Package 'clintools'

Title: Tools for Clinical Research
Description: Every research team have their own script for data management, statistics and most importantly hemodynamic indices. The purpose is to standardize scripts utilized in clinical research. The hemodynamic indices can be used in a long-format dataframe, and add both periods of interest (trigger-periods), and delete artifacts with deleter-files. Transfer function analysis (Claassen et al. (2016) <doi:10.1177/0271678X15626425>) and Mx (Czosnyka et al. (1996) <doi:10.1161/01.str.27.10.1829>) can be calculated using this package.
Authors: Markus Harboe Olsen [cre, aut], Christian Riberholt [ctb], Ronan Berg [ctb], Kirsten Moeller [ctb], Janus Christian Jakobsen [ctb], Aksel Karl Georg Jensen [ctb]
Maintainer: Markus Harboe Olsen <[email protected]>
License: MIT + file LICENSE
Version: 0.9.10.2
Built: 2024-11-27 04:40:32 UTC
Source: https://github.com/lilleoel/clintools

Help Index


Calculation of reliability (calcrel)

Description

calcrel() is a function used to calculate different reliability measures, including Coefficient of variance, smallest real difference, intraclass correlation coefficient, and Bland-Altman plot derived bias with 95% limits of agreement.

Usage

calcrel(d1,d2)

Arguments

d1

list of numbers from measurement one

d2

list of numbers from measurement two (same order as for measurement one)

Value

Returns a nested list of reliability measures.

Examples

d1 <- rnorm(15,10,1)
   d2 <- rnorm(15,10,1)
   calcrel(d1,d2)

Central data monitoring to assess deviations (cdm.fig)

Description

cdm.fig() is a function to assess any deviations

Usage

cdm.fig(df, col, site, meta_title, seedno, output, nmin)

Arguments

df

dateframe to be assessed for missing data

col

column to be assessed

site

column with sites

meta_title

Y-axis lab, if empty then it is the column name

seedno

the numeric site, if empty it is just Sys.Date()

output

if 'fig' then the figure is the output, any other will output the blinded site table

nmin

minimum number of variables in site to be presented

Value

Returns a full markdown output.

Examples

## Not run: 
   cdm.fig(df,col="Mode of birth",
      site="maternal_trial_site")
   cdm.fig(df,col="Gestational Age at birth",
      site="maternal_trial_site")
   library(knitr)
   kable(cdm.fig(df,col="Mode of birth",
      site="maternal_trial_site",output = ""),row.names=F)

## End(Not run)

Quiet any output (cdm.miss)

Description

cdm.miss() is a small function which suppresses any output

Usage

cdm.miss(df, id, cols, fudate, lostFU, filter, blind)

Arguments

df

dateframe to be assessed for missing data

id

column-name for unique id's

cols

columns to be assessed for missing data

fudate

column with the date of follow-up, i.e. when data is missing

lostFU

column for patients lost to follow up, TRUE/FALSE in the column

filter

how many should be shown in figures - 'all' for all, 'waiting' for those with missing or waiting for data, and 'missing' for only those with missing data

blind

boolean if TRUE, participant IDs will be blinded.

Value

Returns a full markdown output.

Examples

## Not run: 
   cdm.miss(data,id=idcols[[1]],cols=missing.cols,lostFU="lostFU",
   fudate = "follow_up_date", filter="missing")

## End(Not run)

Trial status for central data monitoring (cdm.status)

Description

cdm.status() is a function to provide an overview of the trial status

Usage

cdm.status(d, sample.size, planned.years, rolling.average)

Arguments

d

list of dates for each participant included.

sample.size

the planned sample size

planned.years

the planned duration of the trial

rolling.average

the number of participant to be included to calculate the predicted inclusion rate

Value

returns a list where ⁠$fig⁠ is the figure; ⁠$txt⁠ is as summary of the findings; and ⁠$df⁠is the dataframe generated in the function.

Examples

## Not run: 
   tmp <- cdm.status(d,sample.size=1808)

## End(Not run)

Hemodynamic Indices Calculated From Clinical Monitoring (clinmon)

Description

clinmon() uses a continuous recording and returns a dataframe with hemodynamic indices for every period, epoch or block depending on the input. Calculates COest, CPPopt, CVRi, Dx, Mx, PI, PRx, PWA, RI, and Sx (see Hemodynamic indices).

Usage

clinmon(df, variables,
trigger = NULL, deleter = NULL,
blocksize = 3, epochsize = 20,
overlapping = FALSE, freq = 1000,
blockmin = 0.5, epochmin = 0.5,
output = "period", fast = FALSE)

