Incidence, Prevalence, and Racial and Ethnic Distribution of Inflammatory Bowel Disease in the United States.

BACKGROUND & AIMS: We sought to estimate the incidence, prevalence, and racial-ethnic distribution of physician-diagnosed inflammatory bowel disease (IBD) in the United States. METHODS: The study used 4 administrative claims data sets: a 20% random sample of national fee-for-service Medicare data (2007 to 2017); Medicaid data from Florida, New York, Pennsylvania, Ohio, and California (1999 to 2012); and commercial health insurance data from Anthem beneficiaries (2006 to 2018) and Optum's deidentified Clinformatics Data Mart (2000 to 2017). We used validated combinations of medical diagnoses, diagnostic procedures, and prescription medications to identify incident and prevalent diagnoses. We computed pooled age-, sex-, and race/ethnicity-specific insurance-weighted estimates and pooled estimates standardized to 2018 United States Census estimates with 95% confidence intervals (CIs). RESULTS: The age- and sex-standardized incidence of IBD per 100,000 person-years was 10.9 (95% CI, 10.6-11.2). The incidence of IBD peaked in the third decade of life, decreased to a relatively stable level across the fourth to eighth decades, and declined further. The age-, sex- and insurance-standardized prevalence of IBD was 721 per 100,000 population (95% CI, 717-726). Extrapolated to the 2020 United States Census, an estimated 2.39 million Americans are diagnosed with IBD. The prevalence of IBD per 100,000 population was 812 (95% CI, 802-823) in White, 504 (95% CI, 482-526) in Black, 403 (95% CI, 373-433) in Asian, and 458 (95% CI, 440-476) in Hispanic Americans. CONCLUSIONS: IBD is diagnosed in >0.7% of Americans. The incidence peaks in early adulthood and then plateaus at a lower rate. The disease is less commonly diagnosed in Black, Asian, and Hispanic Americans.

Utilization of Treat-to-Target Monitoring Colonoscopy After Treatment Initiation in the US-Based Study of a Prospective Adult Research Cohort With Inflammatory Bowel Disease.

INTRODUCTION: Endoscopic healing has been associated with improved long-term clinical outcomes in inflammatory bowel disease (IBD) and is a recommended target for treatment. Evidence is limited regarding real-world uptake and patterns of treat-to-target monitoring to assess endoscopic healing after treatment initiation. We aimed to estimate the proportion of patients in the Study of a Prospective Adult Research Cohort with IBD (SPARC IBD) who received colonoscopy in the 3-15 months after starting a new IBD treatment. METHODS: We identified SPARC IBD patients who initiated a new biologic (infliximab, adalimumab, certolizumab pegol, golimumab, vedolizumab, and ustekinumab) or tofacitinib. We estimated the proportion of patients who received colonoscopies in the 3-15 months after IBD treatment initiation and described use by patient subgroups. RESULTS: Among 1,708 eligible initiations from 2017 to 2022, the most common medications were ustekinumab (32%), infliximab (22%), vedolizumab (20%), and adalimumab (16%). The median patient age was 38 years, with 66% Crohn's disease; 55% were female, and 12% were non-White. In the 3-15 months after medication initiation, 49.3% (95% confidence interval 46.2%-52.5%) of initiations were followed by a colonoscopy. Colonoscopy use was similar between ulcerative colitis and Crohn's disease, but was higher among male patients, those older than 40 years, and those who received colonoscopy within 3 months of initiation. Colonoscopy use varied between study sites, from 26.6% (15.0%-38.3%) to 63.2% (54.5%-72.0%). DISCUSSION: Approximately half of SPARC IBD patients received colonoscopy in the 3-15 months after initiation to a new IBD treatment, suggesting a low uptake of treat-to-target colonoscopy for the assessment of mucosal healing in real-world clinical practice. The variation in colonoscopy use between study sites suggests a lack of consensus and a need for more robust evidence around whether or not the practice of routine monitoring colonoscopy is associated with improved patient outcomes.

