Symptoms of Multiple Myeloma: Results of Hybrid Concept Elicitation/Cognitive Debriefing Interviews

Aims:

Multiple myeloma (MM) is a malignant plasma cell disease that is characterized by clonal proliferation of plasma cells in the bone marrow and the production of excessive amounts of a monoclonal immunoglobulin (usually of the IgG or IgA type or free urinary light chain [paraprotein, M protein, or M-component]). Hallmark symptoms of MM include bone disease, which contributes to pain, and anemia, which manifests itself as tiredness and fatigue. Recently, we developed a new MM Symptom Scale based on a systematic literature review and previously conducted qualitative interviews with MM patients. The instrument presents a set of symptoms and evaluates their frequency and severity over the last seven days. In this study, we conducted one-on-one interviews with third-line plus relapsed or refractory (RR) MM patients to: (1) elicit and confirm key disease symptoms that patients describe in response to MM using open-ended questions; and (2) assess the clarity, understanding, and content validity of the newly-developed draft MM Symptom Scale.

Methods:

Third-line plus RR MM patients were recruited for one-on-one interviews in San Diego, CA and Fort Lauderdale, FL. All participants had to be adult, symptomatic RR MM patients who had previously been treated with an immunomodulary drug and a proteasome inhibitor. They also had to have evidence of disease progression or be currently on treatment to qualify for the study.

The first half of the interview focused on open-ended questions regarding important symptoms that patients had experienced. In the second half of the interview, the MM Symptom Scale was introduced, the patient completed the scale in a think-aloud cognitive-debriefing interview, and each question was evaluated for clarity and understanding.

Results:

A total of nine patients participated in the hybrid interviews of whom four were female and five were male. The average age of the participants was 61.6 years. The average severity of MM symptoms across the nine participants was 6.2 on a scale of 1-10. The average report of the worst level of pain experienced in the last week was 5.2 on a scale of 1-10. The average report on the worst level of tiredness experienced in the last week was 6.2 on a scale of 1-10. The most frequently-reported symptoms were pain (specifically back pain) and tiredness (100% of participants). Other commonly-reported symptoms include swelling of the extremities, itching, feeling depressed, and diarrhea.

During the cognitive-debriefing portion of the interview, most participants did not find difficulty in understanding any of the items. Some symptoms, however, were deemed not particularly relevant for the nine MM patients. For example, all of the nine MM patients believed that the symptoms “loss of bladder control” and “loss of bowel control” did not apply to them. These and other symptoms will be evaluated more closely for potential exclusion from the MM Symptom Scale. Some symptoms – such as neuropathy, sleep difficulty, constipation, and weight gain − were endorsed by at least three patients and will be considered for inclusion in the MM Symptom Scale.

Conclusions:

Health-related quality of life (HRQoL) in MM patients is characterized largely by the burden of pain and tiredness in addition to a few other key symptoms. These can be reliably and validly quantified using HRQoL instruments. The MM Symptom Scale is currently being refined to provide a standardized way through which clinician investigators can assess the impact of novel treatments on patients’ HRQoL.