Arguments

df

Raw continuous recording with all numeric data and first column has to be time in seconds. (dataframe)

variables

Defining the type and order of the recorded variables as a list. Middle cerebral artery blood velocity ('mcav'), Arterial blood pressure ('abp'), cerebral perfusion pressure ('cpp'), intracranial pressure ('icp'), and heart rate ('hr') is currently supported. It is necessary that time is the first row. (list)

trigger

Trigger with two columns: first is start, and second is end of periods to be analyzed. Every row corresponds to a period. Default is NULL, which results in analysis of the full dataframe. (dataframe)

deleter

Deleter with two columns: first is start and second is end of period with artefacts, which need to be deleted. Every row is a period with artefacts. Default is NULL. (dataframe)

blocksize

Length of a block, in seconds. Default is 3. (numeric)

epochsize

Size of epochs in number of blocks. Default is 20. (numeric)

overlapping

The number of block which should overlap when calculating correlation based indices, and remain blank if overlapping calculations should not be utilized. Default is FALSE. (numeric)

freq

Frequency of recorded data, in Hz. Default is 1000. (numeric)

blockmin

Minimum measurements required to create a block in ratio. Default is 0.5 corresponding to 50%. If the block holds less than the defined ratio the block will be omitted. (numeric)

epochmin

Minimum number of blocks required to create an epoch in ratio. Default is 0.5 corresponding to 50%. If the epoch holds less than the defined ration the epoch will be omitted. (numeric)

output

Select what each row should represent in the output. Correlation based indices are not presented when selecting blocks for every row. Currently 'block', 'epoch', 'period' or 'cppopt' is supported. Default is 'period'. (string)

fast

Select if you want the data to aggregated before analysis resulting in a faster, but perhaps more imprecise run, in Hz. Default is FALSE. (numeric)

Details

Using a continuous raw recording, clinmon() calculates hemodynamic indices for every period, epoch or block depending on the chosen output.

View(data)
time abp mcav
7.00 78 45
7.01 78 46
... ... ...
301.82 82 70
301.83 81 69

To calculate the indices insert the data and select the relevant variables.

clinmon(df=data, variables=c("abp","mcav"))

See Value for output description.

Value

Returns a dataframe with the results, with either every blocks, epochs or periods as rows, depending on the chosen output.

The columns of the output are:

  • period - The period number corresponding to the row-number in the trigger file.

  • epoch - The epoch number, or if period is chosen as output it reflects the number of epochs in the period.

  • block - The block number, or if period or epoch is chosen as output it reflects the number of blocks in the period or epoch.

  • time_min - The minimum time value or the period, epoch or block.

  • time_max - The maximum time value or the period, epoch or block.

  • missing_percent - The percentage of missing data in the period, epoch or block.

  • XX_mean - The mean value of each variable for the period, epoch or block.

  • XX_min - The minimum value of each variable for the period, epoch or block.

  • XX_max - The maximum value of each variable for the period, epoch or block.

  • YY - The indices in each column.

Hemodynamic indices

COest | Estimated cardiac output

Required variables: abp, hr; Required output: -.

Estimated cardiac output (COest) is calculated by utilizing the method described by Koenig et al. [1]:

COest=PP/(SBP+DBP)HRCOest = PP / (SBP+DBP) * HR

PP: Pulse pressure; SBP: systolic blood pressure; DBP: diastolic blood pressure; HR: heart rate.

CPPopt | Optimal cerebral perfusion pressure

Required variables: abp, icp; Required output: period.

Optimal cerebral perfusion pressure (CPPopt) is calculated utilizing the method described by Steiner et al. [2]. The CPPopt return NA if CPPopt is the maximum or minimum CPP investigated. CPPopt is recommended to only be calculated after 'several hours' of recording:

CPPopt=The5mmHgCPPIntervalWithLowestMeanPRxCPPopt = The 5 mmHg CPP Interval With Lowest Mean PRx

CPP: cerebral perfusion pressure; PRx: Pressure reactivity index.

CVRi | Cardiovascular resistance index

Required variables: abp, mcav; Required output: -.

Cardiovascular resistance index (CVRi) is calculated utilizing the method described by Fan et al. [3]:

CVRi=meanABP/meanMCAvCVRi = mean ABP / mean MCAv

ABP: arterial blood pressure; MCAv: middle cerebral artery blood velocity.

Dx | Diastolic flow index

Required variables: cpp/abp, mcav; Required output: epoch, period.

Diastolic flow index (Dx) is calculated utilizing the method described by Reinhard et al. [4]:

Dxc=cor(meanCPP/minMCAv)Dxc = cor( mean CPP / min MCAv )

Dxa=cor(meanABP/minMCAv)Dxa = cor( mean ABP / min MCAv )

cor: correlation coefficient; CPP: cerebral perfusion pressure; ABP: arterial blood pressure; MCAv: middle cerebral artery blood velocity.

Mx | Mean flow index

Required variables: cpp/abp, mcav; Required output: epoch, period.

Mean flow index (Mx) is calculated utilizing the method described by Czosnyka et al. [5]:

Mxc=cor(meanCPP/meanMCAv)Mxc = cor( mean CPP / mean MCAv )

Mxa=cor(meanABP/meanMCAv)Mxa = cor( mean ABP / mean MCAv )

cor: correlation coefficient; CPP: cerebral perfusion pressure; ABP: arterial blood pressure; MCAv: middle cerebral artery blood velocity.

PI | Gosling index of pulsatility

Required variables: mcav; Required output: -.

Gosling index of pulsatility (PI) is calculated utilizing the method described by Michel et al. [6]:

PI=(systolicMCAvdiastolicMCAv)/meanMCAvPI = (systolic MCAv - diastolic MCAv) / mean MCAv

MCAv: middle cerebral artery blood velocity.

