Effects of biologics on reducing the risks of total knee replacement and total hip replacement in rheumatoid arthritis.

OBJECTIVES: RA damages the joints and increases the risks of total knee replacement (TKR) and total hip replacement (THR). However, the benefits of biologics in preventing TKR or THR remain unclear. METHODS: This retrospective nationwide study used the 2000-2013 claims-based National Health Insurance dataset. Biologics are reimbursed for refractory cases. The risks of TKR and THR in the biologic cohort were compared with those of an age- and sex-matched csDMARD cohort. A multivariate Cox regression model was used to investigate the benefits of bDMARDs for TKR and THR. RESULTS: TKR was performed in 5979 biologic cases and 11 958 matched controls, of which 249 (4.16%) and 871 (7.28%) cases received TKR, respectively. THR was performed in 6245 biologic cases and 12 490 matched controls, of which 159 (2.55%) and 516 (4.13%) cases had THR, respectively. The biologic cohort had significantly lower incidence rates of TKR (11.73 vs 16.33/1000 person-years, P < 0.001) and THR (7.09 vs 9.16/1000 person-years, P < 0.001). After adjustment for confounding factors, the regular bDMARD subgroup (average dose >0.95 defined daily dose/day) had significantly lower risks of TKR (aHR: 0.55, 95% CI: 0.38, 0.81) and THR (aHR: 0.63, 95% CI: 0.40, 0.98). Those without MTX use, with steroid use, with biologic switch, and overlapping antiphospholipid syndrome had significantly higher risks of TKR and THR. CONCLUSIONS: Compared with the csDMARD cohort, the risks of TKR and THR in the bDMARD cohort were the same as those in the low-to-moderate dose subgroups and significantly lower in those with regular bDMARD use.

Spinal cord injury and spinal fracture in patients with ankylosing spondylitis.

BACKGROUND: Spinal cord injury (SCI) and spinal fracture are major complications in patients with ankylosing spondylitis (AS) who sustain spinal trauma. The purpose of this study was to investigate the incidence, predictors, and sequelae of spinal trauma in patients with AS. METHODS: This retrospective study included patients with AS who were admitted for spinal trauma between January 1, 2006, and June 30, 2016. The study compared clinical outcomes of patients between group 1: SCI alone, group 2: spinal fracture alone (no SCI), and group 3: both SCI and spinal fracture. RESULTS: Of the 6285 patients with AS admitted during the retrospective study period, only 105 suffered from spinal trauma and were enrolled in the study. Case number in group 1, 2, and 3 was 11(10.48%), 45(42.85%), and 49(46.67%), respectively. Among the patients with spinal fractures, 52.1% had SCI. Bamboo spine was significantly more prevalent in the fracture group than in the nonfracture group (78.7% vs. 36.4%; P = 0.006). Patients with SCI had more instances of subluxation or dislocation (48.3% vs. 8.9%; P < 0.001) and more cases of spinal epidural hematoma (SEH; 21.7% vs. 2.2%; P = 0.003) than patients without SCI. The rate of delayed diagnosis for spinal fracture was 31.4%, with one-third of patients developing delayed SCI. Among the patients with incomplete SCI, 58.3% achieved neurological improvement after treatment (P = 0.004). CONCLUSIONS: Patients with AS and bamboo spine at radiograph had a higher rate of spinal fracture, which may be an important factor in SCI in patients with AS. Spinal fractures involving the C3-C7 region, subluxation or dislocation, severe spinal fracture, and SEH were found to be predictive of SCI, and SCI in patients with AS resulted in higher mortality and complication rates.

Thymectomy in patients with myasthenia gravis increases the risk of autoimmune rheumatic diseases: a nationwide cohort study.

