Table 4

Sensitivity analysis results

Cost differenceQALY differenceICER
(£/QALY)
Cohort age (years)
 40356.320.018419 373.50
50 465.87 0.0281 16 596.28
 60520.270.033315 645.62
 70448.610.026516 915.53
Screening interval (years)
 1910.080.046519 586.35
3 465.87 0.0281 16 596.28
 5334.090.021015 922.52
 10217.000.014315 219.88
Time horizon (years)
 20316.940.014721 522.47
 30411.870.022618 206.16
 40458.440.027216 883.96
50 465.87 0.0281 16 596.28
Spirometry attendance rate
 10.5% (threshold 2)159.210.005429 556.13
 26.3% (threshold 1)260.330.013020 097.49
66.1% (base case) 465.87 0.0281 16 596.28
Questionnaire response rate
 4.0% (threshold 2)122.880.004030 364.90
 11.6% (threshold 1)219.190.010920 056.90
35.0% (base case) 465.98 0.0281 16 595.80
Utility gain from treatment
 0.0000465.870.011540 456.80
 0.0092 (threshold 2)465.870.015530 011.41
 0.0269 (threshold 1)465.870.023319 999.67
0.0367 (base case) 465.87 0.0281 16 596.28
  • Threshold 1=willingness-to-pay threshold at £20 000 per QALY.

  • Threshold 2=willingness-to-pay threshold at £30 000 per QALY.

  • Questionnaire response rate after the initial invite in the TargetCOPD trial=15% (2312/15 387). 12

  • Questionnaire response rate after the first reminder in the TargetCOPD trial=25% (3936/15 387). 12

  • Base case values are in bold fonts.

  • ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-year.