PRx | Pressure reactivity index

Required variables: abp, icp; Required output: epoch, period.

Pressure reactivity index (PRx) is calculated utilizing the method described by Czosnyka et al. [7]:

PRx=cor(meanABP/meanICP)PRx = cor( mean ABP / mean ICP )

cor: correlation coefficient; CPP: cerebral perfusion pressure; ICP: intracranial pressure.

PWA | Pulse wave amplitude

Required variables: cpp/icp/abp/mcav; Required output: -.

Pulse wave amplitude (PWA) is calculated utilizing the method described by Norager et al. [8]:

PWA=systolicdiastolicPWA = systolic - diastolic

RI | Pourcelots resistive (resistance) index

Required variables: mcav; Required output: -.

Pourcelots resistive (resistance) index (RI) is calculated utilizing the method described by Forster et al. [9]:

RI=(systolicMCAvdiastolicMCAv)/systolicMCAvRI = (systolic MCAv - diastolic MCAv) / systolic MCAv

MCAv: middle cerebral artery blood velocity.

Sx | Systolic flow index

Required variables: cpp/abp, mcav; Required output: epoch, period.

Systolic flow index (Sx) is calculated utilizing the method described by Czosnyka et al. [5]:

Sxc=cor(meanCPP/systolicMCAv)Sxc = cor( mean CPP / systolic MCAv )

Sxa=cor(meanABP/systolicMCAv)Sxa = cor( mean ABP / systolic MCAv )

cor: correlation coefficient; CPP: cerebral perfusion pressure; ABP: arterial blood pressure; MCAv: middle cerebral artery blood velocity.

References

  1. Koenig et al. (2015) Biomed Sci Instrum. 2015;51:85-90. (PubMed)

  2. Steiner et al. (2002) Crit Care Med. 2002 Apr;30(4):733-8. (PubMed)

  3. Fan et al. (2018) Front Physiol. 2018 Jul 16;9:869. (PubMed)

  4. Reinhard et al. (2003) Stroke. 2003 Sep;34(9):2138-44. (PubMed)

  5. Czosnyka et al. (1996) Stroke. 1996 Oct;27(10):1829-34. (PubMed)

  6. Michel et al. (1998) Ultrasound Med Biol. 1998 May;24(4):597-9. (PubMed)

  7. Czosnyka et al. (1997) Neurosurgery. 1997 Jul;41(1):11-7; discussion 17-9. (PubMed)

  8. Norager et al. (2020) Acta Neurochir (Wien). 2020 Dec;162(12):2983-2989. (PubMed)

  9. Forster et al. (2017) J Paediatr Child Health. 2018 Jan;54(1):61-68. (PubMed)

Examples

data(testdata)
clinmon(df.data10, variables=c('abp','mcav','hr'), freq=10)

Compare measures of reliability (comparerel)

Description

comparerel() is a function which compares measures from calcrel using bootstrapping.

Usage

comparerel(d1,d2,d3,d4,n_boot,seedno)

Arguments

d1

list of numbers from measurement one of sample 1

d2

list of numbers from measurement two of sample 1 (same order as for d1)

d3

list of numbers from measurement one of sample 2

d4

list of numbers from measurement two of sample 2 (same order as for d2)

n_boot

numbers of iterations (default is 1000)

seedno

the seed number used for bootstrapping (default is)

Value

Returns a nested list of difference between reliability measures using bootstrapping.

Examples

## Not run: 
   d1 <- rnorm(15,10,1)
   d2 <- rnorm(15,10,1)
   d3 <- rnorm(15,10,1)
   d4 <- rnorm(15,10,1)
   comparerel(d1,d2,d3,d4)

## End(Not run)

Danish CPR number to birthday and sex (danishcpr)

Description

danishcpr() converts a list of CPR-numbers to a corresponding list birthday and sex.

Usage

danishcpr(code)

Arguments

code

list of CPR numbers (list)

Value

Returns a list with $birthday which is a list of dates, and $sex which is a list of Male/Female.

Examples

## Not run: 
   cpr <- danishcpr(code)
   birthdays <- cpr$birthday
   sex <- cpr$sex

## End(Not run)

Test-data - 1000 Hz

Description

Recording with four columns: time (t), non-invasive arterial blood pressure (abp), middle cerebral artery velocity measured using transcranial Doppler (mcav), and heart rate (hr).

Usage

data(testdata)

Format

An object of class "dataframe"; an example of the usage in clinmon-function.

References

Olsen MH et al. (Unpublished data, 2020) (GitHub)

Examples

data(testdata)
variables <- c("abp","mcav","hr")
clinmon(df.data1000,variables,fast=50)

Test-deleter

Description

Deleter dataframe with two columns: start (start) and end (end) of the deleter-period.

Usage

data(testdata)

Format

An object of class "dataframe"; an example of the usage in clinmon-function.

References

Olsen MH et al. (Unpublished data, 2020) (GitHub)

Examples

data(testdata)
variables <- c("abp","mcav","hr")
clinmon(df.data1000,variables,deleter=df.deleter,fast=50)

Assess dilations from PLR3000-output.

