Validation of an ICD-9-based claims algorithm for identifying patients with chronic idiopathic/spontaneous urticaria

Claims-based Prevalence of Disease Progression among Patients with Non-IPF Fibrosing Interstitial Lung Disease in the US

Rationale

Chronic fibrosing interstitial lung disease (ILD) with a progressive phenotype is a clinical concept describing the broad group of ILDs characterized by progressive pulmonary fibrosis. The prevalence of progressive fibrotic ILDs other than idiopathic pulmonary fibrosis (IPF) is not well understood.

Objectives

We used a novel algorithm to estimate the prevalence range of disease progression among patients with non-IPF fibrotic ILD in a U.S. claims database.

Methods

This was a retrospective study including adults with commercial or Medicare Advantage with Part D (MAPD) insurance using administrative claims data from October 2015 to September 2019. Patients likely to have non-IPF fibrosing ILD with a progressive phenotype were identified via an algorithm that incorporated ILD-related diagnosis codes (excluding IPF) and claims-based proxies for fibrotic ILD progression, including pulmonary function tests, chest imaging, oral corticosteroid (OCS) medications, immunosuppressive medications, lung transplant, oxygen therapy, palliative care, and respiratory hospitalization. The prevalence range of non-IPF fibrotic ILD with progressive disease behavior was calculated using strict and lenient case definitions to account for potential imprecision in the progression proxies.

Results

Of nearly 9 million study-eligible patients, 17,136 were identified with non-IPF fibrosing ILD. The prevalence of disease progression per 10,000 (95% confidence interval) ranged from 12.14 (11.74–12.54) to 29.05 (28.43–29.67) over a mean observation time of 1.44 years for MAPD enrollees (n = 14,686), and from 0.89 (0.81–0.97) to 2.36 (2.24–2.48) over a mean observation time of 1.29 years for commercial enrollees (n = 2,450). Prevalence estimates increased with age for both insurance types. Among patients with progression, 4,097 met at least two progression proxies not considering OCS (strict case definition) and 9,946 met at least one progression proxy (lenient case definition). The mean (standard deviation) number of proxies met was 2.1 (1.3), and the most common individual proxies met (alone or in combination with other proxies) were OCS use (48.9%), respiratory hospitalization (44.2%), and oxygen therapy (44.1%).

Conclusions

This is among the first claims-based estimates of the prevalence of non-IPF chronic fibrosing ILD with a progressive phenotype. Our analysis indicates that this phenotype is rare in the overall population but increases substantially with increasing age.

Association of herpes zoster and chronic inflammatory skin disease in US inpatients

BACKGROUND

Patients with chronic inflammatory skin disease (CISD) have potential risk factors for herpes zoster (HZ). However, little is known about HZ risk in CISD.

OBJECTIVE

To determine whether CISD is associated with HZ.

METHODS

Data were analyzed from the 2002 to 2012 Nationwide Inpatient Sample, a representative cohort of US hospitalizations (N = 68,088,221 children and adults).

RESULTS

In multivariable logistic regression models including age, sex, race/ethnicity, insurance, household income, and long-term systemic corticosteroid use, hospitalization for HZ was associated with atopic dermatitis (adjusted odds ratio [95% confidence interval], 1.38 [1.14-1.68]), psoriasis (4.78 [2.83-8.08]), pemphigus (1.77 [1.01-3.12]), bullous pemphigoid (1.77 [1.01-3.12]), mycosis fungoides (3.79 [2.55-5.65]), dermatomyositis (7.31 [5.27-10.12]), systemic sclerosis (1.92 [1.47-2.53]), cutaneous lupus erythematosus (1.94 [1.10-3.44]), vitiligo (2.00 [1.04-3.85]), and sarcoidosis (1.52 [1.22-1.90]). Only lichen planus (crude odds ratio [95% confidence interval], 3.01 [1.36-6.67]), Sézary syndrome (12.14 [5.20-28.31]), morphea (2.74 [1.36-5.51]), and pyoderma gangrenosum (2.44 [1.16-5.13]) showed increased odds in bivariable models. Sensitivity analyses among those younger than 60 and younger than 50 years showed similar results. Predictors of HZ in CISD included female sex, fewer chronic conditions, and long-term systemic corticosteroid use.

