PHQ-D

The questionnaire PHQ-D

The health questionnaire for patients (short PHQ-D from English Patient Health Questionnaire ) is an instrument of psychological diagnostics , it serves as a test procedure for recording the severity of mental disorders or the success of treatment. The PHQ-D is used in clinical practice, research and epidemiology. It is available in different versions, for example as a complete version with 78 items , in short form with, for example, 15 items in the module on the severity of somatic symptoms or in the ultra-short form for depression with two items (PHQ-15 & PHQ-2).

The questions about the individual disorders were derived from the diagnostic criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders ( DSM-IV ). However, there is also a high degree of compatibility with the currently conceived criteria for the DSM-5. The American Psychiatric Association (APA) recommends scales of the PHQ in the concept of DSM-5 for measuring the severity of disorders in the areas of anxiety, depression and somatization.

Origin and dissemination of the PHQ

The complete version and short forms of the PHQ-D are the authorized German versions of the international instrument family of the "Patient Health Questionnaire (PHQ)". These originally American self-assessment instruments are further developments of the so-called "PRIME MD (Primary Care Evaluation of Mental Disorders)", the first Instrument was designed to detect certain mental illnesses in patients by querying the diagnostic criteria of the DSM-IV. While the original PRIME-MD was carried out in two stages - a short questionnaire for self-assessment by the patient, followed by a semi-structured interview by the treating doctor - the further development of the PHQ is purely a self-assessment tool. The aim of this further development was to provide a more time-efficient screening instrument for use in clinical practice. Originally, the instrument was intended primarily for use in primary medicine; However, due to its relation to the diagnostic criteria, the instrument is broadly applicable and is therefore used in many areas of medicine, psychology and epidemiology. The "Health Questionnaire for Patients (PHQ-D)" was developed as a German version of the "Patient Health Questionnaire (PHQ)" by a working group around Bernd Löwe (then University of Heidelberg, now University of Hamburg) in cooperation with the authors of the original version. The translation was carried out according to state of the art criteria in several steps of translation and back translation.

Due to its brevity and simple evaluation, its good diagnostic test properties and its international availability, the PHQ has become a standard instrument for the diagnosis of mental syndromes in the USA, Great Britain and many other countries. The PHQ-9 , the depression module of the PHQ, exists in more than 30 languages and the full version of the PHQ is available in almost as many languages.

Structure of the PHQ-D

Complete version of the PHQ-D

The complete version of the PHQ-D consists of modules for recording somatoform disorders, depressive disorders, anxiety disorders, eating disorders and alcohol abuse. It also includes questions about psychosocial functioning, stressors, critical life events and - for women - menstruation, pregnancy and childbirth. The questionnaire comprises a total of 78 questions. Depending on the module, the degree of consent is queried on a two- to five-level response scale. Patients need about 10 minutes to process the four-sided complete version of the PHQ-D. The evaluation by the doctor takes less than two minutes.

Short form of PHQ-D

The short form of the PHQ-D covers depressive disorders, panic disorder and psychosocial functioning. Patients need about three minutes to process the one-sided short version of the PHQ-D. The evaluation by the doctor or psychotherapist is completed in less than a minute.

Ultra short form of the PHQ-D

Ultra-short forms of the PHQ-D exist for recording generalized anxiety ( GAD-2 ), depression ( PHQ-2 ) and for the combined recording of generalized anxiety and depression ( PHQ-4 ).

Composition of the individual modules of the PHQ-D

The individual modules of the complete PHQ-D or the short form can be put together flexibly.

The individual use of the module on depressive illnesses ( PHQ-9 ), the module on panic disorder ( PHQ panic module ), the module on generalized anxiety ( GAD-7 ), the module on the severity of somatic symptoms ( PHQ-15 ) and the module for stress assessment ( PHQ stress module ). The ( PHQ-SADS ) combines the module on depressive disorders (PHQ-9), the module on generalized anxiety (GAD-7) and the module on the severity of somatic symptoms (PHQ-15) into one instrument.

Areas of application of the PHQ-D

In its complete or short form, the PHQ-D can be used as a psychodiagnostic instrument in clinical practice, in epidemiological studies and in research. It is suitable for screening, measuring the degree of severity and assessing the course of mental disorders.

Evaluation of the PHQ-D

The PHQ-D in its complete and short form is based exclusively on the patient's own information. For this reason, the attending physician or psychologist must check the questionnaire diagnoses in a conversation with the patient to ensure that they are correct. It should be clarified whether the patient has correctly understood the questions of the PHQ-D. The practitioner should collect additional personal and / or external anamnestic information in order to increase the diagnostic reliability. Since the PHQ-D alone cannot collect all of the information that is necessary for a complete psychodiagnostics, it is primarily a diagnosis on the syndrome level, not on the disorder level. For example, the diagnosis of major depression according to DSM-IV (disorder level) - unlike the syndrome - requires the exclusion of a simple grief reaction, a history of a manic episode (bipolar disorder) and the exclusion of physical illnesses, medications or other drugs that contain a could be the biological cause of the depressive symptoms.

