estimate_mdiff_paired {esci}

Estimates for a repeated-measures study with two measures of a continuous variable

Description

Returns object estimate_mdiff_paired is suitable for a simple paired design with a continuous outcome variable. It provides estimates and CIs for the population mean difference between the repeated measures, the standardized mean difference (SMD; Cohen's d) between the repeated measures, and the median difference between the repeated measures (raw data only). You can pass raw data or summary data.

Usage

estimate_mdiff_paired(
  data = NULL,
  comparison_measure = NULL,
  reference_measure = NULL,
  comparison_mean = NULL,
  comparison_sd = NULL,
  reference_mean = NULL,
  reference_sd = NULL,
  n = NULL,
  correlation = NULL,
  comparison_measure_name = "Comparison measure",
  reference_measure_name = "Reference measure",
  conf_level = 0.95,
  save_raw_data = TRUE
)

Arguments

data

For raw data - a data frame or tibble

comparison_measure

For raw data - The column name of comparison measure of the outcome variable, or a vector of numeric data

reference_measure

For raw data - The column name of the reference measure of the outcome variable, or a vector of numeric data

comparison_mean

For summary data, a numeric

comparison_sd

For summary data, numeric > 0

reference_mean

For summary data, a numeric

reference_sd

For summary data, numeric > 0

n

For summary data, a numeric integer > 0

correlation

For summary data, correlation between measures, a numeric that is > -1 and < 1

comparison_measure_name

For summary data - An optional character label for the comparison measure. Defaults to 'Comparison measure'

reference_measure_name

For summary data - An optional character label for the reference measure. Defaults to 'Reference measure'

conf_level

The confidence level for the confidence interval. Given in decimal form. Defaults to 0.95.

save_raw_data

For raw data; defaults to TRUE; set to FALSE to save memory by not returning raw data in estimate object

Details

Reach for this function in place of a paired-samples t-test.

Once you generate an estimate with this function, you can visualize it with plot_mdiff() and you can test hypotheses with test_mdiff().

The estimated mean differences are from statpsych::ci.mean.ps().

The estimated SMDs are from CI_smd_ind_contrast().

The estimated median differences are from statpsych::ci.median.ps().

Value

Returns object of class esci_estimate

• overview

  • outcome_variable_name -

  • mean -

  • mean_LL -

  • mean_UL -

  • median -

  • median_LL -

  • median_UL -

  • sd -

  • min -

  • max -

  • q1 -

  • q3 -

  • n -

  • missing -

  • df -

  • mean_SE -

  • median_SE -

• es_mean_difference

  • type -

  • comparison_measure_name -

  • reference_measure_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • SE -

  • df -

  • ta_LL -

  • ta_UL -

• es_smd

  • comparison_measure_name -

  • reference_measure_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • numerator -

  • denominator -

  • SE -

  • d_biased -

  • df -

• es_r

  • x_variable_name -

  • y_variable_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • SE -

  • n -

  • df -

  • ta_LL -

  • ta_UL -

• es_median_difference

  • type -

  • comparison_measure_name -

  • reference_measure_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • SE -

  • ta_LL -

  • ta_UL -

• es_mean_ratio

  • comparison_measure_name -

  • reference_measure_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • comparison_mean -

  • reference_mean -

• es_median_ratio

  • comparison_measure_name -

  • reference_measure_name -

  • effect -

  • effect_size -

  • LL -

  • UL -

  • comparison_median -

  • reference_median -

• raw_data

  • comparison_measure -

  • reference_measure -

Examples

# From raw data
data("data_thomason_1")

estimate_from_raw <- esci::estimate_mdiff_paired(
  data = esci::data_thomason_1,
  comparison_measure = Posttest,
  reference_measure = Pretest
)

# To visualize the estimated median difference (raw data only)
myplot_from_raw <- esci::plot_mdiff(estimate_from_raw, effect_size = "median")

# To conduct a hypothesis test
res_htest_from_raw <- esci::test_mdiff(
  estimate_from_raw,
  effect_size = "median",
  rope = c(-2, 2)
)


sd1 <- 4.28
sd2 <- 3.4
sdiff <- 2.13

cor <- (sd1^2 + sd2^2 - sdiff^2) / (2*sd1*sd2)

estimate_from_summary <- esci::estimate_mdiff_paired(
  comparison_mean = 14.25,
  comparison_sd = 4.28,
  reference_mean = 12.88,
  reference_sd = 3.4,
  n = 16,
  correlation = 0.87072223749,
  comparison_measure_name = "After",
  reference_measure_name = "Before"
)

# To visualize the estimated mean difference
myplot_from_summary <- esci::plot_mdiff(
  estimate_from_summary,
  effect_size = "mean"
)

# To conduct a hypothesis test
res_htest_from_summary <- esci::test_mdiff(
  estimate_from_summary,
  effect_size = "mean",
  rope = c(-2, 2)
)