Table 5—

Sensitivity analysis of the differences in costs and health outcomes between tiotropium and ipratropium

Difference in cost per patientNo of exacerbations avoidedDifference in the proportion of patients improved on the SGRQ %ICER
Cost per exacerbation avoidedCost per patient improved on the SGRQ
Base-case180 (228)0.27 (0.13)16.6 (0.05)6671084
SA 1111 (277)0.27 (0.13)16.6 (0.05)411669
SA 2221 (229)0.27 (0.13)16.6 (0.05)8191331
SA 3203 (243)0.25 (0.12)13.9 (0.05)8121460
SA 4159 (635)0.43 (0.51)33.2 (0.13)370479
SA 548 (228)0.27 (0.13)16.6 (0.05)178289
SA 6180 (228)0.27 (0.13)13.3 (0.05)6671353
SA 7180 (228)0.27 (0.13)11.1 (0.04)6671622
  • All data presented as mean (sem) unless otherwise stated

  • ICER: incremental cost-effectiveness ratio

  • SGRQ: St George's Respiratory Questionnaire

  • SA: sensitivity analysis

  • SA1: inclusion of all resource use

  • SA2: valuation based on country-specific prices

  • SA3: Dutch patients only tiotropium n=294, ipratropium n=151

  • SA4: Belgian patients only, tiotropium n=50, ipratropium n=24

  • SA5: price ipratropium based on the average of the metered dose inhaler (MDI) and the dry powder inhaler, weighted by the actual use of these devices in the Netherlands (MDI: 44%, DPI:56%)

  • SA6: threshold value of a relevant improvement on the SGRQ set to six units

  • SA7: threshold value of a relevant improvement on the SGRQ set to eight units