Selection bias in clinical trials.

作者：Karen Hamm Antman, Dante Amato, W. C. Wood, John M. Carson, Herman D. Suit, Karl H. Proppe, Robert W. Carey, Joel S. Greenberger, Renée F Wilson, Emil Frei · 发表于：Journal of Clinical Oncology · 年份：1985 · DOI：10.1200/jco.1985.3.8.1142 · 被引用次数：151 · 研究领域：Statistical Methods in Clinical Trials、Pharmaceutical studies and practices、Sarcoma Diagnosis and Treatment

Of 90 patients with intermediate or high-grade sarcoma eligible for a randomized trial of adjuvant doxorubicin (Adriamycin, Adria Laboratories, Columbus, Ohio), 48 were not entered: 24 (27%) by physician's choice and 24 refused randomization. Sixty-five percent of lower stage patients were randomized compared with 37% of those with higher stage (P = .02). Patients with extremity lesions were more frequently offered participation in the study (P = .07). Patients with lower stage lesions accepted randomization more readily than those with higher stage lesions (P = .01). As predicted by the higher stage and percentage of central lesions, the disease-free survival of nonrandomized patients was inferior to that of randomized patients (P = .15). Thus, patients at high risk appeared to avoid randomization and adjuvant doxorubicin in this trial, resulting in an inferior disease-free survival for the nonrandomized control group. Important questions generally require randomized trials that reliably determine relative treatment differences. If, however, the patients in a clinical trial are not representative of the entire patient population because of patient and physician selection biases, the generalizability of the results to the entire patient population may be compromised. For example, the prognosis of the general population cannot necessarily be inferred from the selected group in the study. In this study, the randomized and nonrandomized series yielded differing conclusions regar...