Validity of ICD-10-CM diagnoses to identify hospitalizations for serious infections among patients treated with biologic therapies

Prevalence of clinical characteristics of lipodystrophy in the US adult population in a healthcare claims database

BACKGROUND

Lipodystrophy is characterized by progressive loss of adipose tissue and consequential metabolic abnormalities. With new treatments emerging for lipodystrophy, there is a growing need to understand the prevalence of specific comorbidities that may be commonly associated with lipodystrophy to contextualize the natural history of lipodystrophy without any disease modifying therapy.

OBJECTIVE

To examine the risk of specific clinical characteristics in people living with lipodystrophy (LD) in 2018-2019 compared with the general US population, among the commercially insured US population.

METHODS

A retrospective cohort study was conducted using the 2018-2019 Clinformatics® Data Mart database. An adult LD cohort (age ≥ 18 years) with at least ≥ 1 inpatient or ≥ 2 outpatient LD diagnoses was created. The LD cohort included non-HIV-associated LD (non-HIV-LD) and HIV-associated LD (HIV-LD) subgroups and compared against age- and sex-matched control groups with a 1:4 ratio from the general population with neither an LD or an HIV diagnosis using odds ratios (ORs) with 95% confidence intervals.

RESULTS

We identified 546 individuals with non-HIV-LD (mean age, 60.3 ± 14.9 years; female, 67.6%) and 334 individuals with HIV-LD (mean age, 59.2 ± 8.3 years; female, 15.0%) in 2018-2019. Compared with the general population, individuals with non-HIV-LD had higher risks (odds ratio [95% confidence interval]) for hyperlipidemia (3.32 [2.71-4.09]), hypertension (3.58 [2.89-4.44]), diabetes mellitus (4.72 [3.85-5.79]), kidney disease (2.78 [2.19-3.53]), liver fibrosis or cirrhosis (4.06 [1.66-9.95]), cancer (2.20 [1.59-3.01]), and serious infections resulting in hospitalization (3.00 [2.19-4.10]). Compared with individuals with HIV, those with HIV-LD have higher odds of hypertension (1.47 [1.13-1.92]), hyperlipidemia (2.46 [1.86-3.28]), and diabetes (1.37 [1.04-1.79]).

CONCLUSIONS

LD imposes a substantial burden on affected individuals due to a high prevalence of metabolic comorbidities and other complications as compared with the general non-LD population. Future longitudinal follow-up studies investigating the causality between LD and observed comorbidities are warranted.

Hospitalizations for opportunistic infections following transplantation and associated risk factors: A national cohort study of Medicare beneficiaries

BACKGROUND

Opportunistic infections (OIs) are a significant cause of morbidity and mortality after organ transplantation, though data in the liver transplant (LT) population are limited.

METHODS

We performed a retrospective cohort study of LT recipients between January 1, 2007 and Deceber 31, 2016 using Medicare claims data linked to the Organ Procurement and Transplantation Network database. Multivariable Cox regression models evaluated factors independently associated with hospitalizations for early (≤1 year post transplant) and late (>1 year) OIs, with a particular focus on immunosuppression.

RESULTS

There were 11 320 LT recipients included in the study, of which 13.2% had at least one OI hospitalization during follow-up. Of the 2638 OI hospitalizations, 61.9% were early post-LT. Cytomegalovirus was the most common OI (45.4% overall), although relative frequency decreased after the first year (25.3%). Neither induction or maintenance immunosuppression were associated with early OI hospitalization (all p > .05). The highest risk of early OI was seen with primary sclerosing cholangitis (aHR 1.74; p = .003 overall). Steroid-based and mechanistic target of rapamycin inhibitor-based immunosuppression at 1 year post LT were independently associated with increased late OI (p < .001 overall).

CONCLUSION

This study found OI hospitalizations to be relatively common among LT recipients and frequently occur later than previously reported. Immunosuppression regimen may be an important modifiable risk factor for late OIs.

Real-world Evidence Comparing Tofacitinib and Vedolizumab in Anti-TNF-experienced Patients With Ulcerative Colitis

BACKGROUND

Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patients with ulcerative colitis (UC). With time, patients tend to lose response or become intolerant, necessitating switching to small cell biologics such as tofacitinib or vedolizumab. In this real-world study of a large, geographically diverse US population of TNF-experienced patients with UC, we evaluated the effectiveness and safety of newly initiating treatment with tofacitinib vs vedolizumab.

