Purpose: This report describes interventions undertaken by the National Surgical Adjuvant Breast and Bowel Project (NSABP) to improve compliance with patient-reported outcome (PRO) assessments in the setting of multicenter cancer clinical trials. We describe the effectiveness of several interventions and of observational factors.
Methods: PRO submission rates were analyzed for the following three NSABP protocols: the Study of Raloxifene and Tamoxifen (STAR), B-32, and B-35. Institutions participating in protocol B-35 were randomly assigned to receive automated reminders of upcoming assessments or not. Compliance was analyzed with a logistic repeated measures mixed modeling.
Results: Compliance was high in the three protocols, with rates greater than 80% for nearly all time points. Institutions were a significant source of variability (P < .01). The largest institutions had the highest compliance in STAR (odds ratio [OR] = 0.68 for < 50 participants enrolled and OR = 0.82 for 50 to 99 participants enrolled v larger institutions; P < .001). Midsized institutions had highest compliance in B-32 (OR = 4.63 for 31 to 50 patients enrolled and OR = 3.12 for > 50 patients enrolled v small institutions; P = .007). Compliance increased with participant age in STAR (OR = 0.57, 0.89, and 1.01 for ages < 50, 50 to 60, and 60 to 70 years, respectively, v > 70 years; P < .001). Race was significant in B-32 (OR = 2.63 for white v nonwhite; P < .001) and in STAR (OR = 1.41 for white v nonwhite; P < .001). Treatment group was significant in B-32 (OR = 0.74; P = .006). The B-35 prospective reminder did not improve compliance significantly (P = .30), but in B-32, delinquency sanctions were significant (OR = 1.56; P = .007).
Conclusion: Compliance in NSABP PRO studies is higher now than a decade ago. Results for compliance initiatives were mixed. Age and race are important factors, but institutional variation remains significant and largely unexplained.