PEDALFAST Data

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options(qwraps2_markup = "markdown")
knitr::opts_chunk$set(collapse = TRUE)

Introduction

The PEDALFAST (PEDiatric vALidation oF vAriableS in TBI) project was a prospective cohort study conducted at multiple American College of Surgeons freestanding level I Pediatric Trauma Centers. The cohort consists of patients under 18 years of age who were admitted to the intensive care unit (ICU) with an acute traumatic brain injury (TBI) diagnosis and Glasgow Coma Scale (GCS) score not exceeding 12 or a neurosurgical procedure (intracranial pressure [ICP] monitor, external ventricular drain [EVD], craniotomy, or craniectomy) within the first 24 hours of admission.

This data set was used for several publications:

Funded by NICHD grant number R03HD094912 we retroactively mapped the data collected by the PEDALFAST project the Federal Interagency Traumatic Brain Injury Research (FITBIR) data standard. The R data package r qwraps2::Rpkg(pedalfast.data) provides the data submitted to FITBIR as both raw files and in ready to use R data sets.

The PEDALFAST study data were collected and managed using REDCap electronic data capture tools hosted at the University of Colorado Denver. [@harris2009research] REDCap (Research Electronic Data Capture) is a secure, web-based application designed to support data capture for research studies, providing 1) an intuitive interface for validated data entry; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for importing data from external sources.

This vignette documents the provided data set and other utilities of this package.

Provided Data Sets

The r qwraps2::Rpkg(pedalfast.data) package provides the following data objects:

data(package = "pedalfast.data")$results[, c("Item", "Title")]

Each of these objects will be described in detail in the following sections.

The provided data sets are data.frames. Examples for working with the provided data sets will be done using base R, the tidyverse, and data.table. Click the following buttons to have the different data paradigms displayed or not while reading this vignette.

PEDALFAST Data

The data collected during the PEDALFAST study has been provided in two data.frames so the end user may opt into using another paradigm such as r qwraps2::CRANpkg(data.table) or the tidyverse. The following will focus on use of base R methods only.

Reproduction of the examples in this vignette will require the following namespaces.

library(pedalfast.data)

Load the provided data sets into the active session via data as follows.

data(pedalfast,          package = "pedalfast.data")
data(pedalfast_metadata, package = "pedalfast.data")

str(pedalfast,          max.level = 0)
str(pedalfast_metadata, max.level = 0)

The r qwraps2::backtick(pedalfast) is a data frame with each row reporting the collected data for one subject, and each column being a unique variable. The r qwraps2::backtick(pedalfast_metadata) data frame is a selection of columns from the data dictionary provided by a REDCap export of the project. In the following you will find examples of specific utilities provided in this package to make formatting the data easier.

Let's look at the first three columns of pedalfast, and the first three rows of pedalfast_metadata.

head(pedalfast[, 1:3])
pedalfast_metadata[1:3, ]

The first column of r qwraps2::backtick(pedalfast) is the studyid, and the first row of r qwraps2::backtick(pedalfast_metadata) is the documentation for the studyid. Similarly, the second column of r qwraps2::backtick(pedalfast) and second row of r qwraps2::backtick(pedalfast_metadata) are for the age of the patient. The first notable change in is in the third row of the r qwraps2::backtick(pedalfast_metadata) where the indicator for r pedalfast_metadata[3, "variable"] is documented including the mapping from integer to English: r pedalfast_metadata[3, "values"]

The rest of this section of the vignette provides details on each of the variables in the data set and provides some examples for data use.

