Infliximab maintenance therapy is associated with decreases in direct resource use in patients with luminal or fistulizing Crohn's disease

Epidemiology, Disease Course, and Clinical Outcomes of Perianal Fistulas and Fissures Crohn's Disease: A Nationwide Population-Based Study in Taiwan

Background

Population-based data on the course of perianal disease in East Asian populations with Crohn's disease (CD) are limited. This study examined the prevalence, clinical course, and compared the outcomes of CD patients with perianal CD (pCD) versus without pCD in Taiwan.

Methods

A nationwide population-based study was implemented from 2000 to 2017 by using the Taiwan National Health Insurance Research Database.

Results

Of 2424 patients with CD, 358 (14.8%) patients with pCD were identified. Most patients with CD and pCD were men (79.3%). The mean age at CD diagnosis was lower in patients with pCD (33.7 years) than in those without pCD (44.9 years). Approximately half the patients with pCD received the pCD diagnosis at least 6 months before receiving a CD diagnosis. Approximately one-third (121/358) of patients with pCD had recurrent fistula; the median recurrence interval was 239 days. Compared with patients without pCD, patients with pCD had higher mean incidences of hospitalization (7.0 vs 3.8, P < .01), outpatient visits (13 vs 2.9, P < .01), and emergency room visits (10.3 vs 4.4, P < .01) over a 15-year period. Although patients with pCD had higher rates of healthcare utilization, their 15-year mortality rate was lower than that of those without pCD (6.1% vs 17.3%, P < .01).

Conclusions

The period prevalence of pCD in Taiwanese patients with CD was 14.8%. Although patients with pCD required more intensive care and had greater healthcare utilization, they did not have inferior survival outcomes compared with those without pCD.

Comparative Efficacy of Biologic Therapies for Inducing Response and Remission in Fistulizing Crohn's Disease: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The medical treatment of fistulizing Crohn's disease (CD) remains a challenge to clinicians. Over the last 20 years, biologic therapies have been the mainstay of medical treatment of fistulizing CD. The purpose of this study is to compare the efficacy of biologic therapies in inducing response and remission in fistulizing CD.

METHODS

We performed a systematic review of the EMBASE, MEDLINE, and Cochrane Central databases from inception to December 2021. Inclusion criteria were any randomized controlled trials (RCTs) that evaluated the efficacy of biologic therapies against an active comparator or placebo for induction of response or remission in adults with fistulizing CD. The proportion of patients with fistula response or remission, as defined by each clinical trial, was our primary study outcome. A Bayesian random-effects network meta-analysis was used to measure treatment effects and results were reported as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

In our analysis, 10 studies were included, and all were RCTs. Infliximab was superior to adalimumab in inducing response (OR, 0.24; 95% CI, 0.06-0.99) but not in inducing remission (OR, 0.31; 95% CI, 0.04-2.27). Tumor necrosis factor antagonists were superior to placebo in the induction of response (OR, 0.51; 95% CI, 0.35-0.750) and remission (OR, 0.36; 95% CI, 0.22-0.58). Infliximab was superior to placebo in inducing response (OR, 0.36; 95% CI, 0.17-0.75) and remission (OR, 0.17; 95% CI, 0.03-0.87). Ustekinumab was superior to placebo in inducing response (OR, 0.48; 95% CI, 0.26-0.860) but not in inducing remission (OR, 0.50; 95% CI, 0.13-1.93). When comparing biologic therapies against each other, there was no statistical difference in inducing remission. Vedolizumab was not superior to placebo in inducing remission (OR, 0.32; 95% CI, 0.04-2.29). Certolizumab was not superior to placebo in inducing response (OR, 0.78; 95% CI, 0.40-1.55) or remission (OR, 0.78; 95% CI, 0.40-1.55).

CONCLUSIONS

Tumor necrosis factor antagonists are effective in inducing response and remission in fistulizing CD. Infliximab was superior to adalimumab for inducing response but not for inducing remission. Ustekinumab is effective in the induction of response but not in the induction of remission. When compared against each other, biologic therapies showed no significant difference in the induction of remission. Based on the available data, infliximab is the preferred first-line treatment. As for other biologics, the limited published data do not allow us to make firm recommendations. This study supports current practice and emphasizes the need for dedicated RCTs to evaluate the efficacy of biologic therapies in fistulizing CD.