Development and Validation of Claims-Based Definitions to Identify Incident and Prevalent Inflammatory Bowel Disease in Administrative Healthcare Databases.

BACKGROUND: To facilitate inflammatory bowel disease (IBD) research in the United States, we developed and validated claims-based definitions to identify incident and prevalent IBD diagnoses using administrative healthcare claims data among multiple payers. METHODS: We used data from Medicare, Medicaid, and the HealthCore Integrated Research Database (Anthem commercial and Medicare Advantage claims). The gold standard for validation was review of medical records. We evaluated 1 incidence and 4 prevalence algorithms based on a combination of International Classification of Diseases codes, National Drug Codes, and Current Procedural Terminology codes. The claims-based incident diagnosis date needed to be within ±90 days of that recorded in the medical record to be valid. RESULTS: We reviewed 111 charts of patients with a potentially incident diagnosis. The positive predictive value (PPV) of the claims algorithm was 91% (95% confidence interval [CI], 81%-97%). We reviewed 332 charts to validate prevalent case definition algorithms. The PPV was 94% (95% CI, 86%-98%) for ≥2 IBD diagnoses and presence of prescriptions for IBD medications, 92% (95% CI, 85%-97%) for ≥2 diagnoses without any medications, 78% (95% CI, 67%-87%) for a single diagnosis and presence of an IBD medication, and 35% (95% CI, 25%-46%) for 1 physician diagnosis and no IBD medications. CONCLUSIONS: Through a combination of diagnosis, procedural, and medication codes in insurance claims data, we were able to identify incident and prevalent IBD cases with high accuracy. These algorithms can be useful for the ascertainment of IBD cases in future studies.

Utilization of Colonoscopy Following Treatment Initiation in U.S. Commercially Insured Patients With Inflammatory Bowel Disease, 2013-2019.

BACKGROUND: Evaluation of mucosal healing with colonoscopy is recommended for inflammatory bowel disease (IBD) management; however, little is known about real-world use of treat-to-target monitoring following IBD treatment initiation. We aimed to estimate the proportion of U.S. commercially insured IBD patients who receive colonoscopy in the 3 to 15 months after initiating treatment. METHODS: We identified IBD patients, 18 to 64 years of age, in the IBM MarketScan Commercial Claims and Encounters database as those with ≥3 IBD diagnoses prior to initiation of biologic, small molecule, or immunomodulatory treatment. We excluded patients with prior colectomy and with rheumatologic and other indications for these therapies. Colonoscopies were identified using International Classification of Diseases-Ninth Revision, International Classification of Diseases-Tenth Revision, and Current Procedural Terminology procedure codes. We used Kaplan-Meier methods to estimate the proportion of newly treated IBD patients who received colonoscopy in the 3 to 6 months, 3 to 12 months, and 3 to 15 months following treatment initiation, and stratified trends by year, patient age and sex, and region. RESULTS: From 2013 to 2019, we identified 39 734 initiators of IBD medications (51.9% female, mean age 39.4 years). We observed similar colonoscopy incidence among ulcerative colitis patients (3-6 months: 14.2% [95% confidence interval (CI), 13.6%-14.8%]; 3-12 months: 37.7% [95% CI, 36.8%-38.6%]; 3-15 months: 46.1% [95% CI, 45.2%-47.1%]) and Crohn's disease patients (3-6 months: 11.2% [95% CI, 10.8%-11.6%]; 3-12 months: 32.2% [95% CI, 31.5%-32.9%]; 3-15 months: CD: 40.1% [95% CI, 39.3%-40.8%]). Overall colonoscopy use was slightly higher among women, patients in the Northeast, and those initiating newer biologic therapies. CONCLUSIONS: Fewer than half of newly treated IBD patients underwent colonoscopy within 3 to 15 months of initiating new treatment, suggesting low uptake of treat-to-target endoscopic disease monitoring in real-world practice.