METHODS

We conducted a cohort study using secondary data from a large US insurer (Anthem, Inc.). Our cohort included patients with UC newly initiating treatment with tofacitinib or vedolizumab. Patients were required to have evidence of treatment with anti-TNF inhibitors in the 6 months prior to cohort entry. The primary outcome was treatment persistence >52 weeks. Additionally, we evaluated the following secondary outcomes as additional measures of effectiveness and safety: (1) all-cause hospitalization; (2) total abdominal colectomy; (3) hospitalization for infection; (4) hospitalization for malignancy; (5) hospitalization for cardiac events; and (6) hospitalization for thromboembolic events. We used fine stratification by propensity scores to control for confounding by demographics, clinical factors, and treatment history at baseline.

RESULTS

Our primary cohort included 168 new users of tofacitinib and 568 new users of vedolizumab. Tofacitinib was associated with lower treatment persistence (adjusted risked ratio, 0.77; 95% CI, 0.60 -0.99). Differences in secondary measures of effectiveness or safety between tofacitinib initiators vs vedolizumab initiators were not statistically significant (all-cause hospitalization, adjusted hazard ratio, 1.23; 95% CI, 0.83-1.84; total abdominal colectomy, adjusted HR, 1.79; 95% CI, 0.93-3.44;and hospitalization for any infection, adjusted HR, 1.94; 95% CI, 0.83-4.52).

DISCUSSION

Ulcerative colitis patients with prior anti-TNF experience initiating tofacitinib demonstrated lower treatment persistence compared with those initiating vedolizumab. This finding is in contrast to other recent studies suggesting superior effectiveness of tofacitinib. Ultimately, head-to-head randomized, controlled trials that focus on directly measured end points may be needed to best inform clinical practice.

Multiple morbidities are associated with serious infections in patients with rheumatoid arthritis

OBJECTIVE

To assess the association between a comprehensive list of morbidities and serious infection (SI) in patients with rheumatoid arthritis (RA).

METHODS

This study evaluated SI risk associated with 55 comorbidities using a population-based inception cohort including all adult patients with incident RA from 1999 through 2014 with follow up through 2021. Morbidities and SI were ascertained using previously validated international classification of disease (ICD)-9 and ICD-10 codes. Conditional frailty models were utilized to analyze the association between each morbidity and SI: Model 1 adjusted for age, sex, and calendar year; Model 2 adjusted for factors in Model 1 and the Rheumatoid Arthritis Observation of Biologic Therapy (RABBIT) Risk Score of Infections; and Model 3 adjusted for factors in Model 1 and the Mayo SI Risk Score.

RESULTS

911 patients (70 % female, mean age 56 years, 66 % seropositive) were included. There were 293 SI among 155 patients (17 %), corresponding to an incidence of 3.9 SI per 100 person-years. Eighteen SI were fatal. Risk of SI was significantly increased in 27 of 55 morbidities in Model 1, 11 morbidities in Model 2, and 23 morbidities in Model 3. Additionally, several morbidities included in the RABBIT and Mayo risk scores continued to have large effect sizes despite adjustment. Serious infection risk increased by 11-16 % per morbidity in the three models.

CONCLUSIONS

Several morbidities are associated with an increased risk for SI. Future risk scores may include morbidities identified in this study for improved SI risk assessment.

Investigating the occurrence of autoimmune diseases among children and adolescents hospitalized for Mycoplasma pneumoniae infections

Background

Mycoplasma pneumoniae infection is common in the general population and may be followed by immune dysfunction, but links with subsequent autoimmune disease remain inconclusive.

Objective

To estimate the association of M. pneumoniae infection with the risk of subsequent autoimmune disease.

Methods

This retrospective cohort study examined the medical records of South Korean children from 01/01/2002 to 31/12/2017. The exposed cohort was identified as patients hospitalized for M. pneumoniae infection. Each exposed patient was matched with unexposed controls based on birth year and sex at a 1:10 ratio using incidence density sampling calculations. The outcome was subsequent diagnosis of autoimmune disease, and hazard ratios (HRs) were estimated with control for confounders. Further estimation was performed using hospital-based databases which were converted to a common data model (CDM) to allow comparisons of the different databases.

