A draft version of a 10-item patient-reported outcome (PRO) questionnaire has been developed to evaluate the impact of immune thrombocytopenia (ITP) on patients and assist in shared decision-making between patients and physicians. Results from a recent study led by Nichola Cooper, MD, of Imperial College London in the U.K., confirmed the content validity of the ITP Life Quality Index (ILQI). These findings also suggest the concepts assessed using the PRO are relative to and understood by most patients with ITP.
Dr. Cooper and colleagues conducted a qualitative telephone interview with 15 adult patients with ITP. The interview, which featured concept elicitation and cognitive debriefing portions, explored ITP symptoms and the impact these symptoms had on patients and sought to confirm the ILQI content validity.
The concept elicitation phase focused on broad, open-ended questions to gain information on ITP symptoms, the impacts of these symptoms, and the treatments used for ITP. Focused questions followed to investigate other concepts, including the impact ITP had on patients’ emotional well-being and social lives.
Additionally, the cognitive debriefing phase of the interview asked patients to complete the ILQI using a “think-aloud” exercise, in which they speak aloud their thoughts while reading the questionnaire’s instructions and select a response for each item. Researchers asked patients detailed questions about their understanding and the relevance of each ILQI item, instruction, and answer options. Patient feedback on the draft’s wording and suggestions for alternative terminology were also requested.
The mean age of patients interviewed was 51.3 years, and the majority were white (n=14) and female (n=10). An ITP diagnosis was made at a mean age of 40.9 years, with a mean disease duration of 10 years. Nine patients reported that it took several months after presentation to be diagnosed with ITP.
During the concept elicitation phase, the participants reported 13 symptom concepts, including bruising (100%), fatigue (93.3%), and bleeding from gums/blood blisters (86.7%). Several impacts of ITP were also reported by patients, including decreased or complete lack of ability to participate in sports (100%), anxiety (80%), and the need to avoid non-sporting activities (73.3%).
In the cognitive debriefing phase, all patients said they understood the ILQI instructions. The researchers noted that the clear instructions enabled patients to complete the ILQI independently.
While the draft ILQI featured a one-week recall period, 86.7% of participants said this period was not appropriate, given that the patients’ experiences with ITP did not change weekly, nor were the activities listed in the PRO measure consistently practiced each week. Therefore, the researchers increased the recall period for the ILQI to “the past month.”
More than half of patients with ITP (66.7%) said the draft response options were appropriate, but 33.5% suggested changes to response options. These changes, as suggested by participants, included changing to a 0 to 10 numeric rating scale for each item, changing “more than half the time” to “half the time,” and eliminating “more than half the time.”
Limitations of this study included the small sample size as well as the inclusion of mostly white participants from the U.K. As a result, these findings may not be generalizable to the wider ITP population.
Despite these limitations, “[we hope] that cross-cultural implementation of the ILQI will lead to more consistency of treatment in clinical practice and better outcomes for patients with ITP,” the authors wrote.
Researchers reported relationships with Novartis, which funded the study.
Cooper N, Cuker A, Bonner N, et al. Qualitative study to support the content validity of the immune thrombocytopenia (ITP) Life Quality Index (ILQI). Br J Haematol. 2021;194:759-766.