Meaningful cut-off pain intensity for breakthrough pain changes in advanced cancer patients

To assess the level of pain intensity at which patients feel the impetus to ask for a breakthrough cancer pain (BTcP) medication, and level of pain intensity at which patients consider they have achieved acceptable pain control after receiving a BTcP medication.

A consecutive sample of patients who were receiving oral morphine equivalents equal to or more than 60 mg daily, and were prescribed rapid onset opioids for the management of episodes of BTcP, were included in the study. Focused educational activities regarding BTcP and numerical scales were established during hospital admission. At discharge patients were interviewed to find out what was the pain intensity level which gave the impetus to take the BTcP medication, what was the pain intensity for acceptable pain control after a BTcP medication had been given, and which factors prevented the patient calling for BTcP medication. A brief COPE (coping orientation to problems experienced) questionnaire was also administered.

Fifty-two patients were recruited for this study. The meaningful pain intensity for asking for a BTcP medication was 7.1; 77% of patients had a pain intensity of 7-8 on a numerical scale of 0-10. The meaningful pain intensity for adequate analgesia after a BTcP medication was 3.5. Similarly, 77% of patients had a pain intensity of 3-4. There was no relationship with the variables examined. Concerns by patients about the use of BTcP medications were minimal.

The meaningful BTcP intensity and pain intensity expected after BTcP medication can be useful in selecting patients in studies of BTcP. The principal limitation of this study was the specific setting of an acute unit with specific features and the relatively low number of patients. This observation should be followed up by further surveys with a larger number of patients and different settings.