Results

The exposed cohort consisted of 49,937 children and the matched unexposed of 499,370 children. The median age at diagnosis of M. pneumoniae infection was 4 years (interquartile range, 2.5-6.5 years). During a mean follow-up time of 9.0 ± 3.8 years, the incidence rate of autoimmune diseases was 66.5 per 10,000 person-years (95% CI: 64.3-68.8) in the exposed cohort and 52.3 per 10,000 person-years (95% CI: 51.7-52.9) in the unexposed cohort, corresponding to an absolute rate of difference of 14.3 per 10,000 person-years (95% CI: 11.9-16.6). Children in the exposed cohort had an increased risk of autoimmune disease (HR: 1.26; 95% CI: 1.21-1.31), and this association was similar in the separate analysis of hospital databases (HR: 1.25; 95% CI 1.06-1.49).

Conclusion

M. pneumoniae infection requiring hospitalization may be associated with an increase in subsequent diagnoses of autoimmune diseases.

Comparative Risks of Infection With Belimumab Versus Oral Immunosuppressants in Patients With Nonrenal Systemic Lupus Erythematosus

OBJECTIVE

We investigated the comparative risk of infection with belimumab versus oral immunosuppressants for the treatment of systemic lupus erythematosus (SLE).

METHODS

Using observational data from a US multicenter electronic health record database, we identified patients with SLE but without lupus nephritis who initiated belimumab, azathioprine, methotrexate, or mycophenolate between 2011 and 2021. We designed and emulated hypothetical target trials to estimate the cumulative incidence and hazard ratios (HRs) of serious infection and hospitalization for serious infection comparing belimumab versus each oral immunosuppressant. We used propensity score overlap weighting to balance baseline covariates and adjusted for adherence to treatment group using inverse probability of treatment weighting. We also assessed the control outcome of traumatic injury.

RESULTS

Among 21,481 patients, we compared 2841 and 6343 initiators of belimumab and azathioprine, 2642 and 8242 initiators of belimumab and methotrexate, and 2813 and 8407 initiators of belimumab and mycophenolate, respectively. After propensity score overlap weighting, all covariates were balanced in each comparison. The mean age of the cohort was 45 years, and 94% were women. Compared with azathioprine and mycophenolate, belimumab was associated with lower risks of both serious infection (HR 0.82; 95% confidence interval [CI] 0.72-0.92 and HR 0.69; 95% CI 0.61-0.78) and hospitalization for infection (HR 0.73; 95% CI 0.57-0.94 and HR 0.56 95% CI 0.43-0.71). The risk of infection was also lower for belimumab compared with methotrexate (HR 0.86; 95% CI 0.76-0.97). There were no differences in traumatic injury risks across treatment groups.

CONCLUSION

Belimumab was associated with lower risks of serious infection than with oral immunosuppressants. This finding should inform risk/benefit considerations for SLE treatment.

Six Years of the US Food and Drug Administration's Postmarket Active Risk Identification and Analysis System in the Sentinel Initiative: Implications for Real World Evidence Generation

Congress mandated the creation of a postmarket Active Risk Identification and Analysis (ARIA) system containing data on 100 million individuals for monitoring risks associated with drug and biologic products using data from disparate sources to complement the US Food and Drug Administration's (FDA's) existing postmarket capabilities. We report on the first 6 years of ARIA utilization in the Sentinel System (2016-2021). The FDA has used the ARIA system to evaluate 133 safety concerns; 54 of these evaluations have closed with regulatory determinations, whereas the rest remain in progress. If the ARIA system and the FDA's Adverse Event Reporting System are deemed insufficient to address a safety concern, then the FDA may issue a postmarket requirement to a product's manufacturer. One hundred ninety-seven ARIA insufficiency determinations have been made. The most common situation for which ARIA was found to be insufficient is the evaluation of adverse pregnancy and fetal outcomes following in utero drug exposure, followed by neoplasms and death. ARIA was most likely to be sufficient for thromboembolic events, which have high positive predictive value in claims data alone and do not require supplemental clinical data. The lessons learned from this experience illustrate the continued challenges using administrative claims data, especially to define novel clinical outcomes. This analysis can help to identify where more granular clinical data are needed to fill gaps to improve the use of real-world data for drug safety analyses and provide insights into what is needed to efficiently generate high-quality real-world evidence for efficacy.

