| convert.threshold.to.er {behaviorchange} | R Documentation |
Visualising Numbers Needed for Change
Description
These functions can be used to visualise Numbers Needed for Change (or
Numbers Needed to Treat).
erDataSeq is a helper function to generate an Event Rate Data
Sequence, and it uses convert.threshold.to.er and
convert.er.to.threshold to convert thresholds to event rates and vice
versa.
Usage
convert.threshold.to.er(
threshold,
mean,
sd,
eventIfHigher = TRUE,
pdist = stats::pnorm
)
convert.er.to.threshold(
er,
mean,
sd,
eventIfHigher = TRUE,
qdist = stats::qnorm
)
erDataSeq(
er = NULL,
threshold = NULL,
mean = NULL,
sd = NULL,
eventIfHigher = TRUE,
pRange = c(1e-06, 0.99999),
xStep = 0.01
)
ggNNC(
cerDataSeq,
d = NULL,
eventDesirable = TRUE,
r = 1,
xlab = "Continuous outcome",
plotTitle = c("Numbers Needed for Change = ", ""),
theme = ggplot2::theme_bw(),
lineSize = 1,
cerColor = "#EBF2F8",
eerColor = "#172F47",
cerLineColor = "#888888",
eerLineColor = "#000000",
dArrowColor = "#000000",
cerAlpha = 0.66,
eerAlpha = 0.66,
xLim = NULL,
xLimAutoDensityTolerance = 0.001,
showLegend = TRUE,
verticalLineColor = "#172F47",
desirableColor = "#00FF00",
desirableAlpha = 0.2,
undesirableColor = "#FF0000",
undesirableAlpha = 0.2,
desirableTextColor = "#009900",
undesirableTextColor = "#990000",
dArrowDistance = 0.04 * max(cerDataSeq$density),
dLabelDistance = 0.08 * max(cerDataSeq$density)
)
Arguments
threshold |
If the event rate is not available, a threshold value can
be specified instead, which is then used in conjunction with the mean
( |
mean |
The mean of the control group distribution. |
sd |
The standard deviation (of the control distribution, but assumed to be the same for both distributions). |
eventIfHigher |
Whether scores above or below the threshold are considered 'an event'. |
pdist, qdist |
Distributions to use when converting thresholds to event rates and vice versa; defaults to the normal distribution. |
er |
Event rate to visualise (or convert). |
pRange |
The range of probabilities for which to so the distribution. |
xStep |
Precision of the drawn distribution; higher values mean lower precision/granularity/resolution. |
cerDataSeq |
The |
d |
The value of Cohen's d. |
eventDesirable |
Whether an event is desirable or undesirable. |
r |
The correlation between the determinant and behavior (for mediated NNC's). |
xlab |
The label to display for the X axis. |
plotTitle |
The title of the plot; either one character value, this value if used; if two, they are considered a prefix and suffix to be pre/appended to the NNC value. |
theme |
The theme to use for the plot. |
lineSize |
The thickness of the lines in the plot. |
cerColor |
The color to use for the event rate portion of the control group distribution. |
eerColor |
The color to use for the event rate portion of the experimental group distribution. |
cerLineColor |
The line color to use for the control group distribution. |
eerLineColor |
The line color to use for the experimental group distribution. |
dArrowColor |
The color of the arrow to show the effect size. |
cerAlpha |
The alpha value (transparency) to use for the control group distribution. |
eerAlpha |
The alpha value (transparency) to use for the control group distribution. |
xLim |
This can be used to manually specify the limits for the X axis;
if |
xLimAutoDensityTolerance |
If |
showLegend |
Whether to show the legend (only if showing two distributions). |
verticalLineColor |
The color of the vertical line used to indicate the threshold. |
desirableColor |
The color for the desirable portion of the X axis. |
desirableAlpha |
The alpha for the desirable portion of the X axis. |
undesirableColor |
The color for the undesirable portion of the X axis. |
undesirableAlpha |
The color for the undesirable portion of the X axis. |
desirableTextColor |
The color for the text to indicate the desirable portion of the X axis. |
undesirableTextColor |
The color for the text to indicate the undesirable portion of the X axis. |
dArrowDistance |
The distance of the effect size arrow from the top of the distributions. |
dLabelDistance |
The distance of the effect size label from the top of the distributions. |
Details
These functions are used by nnc() to show the distributions, and
event rates. They probably won't be used much on their own.
Value
erDataSeq returns a data sequence; ggNNC a
ggplot2::ggplot().
Author(s)
Gjalt-Jorn Peters & Stefan Gruijters
Maintainer: Gjalt-Jorn Peters gjalt-jorn@userfriendlyscience.com
References
Gruijters, S. L., & Peters, G. Y. (2019). Gauging the impact of behavior change interventions: A tutorial on the Numbers Needed to Treat. PsyArXiv. doi:10.31234/osf.io/2bau7
See Also
Examples
### Show distribution for an event rate value of 125
behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125, mean=90, sd=30));
### If the event occurs under the threshold instead of
### above it
behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125,
mean=90, sd=30,
eventIfHigher = FALSE));
### ... And for undesirable events (note how
### desirability is an argument for ggNNC, whereas
### whether an event occurs 'above' or 'below' the
### threshold is an argument for erDataSeq):
behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125,
mean=90, sd=30,
eventIfHigher = FALSE),
eventDesirable = FALSE);
### Show event rate for both experimental and
### control conditions, and show the numbers
### needed for change
behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125,
mean=90, sd=30),
d=.5);
### Illustration of how even with very large effect
### sizes, if the control event rate is very high,
### you'll still need a high number of NNC
behaviorchange::ggNNC(behaviorchange::erDataSeq(er=.9),
d=1);