Description

dilations() is a function which converts longformat recording of pupillary size and uses markers to generate a dataframe, plot, and markdown output to inspect the results.

Usage

dilations(pupils, markers,
  remove_markers = NULL, add_markers = NULL,
  not_assess = NULL, artefacts_static = c(0.55,9.95),
  artefacts_dynamic = c(`1` = 1.5, `0.66` = 1, `0.33` = 0.5),
  time_assess = c(`1` = 10, `3` = 5),
  sig.level = 0.05, min_change = NULL,
  resting_delay = c(`3` = 0))

Arguments

pupils

recording of pupillary function. long format dataframe with at least three columns: record_id, time, and size.

markers

time of markers. long format dataframe with at least two columns: record_id and time.

remove_markers

markers which should be removed. long format dataframe with at least two columns: record_id and time. The time column need one decimal.

add_markers

markers which should be added. long format dataframe with at least two columns: record_id and time. The time column need one decimal.

not_assess

a list of record ids which should no be assessed.

artefacts_static

a list of the limits of the artefacts. The first number in the list is the minimum size to be assessed and the second is the maximum size to be assessed

artefacts_dynamic

a named list where max change in millimeter within the duration (name in list) is removed. Will use the first 1 second of the recording to create a baseline, thus suspectible to artefacts in the start of the recording.

time_assess

This named list define the number of seconds which should be used in the assessment of dilatios. The name is the number of periods-of-interest and the value is the seconds.

sig.level

This is the significance level to be used when comparing the size of the period-of-interest. The significance level corresponds to the Wilcox.test used.

min_change

This is the minimum size of mm which needs to change before a dilation can be identified. Default is no minimum requirement.

resting_delay

This can be used if the subsequent resting period to compare should be delayed, i.e. if we should wait 5 second for those investigations with three periods of interest create a named list with periods of interest as names and seconds to delay as input.

Value

Returns a nested list one dataframe of the results ($dilations), plot ($plot$id[record id]), and a markdown output ($plot$markdown$id[record_id]). The dilations dataframe include the following columns: Record ID (record_id); Patient ID (pt_id); Date (date); pupil side (side); start of the period (min); end of the period (max); length of period (rec_length); number of measurements (n); median size (median); P value when comparing with the previous period (p_before); P value when comparing with the following period (p_after); and if dilation is identified (dilation, 1 is successful dilation and 0 is no dilation).

Examples

## Not run: 
   recordings <- PLR3000("C:/PLR3000/R_20200105_205901.xls")
   dilations <- dilations(recordings$pupils,recordings$markers)

   # The dataframe of the results
   dilations$dilations

   # The plot of one of the recordings
   dilations$plot$id833

   # The markdown output of one of the recordings
   dilations$markdown$id833

 
## End(Not run)

ISCUSFlex-values to dataframe (iscus)

Description

iscus() is a function which converts XML files extracted from the Microdialysis-apparatur of ISCUSFlex apparatus to a dataframe.

Usage

iscus(filename)

Arguments

filename

path to the XML-file with the measurements

Value

Returns a dataframe with the measurements.

Examples

## Not run: 
   iscus("C:/ISCUSfiles/7888e844-1c7a-40af-a3f2-3bb27a8dd9e5.xml")
 
## End(Not run)

Logistic regression table with Odds ratio (ortable)

Description

ortable() is a small function which utilises the output from the glm-function to print a dataframe with odds ratio, confidence limits, and p-values.

Usage

ortable(x, d, d_p, intercept, simple)

Arguments

x

Utilises the output from a glm-function. (glm-output)

d

Refers to the number of digits for odds ratio and confidence intervals. Default is 2. (numeric)

d_p

Refers to the number of digits for odds ratio and confidence intervals. Default is 3. (numeric)

intercept

The intercept is presented in the table if TRUE. Default is FALSE. (boolian)

simple

Odds ratio and confidence intervals are merged into one column if TRUE. Default is TRUE. (boolian)

Value

Returns a dataframe with with odds ratio, confidence limits, and p-values.

Examples

df <- data.frame(outcome=sample(0:1, 100,replace=TRUE),
        var=sample(0:100,100,replace=TRUE))
ortable(glm(outcome ~ ., data=df))

NeurOpticsTM PLR-3000 pupillometer file to dataframe (PLR3000)

Description

PLR3000() is a function which converts the XLS file imported from the eurOpticsTM PLR-3000 pupillometer to a nested list with two dataframes.

Usage

PLR3000(filename = NULL, df = NULL)

Arguments

filename

path to the XLS-file with the measurements

df

the dataframe can also be used for the function if data is already imported.

Value

Returns a list with two dataframe, one with the measurements (pupils) and one with the markers (markers).

Examples

## Not run: 
   PLR3000("C:/PLR3000/R_20200105_205901.xls")
 
## End(Not run)

Calculate scores from questionaires (questionaire)

Description

questionaire() is a function which calculates scores from a questionaire.

Usage

questionaire(df,id,questions,scale,prefix,...)

