Comparison of healthcare resource utilization and medical costs between patients with seropositive and seronegative rheumatoid arthritis.

OBJECTIVES: To compare healthcare utilization and medical costs between patients with seronegative (SN) and seropositive (SP) rheumatoid arthritis (RA). METHODS: We conducted a nationwide population study using the Korean health insurance claims database in 2016. We divided patients with RA into SN and SP groups and compared healthcare utilization including medications, medical utilization, and direct medical costs for 1 year between the groups in a cross-sectional analysis. Differences in costs between patients with SPRA and SNRA were assessed using the quantile regression model. We performed longitudinal analysis using data from 2012 and 2016 to examine changes over time. RESULTS: A total of 103,815 SPRA and 75,809 SNRA patients were included in the analyses. The SPRA group used significantly more methotrexate (73.2% versus 30.3%) and biologic agents (7.9% versus 2.9%) than the SNRA group. The number of RA-related outpatient visits [6.0 ± 3.7 versus 4.4 ± 4.0 times/year, standardized difference (SD) = 0.41] and annual medical costs per patient ($1027 versus $450/year, SD = 0.25) were higher in the SPRA group than the SNRA group. Quantile regression results indicated that the incremental cost of seropositivity on total medical costs of RA patients gradually increased as medical costs approached the upper quantile. The annual direct medical costs for each patient between 2012 and 2016 increased in both groups: by 25.1% in the SPRA group and 37.6% in the SNRA group. CONCLUSION: Annual RA-related direct medical costs and RA-related healthcare utilization per patient are higher in patients with SPRA than those with SNRA.

Temporal relationship between idiopathic inflammatory myopathies and malignancies and its mortality: a nationwide population-based study.

OBJECTIVES: To examine the temporal relationship between malignancies and idiopathic inflammatory myopathies (IIMs) and its impact on mortality. METHODS: A retrospective cohort for IIM patients was conducted using the Korean National Health Insurance Service databases. We observed more than 5 years before and after the diagnosis of IIM (2002~2016) to identify IIM patients who developed any malignancy and classified these patients into two groups: the cancer-associated myositis (CAM) group, who developed malignancy within 3 years before or after the diagnosis of IIM and the cancer-not-associated myositis (CNAM) group, who developed malignancy beyond 3 years of IIM onset. The survival rates of the two groups were compared. RESULTS: We identified 1072 incident cases of IIM between 2007 and 2011. A total 225 patients of these patients were diagnosed with malignancy. The development of malignancy was frequent within 1 year before and after the time of IIM diagnosis. The common sites of malignancies in the CAM group differed from those in the CNAM group: the lung, hematologic malignancy, and the liver were common in both groups, but thyroid and oropharynx followed them in CAM while prostate, stomach, breast, and thyroid followed them in CNAM. CAM patient mortality was worse compared with CNAM patients (log-rank test, p < 0.01). CONCLUSIONS: Among IIM patients with malignancy, common sites of malignancy were different between the CAM and CNAM groups, and patients with CAM had poor prognosis compared with CNAM patients. Key Points • The malignancies commonly occurred in incident idiopathic inflammatory myopathy (IIM) patients, especially within 1 year before and after the initial IIM diagnosis. • Patients with malignancy had poor survival compared with patients without malignancy. • Among the IIM patients with malignancy, patients who developed malignancy within 3 years of IIM diagnosis (cancer-associated myositis, or CAM, group) showed higher mortality than cancer-not-associated myositis, CNAM group. • We also found that the common types of malignancy were different between the CAM and CNAM groups.

Factors for starting biosimilar TNF inhibitors in patients with rheumatic diseases in the real world.

BACKGROUND: To identify factors for starting biosimilar TNF inhibitors (TNFI) in patients with rheumatic diseases. METHODS AND FINDING: Using a national claims database, we identified patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) who had used TNFIs since they were approved in Korea in 2004. We assessed changes in the proportion of each form of TNFI used between 2004 and 2017. We then selected patients starting on TNFIs between 2013 and 2017 to identify factors for starting biosimilars. In RA (n = 4,216), biosimilars were more likely to be initiated in clinics [odds ratio (OR) 2.54] and in the metropolitan area (OR, 2.02), but were less likely to be initiated in general hospitals (OR 0.40) or orthopedics (OR 0.44). In AS (n = 2,338), biosimilars were common at the hospital level (OR 2.20) and tended to increase over the years (OR 1.16), but were initiated less in orthopedics (OR 0.07). In addition, RA patients were more likely to initiate biosimilars in combination with methotrexate (OR 1.37), but biosimilars were not initiated frequently by patients with higher comorbidity scores (OR 0.97) or receiving glucocorticoids (OR 0.67). The patient factors favoring biosimilar in AS use were not clear. CONCLUSIONS: In Korea, the proportion of biosimilar TNFIs has increased. Type of institution and physician specialty are more important than patient factors in affecting biosimilar use. In RA, biosimilar TNFIs tend to be initiated in combination with MTX, and are less likely to be initiated in patients taking glucocorticoids or in those with high comorbidities.