Among 39 734 newly treated, commercially insured inflammatory bowel disease patients in the United States, fewer than half (42%) received colonoscopy in the 3 to 15 months following treatment initiation, suggesting low uptake of STRIDE (Selecting Therapeutic Targets in Inflammatory Bowel Disease)-recommended treat-to-target endoscopic disease activity monitoring in real-world practice.

Leveraging auxiliary data to improve precision in inverse probability-weighted analyses.

PURPOSE: To demonstrate improvements in the precision of inverse probability-weighted estimators by use of auxiliary variables, i.e., determinants of the outcome that are independent of treatment, missingness or selection. METHODS: First with simulated data, and then with public data from the National Health and Nutrition Examination Survey (NHANES), we estimated the mean of a continuous outcome using inverse probability weights to account for informative missingness. We assessed gains in precision resulting from the inclusion of auxiliary variables in the model for the weights. We compared the performance of robust and nonparametric bootstrap variance estimators in this setting. RESULTS: We found that the inclusion of auxiliary variables reduced the empirical variance of inverse probability-weighted estimators. However, that reduction was not captured in standard errors computed using the robust variance estimator, which is widely used in weighted analyses due to the non-independence of weighted observations. In contrast, a nonparametric bootstrap estimator properly captured the precision gain. CONCLUSIONS: Epidemiologists can leverage auxiliary data to improve the precision of weighted estimators by using bootstrap variance estimation, or a closed-form variance estimator that properly accounts for the estimation of the weights, in place of the standard robust variance estimator.

Auditing Management of Acute Pancreatitis Using Comprehensive Quality Indicators.

OBJECTIVES: Recently, 40 comprehensive quality indicators in various management domains were created. The aim was to determine if these indicators could be used to audit the management of acute pancreatitis. METHODS: A retrospective study of consecutive patients admitted with acute pancreatitis in 2018 was conducted. Adherence rates with the individual quality indicators were calculated and compared between services. RESULTS: A total of 320 patients were included in this study. Twenty-eight of the 40 quality indicators (70%) could be used to audit management retrospectively. The medical service was found to have lower adherence rates for quality indicators 12 (initial assessment and risk stratification domain; 11% vs 22%, P = 0.009), 14 (initial management domain; 72% vs 88%, P = 0.003), and 33 (surgery domain; 83% vs 100%, P = 0.006). The surgical service was noted to have statistically significant lower adherence rates for quality indicators 4, 5, and 6 of the etiology domain (54% vs 72%, P = 0.002; 86% vs 96%, P = 0.004; and 45% vs 71%, P < 0.0001, respectively), and 21 of the nutrition domain (76% vs 93%, P < 0.0001). CONCLUSIONS: We show that these quality indicators can be used to audit the management of acute pancreatitis in specific management domains.

Effect of Carbon Chain Length, Ionic Strength, and pH on the In Vitro Release Kinetics of Cationic Drugs from Fatty-Acid-Loaded Contact Lenses.

This paper explores the use of fatty acids in silicone hydrogel contact lenses for extending the release duration of cationic drugs. Drug release kinetics was dependent on the carbon chain length of the fatty acid loaded in the lens, with 12-, 14- and 18-carbon chain length fatty acids increasing the uptake and the release duration of ketotifen fumarate (KTF) and tetracaine hydrochloride (THCL). Drug release kinetics from oleic acid-loaded lenses was evaluated in phosphate buffer saline (PBS) at different ionic strengths (I = 167, 500, 1665 mM); the release duration of KTF and THCL was decreased with increasing ionic strength of the release medium. Furthermore, the release of KTF and THCL in deionized water did not show a burst and was significantly slower compared to that in PBS. The release kinetics of KTF and THCL was significantly faster when the pH of the release medium was decreased from 7.4 towards 5.5 because of the decrease in the relative amounts of oleate anions in the lens mostly populated at the polymer-pore interfaces. The use of boundary charges at the polymer-pore interfaces of a contact lens to enhance drug partition and extend its release is further confirmed by loading cationic phytosphingosine in contact lenses to attract an anionic drug.