Arguments

df

dataframe. (df)

id

Column name of participant id (string)

questions

Column names of ordered list of questions (list)

scale

name of the questionaire (string)

prefix

prefix of column names of questionaire scores (string)

...

additional questionaire specific parameters

Details

PARCA-R (Parent Report of Children’s Abilities-Revised)

This only calculates the scores for the 34 Non-verbal cognitive score. The questionaire needs to have 34 questions, scale = "PARCA-R", and the following additional parameters need to be set:

  • birthday | The name of the column for the birthday; if children are born before 37 weeks of gestatoin it is suggested to have corrected age; and then the column should be date of term.

  • date | The name of the column for the date of when the participants went through the questionaire.

  • sex | The name of the column for the sex of the participants. Male's must be coded as M and females as F.

The calculation summarizes both the raw score and the standard score. As per the PARCA-R manual from 2019 and from the protocol from SafeBoosC-III follow-up study Rasmussen et al. 2029 moderate-or-severe cognitive impairment is defined as < -2SD. This corresponds to a standard score below 70.

CBI (Copenhagen Burnout Inventory)

Using the 19 questions from the CBI it will both calculate score and group.

Using setting it can either be the English version (default; score = 'english') or the Danish version (score = 'danish'). In the English version the Likert-scale is converted to 100, 75, 50, 25, 0. Here, no more than 3 questions may be missing in each subscore English CBI.

The groups are based on the average score:

  • 0-25: 'no burnout'

  • 25-50: 'light burnout'

  • 50-75: 'moderate burnout'

  • 75-100: 'severe burnout'

In the Danish score the questions are summed up from 0 to 4 points. Here, all questions must be answered. Danish CBI

The groups are based on the summed score:

  • 0-5: 'no burnout' (0-6 for Work-related burnout)

  • 6-11: 'light burnout' (7-13 for Work-related burnout)

  • 12-17: 'moderate burnout' (14-20 for Work-related burnout)

  • 18+: 'severe burnout' (21+ for Work-related burnout)

KIDSCREEN-52

Works, but not documented

Value

Returns summarised information in dataframe.

Examples

## Not run: 

   df <- df_b[,grepl("ssid|KIDSCREEN52_D_",colnames(df_b))][,c(1:53)]
   k52 <- questionaire(df,id = "ssid",
   questions=colnames(df)[grepl("KIDSCREEN",colnames(df))],
   scale="Kidscreen-52",
   setting="proxy")#'

## End(Not run)

Quiet any output (quietly)

Description

quietly() is a small function which suppresses any output

Usage

quietly(x)

Arguments

x

input to be suppressed

Value

Returns x, but without any output

Examples

## Not run: 
tmp <- quietly(print("hello"))

## End(Not run)

Reorder column (recol)

Description

recol() is a small function which can rename columns and change factors to relevant input

Usage

recol(df, old, new, factors=NULL, remove=TRUE, na=NA)

Arguments

df

dataframe. (df)

old

old column name. (string)

new

new column name. (string)

factors

Named list of factors. If no names then just in alphabetical order (⁠named list⁠)

remove

remove old column from dataframe (boolian)

na

the na.strings (list)

Value

Returns the dataframe with new columns.

Examples

## Not run: 
   # NUMERIC VARIABLE
   df <- recol(df, "X5d_55_Alcohol_127", "Alcohol")
   # FACTOR VARIABLE
   df <- recol(df, "X5d_55_Alcohol_127", "Alcohol", factors=c("No","Yes"))

## End(Not run)

find median of rows similar to rowMeans (rowMedians)

Description

rowMedians() converts a dataframe to a list of row medians.

Usage

rowMedians(x, na.rm=FALSE)

Arguments

x

a dataframe where median of row should be calculated. (data.frame)

na.rm

Should missing values be omitted fro the calculations? (boolian)

Value

Returns a list of the median of each row in the inputted dataframe.

Examples

## Not run: 
   rowMedians(df[,c("test1","test2","test3")])

## End(Not run)

Relative risk derived by G-computation (rrGcomp)

Description

rrGcomp() is a small function which generates population-level (marginal) relative risks derived by G-computation. For models with random effects mixed-effects generalized linear model with a logit link with adjustment for stratification variables will be used, while those without random effects a logistic regression will be used. The code is based on the method used in the paper by Dankiewicz et al. (2021) N Engl J Med. Jun 17;384(24):2283-2294. (PubMed

Usage

rrGcomp(df, outcome_col, group_col,
fixed_strata = NULL, random_strata = NULL,
nbrIter = 5000, conf_level = 0.95)

Arguments

df

the individual participant dataframe

outcome_col

column name for the outcome column

group_col

column name for the group column

fixed_strata

list of column names for the fixed effect stratification columns

random_strata

list of column names for the random effect stratification columns

nbrIter

number of iterations to be used in the G-computation. The original paper used 5000, which is also the default.

conf_level

the confidence level to be reported.

