The IWQOL is a self-report instrument specifically developed to assess the effect of obesity on quality-of-life. IWQOL-Lite is a short form containing 31 items. Scale scores are obtained by adding item scores, and the total score is obtained by adding scale scores. Higher scores indicate poorer quality of life. (Kolotin et al. 2001)

scoring_iwqoll(
  data,
  items = 1:31,
  keep = TRUE,
  nvalid = list(physical = 6, self = 4, sexual = 2, distress = 3, work = 2),
  digits = NULL
)

Arguments

data

a data.frame containing the IWQOL-Lite items orderd from 1 to 31. The data.frame may contain further variables.

items

A character vector with the IWQOL-Lite item names ordered from 1 to 31, or a numeric vector indicating the column numbers of the IWQOL-Lite items in data.

keep

Logical, whether to keep the single items and whether to return variables containing the number of non-missing items on each scale for each respondent. The default is TRUE.

nvalid

A named list indicating the number of non-missing items required for score calculations. The defaults are:

  • physical = 6 (Physical Function)

  • self = 4 (Self-esteem)

  • sexual = 2 (Sexual Life)

  • distress = 3 (Public Distress)

  • work = 2 (Work)

digits

Integer of length one: value to round to. No rounding by default.

Value

The function returns 12 variables:

  • nvalid.iwqol.pf: Number of valid values of Physical Function scale (MAX=11)

  • nvalid.iwqol.se: Number of valid values of Self-esteem scale (MAX=7)

  • nvalid.iwqol.sl: Number of valid values of Sexual Life scale (MAX=4)

  • nvalid.iwqol.pd: Number of valid values of Public Distress scale (MAX=5)

  • nvalid.iwqol.wo: Number of valid values of Work scale (MAX=4)

  • nvalid.iwqol.ts: Number of valid values of Total scale (MAX=31)

  • score.iwqol.pf: IWQOL Physical Function Score

  • score.iwqol.se: IWQOL Self-esteem Score

  • score.iwqol.sl: IWQOL Sexual Life Score

  • score.iwqol.pd: IWQOL Public Distress Score

  • score.iwqol.wo: IWQOL Work Score

  • score.iwqol.ts: IWQOL Total Score

Details

  • Number of items: 31

  • Item range: 1 to 5

  • Reverse items: none

  • Score range:

    • Physical Function 11 to 55

    • Self-esteem 7 to 35

    • Sexual Life 4 to 20

    • Public Distress 5 to 25

    • Work 4 to 20

    • Total Score 31 to 155

  • Cut-off-values: none

  • Minimal clinically important difference: none

  • Treatment of missing values: Number of valid items:

    • Physical Function 6 of 11

    • Self-esteem 4 of 7

    • Sexual Life 2 of 4

    • Public Distress 3 of 5

    • Work 2 of 4

    • Total Score 24 of 31

References

Kolotkin et al. 2001 (http://doi.wiley.com/10.1038/oby.2001.13)

Kolotkin et al. 2002 (https://doi.org/10.1023/a:1015081805439)

Examples

if (FALSE) { library(dplyr) items.iwqoll <- paste0("IWQOLL_", seq(1, 31, 1)) scoring_iwqoll(mydata, items = items.iwqoll) }