Objectives: Previous studies have shown myasthenia gravis (MG) and autoimmune rheumatic diseases (ARDs) share common pathogenetic mechanisms. Therefore, the present study investigated the possible relationship between MG and ARDs. Methods: We analysed Taiwanese medical data from the Registry of Catastrophic Illness and identified patients with MG. From the entire general population data of the National Health Insurance Research Database, we randomly selected a comparison cohort that was frequency-matched by age (in 5-year increments), sex, and index date. We analysed the risk of ARDs by using a Cox proportional hazards regression model stratified by sex, age and treatment. Results: In the present study, we enrolled 6478 patients with MG (58.03% women; mean age, 50.55 years) and 25 912 age- and sex-matched controls. The risk of total ARDs was 6.25 times higher in the MG cohort than in the non-MG cohort after adjustment for age and sex. Furthermore, the MG cohort was associated with a significantly higher risk of primary SS (pSS), SLE and other ARD types (adjusted hazard ratios: 15.84 [95% CI: 8.39, 23.91]; 11.32 [95% CI: 5.04, 25.429]; and 4.07 [95% CI: 1.31, 12.62], respectively). The MG cohort who underwent thymectomy had an increased risk of RA, pSS and SLE (adjusted hazard ratios: 4.41; 15.06; and 23.68, respectively). Conclusion: The present nationwide cohort study revealed an association between MG and incident ARDs. The MG cohort who underwent thymectomy had an increased risk of RA, pSS and SLE. Future studies are needed to elucidate the underlying pathogenesis and to translate this into clinical therapeutic options.

Identification of tophi in ultrasound imaging based on transfer learning and clinical practice.

Gout is a common metabolic disorder characterized by deposits of monosodium urate monohydrate crystals (tophi) in soft tissue, triggering intense and acute arthritis with intolerable pain as well as articular and periarticular inflammation. Tophi can also promote chronic inflammatory and erosive arthritis. 2015 ACR/EULAR Gout Classification criteria include clinical, laboratory, and imaging findings, where cases of gout are indicated by a threshold score of ≥ 8. Some imaging-related findings, such as a double contour sign in ultrasound, urate in dual-energy computed tomography, or radiographic gout-related erosion, generate a score of up to 4. Clearly, the diagnosis of gout is largely assisted by imaging findings; however, dual-energy computed tomography is expensive and exposes the patient to high levels of radiation. Although musculoskeletal ultrasound is non-invasive and inexpensive, the reliability of the results depends on expert experience. In the current study, we applied transfer learning to train a convolutional neural network for the identification of tophi in ultrasound images. The accuracy of predictions varied with the convolutional neural network model, as follows: InceptionV3 (0.871 ± 0.020), ResNet101 (0.913 ± 0.015), and VGG19 (0.918 ± 0.020). The sensitivity was as follows: InceptionV3 (0.507 ± 0.060), ResNet101 (0.680 ± 0.056), and VGG19 (0.747 ± 0.056). The precision was as follows: InceptionV3 (0.767 ± 0.091), ResNet101 (0.863 ± 0.098), and VGG19 (0.825 ± 0.062). Our results demonstrate that it is possible to retrain deep convolutional neural networks to identify the patterns of tophi in ultrasound images with a high degree of accuracy.

Association of interferon-based therapy with risk of autoimmune diseases in patients with chronic hepatitis C virus infection: A population-based Taiwanese cohort study.

Background: Interferon in combination with ribavirin has been the standard of care for chronic hepatitis C virus infection (HCV) for the past few decades. However, its effect on the risk of autoimmune diseases (ADs) among patients with HCV infection remains unclear. We assessed the potential association between interferon-based therapy (IBT) and AD risk in patients with HCV infection. Methods: This retrospective cohort study identified patients diagnosed with HCV infection between January 1, 2006, and December 31, 2015, from Taiwan's National Health Insurance Research Database. In total, 16,029 patients with HCV infection who received IBT and 141,214 patients with HCV infection who did not receive IBT were included. Both cohorts were followed up to assess the development of ADs. Hazard ratios (HRs) were calculated using the Cox proportional hazards regression model, which was adjusted for potential confounders. Results: The median follow-up period for IBT and non-IBT users was 4.53 and 3.34 years, respectively. No significant difference in the risk of overall ADs (adjusted HR [aHR]: 0.96, 95% confidence interval [CI]: 0.81-1.14) or systemic ADs (aHR: 0.88, 95% CI: 0.71-1.10) was noted during the study period. However, a slight increase in the risk of organ-specific ADs was noted among IBT users (incidence rate ratio: 1.33, 95% CI: 1.02-1.72). Furthermore, analysis of AD subgroups revealed a significant increase in the risks of Graves' disease (aHR: 6.06, 95% CI: 1.27-28.8) and Hashimoto's thyroiditis (aHR 1.49, 95% CI 1.01-2.21) among IBT users. Conclusions: IBT use increases the risk of autoimmune thyroid diseases (Hashimoto's thyroiditis and Graves' disease) in patients with HCV infection to a greater extent than non-IBT use.