Value

Returns a list with relative risk (rr), simulated rr (simRR), lower- and upper confidence level (simLCL/simUCL), and the p-value (p_val)

Examples

df <- sRCT(n_sites=3,n_pop=50)
rrGcomp(df,outcome_col="outcome",group_col="Var1",random_strata="site",nbrIter=10)

simulated Randomised Clinical Trial (sRCT)

Description

sRCT() is a function which simulates a randomised clinical trial with a binary outcome and returns a dataframe. This version is validated to be used for analysis of interaction in a factorial design.

Usage

sRCT(all_sizes = NULL, n_pop = 1000,
n_sites = 10, design = c(2,2,2),
rrr = c(0.05,0.05,0), outcome_risk = 0.492,
interaction = c(`1-2` = 0.05, `1-2-3` = -0.05),
site_re = 0.05)

Arguments

all_sizes

Size of blocks in allocation table. If left empty the three lowest possible block sizes will be randomly assigned.

n_pop

Number of participants included in the trial.

n_sites

Number of sites

design

Number of sites as a list where each element corresponds to an intervention and the number in the element is the number of groups. So for a 2x2 factorial design c(2,2) should be used.

rrr

relative risk reduction for each intervention so for the abovementioned 2x2 factorial design with RRR of 0.05 and 0.10 we would use c(0.05,0.10).

outcome_risk

The baseline risk (probability in absolute percentage) of the dichotomous primary outcome.

interaction

Interaction between interventions with a named list. If interaction exists between intervention 1 and 2 we would use 1-2 = 0.05.

site_re

The size of the random effect of site, default is 0.05.

Details

The sRCT function is continuously being developed to answer specific questions in simulation studies. sRCT will be updated and tested for each specific question. For each update the function will be validated for the current purpose and all previous purposes. sRCT is not validated for all simulation studies

Value

Returns a dataframe with an individual participant data frame.

Examples

sRCT()

Create a table (tbl)

Description

tbl() is a function which create a dataframe, which can be copied directly into word or presented in as a summary table.

Usage

tbl(df,strata,vars,render.numeric,
render.factor, tests, test.vars, paired,
   digs_n,digs_f, digs_p, digs_s,
   only_stats, strata.fixed, strata.random,
   time.to, present.missing, conf.level,
   zeroonetoyn,
   markdown, caption)

Arguments

df

dataframe. (df)

strata

Column name of stratification (string)

vars

Column names of variables of interest (list)

render.numeric

list of presentation of numeric variables (list)

render.factor

presentation of factors, with simple removing one factor when only two exists

tests

list of tests carried out, currently the following works: t.test, wilcox.test, fisher.test, auc, lm, and glm. (list)

test.vars

a list of variable names from vars, where analyses should be carried out. If left NA all variable will be analysed (list)

paired

if tests should be paired (boolean)

digs_n

digits for numeric (numeric)

digs_f

digits for factors (numeric)

digs_p

digits for p-values (numeric)

digs_s

digits for statistics (numeric)

only_stats

if only stats should be presented (booolean)

strata.fixed

list of columns which should be used as fixed stratification (list)

strata.random

list of columns which should be used as random stratification (list)

time.to

Column name of the time column for cox regression (list)

present.missing

default is dynamic where non-missing variables are not presented. FALSE removes missingness from presentation.

conf.level

confidence intervals which should be presented (numeric).

zeroonetoyn

for factor variables which are 0 and 1, convert them to No and Yes (boolean)

markdown

default is true and output is pander, while false output is a dataframe (boolean)

caption

Table caption only in use when markdown is true (string)

Value

Returns summarised information in dataframe.

Examples

## Not run: 
   hmm <- tbl(df,strata="group",
   vars = c("Gestational Age at birth","Maternal preeclampsia"),
   tests=c("wilcox.test","glm"),only_stats=F,strata.random = "site",
   markdown=F)
   pander::pander(hmm, keep.line.breaks = TRUE,split.tables=Inf, row.names = F)

## End(Not run)

Test-data - 10 Hz

Description

Recording with four columns: time (t), non-invasive arterial blood pressure (abp), middle cerebral artery velocity measured using transcranial Doppler (mcav), and heart rate (hr).

Usage

data(testdata)

Format

An object of class "dataframe"; an example of the usage in clinmon-function.

References

Olsen MH et al. (Unpublished data, 2020) (GitHub)

Examples

data(testdata)
variables <- c("abp","mcav","hr")
clinmon(df.data10,variables,freq=10)

Transfer function analysis of dynamic cerebral autoregulation (TFA)

Description

TFA() calculates dynamic cerebral autoregulation trough a transfer function analysis from a continuous recording. This function follows the recommendations from Claassen et al. [1] and mimicks the matlab script created by David Simpsons in 2015 (Matlab TFA function). TFA() also includes the possibility to analyse raw recordings with application of cyclic (beat-to-beat) average with the possiblity of utilizing interpolation. (see details).

