scan (version 0.64.0)

rci: Reliable change index

Description

The rci() function computes indices of reliable change (Wise, 2004) and corresponding descriptive statistics.

Usage

rci(data, dvar, pvar, rel, ci = 0.95, graph = FALSE, phases = c(1, 2))

Arguments

data

A single-case data frame. See scdf() to learn about this format.

dvar

Character string with the name of the dependent variable. Defaults to the attributes in the scdf file.

pvar

Character string with the name of the phase variable. Defaults to the attributes in the scdf file.

rel

Reliability of the measure, used to compute the standard error.

ci

Width of confidence interval as a decimal. Default is ci = 0.95 applying a 95 percent confidence interval.

graph

If set TRUE, a box plot of phase A and B scores is displayed. graph = FALSE by default.

phases

A vector of two characters or numbers indicating the two phases that should be compared. E.g., phases = c("A","C") or phases = c(2,4) for comparing the second to the fourth phase. Phases could be combined by providing a list with two elements. E.g., phases = list(A = c(1,3), B = c(2,4)) will compare phases 1 and 3 (as A) against 2 and 4 (as B). Default is phases = c(1,2).

Author

Juergen Wilbert

References

Christensen, L., & Mendoza, J. L. (1986). A method of assessing change in a single subject: An alteration of the RC index. Behavior Therapy, 17, 305-308.

Jacobson, N. S., & Truax, P. (1991). Clinical Significance: A statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59, 12-19.

Wise, E. A. (2004). Methods for analyzing psychotherapy outcomes: A review of clinical significance, reliable change, and recommendations for future directions. Journal of Personality Assessment, 82, 50 - 59.

Examples

## Report the RCIs of the first case from the byHeart data and include a graph
rci(byHeart2011[1], graph = TRUE, rel = 0.8)