Tiotropium Alone vs Combination Therapy on COPD Outcomes
Tiotropium Alone vs Combination Therapy on COPD Outcomes
The number of persons in the database with a ≥ 1 prescription claim for TIO during the study period was 85,153 (Table 1). Of this group, 3333 patients (n = 852 FSC+TIO, n = 2481 TIO) met all eligibility criteria and comprised the study sample. The most common reason for exclusion of those with ≥ 1 prescription claim for TIO during the study period from the study sample was absence of a COPD-related exacerbation in the pre-index period (72.4%, or 61,619 of the patients excluded) (Table 1).
Table 1 shows demographics as well as pre-index clinical characteristics, healthcare use, and costs. The cohorts were generally comparable with some exceptions. The TIO+FSC cohort was slightly younger and had more comorbidities than the TIO cohort. During the pre-index period, severity measures related to medical use tended to reflect greater COPD severity in the TIO+FSC cohort whereas severity measures related to pharmacy use tended to reflect greater severity in the TIO cohort. For example, more patients in the TIO+FSC cohort than patients in the TIO cohort had a COPD-related hospitalization (26.8% versus 18.8%, P < 0.001) whereas the number of oral corticosteroid prescriptions was higher in the TIO cohort than the TIO+FSC cohort (2.09 versus 1.87, P = 0.025). These differences were reflected in the costs such that the TIO cohort had higher pharmacy costs than the TIO+FSC cohort ($1494 versus $1296, P < 0.001). Medical costs were higher for the TIO+FSC cohort than the TIO cohort, but the difference was not statistically significant.
Patients in the TIO cohort had a longer follow-up time (in days) compared to the TIO+FSC cohort (mean [SD], median: 143.9 [118.4], 98.0 versus 106.7 [93.4], 66.5). Table 2 shows unadjusted and adjusted data on COPD-related exacerbations. After controlling for differences in baseline covariates between the cohorts, the TIO+FSC cohort had a 23% lower hazard of experiencing any COPD-related exacerbation (P = 0.007) and a 24% lower hazard of experiencing a moderate COPD-related exacerbation (P = 0.013) during the follow-up period. A reduction in the adjusted rate of combined hospitalization/emergency room visit with TIO+FSC versus TIO was also found but was not statistically significant.
Table 3 shows unadjusted and adjusted data on COPD-related costs. Unadjusted COPD-related total cost/month was significantly lower by ~$200 on average for the TIO+FSC cohort compared with the TIO cohort, a difference primarily attributable to a significant difference in medical cost/month. However, after adjusting for baseline differences, the lower monthly COPD-related medical cost/patient found for the TIO+FSC cohort compared with the TIO cohort ($490 versus $543, P > 0.05) was not statistically significant, and COPD-related total costs/month between cohorts were similar
Results
Sample
The number of persons in the database with a ≥ 1 prescription claim for TIO during the study period was 85,153 (Table 1). Of this group, 3333 patients (n = 852 FSC+TIO, n = 2481 TIO) met all eligibility criteria and comprised the study sample. The most common reason for exclusion of those with ≥ 1 prescription claim for TIO during the study period from the study sample was absence of a COPD-related exacerbation in the pre-index period (72.4%, or 61,619 of the patients excluded) (Table 1).
Table 1 shows demographics as well as pre-index clinical characteristics, healthcare use, and costs. The cohorts were generally comparable with some exceptions. The TIO+FSC cohort was slightly younger and had more comorbidities than the TIO cohort. During the pre-index period, severity measures related to medical use tended to reflect greater COPD severity in the TIO+FSC cohort whereas severity measures related to pharmacy use tended to reflect greater severity in the TIO cohort. For example, more patients in the TIO+FSC cohort than patients in the TIO cohort had a COPD-related hospitalization (26.8% versus 18.8%, P < 0.001) whereas the number of oral corticosteroid prescriptions was higher in the TIO cohort than the TIO+FSC cohort (2.09 versus 1.87, P = 0.025). These differences were reflected in the costs such that the TIO cohort had higher pharmacy costs than the TIO+FSC cohort ($1494 versus $1296, P < 0.001). Medical costs were higher for the TIO+FSC cohort than the TIO cohort, but the difference was not statistically significant.
COPD-related Exacerbations
Patients in the TIO cohort had a longer follow-up time (in days) compared to the TIO+FSC cohort (mean [SD], median: 143.9 [118.4], 98.0 versus 106.7 [93.4], 66.5). Table 2 shows unadjusted and adjusted data on COPD-related exacerbations. After controlling for differences in baseline covariates between the cohorts, the TIO+FSC cohort had a 23% lower hazard of experiencing any COPD-related exacerbation (P = 0.007) and a 24% lower hazard of experiencing a moderate COPD-related exacerbation (P = 0.013) during the follow-up period. A reduction in the adjusted rate of combined hospitalization/emergency room visit with TIO+FSC versus TIO was also found but was not statistically significant.
COPD-related Costs
Table 3 shows unadjusted and adjusted data on COPD-related costs. Unadjusted COPD-related total cost/month was significantly lower by ~$200 on average for the TIO+FSC cohort compared with the TIO cohort, a difference primarily attributable to a significant difference in medical cost/month. However, after adjusting for baseline differences, the lower monthly COPD-related medical cost/patient found for the TIO+FSC cohort compared with the TIO cohort ($490 versus $543, P > 0.05) was not statistically significant, and COPD-related total costs/month between cohorts were similar