Usage

TFA(df, variables,
trigger = NULL, deleter = NULL,
freq = 1000, fast = 50, raw_data = FALSE,
interpolation = 3, output = "table",
vlf = c(0.02,0.07),lf = c(0.07,0.2),
hf = c(0.2,0.5), detrend = FALSE,
spectral_smoothing = 3,
coherence2_thresholds = cbind(c(3:15),
c(0.51,0.40,0.34,0.29,0.25,0.22,0.20,0.18,
0.17,0.15,0.14,0.13,0.12)),
apply_coherence2_threshold = TRUE,
remove_negative_phase = TRUE,
remove_negative_phase_f_cutoff = 0.1,
normalize_ABP = FALSE,
normalize_CBFV = FALSE,
window_type = 'hanning',
window_length = 102.4,
overlap = 59.99,
overlap_adjust = TRUE,
na_as_mean = TRUE)

Arguments

df

Raw continuous recording with numeric data and first column has to be time in seconds. (dataframe)

variables

Definition of the type and order of recorded variables as a list. Middle cerebral artery blood velocity ('mcav') and arterial blood pressure ('abp') is currently supported. (list)

trigger

Trigger with two columns: first is start, and second is end of period to be analyzed. Every row is a period for analysis. Default is NULL, which results in analysis of the full dataframe. (dataframe)

deleter

Deleter with two columns: first is start and second is end of period with artefacts, which need to be deleted. Every row is a period with artefacts. Default is NULL. (dataframe)

freq

Frequency of recorded data, in Hz. Default is 1000. (numeric)

fast

Select if you want the data to aggregated resulting in a faster, but perhaps more imprecise run, in Hz. Default is 50 (numeric)

raw_data

Select TRUE if the data is raw and cyclic mean should be calculated. NB: this function have not been validated, why validated methods for calculating cyclic mean are preferred. Only 1 period can be analysed using raw_data. Default is FALSE (boolian)

interpolation

Select the number of beats which should be interpolated. Default is up to 3 beats and 0 results in no interpolation. (numeric)

output

Select what the output should be. 'table' results in a dataframe with values for the three frequencies defined by Claassen et al. [1]; 'long' results in a dataframe with the results in a long format; 'plot' results in a daframe which can help plot gain, phase and coherence; 'plot-peak' results in a dataframe, which can be used to validate the cyclic average, and 'raw' results in a nested list with results primarily for debugging. Default is 'table'. (string)

vlf, lf, hf, detrend, spectral_smoothing, coherence2_thresholds

See TFA-parameters

apply_coherence2_threshold, remove_negative_phase

See TFA-parameters

remove_negative_phase_f_cutoff, normalize_ABP

See TFA-parameters

normalize_CBFV, window_type, window_length, overlap

See TFA-parameters

overlap_adjust, na_as_mean

See TFA-parameters

Details

Using a continuous raw recording, TFA() calculates dynamic cerebral autoregulation trough a transfer function analysis. This function utilizes the recommendations from Claassen et al [1] and mimicks the matlab script created by David Simpsons in 2015.

View(data)
time abp mcav
7.00 78 45
7.01 78 46
... ... ...
301.82 82 70
301.83 81 69

To calculate the variables insert the data and select the relevant variables.

TFA(df=data, variables=c("abp","mcav"))

See Value for output description.

Value

TFA() returns a dataframe depending on the output selected. 'table' results in a dataframe with values for the three frequencies defined by Claassen et al. [1]; 'long' results in a dataframe with the results in a long format; 'plot' results in a daframe which can help plot gain, phase and coherence; 'plot-peak' results in a dataframe, which can be used to validate the cyclic average, and 'raw' results in a nested list with results primarily for debugging.

Some generic variables are listed below:

  • abp_power - The blood pressure power measured in mmHg^2.

  • cbfv_power - The cerebral blood flow velocity power measured in cm^2\*s^-2

  • coherence - Coherence.

  • gain_not_normal - Not normalized gain measured in cm\*s^-1\*mmHg^-1.

  • gain_normal - Normalized gain measured in %\*mmHg^-1.

  • phase - Phase measured in radians.

output = 'table'

Wide format output table with period, VLF, LF, and HF as columns, and the TFA-variables as rows.

period variable vlf lf hf
1 abp_power 6.25 1.56 0.21
1 cbfv_power 3.22 2.25 0.30
... ... ... ... ...
3 gain_normal 1.04 1.48 1.85
3 phase 53.0 25.4 9.38

output = 'long'

Long format output table which can be manipulated depending on the intended use, with period, interval, variables and values as columns.

period interval variable values
1 hf abp_power 6.25
1 hf cbfv_power 3.22
... ... ... ...
2 vlf gain_norm 1.85
2 vlf phase 9.38

output = 'plot'

Plot format output table which can be used to draw figures with gain, phase and coherence depending on frequency.

period freq gain phase coherence
1 0.00 0.16 0.00 0.04
1 0.01 0.29 4.22 0.29
... ... ... ... ...
2 1.55 1.15 -43.2 0.64
2 1.56 1.16 -41.1 0.42

TFA-paramters

A series of parameters that control TFA analysis (window-length, frequency bands …). If this is not provided, default values, corresponding to those recommended in the white paper, will be used. These default values are given below for each parameter.

  • vlf Limits of very low frequency band (in Hz). This corresponds to the matematical inclusion of ⁠[X:Y[⁠. Default is c(0.02-0.07).

  • lf Limits of low frequency band (in Hz). This corresponds to the matematical inclusion of ⁠[X:Y[⁠. Default is c(0.07-0.2).

