Risk of hepatotoxicity-related hospitalizations among patients treated with opioid/acetaminophen combination prescription pain medications.

OBJECTIVE: This study determined the risk of serious hepatotoxicity resulting in hospitalizations among patients prescribed opioid/acetaminophen combinations. METHODS: A retrospective cohort study using an insurance claims database was conducted. Adult patients with ≥1 claim for oxycodone/acetaminophen or hydrocodone/acetaminophen combinations were included (N = 1,228,356). A pre-post design was employed to compare serious hepatotoxicity risk before versus after initiation of opioid/acetaminophen combination. Serious hepatotoxicity risk between the opioid/acetaminophen group and a control group of opioid-alone users (N = 11,809) was also examined. Within the opioid/acetaminophen group, risk of hepatotoxicity-related hospitalizations pre- versus post-opioid/acetaminophen treatment was compared using the normal approximation with the binomial distribution. The incidence rate of hepatotoxicity-related hospitalizations for the opioid/acetaminophen group was compared with the opioid-alone group using multivariate Poisson regression adjusting for baseline differences between groups. RESULTS: Of the opioid/acetaminophen cohort, hepatotoxicity-related hospitalization risk in the 6-month post-opioid/acetaminophen period was lower than that in the pre-period with a risk reduction of 1.2 per 10,000 (pre-period = 0.12%; 95% confidence interval [CI], 0.12 to 0.13; post-period = 0.11%; 95% CI, 0.11 to 0.12). In the 12-month period, risk increased in the post-period by 2.4 per 10,000 (pre-period = 0.14%; 95% CI, 0.14 to 0.15; post-period = 0.17%; 95% CI, 0.16 to 0.18). After adjusting for confounders, the opioid-alone group did not demonstrate a lower rate of hepatotoxicity-related hospitalizations than the opioid/acetaminophen group (incidence rate ratio of opioid-alone over opioid/acetaminophen = 2.9; 95% CI, 1.8 to 4.7). CONCLUSIONS: There is no population data-based evidence supporting elevated risk of hepatotoxicity-related hospitalization associated with opioid/acetaminophen combinations.

Matching-adjusted indirect comparison of adalimumab vs etanercept and infliximab for the treatment of psoriatic arthritis.

OBJECTIVES: No head-to-head trial has compared the efficacy of adalimumab vs etanercept and infliximab for psoriatic arthritis (PsA). This study implements a matching-adjusted indirect comparison technique to address that gap. METHODS: Patient-level data from a placebo-controlled trial of adalimumab (ADEPT) were re-weighted to match average baseline characteristics from pivotal published trials of etanercept and infliximab. ADEPT patients were re-weighted by odds of enrollment in comparator trials, estimated using logistic regression. Matched-on characteristics included PsA duration, age, gender, severity, active psoriasis, and concomitant treatment. After matching, placebo-adjusted treatment arms were compared at weeks 12 (or 14) and 24. Outcomes included ACR20/50/70, PsARC, HAQ, and modified TSS. PASI50/75/90 were compared for patients with active psoriasis. Cost per responder (CPR) was assessed in the US and Germany using matching-adjusted end-points and drug list prices. Statistical significance was assessed using weighted t-tests. RESULTS: After matching, adalimumab-treated patients had greater placebo-adjusted rates of ACR70 and PASI50/75/90 at week 24 compared with etanercept (all p < 0.05). Adalimumab patients had a higher placebo-adjusted rate of ACR70 than infliximab at week 14 (p = 0.034). Adalimumab treatment had lower CPR for ACR70 and PASI50/75/90 compared with etanercept at week 24, in both the US and Germany (all p < 0.02). Adalimumab had lower CPR than infliximab for all outcomes at week 24 (all p < 0.05). CONCLUSION: Adalimumab is associated with higher ACR70 and PASI50/75/90 response rates than etanercept at week 24 and a higher ACR70 response rate than infliximab at week 14. Adalimumab has significant advantages over etanercept and infliximab in CPR across multiple end-points. KEY LIMITATIONS: The matching-adjusted indirect comparison method cannot account for unobserved differences in patient characteristics across trials, and only a head-to-head randomized clinical trial can fully avoid the limitations of indirect comparisons. CPR findings are limited to the US and German markets, and may not be generalizable to other markets with different relative pricing.