H1-Antihistamines Reduce the Risk of Hepatocellular Carcinoma in Patients With Hepatitis B Virus, Hepatitis C Virus, or Dual Hepatitis B Virus-Hepatitis C Virus Infection.

PURPOSE: H1-antihistamines (AHs) may exert protective effects against cancer. This study investigated the association of AH use with the risk of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV), hepatitis C virus (HCV), or dual HBV-HCV virus infection. MATERIALS AND METHODS: Patients with HBV, HCV, or dual HBV-HCV infection were enrolled from Taiwan's National Health Insurance Research Database and examined for the period from January 1, 2006, to December 31, 2015. We used the Kaplan-Meier method and Cox proportional hazards regression to evaluate the association between AH use and HCC risk. RESULTS: We included patients with HBV infection (n = 521,071), HCV (n = 169,159), and dual HBV-HCV (n = 39,016). Patients with HBV, HCV, or dual virus infection who used AHs exhibited significantly lower risk of HCC relative to patients who did not use AH, with their adjusted hazard ratio being 0.489 (95% CI, 0.455 to 0.524), 0.484 (95% CI, 0.450 to 0.522), and 0.469 (95% CI, 0.416 to 0.529), respectively. Furthermore, there was a dose-response relationship between AH use and the risk of HCC in the HBV cohort. The adjusted hazard ratios were 0.597 (95% CI, 0.530 to 0.674), 0.528 (0.465 to 0.600), 0.470 (0.416 to 0.531), and 0.407 (0.362 to 0.457) for AH use of 28-42, 43-63, 64-119, and ≥ 120 cumulative defined daily doses, respectively, relative to no AH use. Additionally, there was also a dose-response relationship between AH use and the risk of HCC in the HCV and dual HBV-HCV cohorts. CONCLUSION: AH use may reduce the risk for HCC among patients with HBV, HCV, or dual infection in a dose-dependent manner. Further mechanistic research is needed.

Primary Sjogren syndrome increases the risk of bisphosphonate-related osteonecrosis of the jaw.

The risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in primary Sjogren syndrome (pSS) has rarely been explored. To explore the association between BRONJ and pSS, we conducted a population-based propensity-score-matched cohort study using Taiwan's National Health Insurance Research Database, including pSS patients receiving antiosteoporotic therapy and patients without pSS receiving antiosteoporotic therapy. A 1:4 matched-pair cohort based on propensity score was created. The stratified Cox proportional hazards model compared the risk of BRONJ in the pSS and non-pSS groups. In the study, 23,280 pSS patients and 28,712,152 controls were enrolled. After matching, 348 patients with pSS receiving antiosteoporotic drugs and 50,145 without pSS receiving antiosteoporotic drugs were included for analysis. The risk of developing BRONJ was 1.96 times higher in pSS patients compared with non-pSS patients after adjustment for age, sex, and comorbidities. No dose-response effect was observed in the bisphosphonate-treated pSS cohorts, documented as the cumulative defined daily doses of either < 224 or ≥ 224 (hazard ratio [HR]: 2.407, 95% confidence interval [CI] 1.412-7.790; HR: 2.143, 95% CI 1.046-4.393, respectively) increased risk of developing osteonecrosis of the jaw. In conclusion, the risk of BRONJ is significantly higher in patients with pSS compared with the general population.

Proton Pump Inhibitors Increase the Risk of Autoimmune Diseases: A Nationwide Cohort Study.

Background: Previous study revealed proton pump inhibitors (PPIs) have an effect on gut microbiota. Alteration of the microbiome causes changes of the host immune system and then induces the development of autoimmune diseases (ADs). This study aimed to explore the possible association between PPIs use and ADs. Methods: This study was conducted using data from the Taiwan National Health Insurance Research Database in the period between 2002 and 2015. We performed multivariate and stratified analysis through the Kaplan-Meier method and Cox proportional hazard models to estimate the association between proton pump inhibitor use and the risk of autoimmune diseases. Results: Of the 297,099 patients treated with PPI identified, the overall mean (SD) age was 49.17 (15.63) years and 56.28% of the subjects was male. As compared with the non-PPI group, the adjusted hazard ratio (aHR) were higher for incident organ specific ADs such as Graves disease (aHR=3.28), Hashmoto thyroiditis (aHR=3.61), autoimmune hemolytic anemia (aHR=8.88), immune thrombocytopenic purpura (aHR=5.05) Henoch-Schonlein pupura (aHR=4.83) and Myasthenia gravis (aHR=8.73). Furthermore, the adjusted hazard ratio (aHR) were also higher for incident systemic ADs such as ankylosing spondylitis (aHR=3.67), rheumatoid arthritis (aHR=3.96), primary Sjogren syndrome (aHR=7.81), systemic lupus erythemtoasus (aHR=7.03). systemic vasculitis (aHR=5.10), psoriasis (aHR=2.57), systemic scleroderma (aHR=15.85) and inflammatory myopathy (aHR=37.40). Furthermore, we observed no dose-dependent effect between PPI use and the risk of ADs. Conclusions: Our retrospective population-based cohort study showed that the prescription of proton pump inhibitors is associated with a higher risk of ADs.

