Comparative Effectiveness of Two Tiotropium Formulations: A Retrospective Cohort Study

Figures & data

Table 1. Hazard ratios for the primary outcomes of patients treated with Respimat^® versus HandiHaler^®.

Outcomes	Unmatched cohort^a			Propensity–score matched cohort^a
	No (%) of cases		Unadjusted hazard ratio (95% CI)	No (%) of cases		Adjusted hazard ratio (95% CI)
	Respimat No 15 937	HandiHaler No 53 088		Respimat No 15 667	HandiHaler No 15 667
Primary outcome^b	485 (3.04)	2133 (4.02)	0.82 (0.75–0.91)	477 (3.04)	558 (3.56)	0.95 (0.84–1.07)
COPD exacerbation	203 (1.27)	982 (1.85)	0.81 (0.70–0.94)	197 (1.26)	266 (1.70)	0.91 (0.76–1.10)
Acute respiratory failure	149 (0.93)	601 (1.13)	0.94 (0.79–1.13)	147 (0.94)	148 (1.58)	0.96 (0.93–1.48)
Pneumonia	127 (0.80)	519 (0.98)	0.94 (0.77–1.14)	127 (0.81)	137 (0.87)	1.12 (0.88–1.42)

No: number; %: proportion of patients with events; CI: confidence interval; COPD: Chronic Obstructive Pulmonary Disease.

^a After conducting the propensity score matching the study population decreases from 69,025 to 31,334 patients and the corresponding number of events from 2618 to 1035.

^bHypoxemia/hyperventilation were not detailed due to the small number of events (37 events in the unmatched cohort; 13 events in the matched cohort).

Figure 1. Hazard ratios for the primary outcome of patients treated with Respimat^® versus HandiHaler^® according to risk factors (patient characteristics and comorbidities; only risk factors with at least 40 events per group were included in the graph, with the exception of region). HR: Hazard Ratio; CI: Confidence Interval; COPD: Chronic Obstructive Pulmonary Disease.

Table 2. Hazard ratios of the primary outcomes for the specific subgroups of patients at higher risk treated with Respimat^® versus HandiHaler^®.

	Propensity-score matched analysis
	No. of events/Total No. of patients		Adjusted HR (95% CI)
	Respimat	HandiHaler
Previous severe respiratory disease	163/1950	174/1813	0.98 (0.79–1.21)
Frail population	173/3857	186/3768	1.04 (0.85–1.28)
Number of respiratory drugs ≥2	223/5090	223/4723	1.00 (0.83–1.21)

No: number; HR: Hazard Ratio; CI: Confidence Interval.

Previous severe respiratory disease: (respiratory disease AND at least one prescription of antibacterials) OR (pneumonia AND at least one prescription of antibacterials) in the last 12 months from index date.

Respiratory disease: ICD-9 code 490-496; pneumonia: ICD-9 code 480-486; antibacterial: ATC code J01.

Frail population: (age >75 years) AND (acute myocardial infarction OR at least two prescriptions anticoagulants) in the last 12 months from index date.

Acute myocardial infarction: ICD-9 codes 410 and 412; anticoagulants: ATC code B01A.

Number of respiratory drugs: at least two different previous prescriptions of respiratory drugs (glucocorticoids and/or anticholinergics and/or LABA and/or SABA and/or leukotriene receptor antagonists and/or xanthines and/or adrenergics in combination with corticosteroids or other drugs and/or adrenergics in combination with anticholinergics and/or antiallergic agents and/or other systemic drugs for obstructive airway diseases and/or corticosteroids for systemic use, in the last 12 months from index date.