Table 3

 Sensitivity analyses comparing relative risks for oesophageal cancer in relation to prescription of oral bisphosphonates, using varying criteria for definition of exposure and inclusion of adjustment variables

Sensitivity analysesNo of exposed cases of oesophageal cancerRelative risk* (95% CI) 1-1-9 v 0 prescriptionsRelative risk* (95% CI) ≥10 v 0 prescriptions
Main analysis: bisphosphonate exposure defined as ≥1 prescription within observation period; missing data on adjustment variables assigned to separate category900.93 (0.66 to 1.31)1.93 (1.37 to 2.70)
Bisphosphonate exposure defined as ≥2 prescriptions800.93 (0.63 to 1.39)1.93 (1.37 to 2.70)
Restricted to those with full information on adjustment variables681.05 (0.68 to 1.63)1.88 (1.24 to 2.86)
All exposure and adjustment data recorded at least 12 months before index date, and restricted to those with full information on adjustment variables521.09 (0.67 to 1.79)2.00 (1.23 to 3.27)

*Adjusted for smoking status, alcohol intake, and body mass index.