Study ID

The PEDALFAST data was collected at multiple sites. The study id provided is a patient specific random number between 100 and 999 with no mapping to the sites. That is, you should not be able to determine which site provided a specific row of data.

knitr::kable(subset(pedalfast_metadata, variable == "studyid"))
str(pedalfast$studyid)

Age

Age of the patient is reported in days.

knitr::kable(subset(pedalfast_metadata, variable == "age"))
summary(pedalfast$age)          # in days
summary(pedalfast$age / 365.25) # in years

The PEDALFAST data has been submitted to the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System. As part of that submission age of the patient was to be reported as the floor of the patients age in years with the exception of those under one year of age. For those under one year of age the reported value was to be the truncated three decimal age in years. For example, a patient more than one month but less than two months would have a reported age of 0.083 (1/12), a 8 month old would have a reported age of 0.666 (8/12). Note the truncation of the decimal. If you require the same rounding scheme we have provided a function in this package r qwraps2::backtick(round_age) to provide the rounding with the truncation. The function will return age as a character by default, a numeric value will be returned when specified.

fitbir_ages <-
  data.frame(age  = pedalfast$age / 365.25,
             char = round_age(pedalfast$age / 365.25),
             num  = round_age(pedalfast$age / 365.25, type = "numeric"))

plot(fitbir_ages$age, fitbir_ages$num, xlab = "Age (years)", ylab = "FITBIR Age (Years)")

Female/Male

The variable female is an indicator for sex/gender. The category of female/male was made by the attending physicians or reported by the patient/caregivers. This variable was not determined by sex chromosomes genotyping. The intent was to report sex but gender, the social constructed identify of sex, might be more appropriate.

knitr::kable(subset(pedalfast_metadata, variable == "female"))
sum(pedalfast$female)
mean(pedalfast$female)

Injury

Three variables related to injury. The source of information for the injury and the injury mechanism (injurymech) are both categorical variables with known values and are presented as character vectors in the pedalfast data.frame. The time from injury to admission (injurytoadmit) is reported in days, if the date of injury was known.

inj_vars <- c("sourceinj", "injurytoadmit", "injurymech")
knitr::kable(subset(pedalfast_metadata, variable %in% inj_vars))
summary(pedalfast[, inj_vars])

The injurymech is a character vector by default so the end user may build a factor as needed.

table(pedalfast$injurymech, useNA = "always")

Emergency Department

Several variables were collected in both the emergency department (ED) and the intensive care unit (ICU). The following are the notes for the variables collected in the ED.

GCS

The Glasgow Coma Score was assessed in one or both of the Emergency Department (ED) and the ICU. There are several variables noted here for GCS with the suffix 'ed' which are also reported later from the ICU with the suffix 'icu'.

knitr::kable(subset(pedalfast_metadata, grepl("^gcs.*ed$", variable)))
summary(pedalfast[, grep("^gcs.*ed$", names(pedalfast))])

GCS for the eye, verbal, and motor can be used as both numeric values (as reported in the pedalfast data.frame) or as a categorical variable. The r qwraps2::Rpkg(pedalfast.data) package provides functions for quickly mapping from the numeric values to a factor for gcs. The functions r qwraps2::backtick(gcs_as_integer) and r qwraps2::backtick(gcs_as_factor)

While GCS is a common assessment, the specific language used may vary. By providing these functions we are able to report the exact language used on the assessment.

Lower numeric values of GCS correspond to lower neurological functioning. To illustrate this consider, mapping the integer values 1 through 6 to the labels for the GCS scales:

knitr::kable(
             data.frame(integers = 1:6,
                        eye      = gcs_as_factor(1:6, scale = "eye"),
                        motor    = gcs_as_factor(1:6, scale = "motor"),
                        verbal   = gcs_as_factor(1:6, scale = "verbal"))
)

By default, the mapping of the integer values to factor levels will map the the integer value of 1 to level 1. The argument r qwraps2::backtick(highest_first) will reverse the order of the levels. This option has been provided to help make setting a logical reference level for modeling. For example, say we want to estimate hospital length of stay by the motor GCS score.

gcs_example_data <-
  data.frame(los = pedalfast$hosplos,
             motor_int = pedalfast$gcsmotored,
             motor_f1  = gcs_as_factor(pedalfast$gcseyeed, scale = "eye"),
             motor_f2  = gcs_as_factor(pedalfast$gcseyeed, scale = "eye", highest_first = TRUE))

head(gcs_example_data)