LIMITATIONS

Cross-sectional study.

CONCLUSIONS

Many CISDs are associated with increased hospitalization for HZ, even below the ages recommended for HZ vaccination. Additional studies are needed to establish CISD-specific vaccination guidelines.

A primer on quantitative bias analysis with positive predictive values in research using electronic health data

OBJECTIVE

In health informatics, there have been concerns with reuse of electronic health data for research, including potential bias from incorrect or incomplete outcome ascertainment. In this tutorial, we provide a concise review of predictive value-based quantitative bias analysis (QBA), which comprises epidemiologic methods that use estimates of data quality accuracy to quantify the bias caused by outcome misclassification.

TARGET AUDIENCE

Health informaticians and investigators reusing large, electronic health data sources for research.

SCOPE

When electronic health data are reused for research, validation of outcome case definitions is recommended, and positive predictive values (PPVs) are the most commonly reported measure. Typically, case definitions with high PPVs are considered to be appropriate for use in research. However, in some studies, even small amounts of misclassification can cause bias. In this tutorial, we introduce methods for quantifying this bias that use predictive values as inputs. Using epidemiologic principles and examples, we first describe how multiple factors influence misclassification bias, including outcome misclassification levels, outcome prevalence, and whether outcome misclassification levels are the same or different by exposure. We then review 2 predictive value-based QBA methods and why outcome PPVs should be stratified by exposure for bias assessment. Using simulations, we apply and evaluate the methods in hypothetical electronic health record-based immunization schedule safety studies. By providing an overview of predictive value-based QBA, we hope to bridge the disciplines of health informatics and epidemiology to inform how the impact of data quality issues can be quantified in research using electronic health data sources.

High waist circumference rather than high body mass index may be a predictive risk factor for the longer disease duration of chronic spontaneous urticaria

In a previous study, we found that higher waist circumference (WC) and higher body mass index (BMI) both increase the risk of chronic spontaneous urticaria (CSU). The aim of this study was to determine whether WC and BMI also increase the duration of CSU. We used multivariable Cox proportional hazards models to determine the hazard ratio (HR) for longer disease duration (longer than 3 years) according to WC and BMI. A total of 52,667 subjects were enrolled and their mean age was 54.5. After adjustments for other confounding variables the high WC/high BMI group had 1.062 times higher HR (95% CI, 1.028-1.098) than the normal WC/normal BMI group. Interestingly, the high WC/normal BMI group showed a significantly higher HR (1.053; 95% CI, 1.008-1.101) than the normal WC/normal BMI group, but not the normal WC/high BMI group (0.998; 95% CI, 0.951-1.046). Taken together, our results suggest that high WC rather than high BMI is a predictive risk factor for the longer disease duration of CSU.

Peptic Ulcer Disease is Associated with Increased Risk of Chronic Urticaria Independent of Helicobacter pylori Infection: A Population-Based Cohort Study

BACKGROUND

Some studies showed patients with chronic urticaria have a higher rate of peptic ulcer disease (PUD). Whether PUD is a risk factor for chronic urticaria is unclear.

OBJECTIVE

The objective of this study was to evaluate the incidence of and risk factors for chronic urticaria in patients with PUD using the Taiwan National Health Insurance Research Database.

METHODS

We conducted a retrospective nationwide cohort study of the period 2000-2012 and involving 11,901 patients with PUD who underwent Helicobacter pylori (HP) therapy (PUD + HP group) and an equal number of matched patients without HP infection (PUD - HP group). Furthermore, we enrolled 23,802 patients without PUD for comparison (non-PUD group). The Cox proportional hazards regression model was used to analyze chronic urticaria risk after adjusting for potential confounding factors.

RESULTS

The mean ages of the three groups were around 50 years. Approximately 42.6% were female. Chronic urticaria incidences in the PUD + HP and PUD - HP groups were both significantly higher than that in the non-PUD group. The hazard ratios of chronic urticaria in the PUD + HP group and the PUD - HP group were 1.34 (95% confidence interval 1.09-1.64) and 1.45 (95% confidence interval 1.19-1.79), respectively. The risk difference became significant 2 years after patients with PUD had the HP infection tests and persisted till the end of follow-up. The risk increase was significant in patients with PUD who were female or aged 40-64 years. There was no difference in the risk comparison between PUD + HP and PUD - HP groups.

