Table 4

Standardised incidence ratios (SIRs) and 95% confidence intervals (CIs) for squamous cell carcinoma of the oesophagus among pernicious anaemia patients, stratified by follow up duration and age at index hospitalisation

TotalWithout alcohol related diseases†
CharacteristicObs*SIR95% CIObs*SIR95% CI
*Observed number of cancer cases
†Person years before the onset of comorbid diseases were allocated to the comorbidity negative stratum.
Follow up (y)
p value for trend0.030.03
Age at index hospitalisation
p value for trend0.010.01