Just looking at the summary of the example data set shows the order of the factor is different

summary(gcs_example_data)

Thus, simple regression models will use either "no response" or "spontaneous" as the reference level. Pick the one you want to use.

summary(lm(los ~ motor_int, data = gcs_example_data))$coef
summary(lm(los ~ motor_f1,  data = gcs_example_data))$coef
summary(lm(los ~ motor_f2,  data = gcs_example_data))$coef

The total GCS score is provided.

summary(pedalfast$gcsed)

Be careful with factors. Recall that factors are numeric vectors with the first level mapped to the value one, regardless if that is logical or not. Thus:

identical(pedalfast$gcsed,
          pedalfast$gcseyeed + pedalfast$gcsmotored + pedalfast$gcsverbaled)

identical(pedalfast$gcsed,
          as.integer(gcs_as_factor(pedalfast$gcseyeed, "eye")) +
          as.integer(gcs_as_factor(pedalfast$gcsmotored, "motor")) +
          as.integer(gcs_as_factor(pedalfast$gcsverbaled, "verbal")))

identical(pedalfast$gcsed,
          as.integer(gcs_as_factor(pedalfast$gcseyeed, "eye", highest_first = TRUE)) +
          as.integer(gcs_as_factor(pedalfast$gcsmotored, "motor", highest_first = TRUE)) +
          as.integer(gcs_as_factor(pedalfast$gcsverbaled, "verbal", highest_first = TRUE)))

Disposition

Disposition form the emergency department:

knitr::kable(subset(pedalfast_metadata, variable == "eddisposition"))
table(pedalfast$eddisposition, useNA = "always")

Imaging

If the patient had CT imaging the information is provided in one of the variables prefixed by "ct" with the exception of the time from admission to ct.

knitr::kable(subset(pedalfast_metadata, grepl("^(admitto)*ct", variable)))
head(pedalfast[, grepl("^(admitto)*ct", names(pedalfast))])
summary(pedalfast[, grepl("^(admitto)*ct", names(pedalfast))])

ICU

There are several variables groups from the ICU.

Source of information

knitr::kable(subset(pedalfast_metadata, variable == "sourceicu"))
table(pedalfast$sourceicu, useNA = "always")

Pupil Reactivity

knitr::kable(subset(pedalfast_metadata, variable == "puplrcticu"))
table(pedalfast$puplrcticu, useNA = "always")

GCS

GCS in the ICU are similar variables as where noted in the emergency department. Variable names are appended by "icu" for the values attended in the ICU

knitr::kable(subset(pedalfast_metadata, grepl("^gcs.*icu$", variable)))
summary(pedalfast[, grepl("^gcs.*icu$", names(pedalfast))])

Discharge and Readmission to the ICU

The variable admitttoicudc1 is the number of days from admission to discharge from the ICU. If the patient had a readmission to the ICU then the first readmission (second overall admission) occurred admittoicuadmit2 days from admission. The duration of the first readmission (second overall admission) would be the difference between admitttoicudc2 and admittoicuadmit2.

knitr::kable(subset(pedalfast_metadata, grepl("^admittoicu", variable)))
summary(pedalfast[, grepl("^admittoicu", names(pedalfast))])

Mechanical Ventilation

knitr::kable(subset(pedalfast_metadata, variable %in% c("ventyn", "admittoint", "admittoext")))
summary(pedalfast[, c("ventyn", "admittoint", "admittoext")])

Intracranial pressure (ICP) monitors

knitr::kable(subset(pedalfast_metadata, grepl("^(admitto)*icp.+\\d", variable)))
summary(pedalfast[pedalfast$icpyn1 == 1, grepl("^(admitto)*icp.+\\d", names(pedalfast))])

ICP monitor types:

table(pedalfast$icptype1)

Invasive Vascular Catheters

knitr::kable(subset(pedalfast_metadata, grepl("^(admitto)*cath.+\\d", variable)))