Validation of Claims-Based Algorithm for Lyme Disease, Massachusetts, USA

Compared with notifiable disease surveillance, claims-based algorithms estimate higher Lyme disease incidence, but their accuracy is unknown. We applied a previously developed Lyme disease algorithm (diagnosis code plus antimicrobial drug prescription dispensing within 30 days) to an administrative claims database in Massachusetts, USA, to identify a Lyme disease cohort during July 2000-June 2019. Clinicians reviewed and adjudicated medical charts from a cohort subset by using national surveillance case definitions. We calculated positive predictive values (PPVs). We identified 12,229 Lyme disease episodes in the claims database and reviewed and adjudicated 128 medical charts. The algorithm's PPV for confirmed, probable, or suspected cases was 93.8% (95% CI 88.1%-97.3%); the PPV was 66.4% (95% CI 57.5%-74.5%) for confirmed and probable cases only. In a high incidence setting, a claims-based algorithm identified cases with a high PPV, suggesting it can be used to assess Lyme disease burden and supplement traditional surveillance data.

Renal disease and diabetes increase the risk of failed outpatient management of cellulitic hand infections: a retrospective cohort study

BACKGROUND

Hand infections are heterogeneous, and some may undergo successful outpatient management. There are no strict guidelines for determining which patients will likely require inpatient admission for successful treatment, and many patients succeed with outpatient therapy. We sought to determine risk factors for failed outpatient management of cellulitic hand infections.

METHODS

We performed a retrospective review of patients who presented to the Emergency Department (ED) for hand cellulitic infections over five years, from 2014 to 2019. Vital signs, lab markers, Charlson Comorbidity Index (CCI), Elixhauser Comorbidity Measure (ECM), and antibiotic use were investigated. Discharge from the ED without subsequent admission was considered an outpatient success, while admission within 30 days of the prior visit was considered a failure. Continuous variables were compared with Welch's t test, and categorical data with Fisher's exact tests. Multivariable logistic regression was performed on comorbidities. Multiple testing adjustment was performed on p-values to generate q-values.

RESULTS

Outpatient management was attempted for 1,193 patients. 31 (2.6%) infections failed treatment, and 1,162 (97.4%) infections succeeded. Attempted outpatient treatment was 97.4% successful. Multivariable analysis demonstrated higher odds of failure with renal failure according to both CCI (OR 10.2, p < 0.001, q = 0.002) and ECM (OR 12.63, p = 0.003, q = 0.01) and with diabetes with complications according to the CCI (OR 18.29, p = 0.021, q = 0.032).

CONCLUSIONS

Outpatient treatment failure was higher in patients with renal failure and complicated diabetes. These patients require a high index of suspicion for outpatient failure. These comorbidities should influence consideration for inpatient therapy though most patients can undergo successful treatment as outpatients.

LEVEL OF EVIDENCE

Level III.

Infection-related hospitalisation in young adults with systemic lupus erythematosus: data from the National Inpatient Sample

INTRODUCTION

Care of young adults with SLE (YA-SLE, 18-24 years) is challenging due to major life transitions co-occurring with chronic healthcare needs. Studies have demonstrated poorer outcomes in the post-transition period. Epidemiological studies focused on serious infection-related hospitalisation (SIH) in YA-SLE are lacking.

METHODS

We used National Inpatient Sample from 2010 to 2019 to study the epidemiology and outcomes of SIH for five common infections in SLE, namely sepsis, pneumonia, urinary tract infections, skin and soft tissue infections, and opportunistic infections. For time trends, we extended the dataset to cover 2000-2019. The primary outcome was the rate of SIH in YA-SLE compared with adults (25-44 years) with SLE and with young adults without SLE (YA-no SLE).

