Table 2

Rates and crude rate ratios (RRs) of death for use of inhaled corticosteroids (ICS) from the Saskatchewan chronic obstructive pulmonary disease cohort, comparing the three approaches to data analysis

Exposure to regular therapySubjects nPerson-yearsDeaths nRate+RR
Hierarchical intention-to-treat analysis
 ICS (all users)18624608.63407.380.53
 Bronchodilators# (reference)15973726.952013.951.00
Conventional intention-to-treat analysis
 ICS9302417.61546.370.63
 Bronchodilators (reference)2584645764910.051.00
According-to-treatment analysis
 ICS18624608.63407.380.69
 Bronchodilators (reference)22434895.452010.621.00
  During entire follow-up15973726.952013.95
  Prior to ICS6461168.500.00
  • #: only during follow-up

  • : immortal person-time in reference exposure prior to starting ICS exposure, these subjects are part of the 1862 subjects exposed to ICS

  • +: rate of all-cause death per 100 patients per year