The change from baseline to approximately week 5 in the PASS total score. PASS asks participants to indicate how often they engage in each of the 40 thoughts or activities that represent anxiety symptoms on a scale of 0=never to 5=always. The total score has a range of 0-200.

Full analysis set

The change from baseline to approximately week 5 in the PASS subscale scores. PASS asks participants to indicate how often they engage in each of the 40 thoughts or activities that represent anxiety symptoms on a scale of 0=never to 5=always. Those 40 questions are organized into four subscales: fear, cognitive anxiety, somatic anxiety, and escape/avoidance. Each subscale score is obtained by summing the answers to the ten items in the subscore resulting in a range of 0-50.

Full analysis set

Change from baseline to endpoint (week 4 of Treatment period or last post baseline visit) in the Beck Depression Inventory (BDI). The BDI is a self-reporting instrument that asks 21 questions regarding how the participant felt in the past few days. Answers are in sentence form, and offer a scale where the first answer (worth 0 points) indicates no depression and the fourth answer (worth 3 points) indicates significant depression. Totals (0-63) are grouped so that totals of 1-10 are interpreted as 'These ups and downs are considered normal' and scores >40 indicate extreme depression.

Full analysis set of participants who answered the questions.

Change from baseline to endpoint (week 4 of Treatment period or last post baseline visit) in the Multidimensional Pain Inventory Subscales. Answers to questions in the MPI are captured on a 7-point scale, with 0=most positive answer and 6= least positive answer. Twenty questions focus on pain, fourteen on a significant other's response when participant is in pain, and eighteen questions about daily activities. There are a total of 13 subscales with variable ranges. Subscales and corresponding ranges are listed in the results table. The General Activity category combines the Household Chores, Outdoor Work, Activities Away from Home, and Social Activities categories.

Full analysis set

The summary question from the Pain Flare Treatment Satisfaction Questionnaire asked participants which medication they preferred to use for their break-through pain. Options were 1) Prior medication 2) Study medication 3) no preference

Full analysis set of participants who answered the questions.

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to go to work.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to perform at work and includes both work outside the home and housework.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to walk.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to exercise.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to participate in social events.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to have sex.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) participants completed the Patient Assessment of Function Scale which asks 7 questions about the effect of study treatment on the patient's ability to function. This question asks about the ability to enjoy life.

Full analysis set of participants who answered the question

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) investigators completed the Clinical Assessment of Patient Function Scale which asks 5 questions about the effect of study treatment on the patient's ability to function. This question asks about the patient's general activities.

Full analysis set

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) investigators completed the Clinical Assessment of Patient Function Scale which asks 5 questions about the effect of study treatment on the patient's ability to function. This question asks about the patient's walking ability.

Full analysis set. One participant was not assessed by the investigator.

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) investigators completed the Clinical Assessment of Patient Function Scale which asks 5 questions about the effect of study treatment on the patient's ability to function. This question asks about the patient's ability to work and perform activities of daily living.

Full analysis set

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) investigators completed the Clinical Assessment of Patient Function Scale which asks 5 questions about the effect of study treatment on the patient's ability to function. This question asks about the patient's relationship with others.

Full analysis set

At the endpoint of the study (week 4 of Treatment period or last post baseline visit) investigators completed the Clinical Assessment of Patient Function Scale which asks 5 questions about the effect of study treatment on the patient's ability to function. This question asks about the patient's enjoyment of life.

Full analysis set

During the dose titration period, participants self-administered FBT, starting at 100, 200 or 400 mcg (depending on analgesic used pre-study) and titrated to 600 and 800 mcg if needed. For each breakthrough pain (BTP) episode, participants took a dose, and did not take further study drug if adequate pain relief was achieved. If pain was not controlled within 30 minutes, the same dose level was repeated. If pain relief was inadequate 30 minutes after the second dose, usual rescue medication was taken for that BTP episode. Doses were adjusted until pain relief was adequate and side effects were tolerated. This outcome summarizes the successful dose levels identified during the titration period.

Safety analysis set