The expected number of cases was calculated using normal population-based age- and sex-specific reference incidence rates from a recently published study on diabetes incidence in the Kronoberg county of southern Sweden (15) and correspondingly stratified patient-years in KIMS.
This study aimed to have at least 300 patients receive the second rituximab infusion at a faster rate so that an increase of at least 3%to4%4% of IRRs from the weighted reference incidence (8% to 9%, based on historical data for rituximab) would be statistically significant.
The capital cities of these northernmost and southernmost states are located at 27.5º south and 42.9º south, respectively (table 1). Figure 1 shows the pattern of risk for multiple sclerosis for each two month period of birth, expressed as an incidence rate ratio for each period of birth relative to the reference incidence rate ratio (1.0) for May-June.
If a matrix cell had >1 data source after the iNTS incidence data were assigned, the mean incidence from all sources was calculated as the reference incidence for that matrix cell.
Most studies modeled the prescreening incidence trend through the study period to determine reference incidence, though this assumes that incidence would have continued at the same rate without non-linear changes.
External reference incidence rates for leukaemia were calculated from published general population French cancer registers (Bas-Rhin, Doubs and Isère 1978 1992, Calvados 1978 1987, Haut-Rhin 1988–1992) (IARC, 1987; IARC, 1992; IARC, 1997).
Assuming independence, the risk expressed in breast-years would be twice as high as in breast cancer survivors only one breast is at risk for CBC and the reference incidence rates concern cancer in any of two breasts.
We then calculated the number of iNTS cases for each country by using the reference incidence rates from the cell, according to the assignment of each country in the matrix and each country's population stratified by age groups.
Follow-up did not stop at the date of first diagnosis of cancer, and so all primary cancers diagnosed during the follow-up were counted as observed cases and included in the reference incidence rates.
For the study area, we calculated expected numbers of cancers as the number of subjects multiplied by reference incidence rate for that cancer by sex, age, time period, SES, distance to sea, and distance to river.
