During the 1990–1999 time period, a total of 3974 NHL
incident cases was observed: 2147 among males (mean
age: 61.49 years, standard deviation [sd]: 16.21 years),
and 1827 among females (mean age: 66.06 years, sd:
16.44 years). A detailed analysis highlighted a standardised
incidence ratio (SIR) heterogeneity between departments
(Table 1).