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Generate CFA syntax for anchor reliability

Source: R/tr_reliability_model.R
tr_reliability_model.Rd

tr_reliability_model() generates lavaan syntax for estimating the reliability of an anchor or transition rating item using confirmatory factor analysis.

Usage

tr_reliability_model(
  data,
  anchor = NULL,
  xsec = FALSE,
  pair_by = c("position", "suffix"),
  t1_suffix = NULL,
  t2_suffix = NULL,
  factor_names = NULL,
  print_model = TRUE
)

Arguments

data

A data frame containing items and an anchor variable.

anchor

Character. Name of the anchor variable. If NULL, the final column of data is treated as the anchor.

xsec

Logical. If TRUE, generate a cross-sectional one-factor model. If FALSE, generate a longitudinal two-factor model.

pair_by

Pairing method for longitudinal data. "position" assumes Time 1 items followed by Time 2 items. "suffix" detects pairs using t1_suffix and t2_suffix.

t1_suffix

Regex suffix identifying Time 1 items when pair_by = "suffix". Use "" when Time 1 items have no suffix.

t2_suffix

Regex suffix identifying Time 2 items when pair_by = "suffix".

factor_names

Optional character vector of factor name(s). If NULL, defaults to "F1" when xsec = TRUE, and c("F1", "F2") when xsec = FALSE.

print_model

Logical. If TRUE, print the generated lavaan syntax.

Value

An object of class tr_reliability_model. The lavaan syntax can be accessed using $model.

Details

The generated model follows the approach described by Griffiths et al. J Clin Epidemiol. 2022;141:36-45. No constraints are placed on loadings or thresholds. For longitudinal data, residuals of corresponding items across time-points are allowed to correlate to account for item non-independence.

For cross-sectional data, a one-factor model is generated. For longitudinal data, a two-factor model is generated, with the anchor loading on both Time 1 and Time 2 factors.

Examples

set.seed(123)
sim <- simdat(N = 200)
dat <- sim$datw

tr_reliability_model(
  data = dat[, c(sim$item_names$t1_items,
                 sim$item_names$t2_items,
                 "trat")],
  anchor = "trat",
  xsec = FALSE,
  pair_by = "suffix",
  t1_suffix = "",
  t2_suffix = "\\.1"
)
#> 
#> ================ ANCHOR RELIABILITY CFA MODEL ================
#> 
#> 
#> # Factors
#> F1 =~ item1 + item2 + item3 + item4 + item5 + item6 + item7 + item8 + item9 + item10 + trat
#> F2 =~ item1.1 + item2.1 + item3.1 + item4.1 + item5.1 + item6.1 + item7.1 + item8.1 + item9.1 + item10.1 + trat
#> 
#> # Correlated errors over time
#> item1 ~~ item1.1
#> item2 ~~ item2.1
#> item3 ~~ item3.1
#> item4 ~~ item4.1
#> item5 ~~ item5.1
#> item6 ~~ item6.1
#> item7 ~~ item7.1
#> item8 ~~ item8.1
#> item9 ~~ item9.1
#> item10 ~~ item10.1
#> 
#> ===============================================================