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Estimate HiTOP-SR scale reliability

Source: R/reliability_hitopsr.R
reliability_hitopsr.Rd

Compute per-scale internal-consistency reliability — Cronbach's alpha and McDonald's omega — for the HiTOP Self-Report (405 items). Reliability is estimated on the reverse-keyed item responses for each of the scales that score_hitopsr() outputs.

Usage

reliability_hitopsr(
  data,
  items,
  srange = c(1, 4),
  alpha = TRUE,
  omega = TRUE,
  subset = NULL
)

Arguments

data

A data frame containing the HiTOP-SR items (numerically coded): all 405 of them, or, when subset is supplied, that short form's items.

items

A vector of column names (as strings) or numbers (as integers) corresponding to the HiTOP-SR items held in data — all 405, or, when subset is supplied, that short form's items. Items must be supplied in instrument order; duplicated entries are an error.

srange

An optional numeric vector specifying the minimum and maximum values of the HiTOP-SR items, used for reverse-coding. (default = c(1, 4))

alpha

Optional logical; if TRUE, include a column of Cronbach's alpha per scale. (default = TRUE)

omega

Optional logical; if TRUE, include a column of McDonald's omega (total) per scale, estimated via a one-factor CFA (requires the lavaan package). (default = TRUE)

subset

An optional hitop_subset object, as returned by hitop_subset(), describing a short form of the instrument. When supplied, data and items hold only that subset's item columns — in ascending instrument order, as the generate_*_hitopsr() forms lay them out — and one row is returned per subset scale. When NULL, all 405 items are expected and all 76 scales are estimated. (default = NULL)

Value

A tibble with one row per scale and columns scale, nItems, and (when requested) alpha and omega.

Details

Alpha is computed by calc_alpha() (covariance-based, pairwise deletion) and omega by calc_omega() (one-factor lavaan CFA, FIML). A scale whose estimate cannot be computed (e.g. too few items or, for omega, a non-converging CFA or an uninstalled lavaan) is returned as NA rather than aborting the call.

Examples

# Per-scale alpha for the HiTOP-SR
reliability_hitopsr(sim_hitopsr, items = 1:405, omega = FALSE)
#> # A tibble: 76 × 3
#>    scale                nItems    alpha
#>    <chr>                 <int>    <dbl>
#>  1 Agoraphobia               5 -0.108  
#>  2 Antisocial Behavior       8 -0.136  
#>  3 Appetite Loss             3  0.00603
#>  4 Binge Eating              3  0.0509 
#>  5 Bodily Distress           6  0.0879 
#>  6 Body Dissatisfaction      4 -0.0891 
#>  7 Body Focus                5 -0.0282 
#>  8 Callousness               6 -0.347  
#>  9 Checking                  5 -0.247  
#> 10 Cleaning                  6  0.174  
#> # ℹ 66 more rows

# Per-scale alpha for data collected with a two-scale short form. Select the
# item columns by name: `s$items` holds original HiTOP-SR numbers, which are
# column positions only in a data frame that is exactly the 405 items in order.
s <- hitop_subset("hitopsr", scales = c("Agoraphobia", "Appetite Loss"))
short <- sim_hitopsr[paste0("hsr_", s$items)]
reliability_hitopsr(short, items = names(short), subset = s, omega = FALSE)
#> # A tibble: 2 × 3
#>   scale         nItems    alpha
#>   <chr>          <int>    <dbl>
#> 1 Agoraphobia        5 -0.108  
#> 2 Appetite Loss      3  0.00603