The effects of distance from primary treatment centers on survival among patients with multiple myeloma.

Twenty-one comprehensive cancer centers participated in a national reporting system of common data items, recording information on all patients seen between 1977 and 1982. There were 240,531 patients who had data abstracted. This report describes 1,479 patients with multiple myeloma. Parameters that may effect the type of treatment given during the initial episode of therapy in the center and the effect of these characteristics on survival were studied. In the univariate analysis, age, treatment, and distance traveled to the center were statistically associated with survival. In a multivariate analysis adjusting for potentially confounding covariates, blacks survive better than whites and the effects of sex and socioeconomic status (SES) on survival approach significance. Survival consistently improved with increasing distance traveled to treatment centers. This may be a serious confounding variable in assessing the results by both single and multiinstitution clinical trials.