  • hf Limits of high frequency band (in Hz). This corresponds to the matematical inclusion of ⁠[X:Y[⁠. Default is c(0.2-0.5).

  • detrend Linear detrending of data prior to TFA-analysis (detrending is carried out as one continuous trend over the whole length of the recording, not segment-by-segment). Default is FALSE.

  • spectral_smoothing The length, in samples, of the triangular spectral smoothing function. Note that this must be an odd number, to ensure that smoothing is symmetrical around the centre frequency. Default is 3.

  • coherence2_thresholds The critical values (alpha=5%, second column) for coherence for a number of windows (first column, here from 3 to 15). These values were obtained by Monte Carlo simulation, using the default parameter settings for the TFA-analysis (Hanning window, overlap of 50% and 3-point spectral smoothing was assumed). These values should be recalculated for different settings. Note that if overlap_adjust=TRUE, the overlap will vary depending on the length of data. With an overlap of 60% (see below), the critical values increase by between 0.04 (for 3 windows) and 0.02 (for 15 windows). Default is ⁠cbind(c(3:15),c(0.51,0.40,⁠ ⁠0.34,0.29,0.25,0.22,0.20,0.18,0.17,⁠ ⁠0.15,0.14,0.13,0.12))⁠.

  • apply_coherence2_threshold Apply the thresholds given above to the TFA-estimates. All frequencies with magnitude-squared coherence below the threshold value are excluded from averaging when calculating the mean values of gain and phase across the bands. Note that low values of coherence are not excluded in the average of coherence across the bands. Default is TRUE.

  • remove_negative_phase Remove (ignore) negative values of phase in averaging across bands. Negative phase values are removed only for frequencies below the frequency given below, when calculating the average phase in bands. Default is TRUE.

  • remove_negative_phase_f_cutoff The cut-off frequency below-which negative phase values are neglected (only if remove_negative_phase is TRUE). Default is 0.1.

  • normalize_ABP Normalize ABP by dividing by the mean and multiplying by 100, to express ABP change in %. Note that mean-values are always removed from ABP prior to analysis. Default is FALSE.

  • normalize_CBFV Normalize CBFV by dividing by the mean and multiplying by 100, to express CBFV change in %. Note that the band-average values of gain are always calculated both with and without normalization of CBFV, in accordance with the recommendations. Note also that mean-values are always removed from CBFV prior to analysis. Default is FALSE.

  • window_type Chose window 'hanning' or 'boxcar'. Default is 'hanning'.

  • window_length Length of the data-window, in seconds. Default is 102.4.

  • overlap Overlap of the windows, in %. If overlap_adjust is TRUE (see below), then this value may be automatically reduced, to ensure that windows cover the full length of data. Default is ⁠59.99%⁠ rather than 60%, so that with data corresponding to 5 windows of 100 s at an overlap of 50%, 5 windows are indeed chosen.

  • overlap_adjust Ensure that the full length of data is used (i.e. the last window finishes as near as possible to the end of the recording), by adjusting the overlap up to a maximum value given by params.overlap. Default is TRUE.

  • na_as_mean Changes all missing non-interpolated values to the mean value of the corresponding variable. This have not been adressed in the paper by Claassen, and to ensure the dataframes are not 'gathered' this should generate the most stable results. Default is TRUE.

References

  1. Claassen et al. (2016) J Cereb Blood Flow Metab. 2016 Apr;36(4):665-80. (PubMed)

Examples

data(tfa_sample_data)
TFA(tfa_sample_data[,c(1:3)], variables=c("abp","mcav"), freq=10)

TFA sample data

Description

Dataframe with data provided by Prof. Simpsons, with time (t), arterial blood pressure (abp), left MCAv (mcav_l), right MCAv (mcav_r), and end-tidal CO2 (etco2).

Usage

data(tfa_sample_data)

Format

An object of class "dataframe"; an example of the usage in TFA-function.

Source

GitHub

References

Examples

data(tfa_sample_data)
TFA(tfa_sample_data[,c(1:3)], variables=c("abp","mcav"), freq=10)

TFA sample data - 1

Description

Dataframe with data provided by Prof. Simpsons, with time (t), arterial blood pressure (abp), left MCAv (mcav_l), right MCAv (mcav_r), and end-tidal CO2 (etco2).

Usage

data(tfa_sample_data)

Format

An object of class "dataframe"; an example of the usage in TFA-function.

Source

GitHub

References

Examples

data(tfa_sample_data)
TFA(tfa_sample_data_1[,c(1:3)], variables=c("abp","mcav"), freq=10)

TFA sample data - 2

Description

Dataframe with data provided by Prof. Simpsons, with time (t), arterial blood pressure (abp), left MCAv (mcav_l), right MCAv (mcav_r), and end-tidal CO2 (etco2).

Usage

data(tfa_sample_data)

Format

An object of class "dataframe"; an example of the usage in TFA-function.

Source

GitHub

References

Examples

data(tfa_sample_data)
TFA(tfa_sample_data_2[,c(1:3)], variables=c("abp","mcav"), freq=10)