CONCLUSIONS

Peptic ulcer disease, independent of HP infection, is associated with an increased chronic urticaria risk. Patients with PUD who were female or aged 40-64 years are more likely to have chronic urticaria.

Prevalence estimates for chronic urticaria in the United States: A sex- and age-adjusted population analysis

BACKGROUND

Disease burden in chronic urticaria (CU) is poorly understood.

OBJECTIVE

To estimate standardized overall and sex-, age-, and race-specific prevalence estimates for CU among adults in the United States.

METHODS

A cross-sectional analysis with electronic health records data for a demographically heterogeneous population-based sample of >55 million patients across all 4 census regions.

RESULTS

The overall CU prevalence was 0.23%, or 230 CU cases/100,000 adults. The adjusted prevalence in women was 310 (95% confidence interval [CI] 307-312) cases/100,000 adults, more than twice that of men (146 [95% CI 143-148] cases/100,000 adults, P < .001). CU prevalence was highest among patients aged 40-49 years (256 [95% CI 252-261] cases/100,000 adults) and 50-59 years (246 [95% CI 242-251] cases/100,000 adults) compared with all other age groups (P < .0001). Adjusted prevalences for black (292 [95% CI 285-298] cases/100,000 adults) and other (331 [95% CI 323-338] cases/100,000 adults) patients were higher than that for white patients (262 [95% CI 260-264] cases/100,000 adults; P < .001).

LIMITATIONS

Use of administrative data has the potential to underestimate burden.

CONCLUSION

There are >500,000 people estimated to have CU in the United States, most of whom are women or adults ≥40 years of age.

Epidemiology of urticaria including physical urticaria and angioedema in Korea

BACKGROUND/AIMS

Despite the high burden and frequency of urticaria, its epidemiology is not well known. We investigated the epidemiology of various type of urticaria in Korea and changes in its annual prevalence over 5 years.

METHODS

We used data from the 2010 to 2014 Health Insurance Review and Assessment database, which covers the claims of 97.0% of the South Korean population. Patients aged > 10 years old were included in this study. The presence of urticaria was identified on physician-certified diagnoses using the International Classification of Diseases 10th Revision (ICD-10) codes that include various type of urticaria (L500-L509) and angioedema (T783). Epidemiology of all type of urticaria, physical urticaria and angioedema were investigated.

RESULTS

The prevalence of all-type urticaria over the 5 years was 4.5% with a peak in individuals, especially females, aged 30 to 59 years. The age-specific prevalence of all-type urticaria increased with age from the 10- to 19-year age group to the 70- to 79-year age group. The prevalence of dermographism, cholinergic urticaria, and angioedema were 0.12%, 0.025%, and 0.027%, respectively. Cholinergic urticaria was most prevalent in those aged 10 to 29 years with male predominance. The annual prevalence of all-type urticaria, dermographism, and angioedema increased over the 5 years.

CONCLUSION

The prevalence of urticaria has increased annually in Korea. Cholinergic urticaria showed unique distribution in its age and gender, and angioedema showed remarkable increases in annual prevalence, although the prevalence estimation is still exploratory and diagnosis of urticaria based on ICD-10 codes need to be validated.

Association between sleep disorders and subsequent chronic spontaneous urticaria development: A population-based cohort study

Patients with chronic spontaneous urticaria (CSU) often have sleep disorders (SDs) because of pruritus. However, SDs might also contribute to the development of CSU. Here, we present the first population-based cohort study on the association between SDs and subsequent CSU development.This study investigated whether SDs increase the risk of CSU by using a population-based database in Taiwan.This retrospective matched-cohort study included 105,892 patients with new-onset SDs (SD cohort) and 105,892 randomly selected controls (control cohort). Each patient was monitored for 10 years to individually identify patients who were subsequently diagnosed as having CSU during the follow-up period. A Cox proportional hazard regression analysis was conducted to determine the risk of CSU in patients with SDs compared with the controls.All relevant comorbidities were more prevalent in the SD cohort than in the control cohort (P < .001). During the follow-up period, the incidence rates of CSU among the patients with SDs and controls were 53.4 and 28.3 per 10,000 person-years, respectively. After adjustment for age, sex, and comorbidities, the adjusted hazard ratio for CSU in the SD cohort was 1.83 (95% confidence interval = 1.73-1.93, P < .001).The risk of CSU was higher in the patients with SDs than in the controls.