A systemic review and metaanalysis of postoperative outcomes in urgent and elective bowel resection in patients with Crohn's disease

PURPOSE

The study examined whether urgency of surgical intervention affects postoperative outcomes in patients with Crohn's disease (CD) undergoing bowel resection.

METHOD

The review was conducted according to a predefined, published study protocol in Prospero which is an international database of prospectively registered systematic reviews in health. The study reported according to PRIMSMA guidelines. We searched Embase and Pubmed for articles reporting postoperative outcome after urgent and elective surgery in patients with CD undergoing bowel resection. Primary outcome variable was 30-day overall postoperative complications while secondary outcome variables were intraabdominal septic complications (IASCs), mortality, reoperation, and readmission. Assessment of bias was performed using Newcastle-Ottawa score. Two authors independently extracted data on each study, patients, and outcome measures.

RESULTS

The search identified 22 studies in which 955 patients underwent urgent surgeries while 6518 patients underwent elective surgeries. Based on the quality assessment, 19 studies were classified as having high risk of bias, one study as having a medium risk of bias and 2 studies as having low risk of bias (≥ 8 stars). Random-effect metaanalysis showed urgent surgery was associated with ~ 40% increase in overall complications compared to elective surgery (RR = 1.43, 95% CI [1.09; 1.87], p = 0.010). IASCs also increased in patients who had urgent surgery (RR = 1.44, 95% CI [1.08; 1.92], p = 0.013). No significant difference was shown in mortality and readmission rates.

CONCLUSION

Urgent bowel resection in patients with CD is associated with higher risk of overall postoperative complications and IASCs.

The Unsolved Link of Genetic Markers and Crohn's Disease Progression: A North American Cohort Experience

BACKGROUND

While progress has been made in the identification of Crohn's disease (CD) susceptibility loci, efforts to identify a genetic basis for disease progression have been less fruitful. The specific aim of this study was to build upon the major genetic advances made in IBD by applying genome-wide technologies toward predicting disease progression in CD.

METHODS

Crohn's disease cases (n = 1495) from 3 IBD centers were reviewed by experienced physicians. Clinical and demographic details were collected, focusing on the time to first disease progression. Genome-wide association (GWA) analysis was carried out on 3 clinical outcomes: 1) time to disease progression; 2) time to first abdominal surgery; and 3) a binary analysis of indolent vs progressive disease. Cox-proportional hazard and logistic regression models were used.

RESULTS

A GWA analysis was carried out to determine any genetic variation associated with the time to disease progression; 662 cases were included after quality control (QC) and exclusion of any cases with B2/B3 behavior at baseline (n = 450). There were 1360 cases included after QC in the time to abdominal surgery analysis. No variant reached genome-wide significance in any of the 3 analyses performed. Eight known IBD susceptibility single nucleotide polymorphism (SNPs) were found to be associated with time-to-abdominal surgery SMAD3 (rs17293632), CCR6 (rs1819333), CNTF (rs11229555), TSPAN14 (rs7097656), CARD9 (rs10781499), IPMK (rs2790216), IL10 (rs3024505), and SMURF1 (rs9297145) (P < 0.05).

CONCLUSION

Our GWA study failed to show any SNP-phenotype association reaching genome-wide significance. It is likely that multiple variables affect disease progression, with genetic factors potentially having only a small effect size.

Resource use and cost of care with biologicals in Crohn's disease in South Africa: a retrospective analysis from a payer perspective

Background Crohn's disease is a relapsing remitting inflammatory disease of the gastrointestinal tract. Treatment may require expensive biological therapy in severe patients. Affordability of the high cost anti-TNF-α agents has raised concern although evidence suggests cost-offsets can be achieved. There is little information on the resource utilisation of Crohn's patients in low and middle income countries. Objective The objective of this study is to investigate the resource utilisation and costs associated with biologicals treatment of Crohn's disease. Setting The setting for this study is in private healthcare in South Africa from a payer perspective. Method A retrospective longitudinal analysis of an administrative claims database from a large private healthcare insurer of patients who had at least 1 year claims exposure prior to starting biologicals and 2 years follow-up thereafter. Resource utilisation and costs including total Crohn's costs, hospital admissions and surgery, out of hospital costs, biologicals and chronic medicines were analysed. Main outcome measure The primary objective was to compare the change in resource utilisation and costs for Crohn's related conditions before and after starting biological treatment. Results A cohort of 72 patients was identified with a 35% (p = 0.005) reduction in Crohn's related costs (excluding the cost of biologicals) from ZAR 55,925 (U$5369) 1 year before compared to ZAR 36,293 (U$3484) 2 years after starting biological medicines. However, inclusion of the cost of biologicals more than doubled the total costs to ZAR 150,915 (±91,642) U$14,488 (±8798) in Year 2. Significant reductions in out-of hospital Crohn's related spend was also observed. Conclusions A reduction in healthcare costs is seen following starting biologicals in patients with moderate to severe Crohn's disease. However, the high cost of biological therapy outweighs any possible savings achieved in other areas of healthcare utilisation.

