Outpatient Use of Antimicrobials in Patients With Rheumatoid Arthritis Before and After Treatment With Tumor Necrosis Factor Inhibitors: A Nationwide Retrospective Cohort Study

Objective

The objective of this study was to investigate the effect of tumor necrosis factor α inhibitor (TNFi) initiation on the use of antimicrobials among biologic‐naïve patients with rheumatoid arthritis (RA).

Methods

Information on all biologic‐naïve patients with RA was extracted from ICEBIO, a nationwide registry. Each patient was matched on age, sex, and calendar time to five randomly selected individuals from the general population. All filled antimicrobial and glucocorticoid prescriptions in the 2 years before and after initiation of the first TNFi were extracted from the Prescription Medicines Register. Prescriptions were quantified by using the number of filled prescriptions (NP) and defined daily doses.

Results

We extracted information on 359 patients with RA and 1795 comparators. During the 24 months before initiating treatment with TNFi, patients with RA received more prescriptions for antimicrobials than their matched general population comparators (mean ± SD: 2.8 ± 3.4 vs 1.6 ± 2.7; P < 0.001). The 24‐month mean NP for patients with RA increased to 3.5 ± 3.9 (P < 0.001) after initiating TNFi: antibiotics, 2.6 ± 3.2 to 3.2 ± 3.5 (P < 0.001); antivirals, 0.06 ± 0.5 to 0.16 ± 0.7 (P = 0.004); and antimycotics, 0.14 ± 0.5 to 0.22 ± 0.9 (P = 0.06). The 12‐month mean NP was highest in the second year after TNFi initiation (1.9 ± 2.4). No association was found between NP and glucocorticoids, age, body mass index, or pre‐TNFi Disease Activity Score 28‐joint count and C‐reactive protein.

Conclusion

Patients with RA on TNFi are more commonly treated for infections in the outpatient settings than previously reported. Patients are prescribed more antimicrobials in the 2 years preceding TNFi initiation than the general population, and this use further increases after initiation of TNFi. In contrast to what is reported for infections requiring hospitalization, outpatient antimicrobial use remained elevated for at least 2 years.

The majority of patients with psoriatic arthritis are not eligible for randomised clinical trials

OBJECTIVES

To identify the proportion of patients with psoriatic arthritis (PsA) who would meet inclusion criteria of the randomised clinical trials that were performed leading up to registration of the tumour necrosis factor inhibitors (TNFi).

METHODS

Data from 329 patients with PsA were obtained from an Icelandic database, ICEBIO, medical records at the University Hospital of Iceland, and the private out-patient clinic Laeknasetrid Ltd. The patients were classified according to whether they met the inclusion criteria of the clinical trials that were performed ahead of the registration of each respective TNFi. The reasons for exclusion were also explored.

RESULTS

34% of the patients with complete data available met the inclusion criteria. Clinical data in respect to exclusion and inclusion criteria were incomplete for 13% of the cases. The proportion of patients who met the inclusion criteria was highest among those who received adalimumab and etanercept (53%). Patients who received in iximab had the lowest inclusion rate (23%). The main reason why patients did not meet the inclusion criteria was too few swollen and/or tender joints, or in 45% of excluded cases.

CONCLUSIONS

Our results demonstrate that two thirds of patients with PsA in Iceland who are treated with TNFi would not have qualified for the randomised clinical trials performed leading up to the registration of the medications. Further studies with regards to whether outcomes are different between those who met the inclusion criteria and those who did not remain to be performed.

Appropriate use of heparin. Empiric vs nomogram-based dosing

BACKGROUND

A study involving two groups of patients with cardiovascular disease was conducted to compare empiric (clinician-directed) heparin therapy with therapy based on a nomogram-determined dosage. The comparison was based on (1) the average weight-referenced infusion rate yielding a therapeutic activated partial thromboplastin time (APTT) and (2) the time required to reach a therapeutic APTT (55 to 95 seconds) after empiric or nomogram-based heparin therapy was initiated.

METHODS

Data were collected for patients admitted to the cardiology service at a university health science center in two phases: phase 1 (April 1 through June 30, 1992), involving 95 patients receiving heparin therapy, with 88 patients included in the data analysis, and phase 2 (March 11 through June 11, 1993), involving 156 patients receiving heparin therapy, with 45 patients receiving nomogram-guided therapy included in the data analysis.

RESULTS

In phase 1, 66 patients (75.0%) achieved a therapeutic APTT some time during their heparin therapy, with an average time to therapeutic APTT of 20.7 + 19.1 hours. Regression analysis demonstrated a statistically significant relationship between the heparin infusion rate at the time of the patient's first therapeutic APTT and the patient's total body weight (r2 = .3043). An initial infusion rate based on total body weight (13 U/kg per hour) was therefore used as the basis for the nomogram in phase 2. In phase 2, 41 patients (91.1%) achieved a therapeutic APTT at some time during their heparin therapy, with an average time to therapeutic APTT of 13.1 + 11.9 hours, statistically significantly shorter than that in phase 1. A greater proportion of patients in phase 2 compared with patients in phase 1 reached the therapeutic range within 12 hours (62.2% vs 34.1%) and within 24 hours (77.8% vs 54.5%).

CONCLUSIONS

Use of a weight-based nomogram to determine the initial and maintenance heparin infusion rates was associated with a higher percentage of patients admitted to the cardiology service reaching the targeted therapeutic APTT range at a time earlier in the course of therapy compared with empiric dosing.