Pneumocystis jirovecii pneumonia in autoimmune rheumatic diseases: a nationwide population-based study.

OBJECTIVE: To compare Pneumocystis jirovecii pneumonia (PJP) risk between patients with autoimmune rheumatic diseases (ARD) and the general population METHODS: We identified patients with ARD recorded in the National Health Insurance Research Database of Taiwan from 2002 to 2015 and randomly selected a comparison cohort from the general population matched for age and sex. We analyzed PJP risk stratified by sex, age, comorbidities, and medications using Cox proportional hazard model. RESULTS: We enrolled 103,117 patients with ARD. PJP risk significantly increased in patients with any ARD and with each individual ARD like rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sjogren's syndrome (SjS), polymyositis and dermatomyositis (PM/DM), systemic sclerosis (SSc), and systemic vasculitis. Patients with PM/DM showed prominent risk with incidence rate of 12.47/100,000 patient year (95% confidence interval (CI), 32.16-86.70). In a time-dependent Cox proportional hazard model with comorbidities and medications as covariates, PM/DM, SSc, SLE, and SjS significantly increased adjusted hazard ratios (aHR) of 5.40, 5.12, 4.09, and 3.64, respectively (95% CI of 2.82-10.35, 2.16-12.13, 2.41-6.95, and 2.06-6.42, respectively). AHR after adjusting for male sex, cancer, human immunodeficiency virus infection (HIV), and interstitial lung disease also significantly increased. Use of daily oral steroid dose of >10 mg conferred the highest risk followed by mycophenolate. Use of injected steroids, cyclophosphamide, biological agents, methotrexate, and cyclosporine conferred a significantly higher risk. CONCLUSION: Underlying ARD significantly predisposes patients to PJP, with PM/DM posing the highest threat. In addition to underlying disease, comorbidities and concomitant immunosuppressants are major risks. The strongest risk is recent daily steroid dose of >10 mg. Mycophenolate seems to be a more prominent risk factor than cyclophosphamide. Key Points • Autoimmune rheumatic diseases (ARD) significantly increased the overall risk of PJP, and so did each individual ARD. • Use of steroids, mycophenolate, cyclophosphamide, biological agents, methotrexate, and cyclosporine all significantly increased risk of PJP. • Male, elderly, malignancy, HIV, and interstitial lung disease are also related to increased risk of PJP. • Underlying ARD, comorbidities, and use of immunosuppressant should all be considered in determining the overall risk of PJP.

Higher risk of Parkinson disease in patients with primary Sjögren's syndrome.

OBJECTIVE: This study assessed the risk of Parkinson disease (PD) in patients with primary Sjögren's syndrome (pSS) using a nationwide, population-based cohort during a 15-year follow-up period. METHOD: We identified 17,028 patients with pSS by using the catastrophic illness registry in the Taiwan National Health Insurance Research Database, and 68,094 matched non-pSS controls. RESULTS: The pSS cohort showed a higher incidence of PD development than did the non-pSS cohort (1.60% vs. 1.17%, p = 0.0001). The adjusted hazard ratio (aHR) of developing PD was 1.23 times greater in the pSS group than in the non-pSS group. When stratified by sex, age, and comorbidities, the female patients with pSS and patients aged between 61 and 70 years were associated with a higher PD risk (aHR 1.28 and aHR 1.30, respectively). Patients with pSS with no other comorbidity had a higher risk of PD (aHR: 2.17), compared with the non-pSS patients with no other comorbidity. When comparing non-pSS patients without or with comorbidity with pSS without or with comorbidity, pSS patients with comorbidity had highest risk of PD (aHR: 3.814). CONCLUSIONS: All of the above findings suggested that pSS is an independent risk factor for the development of PD. Key Points •The patients with pSS had 1.23 times risk of Parkinson disease than the non-pSS group. •The female patients with pSS and patients aged between 61 and 70 years were associated with a higher PD risk (aHR 1.28 and aHR 1.30, respectively). •The pSS patients with comorbidity had highest risk of PD (aHR: 3.814).