How Will Evolving Future Therapies and Strategies Change How We Position the Use of Biologics in Moderate to Severely Active Inflammatory Bowel Disease

Several biological agents have been added to our armamentarium of treatment options for moderate to severely active inflammatory bowel diseases, and this number is expected to only increase in the near future. With our growing understanding of disease mechanisms and pharmacokinetics, we are now able to target several mechanisms of action to achieve key endpoints (steroid-free remission and mucosal healing) associated with improved long-term disease-related outcomes. In this context, concerns arise regarding the optimal positioning of currently available biologics and key biologics in development. In this review, we will discuss the currently available evidence for comparative effectiveness of biological agents approved for the use in moderate to severely active inflammatory bowel diseases, with a focus on practical considerations to be made when using these agents in practice. We will further review novel biological agents and small molecule inhibitors in development and discuss future opportunities through which providers may personalize treatment decisions to achieve optimal treatment outcomes.

Update on anti-tumor necrosis factor agents in Crohn disease

Anti-tumor necrosis factor-α (TNF) agents, including infliximab, adalimumab, and certolizumab pegol, are effective medications for the management of moderate to severe Crohn disease (CD). They are effective in inducing and maintaining clinical remission, inducing mucosal healing, improving quality of life, and reducing the risk of hospitalization and surgery in adult and pediatric patients with CD. Future research into comparative effectiveness of different agents, as well as better understanding of predictors of response, is warranted to allow optimization of therapeutic response.

Utilization trends of anti-TNF agents and health outcomes in adults and children with inflammatory bowel diseases: a single-center experience

BACKGROUND

Utilization trends and health effects of infliximab and adalimumab in inflammatory bowel disease (IBD) are incompletely understood. We aimed to describe utilization trends of these 2 anti-tumor necrosis factor (TNF) agents, determine the correlation between utilization with rates of hospitalization and surgery and describe differences in use between adults and children.

METHODS

Longitudinal data were analyzed for drug utilization, hospitalization, and abdominal surgery. Descriptive statistics were used to show trends, and utilization quotients were compared for standardization. Multivariate logistic regression analysis assessed the association between drug use and rates of hospitalization and surgery.

RESULTS

Four hundred thirty-eight pediatric and 2514 adult patients with IBD generated a total of 51,882 inpatient and outpatient encounters, representing 1185 Crohn's disease, 1531 ulcerative colitis, and 236 indeterminate colitis patients. From 2007 through 2012, utilization quotients declined for hospitalization but remained unchanged for surgery; adalimumab saw a 3-fold increase, despite continued dominance of infliximab. Median band and mean fitted plots showed downward hospitalization trends from 2006 to 2012. Utilization of infliximab peaked in 2008, Q4 with gradual decline to 2012, Q2; and adalimumab showed moderate increased utilization since 2007, Q1. Use of infliximab (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.70-0.83) and adalimumab (OR, 0.79; 95% CI, 0.72-0.87) was associated with decreased hospitalization risk but not associated with reduced abdominal surgery risk. Children had increased hospitalization (OR, 2.68; 95% CI, 2.49-2.88) but decreased risk for abdominal surgery (OR, 0.57; 95% CI, 0.46-0.70).

CONCLUSIONS

Current infliximab use remains substantially greater than adalimumab use, despite recent increased use of adalimumab. Although trends for hospitalization for IBD are decreasing, it is not reflected in abdominal surgery rates in a tertiary IBD referral center.

A UK retrospective observational study of clinical outcomes and healthcare resource utilisation of infliximab treatment in Crohn's disease

BACKGROUND

Crohn's disease (CD) places a substantial burden on healthcare systems, with the majority of costs arising from hospitalisation and surgery.