Identification of Inpatient Allergic Drug Reactions Using ICD-9-CM Codes

BACKGROUND

The study of allergic drug reactions has been limited because of challenges in identifying and confirming cases.

OBJECTIVE

To determine the utility of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for identifying inpatient allergic drug reactions and to compare findings with previous data in the emergency department.

METHODS

By reviewing medical records of inpatients with ICD-9-CM codes and E codes suggestive of allergic drug reactions at a large urban academic medical center, we determined codes that yielded the most drug allergy cases and identified culprit drugs.

RESULTS

In 2005 and 2010, 3337 and 5282 possible allergic drug reactions during hospitalization were identified and 1367 were reviewed. Allergic drug reactions were found in 409 (30.1%) of the reviewed charts, with 172 (29.7%) in 2005 and 237 (30.5%) in 2010. The codes that identified the highest percentage of true allergic drug reactions were dermatitis due to drug (693.0), allergic urticaria (708), angioneurotic edema (995.1), and anaphylaxis (995.0). Antibiotics were the most common cause (44.4%); however, multiple drug classes were often identified as likely culprit drugs.

CONCLUSION

Specific ICD-9-CM codes can identify patients with allergic drug reactions, with antibiotics accounting for almost half of true reactions. Most patients with codes 693.0, 995.1, 708, and 995.0 had allergic drug reactions, with 693.0 as the highest yield code. An aggregate of multiple specific codes consistently identifies a cohort of patients with confirmed allergic drug reactions.

Real-world use of omalizumab in patients with chronic idiopathic/spontaneous urticaria in the United States

BACKGROUND

Omalizumab was approved for the treatment of chronic idiopathic urticaria (CIU)/chronic spontaneous urticaria (CSU) in the United States in March 2014.

OBJECTIVE

This study sought to describe real-world omalizumab use, in the United States, in a large cohort of patients with CIU/CSU.

METHODS

Patients with CIU/CSU (ages ≥12 years) initiated on omalizumab (index date) with ≥12 months of pre- and postindex data were identified in the an insurance claims data base (January 1, 2013, to July 31, 2016). Treatment patterns, including the dosing regimen and continuous use of omalizumab (no gaps for ≥60 days), were described during the 12-month postindex follow-up period.

RESULTS

A total of 1546 patients (mean ± standard deviation [SD] ages, 44 ± 14.5 years; 73.1% women) were identified. Most of the patients (84.5%) were initiated on omalizumab 300-mg dose; 90% maintained the initial dose, 7.5% had a dose increase, and 4.6% had a dose decrease. The mean ± SD omalizumab treatment duration was 9.1 ± 3.8 months, the mean ± SD number of omalizumab administrations was 8.3 ± 4.8, and the mean ± SD administration frequency was 44 ± 29 days. A proportion of the patients continuously treated with omalizumab for 6, 9, and 12 months was 67.3, 54.8, and 47.4%, respectively. Among the patients who discontinued omalizumab for ≥3 months (39.8%), 21% restarted the treatment after a mean ± SD of 4.4 ± 1.3 months. The proportion of patients who used other CIU/CSU-related medications decreased pre- to postindex (94.8 to 81.1%), with the highest decrease observed in oral corticosteroids (75.7 to 49.9%).

CONCLUSION

In this large real-world study, the majority of the patients with CIU/CSU were initiated on a 300-mg omalizumab dose and treated without titration up or down for 9 months on average. Most of the patients were continuously treated with omalizumab for ≥6 months, and one-fourth of the patients who discontinued treatment resumed it. Moreover, compared with baseline levels, the use of other CIU/CSU-related medications was lower after omalizumab initiation, with the most prominent decrease observed in oral corticosteroids.