Screening

If the PHQ-D or its short forms are used as screening instruments in clinical practice (e.g. in primary care), these should be presented to all patients if possible. In this way, a screening of mental disorders is possible, which is independent of previous findings and enables the diagnosis of mental disorders in patients who were previously inconspicuous in this regard. It makes sense to only exclude those patients from the screening who, due to their physical condition, are not able to fill out the questionnaire or who have already completed the questionnaire within the last six months. If this procedure is not possible, only those patients who are suspected of having a mental disorder can be examined with the PHQ-D. The screening of populations at risk for which there is an increased a priori probability of mental disorders is to be regarded as particularly efficient; z. B. Patients with chronic somatic diseases.

Diagnostics based on the DSM-IV and DSM-V criteria

For three disorders of the DSM-IV, namely major depression, panic disorder and bulimia nervosa, all diagnostic criteria are recorded in the PHQ-D with one question each for the specific diagnosis according to DSM-IV. Based on the procedure for making a diagnosis in accordance with DSM-IV, these three modules of the PHQ-D can be categorically evaluated, that is, a specified number of symptoms in a certain form must have been ticked by the patient per section, so that the corresponding Syndrome is diagnosed. Instructions for the evaluation algorithms for the PHQ-D (both complete and short version) can be found here .

Severity and progress measurement (continuous / dimensional evaluation)

With 4 scales of the PHQ-D, the formation of a point value (score) to measure the degree of severity is possible. The scales are as follows:

Depression ( PHQ-9 )
Anxiety ( GAD-7 )
Somatization ( PHQ-15 )
Stress ( PHQ stress module )

In contrast to categorical diagnostics, with continuous diagnostics total values of the respective scales (modules) are calculated: Each answer option in the PHQ-D is assigned a numerical value, e.g. For example, in the depression module, the answer category “On more than half of the days” is assigned numerical value 2, the answer category “Not at all” 0. Depending on how the items are answered, different total values are calculated for the patients. These total values can be used as degrees of severity which, among other things, can also be used to diagnose the course of the disease (e.g. development of depressive symptoms in a patient during psychotherapy or comparison of the severity of the anxiety symptoms before and after psychotherapy).

Clinical Approach Recommendations

In primary care, it has proven to be efficient to hand over the questionnaire to all patients when they arrive at the practice or clinic and to have them filled out during the waiting period. Since the questionnaire can be evaluated quickly and easily, the diagnostic information can be taken up directly in the medical consultation and used for diagnosis and planning of further treatment. The doctor or psychologist can review the preliminary diagnosis of the PHQ in a conversation. In particular, further clinical information must be included in the decision on how to proceed and the further treatment of the patient. These clinical criteria include, for example:

Were the current symptoms triggered by psychosocial stressors?
How long has the current impairment existed and is the patient already receiving treatment for it?
To what extent is the patient's symptoms restricted in performing work and other activities?
Have there been similar episodes in the past and how were they treated?
Are there any similar cases in the family history?

Notes on usage authorization

The PHQ-D and its subscales are freely available and free of charge and can be used for non-commercial purposes without charge. When using the PHQ-D or a short form, the German version of the instrument must be quoted correctly when the data generated is published.

Test diagnostic properties of the PHQ-D

objectivity

The PHQ-D is standardized with regard to its implementation and evaluation and can be considered objective in this regard.

Criterion validity

The criterion validity of the German version of the PHQ-D was determined on a total of 528 patients (including 357 general medical patients and 171 psychosomatic patients) and with reference to the "Structured Clinical Interview for DSM-IV (SKID-I)" as the gold standard. Most of the scales showed excellent classification properties: The sensitivity of the questionnaire for diagnosing a mental disorder (axis I) is 85% (specificity = 70%) for psychosomatic patients and 77% (specificity = 83%) for medical patients and shows thus has good classification properties. The sensitivity for the diagnosis of the entire group of depressive disorders is 78% (psychosomatic patients) or 75% (medical patients), the specificity 70% (psychosomatic patients) and 90% (medical patients). For the diagnosis of major depression, the PHQ-D has a sensitivity of 78% (psychosomatic patients) or 86% (medical patients) and a corresponding sensitivity of 80% and 94%. The sensitivity for panic disorder in psychosomatic patients is 73% (specificity of 92%), in medical patients likewise 73% (specificity of 98%).

Criterion validity compared to other instruments

In direct comparison with established instruments, the PHQ-D showed significantly better classification properties with regard to the diagnosis of major depression according to DSM-IV, with regard to the diagnosis of depressive episodes according to ICD-10 and with regard to the diagnosis of panic disorder.