AIM

To evaluate the 'real-world' clinical effectiveness, impact on healthcare utilisation and cost of infliximab for the treatment of CD in UK practice.

METHODS

A non-interventional, retrospective analysis of medical records from patients with CD treated with infliximab at 18 hospital centres across the UK. The primary objective was to compare cumulative clinical outcomes and healthcare resource utilisation for the 0- to 24-month post-infliximab period with the 12 months preceding infliximab treatment. Predefined outcomes included the number of elective surgical procedures, hospitalisations and healthcare provider consultations. Costs associated with healthcare utilisation were collected from the perspective of the UK National Health Service (NHS).

RESULTS

The study involved 380 patients. Infliximab significantly reduced the mean number of elective (from 0.18 to 0.11; P = 0.0035) and non-elective (from 0.46 to 0.29; P < 0.0001) hospitalisations, and the number of consultations with gastroenterologists, gastrointestinal surgeons and radiologists (from 4.0 to 3.5, from 0.7 to 0.5 and from 0.5 to 0.2, respectively; all P < 0.001); all decreases were associated with significant cost reductions. The mean number of elective surgical procedures (including correction of severe anal fistulae and abscess drainage) was significantly reduced.

CONCLUSIONS

The observed reductions in numbers of hospitalisations, surgical procedures and consultations with healthcare professionals are key indicators of the clinical effectiveness of infliximab for the treatment of CD. These benefits result in overall decreases in healthcare resource utilisation, which translate into cost savings for the NHS.

Abdominal phlegmons in Crohn's disease: outcomes following antitumor necrosis factor therapy

BACKGROUND

An abdominal phlegmon is an inflammatory mass that can develop in the setting of penetrating Crohn's disease (CD). Anti-tumor necrosis factor (TNF) antibody therapy is typically avoided in CD complicated by phlegmon because of concern for peritoneal infection but may offer an effective alternative to surgical resection after infection has been controlled with antibiotics. The aim of this study was to examine outcomes for patients with CD who developed an abdominal phlegmon that was subsequently treated with an anti-TNF antibody.

METHODS

We retrospectively reviewed the records of all CD patients attending Beth Israel Deaconess Medical Center between 2004 and 2010 with an abdominal phlegmon who were treated with an anti-TNF antibody in order to evaluate the safety and efficacy of this treatment regimen.

RESULTS

There were 13 patients with CD complicated by a phlegmon treated with antibiotics and an anti-TNF antibody at our center between 2004 and 2010. Ten were male. Median time (interquartile range) from diagnosis to development of the phlegmon was 5.9 (1.9-22.7) years. The phlegmon was associated with an abscess in 12 patients. In addition to anti-TNF therapy, all patients were treated with broad-spectrum antibiotics. Anti-TNF therapy was effective without complications in all subjects. Two patients eventually had surgery more than a year after initiating anti-TNF treatment.

CONCLUSIONS

Penetrating CD complicated by phlegmon formation may be safely and effectively managed with a combination of antibiotics and anti-TNF therapy. Larger, prospective trials are required to confirm these initial findings.

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention

BACKGROUND

The prevalence of diabetes is increasing rapidly. Given its pro-inflammatory nature, comorbid diabetes may affect the course of Crohn's disease (CD).

AIM

To determine whether comorbid diabetes influences the natural history of CD.

METHODS

We compared a cohort with CD and comorbid diabetes to a nondiabetic control population and calculated the period prevalence of surgical intervention over a 5-year period. Unadjusted and adjusted odds-ratios were calculated regarding the need for surgical intervention using univariate and multivariate logistic regression.

RESULTS

A total of 240 patients were identified, 16 of whom were diabetics (6.7%). The period prevalence of CD-specific surgery in the diabetic cases was 75.0% and in the nondiabetic controls, 31.7%. The diabetic patients were more obese than the controls (44% vs. 10%; P < 0.0001) and older than the controls (47.4 years vs. 38.6; P < 0.01). There was no difference in the frequency of biologic therapy use, immunomodulator use, smoking, perianal disease, ileal involvement or corticosteroid use between the diabetics and controls. Univariate analysis revealed that diabetes (OR 6.46 [95% CI 2.01-20.8]), smoking (OR 2.46 [95% CI 1.24-4.90]), ileal disease (OR 2.21 [95% CI 1.15-4.24]) and obesity (OR 2.22 [95% CI 1.04-4.77]) were risk factors for needing surgery. After adjustment for covariates, the OR for surgical intervention in diabetics was 5.4 (95% CI 1.65-17.64).