Drug-induced liver injury associated with lopinavir-ritonavir in patients with COVID-19: a disproportionality analysis of U.S. food and drug administration adverse event reporting system (FAERS) data.

Background Liver injury has been documented independently in novel coronavirus disease 2019 (COVID-19) patients and patients treated with lopinavir-ritonavir. Objective to investigate the drug-induced liver injury associated with lopinavir-ritonavir among the patients with COVID-19. Methods We conducted a disproportionality analysis of US Food and Drug Administration Adverse Event Reporting System (FAERS) between 2020Q1 and 2021Q1 to evaluate the association between lopinavir-ritonavir and risk of drug-induced liver injury (or severe drug-induced liver injury) and calculated their reporting odds ratios (RORs) with 95% confidence intervals (CIs). Results A total of 3,425 cases of drug-induced liver injury were reported in 19,782 patients with COVID-19. The ROR for drug-induced liver injury was 2.99 (2.59-3.46), 3.16 (2.68-3.73), and 5.39 (4.63-6.26) when comparing lopinavir-ritonavir with all other drugs, hydroxychloroquine/chloroquine only, and remdesivir, respectively. For severe drug-induced liver injury, RORs for lopinavir-ritonavir provided evidence of an association compared with all other drugs (3.98; 3.15-5.05), compared with hydroxychloroquine/chloroquine only (5.33; 4.09-6.94), and compared with remdesivir (3.85; 3.03-4.89). Conclusions In the FAERS, we observed a disproportional signal for drug-induced liver injury associated with lopinavir-ritonavir in patients with COVID-19.

Acuity patterns of heart failure among emergency departments in a large health system.

BACKGROUND: The prognostic importance of Emergency Heart Failure Mortality Risk Grade (EHMRG) score in assessing short term mortality in Congestive Heart Failure (CHF) patients has been validated in the past, however, few studies have examined acuity patterns in the CHF population across healthcare settings. We aim to understand acuity patterns of CHF patients across a large health system for better resource utilization. METHODS: Retrospective chart review of adult patients with acute CHF in a large Metropolitan health system was performed in 3 community and 3 academic hospitals between January 2014 and January 2016. We collected demographic data, setting type, and calculated EHMRG score. Descriptive analysis of each hospital and mixed-effects negative binomial models were created to see patterns of acuity versus hospital volume. RESULTS: A total of 3312 Emergency Department (ED) visits among 2490 unique patients were included. Academic and community hospitals had 2168 patients and 1144 patients, respectively. Hospitals with higher volume treated a large amount of lower acuity patients. Academic hospitals had 30% of CHF ED visits in the lowest EHMRG quantile versus 20% at community hospital (p < 0.0001). Compared to EHMRG quantile 5b, hospital volume was 17%, 8% and 5% higher in quantile 1, 2, and 3 with a p-value less than 0.05 (IRR = 1.17; 1.08;1.05), respectively, but were not significant compared to quantile 4 and 5a. Revisit rates were lower in academic hospitals; admission rates were lower in community hospitals. CONCLUSION: Academic hospitals had a higher number of Acute Heart Failure (AHF) patients, larger number of low acuity patients, higher admission rates, but less revisit rates to the ED as compared to community hospitals. We suggest acuity specific interventions will help decrease admission and revisit rates.

Newer second-line glucose-lowering drugs versus thiazolidinediones on cirrhosis risk among older US adult patients with type 2 diabetes.

