oecalc {metamisc}R Documentation

Calculate the total O:E ratio

Description

This function calculates (transformed versions of) the ratio of total number of observed versus expected events with the corresponding sampling variance.

Usage

oecalc(OE, OE.se, OE.cilb, OE.ciub, OE.cilv, EO, EO.se, citl, citl.se, N, O, E,
  Po, Po.se, Pe, data, slab, add = 1/2, g = NULL, level = 0.95, ...)

Arguments

OE

vector with the estimated ratio of total observed versus total expected events

OE.se

vector with the standard errors of the estimated O:E ratios

OE.cilb

vector to specify the lower limits of the confidence interval for OE.

OE.ciub

vector to specify the upper limits of the confidence interval for OE.

OE.cilv

vector to specify the levels of aformentioned confidence interval limits. (default: 0.95, which corresponds to the 95% confidence interval).

EO

vector with the estimated ratio of total expected versus total observed events

EO.se

vector with the standard errors of the estimated E:O ratios

citl

vector with the estimated calibration-in-the-large statistics

citl.se

vector with the standard error of the calibration-in-the-large statistics

N

vector to specify the sample/group sizes.

O

vector to specify the total number of observed events.

E

vector to specify the total number of expected events

Po

vector to specify the (cumulative) observed event probabilities.

Po.se

vector with the standard errors of Po.

Pe

vector to specify the (cumulative) expected event probabilites (if specified, during time t.val)

data

optional data frame containing the variables given to the arguments above.

slab

optional vector with labels for the studies.

add

a non-negative number indicating the amount to add to zero counts. See ‘Details’

g

a quoted string that is the function to transform estimates of the total O:E ratio; see the details below.

level

level for confidence interval, default 0.95.

...

Additional arguments.

Value

An array with the following columns:

"theta"

The (transformed) O:E ratio.

"theta.se"

Standard errors of the (transformed) O:E ratio.

"theta.cilb"

Lower confidence interval of the (transformed) O:E ratios. The level is specified in level. Intervals are calculated on the same scale as theta by assuming a Normal distribution.

"theta.ciub"

Upper confidence interval of the (transformed) c-statistics. The level is specified in level. Intervals are calculated on the same scale as theta by assuming a Normal distribution.

"theta.source"

Method used for calculating the (transformed) O:E ratio.

"theta.se.source"

Method used for calculating the standard error of the (transformed) O:E ratio.

Author(s)

Thomas Debray <thomas.debray@gmail.com>

References

Debray TPA, Damen JAAG, Snell KIE, Ensor J, Hooft L, Reitsma JB, et al. A guide to systematic review and meta-analysis of prediction model performance. BMJ. 2017;356:i6460.

Debray TPA, Damen JAAG, Riley R, Snell KIE, Reitsma JB, Hooft L, et al. A framework for meta-analysis of prediction model studies with binary and time-to-event outcomes. Stat Methods Med Res. 2018; In press.

Snell KI, Ensor J, Debray TP, Moons KG, Riley RD. Meta-analysis of prediction model performance across multiple studies: Which scale helps ensure between-study normality for the C -statistic and calibration measures? Statistical Methods in Medical Research. 2017.

Examples

######### Validation of prediction models with a binary outcome #########
data(EuroSCORE)

# Calculate the total O:E ratio and its standard error
oecalc(O=n.events, E=e.events, N=n, data=EuroSCORE, slab=Study)

# Calculate the log of the total O:E ratio and its standard error
oecalc(O=n.events, E=e.events, N=n, data=EuroSCORE, slab=Study, g="log(OE)")


[Package metamisc version 1.0.0 Index]