CONCLUSION

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention.

Thirty-day mortality after elective and emergency total colectomy in Danish patients with inflammatory bowel disease: a population-based nationwide cohort study

OBJECTIVES

The purpose of this investigation was to assess 30-day mortality among Danish inflammatory bowel diseases (IBD) patients and to examine the prognostic impact of hospital total colectomy volume, age, gender and comorbidity.

DESIGN

Cohort study.

SETTING

The authors compared 30-day survival over the period 1996-2010 among 2889 IBD patients with total colectomy identified in the Danish National Registry of Patients. This registry covers all hospitals in Denmark. Postoperative survival patterns for patients with ulcerative colitis and Crohn's disease were compared, using proportional hazard regression. The regression model accounted for the timing of surgery, hospital total colectomy volume, age, gender and comorbidity.

PARTICIPANTS

Patients were enrolled in the study if they had a hospital registry diagnosis of IBD, with accompanying procedure codes for total colectomy (see codes in online appendix table 1). Hospitalisations were described as elective or emergency, and patients were categorised as having Crohn's disease, ulcerative colitis or as a mixed group.

OUTCOME MEASURES

Primary outcome measure was 30-day mortality.

RESULTS

Among 2889 IBD patients with total colectomy, 1439 (50%) underwent surgery during an emergency hospitalisation. Thirty-day mortality was 5.3% (76/1439) among emergency cases compared with 1% (14/1450) among elective cases. The highest mortality (8.1%; 11 of 136) was observed among Crohn's patients undergoing emergency surgery. The mortality of patients with ulcerative colitis undergoing emergency surgery was 5.2% (55/1056). After elective surgery, the 30-day mortality was 0.9% (8/938) among patients with ulcerative colitis and 1.5% (3/201) among Crohn's disease patients. Low hospital total colectomy volume, comorbidity and high age were associated with increased 30-day mortality in ulcerative colitis patients undergoing emergency surgery.

CONCLUSION

Emergency total colectomy among patients with ulcerative colitis and particularly Crohn's disease is associated with substantial 30-day mortality.

Health care resource use and costs in Crohn's disease before and after infliximab therapy

BACKGROUND

Infliximab therapy in patients with Crohn's disease decreases resource use; however, the overall impact on health-related expenditures is unclear, especially beyond one year of study.

METHODS

A retrospective analysis of economic data one and two years before and after infliximab therapy was performed using patients who served as their own controls. Total health care resource use and direct health care costs were compared for patients with or without fistulae.

RESULTS

Patients with one (n=66) and two (n=39) years of economic data before and after infliximab treatment had their resource use and direct health care costs estimated. In the year following initiation of infliximab therapy, there were significant decreases in health care use, reflected in total hospital days (495 to 155 [P<0.05]), inpatient colonoscopies (46 to 24 [P<0.05]), outpatient colonoscopies (58 to 33 [P<0.05]) and major surgeries (10 to 2 [P<0.05]). Direct health care costs of inpatient costs for luminal (-$1,747 [P<0.05]) and fistulizing disease (-$2,530 [P<0.05]), major surgeries (-$1240 [P<0.05]) and outpatient colonoscopies (-$184 [P<0.05]) were also significantly reduced before and after infliximab therapy. Total direct health care costs, including the drug cost of infliximab, increased ($21,416 [P<0.05]). In general, the trends in health care costs analyzed over four consecutive years paralleled the two consecutive-year analysis.&nbsp;

CONCLUSION

Infliximab therapy in patients with Crohn's disease resulted in a significant decrease in both resource use and health care costs, but an increase in total direct health care costs once the cost of infliximab was added.

Hospitalization and surgical rates in patients with Crohn's disease treated with infliximab: a matched analysis

PURPOSE

The majority of subjects with Crohn's Disease (CD) will be hospitalized and will receive surgery for their disease. These interventions account for most of the direct costs of the disease. We sought to explore the association between infliximab use and CD-related surgery and hospitalizations.

