Fifteen studies (n at least 44,558) were included in total. However, only 10 studies (n at least 74,559) reported mortality and hospitalisation data; two of these appeared to use the same population of patients. The 10 studies included one controlled trial, two prospective cohort studies, one nested case-control, two retrospective cohort studies, one retrospective longitudinal study, one retrospective follow-up study, one retrospective data analysis and one reanalysis of existing data.
Mortality (8 studies).
Four studies (two prospective cohort studies, one retrospective follow-up study and one reanalysis of data) showed no significant differences in mortality rates between those taking and those not taking ICS.
One retrospective cohort of COPD patients (n=4,263) reported a significant reduction in mortality in a multivariate analysis among patients taking ICS (mortality 17.1%) or ICS plus long-acting beta-adrenoceptor agonist (10.5%) compared with neither (24.3%).
One controlled trial of newly diagnosed COPD patients (n=4,665) reported patients using fluticasone propionate either alone (adjusted hazard ratio 0.48, 95% CI: 0.31, 0.73) or with salmeterol (adjusted hazard ratio 0.62, 95% CI: 0.45, 0.85) had significantly lower mortality than those using neither drug.
One retrospective cohort of asthma patients (n=6,254) reported a 39% reduction in all-cause mortality for patients who received ICS within 90 days of discharge, compared with those not taking ICS.
One retrospective chart analysis of COPD patients (n=6,740) reported that ICS treatment after discharge resulted in a significantly lower mortality rate (RR 0.75, 95% CI: 0.69, 0.86) and pulmonary-specific mortality rate (RR 0.70, 95% CI: 0.53, 0.93) than no ICS; this reduction was greater for those patients taking medium (52% reduction) to high doses (45% reduction) as compared with low doses (23% reduction).
Hospitalisation (6 studies).
Three studies (one nested case-control study, one prospective cohort and one prospective cohort study) reported no significant differences in hospitalisation rates between those patients taking and those not taking ICS.
One retrospective longitudinal study of patients with moderate to severe COPD (n unknown) reported that greater adherence to ICS treatment was associated with a significant 20% decrease in annual hospitalisation rates and a decrease in the length of hospital stay (0.7 days versus 1.76 days for control patients).
One retrospective cohort of asthma patients (n=6,254) reported a 29% reduction in recurrent hospitalisation for patients who received ICS within 90 days of discharge, compared with those not taking ICS.
One retrospective cohort of COPD patients (n=4,263) reported a reduction in re-hospitalisations in an unadjusted analysis for those patients taking ICS as compared with those not taking ICS (no further data).