What is the recommended use of Patient Health Questionnaire 9 (PHQ9) in an outpatient oncology setting?

From the Guidelines

The Patient Health Questionnaire 9 (PHQ-9) is recommended as a routine screening tool for depression in outpatient oncology settings, ideally administered at initial consultation, at critical treatment transitions, and at regular intervals throughout cancer care, with a recommended cutoff score of 8 for further clinical assessment, as suggested by the most recent guideline update 1.

Key Recommendations

• The PHQ-9 should be used to identify patients experiencing depressive symptoms, with scores of 8 or higher warranting further clinical assessment.
• Implementation should include clear protocols for follow-up care when positive screens occur, including referral pathways to mental health professionals.
• Oncology teams should be trained to sensitively discuss mental health concerns, recognize that some somatic symptoms on the questionnaire may overlap with cancer symptoms, and ensure that positive screens lead to appropriate interventions ranging from supportive care to psychiatric consultation depending on severity.

Rationale

• The high prevalence of depression in cancer patients (estimated at 20-30%) often goes undetected and untreated, and regular screening is particularly important as depression can negatively impact treatment adherence, quality of life, and potentially survival outcomes.
• The PHQ-9 is a valid and reliable measure that features reportable scores (dimensions) that are clinically meaningful, and its use is supported by the American Society of Clinical Oncology guideline adaptation 1.
• A phased screening and assessment approach is recommended, starting with the identification of pertinent history or risk factors, followed by the use of two items from the PHQ-9 to assess for classic depressive symptoms, and then completing the remaining items for patients who endorse either item as occurring for more than half of the time or nearly every day within the last 2 weeks.

Considerations

• Special circumstances in the assessment of depressive symptoms should be considered, including the use of culturally sensitive assessments and treatments, tailoring assessment or treatment for those with learning disabilities or cognitive impairments, and being aware of the difficulty of detecting depression in the older adult.
• The assessment should identify signs and symptoms of depression, the severity of cancer symptoms, possible stressors, risk factors, and times of vulnerability, and should be a shared responsibility of the clinical team.

From the Research

Recommended Use of PHQ9 in Outpatient Oncology Setting

The Patient Health Questionnaire 9 (PHQ9) is a widely used tool for screening depression in various settings, including outpatient oncology. The recommended use of PHQ9 in this setting is as follows:

• Screening for Depression: The PHQ9 can be used to screen for depression in cancer patients, with a high prevalence of depression reported in this population 2, 3, 4, 5.
• Administration: The PHQ9 can be administered on a touch screen computer, which has been shown to be feasible and provide valid depression data in a diverse cancer population 4.
• Scoring and Interpretation: The PHQ9 scores can be used to assess the severity of depression, with higher scores indicating more severe depression 2, 5.
• Monitoring Progress: The PHQ9 can be used to monitor progress in patients with depression, allowing for adjustments to treatment as needed 6.
• Combination with Other Tools: The PHQ9 can be used in combination with other tools, such as the PHQ-2, to increase its specificity and prevent under-diagnosis 6.

Considerations for Use in Outpatient Oncology Setting

When using the PHQ9 in an outpatient oncology setting, the following considerations should be taken into account:

• Somatic Items: The somatic items on the PHQ9 may be less discriminatory than the non-somatic items, but may still be useful as a screening mechanism for identifying at-risk cancer patients with mild/moderate depression 3.
• Fatigue: Fatigue is a common symptom in cancer patients, and may be reflected in the PHQ9 scores, particularly in item 4 2.
• Suicidal Ideation: The PHQ9 includes an item assessing suicidal ideation, which is an important consideration in cancer patients 2.
• Referral to Mental Health Services: Patients with positive PHQ9 screens should be referred to mental health services, although this may not always be accepted by the patient 2.

Evidence for Use in Outpatient Oncology Setting

The use of the PHQ9 in an outpatient oncology setting is supported by several studies, including:

• A pilot study that validated the use of the PHQ-2 and PHQ-9 in a busy outpatient practice 2.
• A study that examined the diagnostic accuracy of somatic versus cognitive-emotional PHQ-9 items in cancer patients 3.
• A study that evaluated the feasibility and construct validity of the PHQ-9 administered on a touch screen computer in a diverse cancer population 4.
• A study that psychometrically tested the PHQ-9 in a large sample of cancer patients and calculated unbiased estimates of the depression burden for several cancer groups 5.