Risk of incident autoimmune diseases in patients with thymectomy.

OBJECTIVES: The data concerning the association between Tx and ADs remain unclear and are scarce. This study was undertaken to investigate whether people with Tx are more likely to develop ADs, compared to those without Tx. METHODS: Individuals who received Tx between 2002 and 2015 were identified and matched on age and sex with individuals without Tx. We performed multivariate and stratified analysis using the Kaplan-Meier method and Cox proportional hazards models in order to estimate the association between Tx and the risk of developing ADs. RESULTS: A total of 2550 thymectomized (Txd) patients and 24,664.941 non-Txd comparison subjects were selected from NHIRD. Tx-MG (myasthenia gravis) as compared with general population (nonTx-nonMG), adjusted hazard ratio (aHR) were higher for incident Addison disease (aHR = 10.40, 95% CI 1.01-107), autoimmune hemolytic anemia (aHR = 21.54, 95% CI 2.06-14.8), Hashmoto thyroiditis (aHR = 5.52, 95% CI 1.34-34.7), ankylosing spondylitis (aHR = 2.73, 95% CI 1.09-6.84), rheumatoid arthritis (aHR = 5.25, 95% CI 1.79-15.47), primary Sjogren syndrome (pSS) (aHR = 3.77, 95% CI 1.30-11.0), and systemic lupus erythemtoasus (aHR = 10.40). Tx-nonMG as compared with general population, aHR were higher for incident autoimmune hemolytic anemia (aHR = 25.50), Hashmoto thyroiditis (aHR = 6.75) and systemic lupus erythematosus (SLE) (aHR = 13.38). NonTx-MG as compared with general population, aHR were higher for incident Hashmoto thyroiditis (aHR = 6.57), pSS (aHR = 4.50), SLE (aHR = 17.29), and systemic vasculitis (aHR = 25.86). INTERPRETATION: In conclusion, based on a retrospective cohort study throughout Taiwan, patients with Tx have a higher risk of new onset ADs than patients without Tx.

Do etoricoxib and indometacin have similar effects and safety for gouty arthritis? A meta-analysis of randomized controlled trials.

BACKGROUND: Gout, a common medical condition that causes pain, can be treated by painkillers and anti-inflammatories. Indometacin and etoricoxib are two such drugs. However, no synthesized evidence exists comparing etoricoxib with indometacin in treating patients with gout. METHODS: We searched PubMed, Embase, Ovid MEDLINE, Web of Science, ScienceDirect, and the Cochrane Library without restrictions on language or publication date for potential randomized clinical trials comparing etoricoxib with indometacin for gout. The meta-analysis was conducted using a random-effects model. RESULTS: Search results yielded 313 references from six electronic databases, four of which met the eligibility criteria. These four were randomized clinical trials, and they involved a total of 609 patients with gouty arthritis. No significant differences were observed in pain score change, tenderness, or swelling between etoricoxib and indometacin; the mean differences were -0.05 (95% CI, -0.21 to 0.10), -0.06 (95% CI, -0.18 to 0.05), and -0.04 (95% CI, -0.17 to 0.09). However, the pooled data revealed that significantly fewer overall adverse events occurred in the etoricoxib group (n=105, 33.5%) than in the indometacin group (n=130, 44.1%) and the risk ratio was 0.77 (95% CI, 0.62-0.94). CONCLUSION: Our meta-analysis revealed that etoricoxib and indometacin have similar effects on pain relief. However, etoricoxib has a significantly lower risk of adverse events than does indometacin, especially digestive system-related adverse events.

Higher risk of dementia in primary Sjogren's syndrome.

