A processed subsample of the Patient Health Questionnaire 9-item (PHQ-9) depression screener from the U.S. National Health and Nutrition Examination Survey (NHANES), September 2024 release. Six hundred respondents were drawn at random from the cycle's PHQ-9 module subject to having complete responses on all nine items, while retaining a realistic share of respondents with a sum-score of zero (n = 8) so that floor behaviour can be illustrated in a Rasch analysis.
Format
A data frame with 600 rows and 12 variables:
- q1
Little interest or pleasure in doing things. Integer 0–3.
- q2
Feeling down, depressed, or hopeless. Integer 0–3.
- q3
Trouble falling/staying asleep, or sleeping too much. Integer 0–3.
- q4
Feeling tired or having little energy. Integer 0–3.
- q5
Poor appetite or overeating. Integer 0–3.
- q6
Feeling bad about yourself — or that you are a failure or have let yourself or your family down. Integer 0–3.
- q7
Trouble concentrating on things, such as reading the newspaper or watching television. Integer 0–3.
- q8
Moving or speaking so slowly that other people could have noticed — or the opposite, being so fidgety or restless that you have been moving around a lot more than usual. Integer 0–3.
- q9
Thoughts that you would be better off dead, or of hurting yourself in some way. Integer 0–3.
- gender
Self-reported gender, factor with levels
"Female"and"Male"(31 respondents with missing values).- age
Age in years (integer, range 15–85).
- edu
Highest educational attainment, factor with levels
"Elementary School","High school","University".
Each PHQ-9 item uses a four-point ordinal response scale, scored
0 ("Not at all"), 1 ("Several days"), 2 ("More than half the days") and 3 ("Nearly every day").
Source
U.S. Centers for Disease Control and Prevention, National Center for Health Statistics. National Health and Nutrition Examination Survey, September 2024 release. https://wwwn.cdc.gov/nchs/nhanes/search/datapage.aspx?Component=Questionnaire&CycleBeginYear=2024. NHANES data are released to the public domain by the U.S. federal government (https://www.cdc.gov/nchs/policy/data-release-policy.html).
Details
The dataset is a processed subsample intended for teaching and for the package's worked example; it should not be treated as a canonical NHANES microdata file. Users wishing to validate against NCHS-published figures should download the original public-use microdata directly from the NHANES website (see Source).
References
Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606–613. doi:10.1046/j.1525-1497.2001.016009606.x
Examples
data(phq9)
str(phq9)
#> 'data.frame': 600 obs. of 12 variables:
#> $ q1 : int 3 0 1 2 3 3 1 3 2 1 ...
#> $ q2 : int 3 0 2 3 3 3 1 3 2 0 ...
#> $ q3 : int 3 1 3 0 3 1 0 3 2 0 ...
#> $ q4 : int 3 1 3 2 3 3 1 3 2 0 ...
#> $ q5 : int 3 0 3 2 3 2 0 1 2 0 ...
#> $ q6 : int 3 2 3 2 3 2 2 3 3 0 ...
#> $ q7 : int 3 3 3 2 3 2 2 3 3 0 ...
#> $ q8 : int 1 0 2 0 3 3 0 0 1 0 ...
#> $ q9 : int 3 0 0 2 3 1 2 0 0 0 ...
#> $ gender: Factor w/ 2 levels "Female","Male": 1 1 1 2 2 2 2 1 2 1 ...
#> $ age : int 29 43 22 44 48 60 31 48 47 25 ...
#> $ edu : Factor w/ 3 levels "Elementary School",..: 2 3 3 3 2 2 3 3 3 3 ...
summary(rowSums(phq9[, 1:9]))
#> Min. 1st Qu. Median Mean 3rd Qu. Max.
#> 0.00 10.00 16.00 15.41 21.00 27.00