First catheter

summary(
  subset(pedalfast,
         !is.na(cathtype1),
         select = grep("cath.*1$", names(pedalfast)))
)
table(pedalfast$cathtype1)

Second catheter

summary(
  subset(pedalfast,
         !is.na(cathtype2),
         select = grep("cath.*2$", names(pedalfast)))
)
table(pedalfast$cathtype2)

Third catheter

summary(
  subset(pedalfast,
         !is.na(cathtype3),
         select = grep("cath.*3$", names(pedalfast)))
)
table(pedalfast$cathtype3)

Fourth catheter

summary(
  subset(pedalfast,
         !is.na(cathtype4),
         select = grep("cath.*4$", names(pedalfast)))
)
table(pedalfast$cathtype4)

Tracheostomy

knitr::kable(subset(pedalfast_metadata, variable %in% c("newtrachyn", "admittotrach")))
summary(pedalfast[pedalfast$newtrachyn == 1, c("newtrachyn", "admittotrach")])

Gastrostomy

knitr::kable(subset(pedalfast_metadata, variable %in% c("newgastyn", "admittogast")))
summary(pedalfast[pedalfast$newgastyn == 1, c("newgastyn", "admittogast")])

Decompressive craniectomy

knitr::kable(subset(pedalfast_metadata, variable %in% c("decomcranyn", "admittocrani")))
summary(pedalfast[pedalfast$decomcranyn == 1, c("decomcranyn", "admittocrani")])

Lumbar Drain

knitr::kable(subset(pedalfast_metadata, variable %in% c("lmbrdrainyn", "admittolmbdrain")))
summary(pedalfast[pedalfast$lmbrdrainyn == 1, c("lmbrdrainyn", "admittolmbdrain")])

Epidural Hematoma Evacuated

knitr::kable(subset(pedalfast_metadata, variable %in% c("epihemyn", "admittoedhevac")))
summary(pedalfast[pedalfast$epihemyn == 1, c("epihemyn", "admittoedhevac")])

Subdural Hematoma Evacuated

knitr::kable(subset(pedalfast_metadata, variable %in% c("subhemyn", "admittosdhevac")))
summary(pedalfast[pedalfast$subhemyn == 1, c("subhemyn", "admittosdhevac")])

Medications

knitr::kable(subset(pedalfast_metadata, grepl("^rx", variable)))
summary(pedalfast[, grepl("^rx", names(pedalfast))])

TPN

knitr::kable(subset(pedalfast_metadata, variable %in% c("tpnyn", "admittotpn")))
summary(pedalfast[pedalfast$tpnyn == 1, c("tpnyn", "admittotpn")])

Enteral Nutrition

knitr::kable(subset(pedalfast_metadata, variable %in% c("entnutyn", "admittoentnut")))
summary(pedalfast[pedalfast$entnutyn == 1, c("entnutyn", "admittoentnut")])

Hospital LOS and Disposition

knitr::kable(subset(pedalfast_metadata, variable %in% c("hosplos", "hospdisposition")))
summary(pedalfast[, c("hosplos", "hospdisposition")])
table(pedalfast$hospdisposition, useNA = "always")

Cardiac Arrest

Indicator and location for cardiac arrest.

knitr::kable(subset(pedalfast_metadata, grepl("^cardiac", variable)))
summary(pedalfast[, grepl("^cardiac", names(pedalfast))])

Functional Status Scale

knitr::kable(subset(pedalfast_metadata, grepl("fss", variable)))
summary(pedalfast[, grepl("fss", names(pedalfast))])

Mapping PEDALFAST to FITBIR

The PEDALFAST data sets have been organized, submitted, and published via the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System.

Funding

The mapping of PEDALFAST data to FITBIR and the construction and release of this R package was funded in part by NIH grant R03HD094912.

The PEDALFAST project was funded in part by NICHD grant number K23HD074620.

References



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pedalfast.data documentation built on Nov. 11, 2023, 1:07 a.m.