METHODS

We obtained patient-level health claims between 1996 and 2007 from the Régie de l'Assurance Maladie du Québec (RAMQ), a Canadian provincial health care insurer. Subjects who were i) enrolled in the RAMQ for at least 2 years, ii) received prescription drug benefits for each year of enrolment and iii) were identified as having CD using a validated algorithm were eligible for the study. For each subject treated with infliximab, up to two closely matched comparison subjects were selected using propensity score methods. We compared time to first CD-related intra-abdominal surgery or hospitalization in infliximab users and non-users.

RESULTS

We matched 338 infliximab users (mean age 34, 45% male) to at least one comparison subject using propensity score matching. Subjects who received infliximab had a significantly lower risk of experiencing a CD-related intra-abdominal surgery (hazard ratio [HR] = 0.64; 95% confidence interval [CI] 0.51-0.81) or hospitalization (HR = 0.73; 95% CI 0.63-0.85). Infliximab users also experienced lower rates of hospitalized days (Rate Ratio = 0.69; 95% CI 0.49-0.97).

CONCLUSIONS

Our results support the real world effectiveness of infliximab therapy in reducing CD-related surgeries and hospitalizations.

Stability of infliximab dosing in inflammatory bowel disease: results from a multicenter US chart review

OBJECTIVE

Infliximab dosing for inflammatory bowel disease (IBD) is based on patient weight and treatment response. Understanding dosing patterns may provide insight into treatment response and predictability of treatment cost. The purpose of this medical record review was to assess dose and dose frequency of infliximab maintenance treatment in patients with IBD using patient chart data.

METHODS

A retrospective chart review was conducted at 14 community gastroenterology clinics (GI clinics). Patients were aged ≥18 years, diagnosed with Crohn's disease (CD) or ulcerative colitis (UC), and had a first infliximab administration (index date) between January 1, 2005 and September 30, 2007. At least 24 months of continuous data availability were required with dosing data collected for 12 months after initiation of infliximab therapy. Patients with biologic use and/or participation in an IBD clinical trial within 12 months before the index date were excluded.

RESULTS

Charts from 182 CD patients and 86 UC patients were analyzed. About half of the patients were female. Over 90% of patients initiated treatment with infliximab 5 mg/kg. Among CD patients and UC patients, respectively, 79% and 61% continued receiving this dose for maintenance therapy at stable intervals.

LIMITATIONS

This retrospective descriptive study is limited by the type and quantity of information available in patient charts from 14 GI clinics during the first year of infliximab treatment. Further, non-anti-tumor necrosis factor medication data were intermittently collected in some charts and, therefore, did not allow for analysis.

CONCLUSIONS

Weight-based dosing and, presumably, patient response enabled providers to find the effective infliximab dose for IBD patients. The maintenance dose and administration frequency remained stable during the initial year.

A population-based study of health-care resource use among infliximab users

OBJECTIVES

We sought to describe the characteristics of health-care utilization (HCU) among patients with Crohn's disease using infliximab (IFX).

METHODS

Using the University of Manitoba Inflammatory Bowel Disease Epidemiology Database (UMIBDED), we extracted all subjects with newly prescribed IFX, newly prescribed purine analogs (azathioprine, AZA) (without IFX), newly prescribed steroids (Ster) (without IFX or purine analogs) after 2001, and those not prescribed any of these drugs (ND). All of the subjects must have had HCU data available for 5 years before initial prescription and for 3 years afterward. We analyzed the number of physician visits, hospital visits, and surgeries.

RESULTS

IBD-associated physician visits were consistently higher for IFX, both pre- and post-initial dosing, although overall physician visits were similar between IFX, AZA, and Ster. There was a steep rise in hospitalizations in the 6 months before initial prescription of IFX, AZA, or Ster, and hospitalizations were higher in the IFX cohort until 18-24 months after the first prescription, at which point levels fell to those evident 2-5 years before initiating IFX and to levels in the other drug groups. Likelihood of surgery post-dosing was greater in IFX than in AZA or ND for up to 36 months but was not different than Ster.

CONCLUSIONS

In a "step-up" approach to IFX use, it takes 2 years for the physician visits to reduce to 2-year pre-dosing rates and 18-24 months to reach hospitalization rates at 2 years pre-dosing and hospitalization rates of the AZA and Ster groups. Surgical rates to 3 years post-dosing were still higher than in AZA or ND groups.