Treatment Patterns, Healthcare Resource Utilization, and Spending Among Medicaid-Enrolled Children with Chronic Idiopathic/Spontaneous Urticaria in the United States

Introduction

Few studies have described chronic idiopathic/spontaneous urticaria (CIU/CSU) healthcare burden in adults, while this information remains largely unknown in children. We aimed to describe treatment patterns, healthcare resource utilization (HRU), and costs in CIU/CSU pediatric patients, as well as to compare HRU and costs in CIU/CSU and CIU/CSU-free pediatric patients.

Methods

Medicaid claims from four states (09/01/2013–03/31/2016) were used to identify patients less than 12 years old. The CIU/CSU cohort included patients with either at least two claims for idiopathic, other, or unspecified urticaria at least 6 weeks apart, or at least one claim for urticaria and at least one claim for angioedema at least 6 weeks apart (index date defined as the first claim). The control cohort included patients without urticaria/angioedema claims (index date randomly assigned). Patients without at least 6 months of continuous Medicaid eligibility pre- and post-index were excluded. HRU and costs were compared between propensity score-matched cohorts during the post-index follow-up.

Results

A total of 548 CIU/CSU patients (mean [SD] age 4.5 [3.3] years; 51.3% male) were matched 1:1 with controls. In the CIU/CSU cohort, 51.8% used non-sedating prescription H₁-antihistamines, 24.3% used oral corticosteroids, and 23.5% used other prescription H₁-antihistamines; 13.5% consulted allergist/immunologists and 2.4% consulted dermatologists in the first 6 months of follow-up. Compared to controls, CIU/CSU patients had significantly more per patient per year (PPPY) inpatient (incidence rate ratio [IRR] 2.05), outpatient (IRR 2.20), and emergency department (IRR 1.64) visits (all p values < 0.05). Moreover, CIU/CSU patients also had significantly higher PPPY healthcare costs (mean cost difference [MCD] $1853), driven by incremental outpatient (MCD $1286) costs (all p values < 0.01).

Conclusions

CIU/CSU pediatric patients had low use of non-sedating H₁-antihistamines and high use of oral corticosteroids. Compared to CIU/CSU-free controls in the same age group, CIU/CSU pediatric patients had higher HRU and healthcare costs.

Funding

Novartis Pharmaceuticals Corporation

Bias from outcome misclassification in immunization schedule safety research

PURPOSE

The Institute of Medicine recommended conducting observational studies of childhood immunization schedule safety. Such studies could be biased by outcome misclassification, leading to incorrect inferences. Using simulations, we evaluated (1) outcome positive predictive values (PPVs) as indicators of bias of an exposure-outcome association, and (2) quantitative bias analyses (QBA) for bias correction.

METHODS

Simulations were conducted based on proposed or ongoing Vaccine Safety Datalink studies. We simulated 4 studies of 2 exposure groups (children with no vaccines or on alternative schedules) and 2 baseline outcome levels (100 and 1000/100 000 person-years), with 3 relative risk (RR) levels (RR = 0.50, 1.00, and 2.00), across 1000 replications using probabilistic modeling. We quantified bias from non-differential and differential outcome misclassification, based on levels previously measured in database research (sensitivity > 95%; specificity > 99%). We calculated median outcome PPVs, median observed RRs, Type 1 error, and bias-corrected RRs following QBA.

RESULTS

We observed PPVs from 34% to 98%. With non-differential misclassification and true RR = 2.00, median bias was toward the null, with severe bias (median observed RR = 1.33) with PPV = 34% and modest bias (median observed RR = 1.83) with PPV = 83%. With differential misclassification, PPVs did not reflect median bias, and there was Type 1 error of 100% with PPV = 90%. QBA was generally effective in correcting misclassification bias.

CONCLUSIONS

In immunization schedule studies, outcome misclassification may be non-differential or differential to exposure. Overall outcome PPVs do not reflect the distribution of false positives by exposure and are poor indicators of bias in individual studies. Our results support QBA for immunization schedule safety research.

