Linkage of the CF foundation patient registry with the pediatric health information system database

Antibiotic Regimen Changes during Cystic Fibrosis Pediatric Pulmonary Exacerbation Treatment

Rationale/Objectives: Antibiotic selection for in-hospital treatment of pulmonary exacerbations (PEx) in people with cystic fibrosis (CF) is typically guided by previous respiratory culture results or past PEx antibiotic treatment. In the absence of clinical improvement during PEx treatment, antibiotics are frequently changed in search of a regimen that better alleviates symptoms and restores lung function. The clinical benefits of changing antibiotics during PEx treatment are largely uncharacterized. Methods: This was a retrospective cohort study using the Cystic Fibrosis Foundation Patient Registry Pediatric Health Information System. PEx were included if they occurred in children with CF from 6 to 21 years old who had been treated with intravenous antibiotics between January 1, 2006, and December 31, 2018. PEx with lengths of stay <5 or >21 days or for which treatment was delivered in an intensive care unit were excluded. An antibiotic change was defined as the addition or subtraction of any intravenous antibiotic between Hospital Day 6 and the day before hospital discharge. Inverse probability of treatment weighting was used to adjust for disease severity and indication bias, which might influence a decision to change antibiotics. Results: In all, 4,099 children with CF contributed 18,745 PEx for analysis, of which 8,169 PEx (43.6%) included a change in intravenous antibiotics on or after Hospital Day 6. The mean change in pre- to post-treatment percent predicted forced expiratory volume in 1 second (ppFEV1) was 11.3 (standard error, 0.21) among events in which an intravenous antibiotic change occurred versus 12.2 (0.18) among PEx without an intravenous antibiotic change (P = 0.001). Similarly, the odds of return to ⩾90% of baseline ppFEV1 were less for PEx with antibiotic changes than for those without changes (odds ratio [OR], 0.89 [95% confidence interval (CI), 0.80-0.98]). The odds of returning to ⩾100% of baseline ppFEV1 did not differ between PEx with versus without antibiotic changes (OR, 0.94 [95% CI, 0.86-1.03]). In addition, PEx treated with intravenous antibiotic changes were associated with higher odds of future PEx (OR, 1.17 [95% CI, 1.12-1.22]). Conclusions: In this retrospective study, changing intravenous antibiotics during PEx treatment in children with CF was common and not associated with improved clinical outcomes.

Polymicrobial infections and antibiotic treatment patterns for cystic fibrosis pulmonary exacerbations

BACKGROUND

No data exist to guide antibiotic selection among people with CF (PwCF) with respiratory cultures positive for multiple CF-related bacteria (polymicrobial infections). This study aimed to describe the number of polymicrobial in-hospital treated pulmonary exacerbations (PEx), to determine the proportion of polymicrobial PEx where antibiotics were prescribed with activity against all bacteria detected (termed complete antibiotic coverage), and to determine clinical and demographic factors associated with complete antibiotic coverage.

METHODS

Retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System dataset. Children aged 1-21 years with an in-hospital treated PEx from 2006 to 2019 were eligible for inclusion. Bacterial culture positivity was based on any positive respiratory culture in the 12 months prior to a study PEx.

RESULTS

A total of 4,923 children contributed 27,669 total PEx of which 20,214 were polymicrobial; of these, 68% of PEx had complete antibiotic coverage. In regression modeling, a prior PEx with complete antibiotic coverage for MRSA was associated with a higher likelihood of having complete antibiotic coverage at a subsequent study PEx (OR (95% CI) 3.48 (2.50, 4.83)).

CONCLUSIONS

The majority of children with CF hospitalized for polymicrobial PEx were prescribed complete antibiotic coverage. Prior PEx treatment with complete antibiotic coverage predicted complete antibiotic coverage at a future PEx for all bacteria studied. Studies are needed comparing outcomes of polymicrobial PEx treated with different antibiotic coverages to optimize PEx antibiotic selection.

Virtual patient identifier (vPID): Improving patient traceability using anonymized identifiers in Japanese healthcare insurance claims database

Objective

Japan's national-level healthcare insurance claims database (NDB) is a collective database that contains the entire information on healthcare services being provided to all citizens. However, existing anonymized identifiers (ID1 and ID2) have a poor capability of tracing patients' claims in the database, hindering longitudinal analyses. This study presents a virtual patient identifier (vPID), which we have developed on top of these existing identifiers, to improve the patient traceability.

Methods

vPID is a new composite identifier that intensively consolidates ID1 and ID2 co-occurring in an identical claim to allow to collect claims of each patient even though its ID1 or ID2 may change due to life events or clerical errors. We conducted a verification test with prefecture-level datasets of healthcare insurance claims and enrollee history records, which allowed us to compare vPID with the ground truth, in terms of an identifiability score (indicating a capability of distinguishing a patient's claims from another patient's claims) and a traceability score (indicating a capability of collecting claims of an identical patient).

