Data pooling and analysis to build a preliminary item bank: an example using bowel function in prostate cancer

Area of Science:

• Oncology
• Psychometrics

Background:

• Prostate cancer treatments can significantly impact patients' quality of life, particularly bowel function.
• Accurate assessment of bowel function is crucial for understanding treatment trade-offs and patient-reported outcomes.

Purpose of the Study:

• To identify and validate the core components of bowel function commonly assessed in prostate cancer studies.
• To lay the groundwork for a comprehensive item bank for clinical and research use in prostate cancer survivorship.

Main Methods:

• Analysis of six archived datasets comprising 4,246 men with prostate cancer.
• Psychometric evaluation and Item Response Theory (IRT) analysis of 31 items from validated instruments.
• Classification of items into domains: diarrhea, rectal urgency, pain, bleeding, bother/distress, and other.

Main Results:

• Four components of bowel function demonstrated adequate psychometric properties: diarrhea, rectal urgency, pain, and bother/distress.
• Four items showed inadequate fit to the IRT model, including items related to bleeding and bother/distress.
• One item assessing hemorrhoids was poorly correlated with other bowel function items.

Conclusions:

• Bowel function in prostate cancer can be reliably assessed through four core components: diarrhea, rectal urgency, pain, and bother/distress.
• These validated components form a basis for developing robust patient-reported outcome measures in prostate cancer care.