Table 1 characterizes the study population. This dataset contained information on 316 HL cases (68.4 % of those contacted) and 1,506 controls (48 % of those contacted). There was no information collected on non-respondents to assess reasons for non-participation. The largest number of cases and controls was from Ontario (39 %). Controls were frequency-matched to cases of HL, NHL, MM, and STS resulting in an average younger age for HL cases than controls because of the bimodal age-incidence distribution for HL. Compared to cases, a slightly higher proportion of controls required a proxy respondent, likely due to the older age of the control group. Sensitivity analyses were also performed excluding subjects whose information was reported by a proxy respondent or whose respondent status was missing to evaluate potential bias.