Construct validity

Patients diagnosed with a psychological syndrome using PHQ-D had significantly more visits to the doctor, were also more severely psychosocially impaired and more than twice as likely to be unable to work as patients who were not diagnosed according to PHQ-D with a psychological syndrome.

Reliability

According to Cronbach, the internal consistency for continuous scales is = 0.88 for the depression module and = .79 for the somatization module. The test-retest reliability of the depression module lies between ICC = 0.81 and ICC = 0.96. ${\ displaystyle \ alpha \,}$ ${\ displaystyle \ alpha \,}$

acceptance

In the German validation study, 96% of the patients and 97% of the doctors rated the use of the PHQ-D as useful. In addition, 94% of patients and 73% of doctors believed that using the PHQ-D would have beneficial effects on therapy.

literature

B. Löwe, RL Spitzer, S. Zipfel, W. Herzog: Health questionnaire for patients (PHQ D). Complete version and short form. Test folder with manual, questionnaires, templates. 2nd Edition. Pfizer, Karlsruhe 2002.

Footnotes

↑ B. Löwe, RL Spitzer, S. Zipfel, W. Herzog: Health questionnaire for patients (PHQ D). Complete version and short form. Test folder with manual, questionnaires, templates. 2nd Edition. Pfizer, Karlsruhe 2002.
↑ Patient Health Questionaire (PHQ-D) in Dorsch - Lexicon of Psychology . Retrieved October 3, 2019.
^ RL Spitzer, K. Kroenke, JB Williams: Validation and utility of a self-report version of PRIME-MD: The PHQ primary care study. In: JAMA. 282, 1999, pp. 1737-1744.
↑ ^a ^b ^c ^d ^e ^f ^g ^h K. Gräfe, S. Zipfel, W. Herzog, B. Löwe: Screening of mental disorders with the "Health questionnaire for patients (PHQ-D). Results of the German validation study. In: Diagnostica. 50 , 2004, pp. 171-181.
↑ ^a ^b B. Löwe, RL Spitzer, K. Gräfe, K. Kroenke, A. Quenter, S. Zipfel et al .: Comparative validity of three screening questionnaires for DSM-IV depressive disorders and physicians' diagnoses. In: J Affect Disord. 78 (2), 2004, pp. 131-140.
^ B. Löwe, K. Gräfe, S. Zipfel, S. Witte, B. Loerch, W. Herzog: Diagnosing ICD-10 depressive episodes: superior criterion validity of the Patient Health Questionnaire. In: Psychother Psychosom. 73 (6), 2004, pp. 386-390.
^ B. Löwe, K. Gräfe, S. Zipfel, RL Spitzer, C. Herrmann-Lingen, S. Witte: Detecting panic disorder in medical and psychosomatic outpatients: Comparative validation of the Hospital Anxiety and Depression Scale, the Patient Health Questionnaire, a screening question, and physicians' diagnosis. In: J Psychosom Res. 55 (6), 2003, pp. 515-519.

[1] B. Löwe, RL Spitzer, S. Zipfel, W. Herzog: Health questionnaire for patients (PHQ D). Complete version and short form. Test folder with manual, questionnaires, templates. 2nd Edition. Pfizer, Karlsruhe 2002.

[dorsch-2] Patient Health Questionaire (PHQ-D) in Dorsch - Lexicon of Psychology . Retrieved October 3, 2019.

[3] RL Spitzer, K. Kroenke, JB Williams: Validation and utility of a self-report version of PRIME-MD: The PHQ primary care study. In: JAMA. 282, 1999, pp. 1737-1744.

[Grafe-4] ↑ ^a ^b ^c ^d ^e ^f ^g ^h K. Gräfe, S. Zipfel, W. Herzog, B. Löwe: Screening of mental disorders with the "Health questionnaire for patients (PHQ-D). Results of the German validation study. In: Diagnostica. 50 , 2004, pp. 171-181.

[Lowe-5] B. Löwe, RL Spitzer, K. Gräfe, K. Kroenke, A. Quenter, S. Zipfel et al .: Comparative validity of three screening questionnaires for DSM-IV depressive disorders and physicians' diagnoses. In: J Affect Disord. 78 (2), 2004, pp. 131-140.

[6] B. Löwe, K. Gräfe, S. Zipfel, S. Witte, B. Loerch, W. Herzog: Diagnosing ICD-10 depressive episodes: superior criterion validity of the Patient Health Questionnaire. In: Psychother Psychosom. 73 (6), 2004, pp. 386-390.

[7] B. Löwe, K. Gräfe, S. Zipfel, RL Spitzer, C. Herrmann-Lingen, S. Witte: Detecting panic disorder in medical and psychosomatic outpatients: Comparative validation of the Hospital Anxiety and Depression Scale, the Patient Health Questionnaire, a screening question, and physicians' diagnosis. In: J Psychosom Res. 55 (6), 2003, pp. 515-519.