RESULTS

From 2010 to 2019, we identified 1 720 883 hospital admissions with SLE in patients aged ≥18 years. Rates of SIH were similar in young adults and adults with SLE (15.0% vs 14.5%, p=0.12), but considerably higher than in the YA-no SLE group (4.2%, p<0.001). Among SLE with SIH, sepsis followed by pneumonia was the most common diagnosis. Significantly higher proportions of SIH among young adults than adults with SLE were comprised of non-white patients, belonged to the lowest income quartile and had Medicaid. However, only race/ethnicity was associated with SIH among YA-SLE. There was a higher prevalence of comorbid lupus nephritis and pleuritis among young adults compared with adults with SLE and SIH, and both comorbidities were associated with SIH in YA-SLE. Increasing rates of SIH, driven by sepsis, were seen over time.

DISCUSSION

YA- SLE had similar rates of SIH to adults with SLE. While hospitalised YA-SLE differed sociodemographically from SLE adults and YA-no SLE, only race/ethnicity was associated with SIH in the YA-SLE group. Lupus nephritis and pleuritis were associated with higher SIH in YA-SLE. Among SLE with SIH, increasing trends of sepsis deserve further study.

Core concepts in pharmacoepidemiology: Validation of health outcomes of interest within real-world healthcare databases

Real-world healthcare data, including administrative and electronic medical record databases, provide a rich source of data for the conduct of pharmacoepidemiologic studies but carry the potential for misclassification of health outcomes of interest (HOIs). Validation studies are important ways to quantify the degree of error associated with case-identifying algorithms for HOIs and are crucial for interpreting study findings within real-world data. This review provides a rationale, framework, and step-by-step approach to validating case-identifying algorithms for HOIs within healthcare databases. Key steps in validating a case-identifying algorithm within a healthcare database include: (1) selecting the appropriate health outcome; (2) determining the reference standard against which to validate the algorithm; (3) developing the algorithm using diagnosis codes, diagnostic tests or their results, procedures, drug therapies, patient-reported symptoms or diagnoses, or some combinations of these parameters; (4) selection of patients and sample sizes for validation; (5) collecting data to confirm the HOI; (6) confirming the HOI; and (7) assessing the algorithm's performance. Additional strategies for algorithm refinement and methods to correct for bias due to misclassification of outcomes are discussed. The review concludes by discussing factors affecting the transportability of case-identifying algorithms and the need for ongoing validation as data elements within healthcare databases, such as diagnosis codes, change over time or new variables, such as patient-generated health data, are included in these data sources.

Real-World Evidence Comparing Vedolizumab and Ustekinumab in Antitumor Necrosis Factor-Experienced Patients With Crohn's Disease

INTRODUCTION

Many patients with Crohn's disease (CD) lose response or become intolerant to antitumor necrosis factor (TNF) therapy and subsequently switch out of class. We compared the effectiveness and safety of ustekinumab to vedolizumab in a large, geographically diverse US population of TNF-experienced patients with CD.

METHODS

We conducted a retrospective cohort study using longitudinal claims data from a large US insurer (Anthem, Inc.). We identified patients with CD initiating vedolizumab or ustekinumab with anti-TNF treatment in the prior 6 months. Our primary outcome was treatment persistence for >52 weeks. Secondary outcomes included (i) all-cause hospitalization, (ii) hospitalization for CD with surgery, (iii) hospitalization for CD without surgery, and (iv) hospitalization for infection. Propensity score fine stratification was used to control for demographic and baseline clinical characteristics and prior treatments.

RESULTS

Among 885 new users of ustekinumab and 490 new users of vedolizumab, we observed no difference in treatment persistence (adjusted risk ratio 1.09 [95% confidence interval 0.95-1.25]). Ustekinumab was associated with a lower rate of all-cause hospitalization (adjusted hazard ratio 0.73 [0.59-0.91]), nonsurgical CD hospitalization (adjusted hazard ratio 0.58 [0.40-0.83]), and hospitalization for infection (adjusted hazard ratio 0.56 [0.34-0.92]).

DISCUSSION

This real-world comparative effectiveness study of anti-TNF-experienced patients with CD initiating vedolizumab or ustekinumab showed similar treatment persistence rates beyond 52 weeks, although secondary outcomes such as all-cause hospitalizations, nonsurgical CD hospitalizations, and hospitalizations for infection favored ustekinumab initiation. We, therefore, advocate for individualized decision making in this medically refractory population, considering patient preference and other factors such as cost and route of administration.