Effect of a Nationwide Real-Time Drug Utilization Review System on Duplicated Nonsteroidal Antiinflammatory Drug Prescriptions in Korea.

OBJECTIVE: Since January 2013, a nationwide drug utilization review (DUR) system for therapeutic duplication (TD) of nonsteroidal antiinflammatory drugs (NSAIDs) has been implemented in Korea. Our objective was to perform an interrupted time series study to assess changes in the pattern of NSAIDs use in knee osteoarthritis patients after implementation of the regulations. METHODS: We compared the prescribing patterns in 2012 and 2013 by means of an interrupted time series study, using the Health Insurance Review and Assessment Service database. TD was defined as use of concurrent NSAIDs either on the same or on different prescriptions for >3 days in a patient. Level change and trend change (with 95% confidence intervals [95% CIs]), and absolute and relative changes in the proportion of TDs, were estimated using segmented regression models. Multivariable logistic regression models were used to explore patient and provider characteristics associated with the TDs. RESULTS: Approximately 2.5 million patients were prescribed NSAIDs in both 2012 and 2013. The proportion of TDs before and after introduction of the DUR system was 7.4% and 5.6%, respectively. Overall, an absolute reduction of 89% and a relative reduction of 30% in TDs were observed. In the postregulation period, older patients, medical aid subscribers (odds ratio [OR] 1.87 [95% CI 1.84, 1.90]), and veterans (OR 3.28 [95% CI 3.10, 3.46]) were most likely to receive NSAID TDs. CONCLUSION: The prescription of NSAID TDs decreased with the introduction of the nationwide DUR system. Continuous adherence to the DUR regulations and safety monitoring are needed, especially with the elderly, medical aid subscribers, and veterans.

Increased risk of malignancy in patients aged over 50 with idiopathic inflammatory myositis compared to patients with osteoarthritis of the knee.

Objectives: To estimate risk of malignancy in patients with idiopathic inflammatory myositis (IIM) compared to patients with knee osteoarthritis (OA).Methods: Patients with IIM and knee OA aged over 50, who had no history of malignancy, were identified using Korean National claims database from January 2012 to December 2014. They had been observed until a malignancy was diagnosed or up to the end of the study, December 2015. The incidence rate (IR) of malignancy in IIM patients was calculated and compared with knee OA patients using standardized incidence ratio (SIR).Results: A total of 634 polymyositis (PM) and 556 dermatomyositis (DM) patients were included. Overall, 100 solid (IR 270.4/10,000 person-years (PY), 95% confidence interval (CI) 217.4-323.4) and 12 hematologic malignancies (IR 32.4/10,000 PY, 95% CI 14.1-50.8) occurred. Compared with knee OA, risk of overall (SIR 1.5, 95% CI 1.2-1.8), solid (SIR 1.4, 95% CI 1.1-1.6), and hematologic malignancy (SIR 5.7, 95% CI 2.5-9.0) were increased in IIM patients. This was due to increased incidence of malignancy in DM (hematologic malignancy, SIR 8.7, 95% CI 2.7-14.7, solid malignancy, SIR 1.5, 95% CI 1.1-1.9).Conclusion: Patients with IIM, especially DM, have an increased risk of malignancy compared to patients with knee OA.

Factors related to the use of opioids as early treatment in patients with knee osteoarthritis.

OBJECTIVE: To examine factors related to the use of opioids as an early treatment option for knee OA patients METHODS: Using the Korean nationwide claim database, we selected knee OA patients between 2013 and 2015. Among them, patients without any claim of knee OA for 2 years before the index date were included as our study population. We analyzed their first claim for prescriptions, including tramadol and stronger opioids, at the index date of each patient. Using a multinomial model, we identified factors associated with the early use of tramadol and stronger opioids in knee OA patients. RESULTS: Among a total of 2,857,999 knee OA patients, 12.2% (n = 348,516) were treated with opioids as their first treatment. However, the prevalence of stronger opioid use was only 0.07% (n = 1972). Male sex (OR 1.28 in tramadol, OR 1.13 in stronger opioids) and comorbidities with depression (OR 1.05, 1.46), low back pain (OR 1.13, 1.30), intervertebral disc disorder (OR 1.11, 1.40), and spinal stenosis (OR 1.27, 1.55) were the factors for the early use of tramadol or stronger opioids in knee OA patients. Patients in a tertiary referral hospital tended to use tramadol or stronger opioids than those in clinics (OR 1.04, 56.63, respectively). CONCLUSION: In Korea, 12.2% of knee OA patients were treated with opioids as an early treatment, and tramadol was used more commonly than stronger opioids. Male sex and having comorbidities such as depression or musculoskeletal disease are patient factors associated with the early use of opioids in knee OA patients.

