Patient preferences for reducing toxicities of treatments for gastrointestinal stromal tumor (GIST)

Abstract

Purpose:To quantify gastrointestinal stromal tumor (GIST) patients’ preferences for reducing treatment toxicities and the likely effect of toxicities on patients’ stated adherence.Methods:English-speaking members of the Life Raft Group, a GIST patient advocacy and research organization, aged 18 years and older, completed a web-enabled survey including a series of treatment-choice questions, each presenting a pair of hypothetical GIST medication toxicity profiles. Each profile was defined by common or concerning toxicities verified via pretest interviews including: severity of edema, diarrhea, nausea, fatigue, rash, hand-foot syndrome, and heart failure; and risk of serious infection. Each subject answered 13 choice-format questions based on a predetermined experimental design with known statistical properties. Subjects were asked to rate the likelihood that they would miss or skip doses of medications with different toxicity profiles. Random-parameters logit was used to estimate a relative preference weight for each level of toxicity.Results:173 subjects completed the survey. Over the ranges of toxicity levels included in the study, heart failure was the most important toxicity. Edema was the least important. For all toxicities, reducing severity from severe to moderate was more important to subjects than reducing severity from moderate to mild. Reducing heart failure from moderate to mild and diarrhea from severe to moderate had the largest effects on subjects’ evaluation of adherence.Conclusions:All toxicities included in the study are important to patients. Treating or reducing severe toxicities is much more important to patients than treating or reducing moderate toxicities. Focused reductions of certain toxicities may improve treatment adherence.

Effect of pill burden on dosing preferences, willingness to pay, and likely adherence among patients with type 2 diabetes

“…When out-of-pocket cost is included as a medication attribute in a DCE, the results can be used to calculate the value of or willingness-to-pay (WTP) for improvements in medication attributes 16–18. DCEs have also been used to elicit patients’ ratings of the effect of medication attributes on likely medication adherence 19–22…”

Treatment preference, adherence and outcomes in patients with cancer: literature review and development of a theoretical model

“…These 18 publications consisted of: four retrospective reviews of patient records; four RCTs; four literature reviews; two randomized cross-over trials; two longitudinal observations studies; one web-based survey; and one qualitative in-depth interview study ( Table 2, I-VII, respectively 6,7,9,10,12,[16][17][18][19][20][21][22][23][24][25][26][27][28] ). Adherence to oral treatments was described in 12 studies, compared with IV treatments in nine studies (Table 2 6,7,9,10,12,[16][17][18][19][20][21][22][23][24][25][26][27][28]. Six articles reported solely on treatment in the adjuvant setting 7,12,16,17,20,21 and four articles reported solely on treatment in the metastatic setting 9,10,…”

“…This variable was modified by the experience of AEs and mode of treatment administration 9,10,12,23,24,27 . Adherence behavior also has a direct relationship to clinical outcome and HRQoL in the model.…”

“…Socio-demographic factors included age, gender, ethnicity and employment status (issues possibly related to employment status, such as education or insurance were not specified in the reviewed literature). Within the literature review, there was conflicting evidence for whether these variables were predictors for patient preference, adherence and outcome 6,7,12,16,18,23 . Therefore, due to these inconsistencies, socio-demographic variables were not included in the theoretical model.…”

“…In particular, AEs had a strong relationship with adherence; many studies cited AEs as possible contributing factors to non-adherence 9,10,12,[17][18][19][20][21][22][23][24][25]27,28 (Table 2) 6,7,9,10,12,[16][17][18][19][20][21][22][23][24][25][26][27][28] . Patient beliefs and values were identified as having a moderating effect on adherence; described in 6 of the 18 studies (Table 2) 6,7,9,10,12,[16][17][18][19][20][21][22][23][24][25][26]…”