Clinical Course of Chronic Spontaneous Urticaria in the Korean Adult Population

Knowledge of the clinical course of chronic spontaneous urticaria (CSU) remains unclear. The purpose of our study was to investigate the clinical course of CSU in the Korean adult population. Each patient in the CSU group who was defined by disease codes between 2003 and 2007 was tracked whether he or she went into remission or not until 2013. Kaplan-Meier survival analysis was carried out to analyze remission, and log-rank tests were performed for between-group comparisons. Demographic differences between subjects who went into remission 1 year after the initial diagnosis and those who did not were analyzed using χ² tests. A total of 13,969 subjects were included in the CSU group. The 1-, 2-, 3-, 4-, and 5-year remission rates of CSU were 21.5%, 33.0%, 38.9%, 42.6%, and 44.6%, respectively. The proportion of subjects in the 65+ age group (P=0.050) and with male gender (P=0.002) was significantly higher among subjects who did not go into remission 1 year after the initial diagnosis. Our study indicates that CSU could have a more persistent course than previously reported.

Adverse and Hypersensitivity Reactions to Prescription Nonsteroidal Anti-Inflammatory Agents in a Large Health Care System

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used medications in the United States. NSAID use can be limited by adverse drug reactions (ADRs), including hypersensitivity reactions (HSRs).

OBJECTIVE

We aimed to use electronic health record data to determine the incidence and predictors of HSRs to prescription NSAIDs.

METHODS

We performed a retrospective cohort study of all adult outpatients in a large health care system prescribed diclofenac, indomethacin, nabumetone, or piroxicam between January 1, 2004, and September 30, 2012. The primary outcome was an ADR or HSR attributed to the prescribed NSAID within 1 year of prescription, determined from a longitudinal allergy database. We used natural language processing to classify known ADRs as either HSRs or side effects. Multivariable logistic regression models were used to identify independent risk factors for NSAID HSRs.

RESULTS

Of 62,719 patients prescribed NSAIDs, 1,035 (1.7%) had an ADR, of which 189 (18.3%) were HSRs. Multivariable regression analysis identified that patients with prior drug HSR history (odds ratio [OR] 1.8 [95% CI 1.3, 2.5]), female sex (OR 1.8 [95% CI 1.3, 2.4]), autoimmune disease (OR 1.7 [95% CI 1.1, 2.7]), and those prescribed the maximum standing NSAID dose (OR 1.5 [95% CI 1.1, 2.0]) had increased odds of NSAID HSR.

CONCLUSIONS

NSAID therapeutic use can be limited by ADRs; about 1 in 5 NSAID ADRs is an HSR. Both patient and drug factors contribute to HSR risk and are important to guide patient counseling.

Epidemiology of Chronic Urticaria in Korea Using the Korean Health Insurance Database, 2010-2014

Purpose

There are very few epidemiological studies on chronic urticaria (CU). We aimed to investigate the prevalence of CU and to depict demographics and medication patterns for the disease in a nationwide population-based study.

Methods

Data on urticaria (L50 of the International Classification of Diseases, 10th revision) from 2010 to 2014 were obtained from the Korean Health Insurance Review and Assessment Service. Algorithms designed to evaluate prescription drug claims for antihistamines were applied to identify CU.

Results

The crude prevalence of CU was 2,256.5 per 100,000 person-years and tended to increase every year. The age-standardized prevalence of CU was significantly higher in females than in males (2,466.8 vs 1,819.2 per 100,000 person-years, P<0.001). Age-specific prevalence was highest for older adults over the age of 65 years and lowest for ages 10-29 years. The median duration of CU was 591 days, and symptoms lasted for at least 1 year in 61.9% of patients. Gastrointestinal disease was the most common comorbidity in adults, whereas allergic rhinitis and common cold were more prevalent in children with CU. Around a third of CU patients were taking antihistamine treatment alone, and 70% were treated with both antihistamines and systemic corticosteroids. Cyclosporine was prescribed for 0.02% of CU patients.

Conclusions

The present study outlines recent longitudinal epidemiological data on the prevalence of CU in Korea. In light of limitations on the use of claims data, including no specific disease code for CU and a possible discordance between drug claims and the presence of urticaria symptoms, further investigations are necessary to describe the exact epidemiologic profile of CU patients.