Results

The verification test has clarified that vPID offers significantly higher traceability scores (0.994, Mie; 0.997, Gifu) than ID1 (0.863, Mie; 0.884, Gifu) and ID2 (0.602, Mie; 0.839, Gifu), and comparable (0.996, Mie) and lower (0.979, Gifu) identifiability scores.

Discussion

vPID is seemingly useful for a wide spectrum of analytic studies unless they focus on sensitive cases to the design limitation of vPID, such as patients experiencing marriage and job change, simultaneously, and same-sex twin children.

Conclusion

vPID successfully improves patient traceability, providing an opportunity for longitudinal analyses that used to be practically impossible for NDB. Further exploration is also necessary, in particular, for mitigating identification errors.

Antibiotics and outcomes of CF pulmonary exacerbations in children infected with MRSA and Pseudomonas aeruginosa

BACKGROUND

Limited data exist to inform antibiotic selection among people with cystic fibrosis (CF) with airway infection by multiple CF-related microorganisms. This study aimed to determine among children with CF co-infected with methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (Pa) if the addition of anti-MRSA antibiotics to antipseudomonal antibiotic treatment for pulmonary exacerbations (PEx) would be associated with improved clinical outcomes compared with antipseudomonal antibiotics alone.

METHODS

Retrospective cohort study using data from the CF Foundation Patient Registry-Pediatric Health Information System linked dataset. The odds of returning to baseline lung function and having a subsequent PEx requiring intravenous antibiotics were compared between PEx treated with anti-MRSA and antipseudomonal antibiotics and those treated with antipseudomonal antibiotics alone, adjusting for confounding by indication using inverse probability of treatment weighting.

RESULTS

943 children with CF co-infected with MRSA and Pa contributed 2,989 PEx for analysis. Of these, 2,331 (78%) PEx were treated with both anti-MRSA and antipseudomonal antibiotics and 658 (22%) PEx were treated with antipseudomonal antibiotics alone. Compared with PEx treated with antipseudomonal antibiotics alone, the addition of anti-MRSA antibiotics to antipseudomonal antibiotic therapy was not associated with a higher odds of returning to ≥90% or ≥100% of baseline lung function or a lower odds of future PEx requiring intravenous antibiotics.

CONCLUSIONS

Children with CF co-infected with MRSA and Pa may not benefit from the addition of anti-MRSA antibiotics for PEx treatment. Prospective studies evaluating optimal antibiotic selection strategies for PEx treatment are needed to optimize clinical outcomes following PEx treatment.

Systemic Corticosteroids in the Management of Pediatric Cystic Fibrosis Pulmonary Exacerbations

Rationale: Pulmonary exacerbation (PEx) events contribute to lung function decline in people with cystic fibrosis (CF). CF Foundation PEx guidelines note that a short course of systemic corticosteroids may offer benefit without contributing to long-term adverse effects. However, insufficient evidence exists to recommend systemic corticosteroids for PEx treatment. Objectives: To determine if systemic corticosteroids for the treatment of in-hospital pediatric PEx are associated with improved clinical outcomes compared with treatment without systemic corticosteroids. Methods: We conducted a retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System linked database. People with CF were included if hospitalized for a PEx between 2006 and 2018 and were 6-21 years of age. Time to next PEx was assessed by Cox proportional hazards regression. Lung function outcomes were assessed by linear mixed-effect modeling and generalized estimating equations. To address confounding by indication, inverse probability treatment weighting was used. Results: A total of 3,471 people with CF contributed 9,787 PEx for analysis. Systemic corticosteroids were used in 15% of all PEx. In our primary analysis, systemic corticosteroids were not associated with better pre- to post-PEx percent predicted forced expiratory volume in 1 second responses (mean difference, -0.36; 95% confidence interval [CI], -1.14, 0.42; P = 0.4) or a higher odds of returning to lung function baseline (odds ratio, 0.97; 95% CI, 0.84-1.12; P = 0.7) but were associated with a reduced chance of future PEx requiring intravenous antibiotics (hazard ratio, 0.91; 95% CI, 0.85-0.96; P = 0.002). When restricting the analysis to one PEx per person, lung function outcomes remained no different among PEx treated with or without systemic corticosteroids, but, in contrast to our primary analysis, the use of systemic corticosteroids was no longer associated with a reduced chance of having a future PEx requiring intravenous antibiotics (hazard ratio, 0.96; 95% CI, 0.86, 1.07; P = 0.42). Conclusions: Systemic corticosteroid treatment for in-hospital pediatric PEx was not associated with improved lung function outcomes. Prospective trials are needed to better evaluate the risks and benefits of systemic corticosteroid use for PEx treatment in children with CF.

