Evaluating the “Good Death” Concept from Iranian Bereaved Family

(e.g., cancer pain, fibromyalgia, neuropathic pain, and
joint diseases). 6
The BPI-SF includes two domains: pain severity and pain
interference. The pain severity domain, the focus of this
report, includes items specific to pain at “worst,” “least,”
“average,” and “now” (current pain), with a numerical response
scale ranging from 0 (no pain) to 10 (pain as bad as
you can imagine). In clinical trials, the worst pain item has
been used alone as a measure of pain severity. 6 Its use as a
single item is supported by a consensus panel on outcome
measures for chronic pain clinical trials. 7 In addition, the
Food and Drug Administration’s (FDA) guidance on PROs
states that a single-item PRO measure of pain severity is
appropriate for assessing the effect of a treatment on pain. 8
Although extensive psychometric evaluation of the BPI-SF
has been conducted, no estimates of the MID are available
for the BPI-SF worst pain item. Establishing the MID for
the BPI-SF worst pain item is important because it will
provide a clinically relevant reference to interpret changes
in pain scores. Therefore, the objective of this current
report was to estimate the MID of the worst pain item of
the BPI-SF.
Methods
STUDY DESIGN
Patients with advanced breast cancer and bone metastases
were enrolled in an international, randomized, double-blind,
double-dummy, active-controlled phase III study comparing
denosumab with zoledronic acid for delaying or preventing
skeletal related events. Patients were eligible to participate if
they had histologically or cytologically confirmed breast adenocarcinoma;
current or prior radiologic, computed tomography,
or magnetic resonance imaging evidence of at least one
bone metastasis; and an Eastern Cooperative Oncology Group
(ECOG) performance status of 0, 1, or 2. Patients with current
or prior intravenous bisphosphonate administration were
excluded. Patients completed PRO assessments, including the
BPI-SF, at baseline, week 5, and every 4 weeks thereafter until
the end of the study. Assessments were scheduled to take
place prior to any study procedures and prior to study drug
administration. Although data collection continued, PRO
analyses for efficacy were truncated when approximately 30%
of patients dropped out of the study due to death, disease
progression, or withdrawn consent.
OUTCOME MEASURES AND ASSESSMENT INTERVALS
A number of outcome measures were assessed in the study
and considered for use as anchors for evaluating the MID of
the BPI-SF worst pain item, including one clinician-reported
measure (ECOG Performance Status) and several PRO measures:
the EuroQoL 5 Dimensions (EQ-5D) Index score, the
Functional Assessment of Cancer Therapy-Breast Cancer
(FACT-B), and the BPI-SF current pain rating.
The ECOG Performance Status, which assesses how a
patient’s disease or its treatment is progressing and how the
disease affects the daily living abilities of the patient, is a
Mathias et al
single-item, six-point, clinician-rated assessment of performance
ranging from 0 (fully active, no restrictions) to 5
(dead). 9 The EQ-5D Index score is a measure of health status,
which assesses five dimensions: mobility, self-care, usual activities,
pain/discomfort, and anxiety/depression. Each dimension
is comprised of three response options: no problems,
some/moderate problems, and extreme problems. Responses
are converted to a weighted health state index, with scores
ranging from �0.594 (worst health) to 1.0 (full health). The
single item on pain from the EQ-5D was also evaluated
separately as an anchor. The FACT-B includes the four core
FACT-General (FACT-G) dimensions of physical well-being,
social/family well-being, emotional well-being, and functional
well-being, for which scale scores and a total score can
be computed. In addition, the FACT-B includes a breast
cancer–specific subscale. 10 The FACT-B Trial Outcome Index
(TOI) is the sum of the physical well-being score, the
functional well-being score, and the breast cancer subscale.
The four FACT-G scale scores, the FACT-G total score, the
FACT-B TOI, and a single-item overall quality-of-life (QOL)
rating from the functional well-being section were all evaluated
as potential anchors. The single-item overall QOL item
from the functional well-being scale was selected to balance
out the single item on pain that was selected from the EQ-5D,
by serving as a more general potential anchor in breadth and
scope. For all of these FACT outcome measures, a higher
score indicates better health-related QOL. Finally, the current
pain rating from the BPI-SF, ranging from 0 (no pain) to
10 (pain as bad as you can imagine), was also considered as an
anchor because it was hypothesized to be highly correlated
with the worst pain rating and because it would assist in
understanding the behavior of other potential anchors.
Several assessment intervals were considered for evaluation
of the MID for the BPI-SF worst pain item: baseline to
week 5, baseline to week 13, and baseline to week 25. The
analysis for each time interval included only those patients
with complete baseline and end-of-interval (i.e., week 5,
week 13, or week 25) assessments on the BPI-SF worst pain
item and the relevant anchor of interest. In addition, a post
hoc confirmatory analysis was conducted using a longer interval
of time, from baseline to week 49. No imputation of
missing data was performed. Analysis was performed on
pooled data, regardless of treatment assignment.
ANCHOR-BASED ANALYSIS
The usefulness of an anchor depends on the correlation
of the PRO change score and the anchor. 11 Therefore, to
select the most appropriate anchors and time interval for estimating
the MID for the BPI-SF worst pain item, Spearman
correlation coefficients were calculated between changes in
the BPI-SF worst pain rating and changes in potential anchors
across each of the potential time intervals. The time interval
with the highest correlations and the anchors with statistically
significant (P � 0.05) a priori specified correlations above 0.30
were selected for inclusion in the MID analysis. 12
VOLUME 9, NUMBER 1 � JANUARY/FEBRUARY 2011 www.SupportiveOncology.net 73