Table 1

Comparison between the biased event-based NNT (per year) and the appropriate ‘instantaneous’ event-based NNT (per day) for three trials of the fluticasone-salmeterol combination inhaler (ICS) reporting the NNT to prevent a COPD exacerbation

Time span for NNTBiased event based (rate per year)Instantaneous event based (rate per day)
TORCH1 3 years0.851.13*40.00230.0031*1250
Kardos344 weeks0.921.4020.00250.0038769
Anzueto6 1 year1.101.5920.00300.0044714
  • COPD, chronic obstructive pulmonary disease; ICS, inhaled corticosteroid; NNT, number needed to treat.

  • *In this Table, â No ICSâ refers to the placebo group of the TORCH trial.