AIMS: Type 2 diabetes (T2D) accelerates progression of chronic liver disease to cirrhosis, yet the effects of most glucose-lowering drugs (GLDs) on cirrhosis risk in T2D are unknown. To address this gap, we compared cirrhosis risk following initiation of newer second-line GLDs vs. thiazolidinediones (TZDs), which improve histology in non-alcoholic fatty liver disease. MATERIALS AND METHODS: Using the US Medicare Fee-for-Service database (2007-2015) and an active comparator, new-user design, we estimated crude incidence rates (IRs) and propensity-score adjusted hazard ratios (aHR) for incident cirrhosis, comparing newer GLDs (dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA), and sodium-glucose co-transporter 2 inhibitors (SGLT2i)) vs. TZDs. RESULTS: Among 239,549 total initiators, we observed 318, 151, and < 30 cirrhosis events when comparing DPP4i vs. TZD, GLP1RA vs. TZD, and SGLT2i vs. TZD, respectively. IRs ranged from 1.7 [95% CI, 0.8-3.6] to 3.6 [2.5-5.2] events per 1000 person-years. Point aHR estimates for cirrhosis were elevated among newer GLD initiators vs. TZD (DPP4i: 1.15 [0.89-1.50]; GLP1RA: 1.34 [0.82-2.20]; SGLT2i: 1.16, [0.44-3.08]), although estimates were imprecise due to short durations of drug exposure. CONCLUSIONS: We observed mildly elevated cirrhosis risk with newer GLDs vs. TZD; however, uncertainty remains due to imprecise and statistically non-significant effect estimates.

Comparative cost-effectiveness of mailed fecal immunochemical testing (FIT)-based interventions for increasing colorectal cancer screening in the Medicaid population.

BACKGROUND: Mailed reminders to promote colorectal cancer (CRC) screening by fecal immunochemical testing (FIT) have been shown to be effective in the Medicaid population, in which screening is underused. However, little is known regarding the cost-effectiveness of these interventions, with or without an included FIT kit. METHODS: The authors conducted a cost-effectiveness analysis of a randomized controlled trial that compared the effectiveness of a reminder + FIT intervention versus a reminder-only intervention in increasing FIT screening. The analysis compared the costs per person screened for CRC screening associated with the reminder + FIT versus the reminder-only alternative using a 1-year time horizon. Input data for a cohort of 35,000 unscreened North Carolina Medicaid enrollees ages 52 to 64 years were derived from the trial and microcosting. Inputs and outputs were estimated from 2 perspectives-the Medicaid/state perspective and the health clinic/facility perspective-using probabilistic sensitivity analysis to evaluate uncertainty. RESULTS: The anticipated number of CRC screenings, including both FIT and screening colonoscopies, was higher for the reminder + FIT alternative (n = 8131; 23.2%) than for the reminder-only alternative (n = 5533; 15.8%). From the Medicaid/state perspective, the reminder + FIT alternative dominated the reminder-only alternative, with lower costs and higher screening rates. From the health clinic/facility perspective, the reminder + FIT versus the reminder-only alternative resulted in an incremental cost-effectiveness ratio of $116 per person screened. CONCLUSIONS: The reminder + FIT alternative was cost saving per additional Medicaid enrollee screened compared with the reminder-only alternative from the Medicaid/state perspective and likely cost-effective from the health clinic/facility perspective. The results also demonstrate that health departments and state Medicaid programs can efficiently mail FIT kits to large numbers of Medicaid enrollees to increase CRC screening completion.

Real-world evidence on sodium-glucose cotransporter-2 inhibitor use and risk of Fournier's gangrene.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been associated with increased occurrence of Fournier's gangrene (FG), a rare but serious form of necrotizing fasciitis, leading to a warning from the Food and Drug Administration. Real-world evidence on FG is needed to validate this warning. METHODS: We used data from IBM MarketScan (2013-2017) to compare the incidence of FG among adult patients who initiated either SGLT2i, a dipeptidyl peptidase-4 inhibitor (DPP4i), or any non-SGLT2i antihyperglycemic medication. FG was defined using inpatient International Classification of Diseases, Ninth Edition and Tenth Edition diagnosis codes 608.83 and N49.3, respectively, combined with procedure codes for debridement, surgery, or systemic antibiotics. We estimated crude incidence rates (IRs) using Poisson regression, and crude and adjusted HRs (aHR) and 95% CIs using standardized mortality ratio-weighted Cox proportional hazards models. Sensitivity analyses examined the impact of alternative outcome definitions. RESULTS: We identified 211 671 initiators of SGLT2i (n=93 197) and DPP4i (n=118 474), and 305 329 initiators of SGLT2i (n=32 868) and non-SGLT2i (n=272 461). Crude FG IR ranged from 3.2 to 3.8 cases per 100 000 person-years during a median follow-up of 0.51-0.58 years. Compared with DPP4i, SGLT2i initiation was not associated with increased risk of FG for any outcome definition, with aHR estimates ranging from 0.25 (0.04-1.74) to 1.14 (0.86-1.51). In the non-SGLT2i comparison, we observed an increased risk of FG for SGLT2i initiators when using FG diagnosis codes alone, using all diagnosis settings (aHR 1.80; 0.53-6.11) and inpatient diagnoses only (aHR 4.58; 0.99-21.21). CONCLUSIONS: No evidence of increased risk of FG associated with SGLT2i was observed compared with DPP4i, arguably the most relevant clinical comparison. However, uncertainty remains based on potentially higher risk in the broader comparison with all non-SGLT2i antihyperglycemic agents and the rarity of FG. TRIAL REGISTRATION NUMBER: EUPAS Register Number 30018.

