and (b) mean absolute error. I1: an interval between 2004/1/1 and 2007/11/31, I2: an interval between 2007/12/1 and 2011/10/31, and I3: an interval between 2011/11/1 and 2015/9/30. LIN: linear regression, RID: ridge regression, LAS: lasso, LAR: least-angle regression (LARS), SGD: stochastic gradient descent, RAF: random forest, and MRS: multivariate adaptive regression splines (MARS).</p

Descriptive statistics of non-temporal variables: The median and interquartile range are shown for non-categorical variables, and the number of patients in each category is shown for categorical variables.

<p>Descriptive statistics of non-temporal variables: The median and interquartile range are shown for non-categorical variables, and the number of patients in each category is shown for categorical variables.</p

Distribution of number of temporal records.

<p>(a) Serum Creatinine (SCr) measurements, (b) CT scans, (c) administration of intravenous (IV) chemotherapeutics, (d) administration of oral chemotherapeutics, and (e) administration of nephrotoxic drugs.</p