Increased Risk of Chronic Spontaneous Urticaria in Patients With Autoimmune Thyroid Diseases: A Nationwide, Population-based Study

There was no previous population-based study on the comparison of the risk of chronic spontaneous urticaria (CSU) between autoimmune thyroid diseases (AITD) and age- and gender-matched controls. The primary objective of this study was to evaluate the risk of CSU after diagnosis of AITD using national registry data from Korea. The secondary objective was to evaluate other risk factors of CSU. Based on the disease code diagnoses in 2003-2005, we composed an AITD group (n=3,659) and an age- and gender-matched control group (n=18,295). Each patient was tracked for whether CSU occurs or not until 2013. After adjusting for demographic differences and comorbidities, patients with AITD had a significantly higher rate of CSU compared to the control group (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.25-1.70; P<0.001). Among the AITD patients, the adjusted HR for CSU was higher in patients with Hashimoto's thyroiditis (HR, 1.50) than in those with Grave's disease (HR, 1.33), although the difference was not statistically significant (P=0.368). Analysis of CSU patients associated with AITD showed that female patients had a significantly higher risk of CSU compared to male ones (HR, 1.34; P=0.001) and that those with allergic rhinitis (HR, 1.51; P<0.001), atopic dermatitis (HR, 2.44; P<0.001), and asthma (HR, 1.50; P<0.001) had a significantly higher risk of CSU compared to patients without respective diseases. Our results demonstrated that AITD could be significantly associated with an increased risk of CSU.

Epidemiology of chronic spontaneous urticaria: results from a nationwide, population-based study in Italy

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common skin disease, but there is a paucity of precise epidemiological data on this disease.

OBJECTIVES

To obtain information on the epidemiology of CSU in Italy.

METHODS

The data source was the Health Search IMS Health Longitudinal Patient Database. The study population was formed by patients aged ≥ 15 years, registered with a total of 700 general practitioners, homogeneously distributed across Italy. An algorithm based on the International Classification of Diseases, ninth revision, Clinical Modification was used for the identification of patients with CSU. The annual prevalence and incidence rates of CSU over a 12-year period (2002-2013) were estimated, along with demographic and clinical determinants.

RESULTS

The annual prevalence of CSU ranged from 0·02% in 2002 to 0·38% in 2013. The incidence was 0·10-1·50 per 1000 person-years. For both prevalence and incidence rates, female patients outnumbered male. The risk of CSU was statistically significantly higher in the presence of the following variables: obesity; anxiety, dissociative and somatoform disorders; malignancies; use of immunosuppressive drugs; and chronic use of systemic corticosteroids. History of autoimmune thyroiditis showed a trend towards an increased risk of CSU, though it was not statistically significant. Smoking was associated with a significantly reduced risk of CSU.

CONCLUSIONS

Our findings on CSU prevalence are consistent with those obtained in previous studies. Furthermore, this large population-based study provides important information regarding the association of CSU with demographic and clinical determinants, which have been examined in the primary-care setting.

Resource use and costs in an insured population of patients with chronic idiopathic/spontaneous urticaria

Background

Chronic idiopathic or spontaneous urticaria (CIU/CSU) impairs patients’ quality of life, and updated information on disease prevalence, treatment patterns, and disease burden is lacking.

Objectives

We aimed to estimate these figures in a large US real-world claims database via a validated algorithm.

Methods

In this retrospective cross-sectional cohort study, we identified patients with CIU/CSU, estimated disease prevalence, comorbidities, and healthcare use (medications, office visits, emergency department visits, and hospitalizations) and costs (urticaria related and all cause).

Results

We identified 6350 CIU/CSU patients in a population of just over 5.8 million: 0.11 % prevalence. Women accounted for the majority of sufferers (68.3 %) and had a greater burden of illness than men. Patients had relatively few comorbidities (mean 3.3, standard deviation 2.2). Primary care physicians and allergists were the most common providers of CIU/CSU-related care. Oral corticosteroids were the most commonly prescribed medication, used in 54.7 % of patients. Patients accumulated a mean of 15.1 office visits per year (standard deviation 12.6). The mean all-cause healthcare cost totaled over US$9000 per year.

Conclusions

Although the disease affects a relatively young population, CIU/CSU carries a substantial cost. Frequent oral corticosteroid use in CIU/CSU patients is a concern because of adverse events associated with the drug.

Electronic supplementary material

The online version of this article (doi:10.1007/s40257-015-0134-8) contains supplementary material, which is available to authorized users.