Rising Mortality From Alcohol-Associated Liver Disease in the United States in the 21st Century.

OBJECTIVES: In contrast with other developed nations, life expectancy is decreasing in the United States, in part due to increasing mortality from alcohol-associated liver disease (ALD). Up-to-date estimates of ALD mortality are necessary for setting public health priorities to reverse this concerning trend. We therefore aimed to assess current (2017) estimates of ALD mortality and temporal trends from 1999 to 2017. METHODS: Using national data from the Centers for Disease Control and Prevention, we analyzed stratified ALD mortality rates between 1999 and 2017. We determined the age-adjusted death rates, stratified by sex and categorized by age, race/ethnicity, urbanization, and census region. We also identified statistically significant changes in the annual rate difference (ARD), annual percentage change (APC), and average APC in ALD mortality. RESULTS: In 2017, mortality from ALD was higher than any other year since 1999 with age-adjusted rates of 13.1 per 100,000 (95% confidence interval [CI] 12.9-13.3) in men and 5.6 per 100,000 (95% CI 5.4-5.7) in women. Mortality was highest among men and women who were middle aged, Native American, and from rural areas. Since 2006, ALD mortality has increased in almost every age group and race with the exception of non-Hispanic black men. Absolute increases in mortality rates have been particularly pronounced in Native American women (2005-2017 ARD 0.8, 95% CI 0.6-0.9), non-Hispanic/white men (2006-2017 ARD 0.4, 95% CI 0.3-0.4), and non-Hispanic/white women (2013-2017 ARD 0.4, 95% CI 0.3-0.5). DISCUSSION: Mortality from ALD is increasing over time in most demographic groups. Increased effort is needed to develop targeted public health strategies to address high and increasing ALD mortality.

Dipeptidyl Peptidase 4 Inhibitors and Risk of Inflammatory Bowel Disease: Real-world Evidence in U.S. Adults.

OBJECTIVE: A recent study raises concerns that dipeptidyl peptidase 4 inhibitors (DPP4i) are associated with increased risk of inflammatory bowel disease (IBD). We evaluated the association between new use of DPP4i and IBD risk compared with other second-line antihyperglycemics. RESEARCH DESIGN AND METHODS: We implemented an active-comparator, new-user cohort design using two U.S. administrative claims databases for commercially insured (MarketScan) and older adult (Medicare fee-for-service, 20% random sample) patients from January 2007 to December 2016. We identified patients, aged ≥18 years, who initiated DPP4i versus sulfonylureas (SUs) or initiated DPP4i versus thiazolidinediones (TZDs) and were without prior diagnosis, treatment, or procedure for IBD. The primary outcome was incident IBD, defined by IBD diagnosis preceded by colonoscopy and biopsy and followed by IBD treatment. We performed propensity score weighting to control for measured baseline confounding, estimated adjusted hazard ratios (aHRs [95% CI]) using weighted Cox proportional hazards models, and used random-effects meta-analysis models to pool aHRs across cohorts. RESULTS: We identified 895,747 eligible patients initiating DPP4i, SU, or TZD; IBD incidence rates ranged from 11.6 to 32.3/100,000 person-years. Over a median treatment duration of 1.09-1.69 years, DPP4i were not associated with increased IBD risk across comparisons. The pooled aHRs for IBD were 0.82 (95% CI 0.41-1.61) when comparing DPP4i (n = 161,612) to SU (n = 310,550) and 0.76 (0.46-1.26) when comparing DPP4i (n = 205,570) to TZD (n = 87,543). CONCLUSIONS: Our population-based cohort study of U.S. adults with diabetes suggests that short-term DPP4i treatment does not increase IBD risk.

