Patient Health Questionnaire – 4 (PHQ-4)¶
Summary
The Patient Health Questionnaire-4 (PHQ-4) is an ultra-brief screening instrument to assess the two leading symptoms of a depression and anxiety (Kroenke et al., 2009). It is included in the SOEP in its original form in 2016 and since 2019 at two-year intervals.
Theoretical Background
The Patient Health Questionnaire-4 (PHQ-4) is an ultra-brief screening instrument to assess the two leading symptoms of a depression and anxiety. It was developed and validated by Kroenke et al. (2009) to account for the fact that those two mental disorders are the most prevalent mental disorders in the general population, both are often comorbid, and patients that are affected by either or both of the disorders often lack the concentration to fill in long and detailed questionnaires. The PHQ-4 consists of four items that can be answered on a four-point Likert-type scale (0 = not at all, 1 = several days, 2 = more than half days, 3 = nearly every day). Two items measure the core symptoms of depression and form the PHQ-2 subscale of the PHQ-4. Two items measure the core symptoms of anxiety and form the GAD-2 subscale of the PHQ-4. Both subscales have independently been shown to be good brief screening tools. The total PHQ–4 score complements the subscale scores as an overall measure of symptom burden, as well as functional impairment and disability. An elevated PHQ–4 score is not diagnostic, but is, instead, an indicator for further inquiry to establish the presence or absence of a clinical disorder warranting treatment.
Scale Development
The two-item PHQ-2 measures anhedonia (“little interest or pleasure in doing things”) and depressed mood (“Feeling down, depressed or hopeless”) over the past two weeks. The final sum score of both item ranges from 0 to 6. Scores of 3 and above indicate a depressive disorder with a sensitivity of 79 % and a specificity of 86 %. The two-item GAD-2 measures general irritability (“feeling nervous, anxious, or on edge”) and worries (“not being able to stop or control worrying”) over the past two weeks. The GAD-2 final sum scores also range from 0 to 6. A cutoff of 3 has reasonable sensitivity for generalized anxiety disorder (88%), panic disorder (76%), and social anxiety disorder (70%), and moderate sensitivity for posttraumatic stress disorder (59%), and good specificity (81%– 83%) for all four disorders. The SOEP has included the PHQ-4 with both subscales in its original form. It has been included since 2016 at two- or three-year intervals. So far it has been assessed in 2016, 2019, and 2021. In addition, it has been assessed in both soep-cov survey waves.
References
Arroll B, Goodyear-smith F, Crengle S, et al. (2010). Validation of PHQ-2 and PHQ-9 to screen for major depression in the primary care population. Annals of Family Medicine, 8, 4, 348-53.
Kroenke K, Spitzer RL, Williams JB. (2003). The Patient Health Questionnaire-2: validity of a two-item depression screener. Medical Care, 1284-1292.
Kroenke, K., Spitzer, R. L., Williams, J. B. W., Löwe, B. (2009) An ultra-brief screening scale for anxiety and depression: the PHQ-4. Psychosomatics, 50, 613-21.
Löwe, B., Wahl, I., Rose, M., Spitzer, C., Glaesmer, H., Wingenfeld, K., … & Brähler, E. (2010). A 4-item measure of depression and anxiety: validation and standardization of the Patient Health Questionnaire-4 (PHQ-4) in the general population. Journal of affective disorders, 122(1-2), 86-95.
Items
Over the last two weeks, how often have you been bothered by any if the following problems? (Jetzt geht es um die letzten zwei Wochen. Wie oft fühlten Sie sich da durch die folgenden Beschwerden beeinträchtigt?)
Little interest or pleasure in doing things / Wenig Interesse oder Freude an Ihren Tätigkeiten (PAQ-2)
Feeling down, depressed, or hopeless / Niedergeschlagenheit, Schwermut oder Hoffnungslosigkeit (PAQ-2)
Feeling nervous, anxious, or on edge / Nervosität, Ängstlichkeit oder Anspannung. (GAD-2)
Unable to stop or control worrying / Nicht in der Lage sein, Sorgen zu stoppen oder zu kontrollieren. (GAD-2)
Answers: 1 = not at all (überhaupt nicht), 2 = several days (an einzelnen Tagen), 3 = more than half days (an mehr als der Hälfte der Tage), 4 = nearly every day ((fast) jeden Tag); Items need to be recoded to 0 to 3 instead of 1 to 4.
Items and Scale Statistics
year |
variable |
count |
mean |
sd |
itemrestcorr |
alpha |
|---|---|---|---|---|---|---|
2016 |
plh0339 |
28550 |
1.71 |
0.74 |
0.51 |
0.80 |
2016 |
plh0340 |
28678 |
1.53 |
0.74 |
0.70 |
0.80 |
2016 |
plh0341 |
28720 |
1.66 |
0.75 |
0.63 |
0.80 |
2016 |
plh0342 |
28585 |
1.45 |
0.73 |
0.64 |
0.80 |
2019 |
plh0339 |
29339 |
1.61 |
0.76 |
0.56 |
0.82 |
2019 |
plh0340 |
29450 |
1.43 |
0.71 |
0.72 |
0.82 |
2019 |
plh0341 |
29462 |
1.51 |
0.72 |
0.65 |
0.82 |
2019 |
plh0342 |
29412 |
1.32 |
0.65 |
0.65 |
0.82 |