How was the ECHOS-NHL study conducted?

This population-based SEER study was conducted in collaboration with researchers at the University of Southern California and the Los Angeles County Cancer Surveillance Program's SEER registry, which provided the sampling frame. Data were collected through a cross-sectional survey mailed to eligible survivors of aggressive NHL who were diagnosed 2-5 years before the study (diagnosis dates ranged from June 1, 1998 to August 31, 2001). The majority of the surveys were mailed between April and August, 2003; a small second wave of data was collected between April and July, 2005.

All survey items went through two rounds of cognitive testing to ensure that they were clearly understood and reliably interpreted by potential respondents. A small pilot test was conducted with 32 survivors of aggressive NHL before the final field administration of the survey.

Of the 744 survivors eligible to participate in the study, 408 (54.8%) responded to the survey; 319 returned the mailed survey and 89 answered a shorter version of the survey by telephone. Complete or partial medical record data were obtained for 244 of the 408 survey respondents.

Details on the sampling design, sample characteristics, conceptual framework and content of the survey are presented in Arora, Hamilton, Potosky, et al. (2007).