Effect of a Cationic Surfactant on Microemulsion Globules and Drug Release from Hydrogel Contact Lenses.

The present study evaluates the in vitro release of diclofenac sodium (DFNa) from contact lenses based on poly-2-hydroxyethyl methacrylate (pHEMA) hydrogels containing an embedded microemulsion to extend release duration. The oil (ethyl butyrate)-in-water microemulsion systems are prepared with two non-ionic surfactants, Brij 97 or Tween 80, together with a long-alkyl chain cationic surfactant, cetalkonium chloride (CKC). Without CKC, Brij 97 or Tween 80-based microemulsions showed average droplet sizes of 12 nm and 18 nm, respectively. The addition of CKC decreased the average droplet sizes to 2-5 nm for both non-ionic surfactants. Such significant reduction in the average droplet size corresponds to an increase in the DFNa release duration as revealed by the in vitro experiments. Contact lens characterization showed that important properties such as optical transparency and water content of Brij 97-based contact lenses with cationic microemulsions was excellent. However, the optical transparency of the corresponding Tween 80 based contact lenses was unsatisfactory. The results indicate that cationic microemulsion-laden contact lenses can benefit from combinatory effects of microemulsions and cationic surfactant at low CKC weight percentage, e.g., with the release of 70% of the drug in 45, 10, and 7 h for B97-CKC-0.45%, CKC-0.45%, and control lenses, respectively. However, the microemulsion effect on extending DFNa release became negligible at the highest CKC weight percentage (1.8%).

Propensity score methods to control for confounding in observational cohort studies: a statistical primer and application to endoscopy research.

BACKGROUND AND AIMS: Confounding is a major concern in nonexperimental studies of endoscopic interventions and can lead to biased estimates of the effects of treatment. Propensity score methods, which are commonly used in the pharmacoepidemiology literature, can effectively control for baseline confounding by balancing measured baseline confounders and risk factors and creating comparable populations of treated and untreated patients. METHODS: We propose the following 5-step checklist to guide the use and evaluation of propensity score methods: (1) select covariates, (2) assess "Table 1" balance in risk factors before propensity score implementation, (3) estimate and implement the propensity score in the study cohort, (4) reassess "Table 1" balance in risk factors after propensity score implementation, and (5) critically evaluate differences between matched and unmatched patients after propensity score implementation. We then applied this checklist to an endoscopy example using a study cohort of 411 adults with newly diagnosed eosinophilic esophagitis (EoE), some of whom were treated with esophageal dilation. RESULTS: We identified 156 patients, aged 18 and older, who were treated with esophageal dilation, and 255 patients who were nondilated. We successfully matched 148 (95%) dilated patients to nondilated patients who had a propensity score within 0.1, based on patient age, sex, race, self-reported food allergy, and presence of narrowing at baseline endoscopy. Crude imbalances were observed before propensity score matching in several baseline covariates, including age, sex, and narrowing; however, propensity score matching was successful in achieving balance across all measured covariates. CONCLUSIONS: We provide an introduction to propensity score methods, including a straightforward checklist for implementing propensity score methods in nonexperimental studies of treatment effectiveness. Moreover, we demonstrate the advantage of using "Table 1" as a simple but effective diagnostic tool for evaluating the success of propensity score methods in an applied example of esophageal dilation in EoE.