Interpersonal Values of Patients Participating in Phase II-III Clinical Trials: Implications for Clinical Trial Representativeness.

Background: An individual's personal values strongly influence their immediate and long-term decisions. Psychological heterogeneity in clinical trial populations contributes to selection bias and may affect treatment outcomes and inevitably trial results.

Objectives: The objective of this study was to characterize for the first time the main interpersonal values of patients who participated in Phase II and III clinical trials.

Methods: This multicenter observational study included 200 participants from 4 different hospitals who participated in a Phase II or III clinical trial. Patients from different therapeutic areas were included in this study. The patients' interpersonal values were studied using the Survey of Interpersonal Values (SIV). The SIV scale is grouped into six subscales that assess specific personal values: (1) support, the need to be treated with kindness and to receive encouragement from other people; (2) conformity, the extent to which one does what is acceptable and considered socially correct; (3) recognition, the need to be highly regarded and admired, to be considered important and recognized by others; (4) independence, the extent to which individuals feel free to make their own decisions; (5) benevolence, the capacity to understand and show generosity towards the less fortunate; and (6) leadership, the value ascribed to coordinating the work of others, being selected for a leadership position, and being in a position to tell others what to do. The results obtained from the patient population were classified using the following categories: "very high" (P95-P99), "high" (P70-90), "medium" (P35-65) low" (P10-30), or "very low" (P1-5), and subsequently compared with those of the Portuguese normative population.

Results: Compared with the normative population, regardless of the patient's underlying disease, the percentile frequency distributions were significantly higher for the independence (p < 0.001) and benevolence (p < 0.001) subscales, and significantly lower for the leadership (p < 0.001) and recognition (p < 0.001) subscales in the patient population. Patient distribution according to underlying disease differed significantly relative differences in distribution relative to the normative population for the majority of subscales. Non-alcoholic steatohepatitis (NASH), heart failure, myocardial infarction, lung cancer, and rheumatoid arthritis patients were those for which the greatest differences were observed across diseases, while stroke, multiple sclerosis, and HIV patients showed the least differences relative to the normative population.

Conclusions: This novel analysis of the interpersonal values of patients that participate in Phase II and III clinical trials revealed that the patients' interpersonal values largely differed from those of the Portuguese normative population. Better understanding the implications of these findings for clinical trial representativeness and outcomes is of crucial importance.