Space-time clustering of Hodgkin's Disease in parts of the UK, 1984-1993.

The object of this study was to examine cases of Hodgkin's Disease (HD) for evidence of space-time clustering of onsets by age group, sex and disease subtype. Data comprised 2024 cases of HD aged 0-79 years arising throughout the period 1984 to 1993 in the areas covered by a specialist population based register of leukaemias and lymphomas. Knox space-time analysis was used separately for 3 different age groups: childhood (0-14 years), young adult (15-34 years) and older adults (35-79 years); for adult cases separate analysis was carried out by sex and for the nodular and non-nodular sclerosing subtypes. Results showed that space-time clustering of onsets was limited to the nodular sclerosing cases. It was more prominent in young adult nodular sclerosing cases aged 15-34 years (particularly females) diagnosed in the period 1984-88, than in those diagnosed in 1989-93. We conclude that clustering may provide further evidence that an infectious process is involved in the aetiology of young adult nodular sclerosing cases of HD.