OBJECTIVE: We studied the risk of dementia in patients with primary Sjögren's syndrome (pSS) using a nationwide, population-based cohort in Taiwan. METHODS: Our study analyzed the medical data of the Taiwanese population from 2000 to 2014. We identified 17,072 patients with pSS and 68,270 controls. Dementia risk was analyzed using a Cox proportional hazards regression model stratified by sex, age, and comorbidities. RESULTS: A higher incidence of dementia development in the pSS group during the observation period (P = 0.0001). In multivariate analysis adjusted by age groups, gender, and the comorbidities, the adjusted hazard ratio (aHR) of developing dementia was 1.246 (95% CI 1.123-1.384) times greater in the pSS group than in the non-pSS group. When stratified by sex, age, and comorbidities, the patients with pSS less than 60 years (aHR 1.67, 95% CI 1.16-2.41), and without any comorbidity (aHR 2.27, 95% CI 1.76-2.93) were particularly associated with a higher risk of dementia. Furthermore, the patients with pSS combined with any other comorbidity had an additionally higher risk of dementia (aHR: 3.978, 95% CI 3.309-4.782), also suggesting that pSS was an independent risk factor for the development of dementia. INTERPRETATION: Primary Sjogren's syndrome is associated with increased dementia risk and further study is needed to understand why and what the specific dementia phenotypes are.

Autoimmune rheumatic diseases increase dementia risk in middle-aged patients: A nationwide cohort study.

OBJECTIVE: Dementia is a common neurological disease that substantially affects public health. A previous study revealed that dementia occurs when the body's immune system attacks the cells of the brain, indicating that dementia may be similar to autoimmune rheumatic diseases (ARDs). In the current retrospective cohort study, we focused on middle-aged ARD patients (45 years or older) to investigate the association between ARDs in middle-aged people and dementia by using a nationwide population-based database in Taiwan. METHOD: Our study analyzed the medical data of the Taiwanese population from 2001 to 2012, with a follow-up period extending until the end of 2011. We identified middle-aged patients with ARDs by using the Taiwan National Health Insurance Research Database. We selected a comparison cohort from the general population that was randomly frequency-matched by age (in 5-year increments), sex, and index year and further analyzed the dementia risk by using a Cox regression model that considers sex, age, and comorbidities. RESULTS: The study enrolled 34,660 middle-aged ARD patients (77% female, mean age = 59.8 years) and 138,640 controls. The risk of developing dementia was 1.18 times higher for middle-aged patients with ARDs compared with patients without ARDs after adjustment for age, sex, and comorbidities. Among the patients with ARDs, the subgroups with rheumatoid arthritis, systemic lupus erythematosus, and Sjögren syndrome (SS) were associated with a significantly higher dementia risk (adjusted hazard ratio [HR] 1.14, 95% confidence index [CI] 1.06-1.32; adjusted HR 1.07, 95% CI 0.86-1.34; adjusted HR 1.46, 95% CI 1.32-1.63, respectively). Furthermore, primary SS and secondary SS patients had the highest risks of dementia among all the ADR subgroups (adjusted HR 1.35, 95% CI 1.18-1.54; adjusted HR 1.67, 95% CI 1.43-1.95 respectively). CONCLUSION: This nationwide retrospective cohort study demonstrated that dementia risk is significantly higher in middle-aged patients with ARDs compared with the general population.

Autoimmune rheumatic diseases and the risk of Parkinson disease: a nationwide population-based cohort study in Taiwan.

BACKGROUNDS: In autoimmune rheumatic diseases (ARDs), the levels of inflammatory mediators are increased and microglia may be activated, resulting in an inflammatory state and the degeneration of dopaminergic neurons. We investigated the association between ARDs and Parkinson disease (PD). METHODS: We identified ARD patients through the Taiwan National Health Insurance Research Database from 2001 to 2012. From the general population, we randomly selected a comparison cohort that was frequency-matched by age (in 5-year increments), sex and index year. We analysed the risk of PD, stratified by sex, age and comorbidities, by using a Cox regression model. RESULTS: The risk of PD was 1.37 times greater in ARD patients than in controls after adjustment for age, sex, and comorbidities. ARD subgroups, such as the rheumatoid arthritis and Sjogren syndrome (SS) cohorts, were associated with a significantly higher risk of PD (adjusted hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.03-1.2 and adjusted HR, 1.56; 95% CI, 1.35-1.79, respectively). Furthermore, primary and secondary SS patients had significantly higher risks of PD (adjusted HR, 1.58; 95% CI, 1.32-1.88 and adjusted HR, 1.53, 95% CI, 1.23-1.90, respectively). CONCLUSIONS: The risk of PD was significantly higher in the ARD patients. Prospective studies are needed to confirm whether ARDs indeed increase the risk of PD.