scoring_phq9: Scoring the PHQ-9 questionnaire

In nrkoehler/qscorer: Procedures for Scoring Health-related Questionnaires

Description

The PHQ-9 (PHQ-D in some sources) is the 9-question depression scale from the Patient Health Questionnaire (PHQ). The results of the PHQ-9 may be used to make a depression diagnosis according to DSM-IV criteria. (see: Wikipedia)

Usage

scoring_phq9(data, items = 1:9, keep = TRUE, nvalid = 6, digits = NULL)

Arguments

data	a data.frame containing the PHQ-9 items orderd from 1 to 9. The data.frame may contain further variables.
items	A character vector with the PHQ-9 item names ordered from 1 to 9, or a numeric vector indicating the column numbers of the PHQ-9 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 numeric value indicating the number of non-missing items required for score calculations. The default is 7.
digits	Integer of length one: value to round to. No rounding by default.

Details

• Number of items: 9

• Item range: 0 to 3

• Reverse items: none

• Score range: 0 to 27

• Cut-off-values: < 5 = "minimal"; 5 to 9 = "mild"; 10 to 15 = "moderate"; 15 to 19 = "moderately severe", ≥ 20 = "severe"

• Minimal clinically important difference: none

• Treatment of missing values: Questionnaires with up to two missing values are scored, replacing any missing values with the average score of the completed items. (Arrietta et al. 2017)

Value

The function returns 3 variables:

• nvalid.phq9: Number of valid values (MAX=9)

• score.phq9: PHQ-9 score

• cutoff.phq9: PHQ-9 as categorical variable

References

Arrieta et al. (2017) (https://doi.org/10.1002/jclp.22390)

Kroenke et al. (2010) (https://doi.org/10.1016/j.genhosppsych.2010.03.006)

Examples

## Not run: 
library(dplyr)
items.phq9 <- paste0("phq_", seq(1, 9, 1))
scoring_phq9(mydata, items = items.phq9)

## End(Not run)

nrkoehler/qscorer documentation built on April 5, 2020, 3:09 a.m.