A Real-World Analysis of Prescribing Patterns and Non-persistence of Anti-TNFα Therapy for Inflammatory Bowel Disease.

BACKGROUND AND OBJECTIVES: Anti-tumor necrosis factor alpha (anti-TNFα) therapy is key to the treatment of inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn's disease (CD). The objective of this study was to investigate prescribing patterns and non-persistence of anti-TNFα therapy for the treatment of IBD in a real-world scenario. METHODS: Data from the Korean National Health Insurance claims database obtained between 2010 and 2014 were evaluated to identify patients with IBD who had received anti-TNFα therapy (infliximab or adalimumab). Patient characteristics and prescribing patterns were investigated. The non-persistence rate and associated reasons were determined in patients who initiated therapy between 2010 and 2012. RESULTS: A total of 131,158 patients with UC and 57,286 with CD were identified. Of these 1747 UC (1.3%) and 3731 (6.5%) CD patients had received anti-TNFα therapy and were included in the analysis. Infliximab was prescribed more frequently than adalimumab (84.6% vs 15.4% in UC and 80.7% vs 19.4% in CD); 81.0% of UC and 72.0% of CD patients received anti-TNFα alone or in combination with 5-aminosalicylic acid. The non-persistence rate of anti-TNFα therapy was 72.6% and 80.4% in the UC and CD groups, respectively, with discontinuation of medication being the most common reason in both the UC and CD groups (63.9% and 73.3%, respectively). CONCLUSION: The use of anti-TNFα therapy was seen to be low, with a high rate of non-persistence. Further research efforts are required to improve the response rate and, therefore, improve persistence in patients with IBD.

Treatment patterns of knee osteoarthritis patients in Korea.

BACKGROUND/AIMS: To evaluate the treatment patterns of knee osteoarthritis (OA) patients in South Korea. METHODS: Using the Korean nationwide claims database, all knee OA patients in Korea during 2014 were identified by the knee OA diagnostic code (M17) or any OA diagnostic code (M15 to M19) in combination with a procedure for a knee X-ray. Patterns of medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CSs), analgesics, and symptomatic slow acting drugs for OA (SYSADOA) were analyzed. Prevalence and characteristics of knee OA patients who received a CS intra-articular injection (IAI) were also evaluated. RESULTS: We identified 2,016,516 knee OA patients whose age (mean ± standard deviation) was 63.2 ± 10.8 years. The number of patients with at least one use of NSAIDs, analgesics, CS, and SYSADOA were 82.5%, 32.2%, 8.6%, and 43.4%, respectively. The use of herbal SYSADOAs was 29.7%. For regular users (medication possession ratios ≥ 50%), the use of NSAIDs was substantially decreased (48.8%), while the use of SYSADOA (37.3%) and CS (6.7%) were not significantly changed. The number of CS IAI users among knee OA patients was 0.18%; they were slightly older (64.4 ± 10.9 vs. 63.2 ± 10.8, p < 0.01) and more skewed towards females (75.7% vs. 71.5%, p < 0.01) than patients who had not received CS IAI. CONCLUSION: In Korea, the use of SYSADOA or CS in knee OA patients was relatively high. Further studies on the effectiveness and the safety of these treatment options for knee OA are needed.

Comparative effectiveness of oral pharmacologic interventions for knee osteoarthritis: A network meta-analysis.

OBJECTIVES: To explore the relative efficacy of oral pharmacologic interventions in the treatment of knee OA. METHODS: A systematic literature review was conducted using the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases to identify trials conducted in patients with knee OA with a minimum 6 weeks of follow-up. The standardized mean differences of the change from baseline to week 6 in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain between the treatment groups were estimated using Bayesian random-effects network meta-analyses. Subgroup analyses of baseline pain status (high, pain score ≥60 mm; low, pain score <60 mm) were performed. RESULTS: Of 4067 manuscripts, 44 were included in the evidence synthesis. Etoricoxib had the highest ranking for improving WOMAC pain (probability of being top ranked, p (best) = .43) followed by naproxen (p (best) = .12), acetaminophen (AAP) (p (best) = .04), and celecoxib (p (best) = .02). The top three ranked interventions were etoricoxib, celecoxib and aceclofenac in the higher pain group, and tramadol, celecoxib, and diclofenac in the lower pain group. CONCLUSION: In the overall analysis, etoricoxib, celecoxib, and aceclofenac had the highest rankings for improving WOMAC pain. The ability to improve knee OA symptoms may differ depending on baseline pain and radiologic features.