RESULTS
The final study cohorts consisted of 475 IXE and 3159 ADA users who fulfilled the eligibility criteria during the 24-month follow-up period (Figure 1). Table 1 presents pre- and postweighting demographics and pre-period clinical characteristics. On average, IXE users were older than ADA users with an unweighted mean (SD) age of. 48.4 (11.0) vs 46.4 (12.1). Most patients had commercial payer coverage (95.6%-96.7%). Both IXE and ADA users had the same mean (SD) DCCI score of 0.3 (0.8) (Table 1).
The most common baseline comorbidities for IXE and ADA users were hypertension (25.5% vs 24.2%; Std. Diff=0.028), hyperlipidemia (21.5% vs 19.2%; Std. Diff=0.057), obesity (17.1% vs 13.6%; Std. Diff=0.095), diabetes (14.9% vs 11.4%; Std. Diff=0.106), and osteoarthritis (6.1% vs 6.0%; Std. Diff=0.034; Table 1). IXE users had a higher percentage of patients with prior use of biologics compared to ADA users (55.6% vs 28.6%; Std. Diff=0.567). Overall, the demographic and baseline characteristics, such as age, primary payer, insurance plan type, geographic region, and the pre-period DCCI, were balanced after weighting (Table 1).
Univariate Analyses
After weighting, IXE users had a significantly higher mean (SD) adherence compared to ADA users (0.57 [0.31] vs 0.53 [0.31]; P=0.027). A significantly greater proportion of IXE users had a PDC≥80% versus ADA users (36.3% vs 28.8%; P<0.001; Table 2). A significantly greater proportion of patients on IXE versus ADA were found to be persistent on treatment (35.2% vs 28.8%; P=0.004) during the 24-month follow-up period. Mean (SD) number of days on persistent treatment was also significantly higher in IXE users compared to ADA users (402 [273] vs 375 [265]; P=0.033). The probability of persistence over 24 months was significantly higher for IXE users compared to ADA users (P=0.048), as estimated using Kaplan-Meier curves (Figure 2). The median time to non-persistence was 355 days (95% CI: 301– 410) for IXE and 302 days (95% CI: 286–321) for ADA.
The most common baseline comorbidities for IXE and ADA users were hypertension (25.5% vs 24.2%; Std. Diff=0.028), hyperlipidemia (21.5% vs 19.2%; Std. Diff=0.057), obesity (17.1% vs 13.6%; Std. Diff=0.095), diabetes (14.9% vs 11.4%; Std. Diff=0.106), and osteoarthritis (6.1% vs 6.0%; Std. Diff=0.034; Table 1). IXE users had a higher percentage of patients with prior use of biologics compared to ADA users (55.6% vs 28.6%; Std. Diff=0.567). Overall, the demographic and baseline characteristics, such as age, primary payer, insurance plan type, geographic region, and the pre-period DCCI, were balanced after weighting (Table 1).
Univariate Analyses
After weighting, IXE users had a significantly higher mean (SD) adherence compared to ADA users (0.57 [0.31] vs 0.53 [0.31]; P=0.027). A significantly greater proportion of IXE users had a PDC≥80% versus ADA users (36.3% vs 28.8%; P<0.001; Table 2). A significantly greater proportion of patients on IXE versus ADA were found to be persistent on treatment (35.2% vs 28.8%; P=0.004) during the 24-month follow-up period. Mean (SD) number of days on persistent treatment was also significantly higher in IXE users compared to ADA users (402 [273] vs 375 [265]; P=0.033). The probability of persistence over 24 months was significantly higher for IXE users compared to ADA users (P=0.048), as estimated using Kaplan-Meier curves (Figure 2). The median time to non-persistence was 355 days (95% CI: 301– 410) for IXE and 302 days (95% CI: 286–321) for ADA.
