Session Information
Date: Monday, November 14, 2016
Title: Rheumatoid Arthritis – Clinical Aspects III: Prevention of Comorbidity
Session Type: ACR Concurrent Abstract Session
Session Time: 4:30PM-6:00PM
Background/Purpose: Patients taking biologic DMARDs often undergo elective surgery, but data to guide if and when to hold biologics before surgery is limited. This study evaluated whether the timing of infliximab before elective hip or knee arthroplasty was associated with an increased risk of serious infection.
Methods: A retrospective cohort study using U.S. Medicare data evaluated adults with rheumatoid arthritis, inflammatory bowel disease, psoriasis, psoriatic arthritis, or ankylosing spondylitis who received infliximab within 6 months of elective inpatient primary or revision total knee or hip arthroplasty from 2007-2013. Multivariable logistic or Cox regression evaluated associations of infliximab stop time (time between most recent infusion and surgery) with 1) hospitalized infection within 30 days of surgery (excluding urinary infections given relative lack of specificity) using a validated set of discharge diagnoses and 2) rate of prosthetic joint infection (PJI, ICD9 996.66) within 1 year (including within 30 days), adjusting for confounders. Analyses considering the propensity of being in each stop time category were also performed using inverse probability weighting.
Results: Among 4288 surgeries in 3867 patients, the 30 day cumulative incidence of infection was 6.3% (n = 270), with bacteremia, skin/soft tissue infection, and pneumonia the most common infections. In adjusted analyses, infliximab stop time < 4 weeks vs 8-12 weeks was not associated with an increase in infection within 30 days [OR 0.85, 95% CI 0.58,1.25] [Table]. Risk factors for infection included oral glucocorticoid dose > 10mg, age > 80, higher Charlson comorbidity, previous hospitalized infection, more outpatient visits, and year 2007-2009 (vs 2010-2013) [Table]. Over 12 months, the rate of PJI was 2.9 per 100 person-years (n = 105 infections) and was similar for patients who stopped infliximab < 4 weeks vs ≥ 4 weeks before surgery [Figure]. After adjustment, infliximab stop time of < 4 weeks vs 8-12 weeks was not associated with increased rate of PJI [HR 1.01, 95% CI 0.56, 1.82]. Risk factors for PJI included glucocorticoid use, revision surgery, previous hospitalized infection, extra-articular RA, and year 2007-2009. Results were similar in propensity-adjusted analyses.
Conclusion: Administering infliximab within 4 weeks of elective total knee or hip arthroplasty was not associated with a higher risk of short or long-term serious infection compared to withholding infliximab for longer periods of time. In contrast, glucocorticoid use, especially > 10mg per day, was associated with an increased risk of infection. Table: Results of multivariable logistic regression analysis for serious infection within 30 days, based on 4283 observations among 3863 patients
|
30 day infection OR (95% CI) |
p-value |
|
| Infliximab pre-operative stop time |
|
|
| < 4 weeks |
0.85 (0.58, 1.25) |
0.40 |
| 4-8 weeks |
0.90 (0.64, 1.26) |
0.53 |
| 8-12 weeks |
Reference |
– |
| 12-16 weeks |
0.88 (0.47, 1.64) |
0.68 |
| ≥ 16 weeks |
1.01 (0.56, 1.83) |
0.98 |
| Glucocorticoid dose |
|
|
| None |
Reference |
– |
| ≤ 5mg/day |
1.00 (0.68, 1.47) |
0.99 |
| 5-10mg/day |
1.15 (0.78, 1.69) |
0.49 |
| > 10mg/day |
2.07 (1.29, 3.34) |
< 0.01 |
| Non-biologic DMARD use |
1.08 (0.83, 1.42) |
0.56 |
| Age ≥ 80 years old |
1.74 (1.22, 2.48) |
< 0.01 |
| Female |
1.10 (.080, 1.51) |
0.57 |
| Autoimmune Disease |
|
|
| Rheumatoid Arthritis |
Reference |
– |
| Inflammatory Bowel Disease |
1.07 (0.70, 1.64) |
0.76 |
| Psoriatic arthritis/psoriasis/ankylosing spondylitis |
0.98 (0.65, 1.47) |
0.93 |
| Charlson score, per 1 point increase |
1.08 (1.03, 1.12) |
< 0.001 |
| Hospitalizations in the past year |
|
|
| None |
Reference |
– |
| Hospitalization without infection |
0.70 (0.48, 1.00) |
0.05 |
| Hospitalization with infection |
1.88 (1.27, 2.79) |
< 0.01 |
| Outpatient visits in the past year, per visit |
1.02 (1.01, 1.03) |
< 0.01 |
| Calendar year |
|
|
| 2007-2009 |
Reference |
– |
| 2010-2013 |
0.68 (0.52, 0.87) |
< 0.01 |
| Region included in the model but not significant with p > 0.05 and not shown. Tested but not included in the final model after step-wise backward selection with p > 0.2 (forcing in age, sex, disease type, glucocorticoid use, traditional DMARD use): race, urban, zip code based median household income quintiles, dual eligibility status, skilled nursing facility stay past year, surgery type, osteonecrosis, extra-articular RA, diabetes, COPD/asthma, kidney disease, obesity, previous biologic therapy, infliximab infusion interval, infliximab dose, antibiotic prescription in the past year | ||
To cite this abstract in AMA style:
George MD, Baker JF, Hsu JY, Wu Q, Xie F, Chen L, Yun H, Curtis J. Preoperative Timing of Infliximab and Risk of Post-Operative Infection in a Medicare Cohort [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/preoperative-timing-of-infliximab-and-risk-of-post-operative-infection-in-a-medicare-cohort/. Accessed .« Back to 2016 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/preoperative-timing-of-infliximab-and-risk-of-post-operative-infection-in-a-medicare-cohort/