Clinical Outcomes of Antipseudomonal versus Other Antibiotics Among Children with Cystic Fibrosis without Pseudomonas aeruginosa

RATIONALE

Antibiotic selection for pulmonary exacerbation (PEx) management in children with CF is typically guided by prior respiratory culture results. While antipseudomonal antibiotics are often used in children with chronic Pseudomonas aeruginosa (Pa) airway infection, no data exist to guide antibiotic selection in children who are culture negative for Pa for ≥1 year.

OBJECTIVES

To determine among children classified as 1-, 2-, or 3-years Pa-negative if PEx treatment with at least 1 oral and/or intravenous anti-Pa antibiotic is associated with improved clinical outcomes compared to treatment with antibiotics not effective against Pa.

METHODS

Retrospective cohort study using the linked CF Foundation Patient Registry-Pediatric Health Information System (CFFPR-PHIS) database. We included children 6-21 years old hospitalized between 2008-2018 consistently culture-negative for Pa 1 year prior to a study PEx. Children were classified as 1- or 2-years Pa-negative if their last Pa-positive culture occurred in the 13-24 months or 25-36 months prior to a study PEx, respectively, with all subsequent cultures negative for Pa. Children classified as 3-years Pa-negative had no Pa-positive cultures in the 36 months prior to a study PEx. Inverse probability of treatment weighted linear or logistic regression models were used to compare clinical outcomes (pre- to post-PEx forced expiratory volume in one second, odds of returning to ≥90% of baseline lung function, and odds of having a future PEx) between anti-Pa and non-anti-Pa antibiotic strategies.

RESULTS

Among all children included in the linked dataset, 1,290 children with 2,347 PEx were eligible for analysis. Among all study PEx, 530, 326, and 1,491 PEx were classified as 1-, 2-, or 3-years Pa-negative, respectively, and anti-Pa antibiotics were administered in 79%, 67%, and 66% of all PEx classified as 1-, 2-, or 3-years Pa-negative, respectively. For all Pa-negative groups, when compared to non-anti-Pa antibiotic regimens, anti-Pa antibiotic treatment was not associated with greater improvement in any studied clinical outcomes.

CONCLUSIONS

Despite its common use, including antibiotics effective against Pa may provide no additional benefit for PEx treatment among children who are Pa-negative for at least 1 year prior. Prospective trials are warranted to directly test this hypothesis.

Prevalence, variability, and predictors of sinus surgery in pediatric patients with cystic fibrosis

INTRODUCTION

Chronic rhinosinusitis is common among individuals with cystic fibrosis (CF) and has an impact on quality of life. Sinus surgery is a treatment option, but minimal literature exists regarding prevalence and indications.

METHODS

Using the linked CF Foundation Patient Registry (CFFPR) - Pediatric Health Information Systems (PHIS) database, we investigated variability in receipt of surgery, predictors of surgery, and time to first surgery. We included individuals less than 18 receiving care between 2006 and 2015 at a CF Foundation care program that is also a PHIS-participating-hospital. We used logistic regression to examine predictors of receipt of surgery and a Kaplan-Meier curve to examine time to first surgery among those born 2005-2007.

RESULTS

There were 11,545 children and adolescents and 2156 (18.7%) received at least one surgery. Variation in number of surgeries was observed across hospitals (median: 63 [IQR, 33-110]). There was an inconsistent pattern between receipt of surgery and markers of disease severity; those receiving surgery having increased odds of treatment use and pulmonary exacerbations and decreased odds of lower lung function and body mass index. Among the cohort of young children, 159 (14%) had at least one surgery with a median age at first surgery of 5.6 (IQR, 3.9-7.0).

CONCLUSIONS

The use of sinus surgery is frequent, but variable, among children and adolescents. Clinical factors are associated with receipt of surgery, but further understanding is needed on other factors that impact variability in use. Our study indicates the need for additional evaluation of the management of CF-related CRS and indications for surgery.

Association of Inhaled Antibiotics in Addition to Standard Intravenous Therapy and Outcomes of Pediatric Inpatient Pulmonary Exacerbations

Rationale: Considerable morbidity and disease progression in people with cystic fibrosis (CF) result from pulmonary exacerbations (PExs). PEx guidelines note insufficient evidence to recommend for or against the concomitant use of inhaled and intravenous antibiotics.Objectives: We hypothesize that the addition of inhaled antibiotics for PEx therapy is associated with improvements in lung function and a longer time to next PEx compared with standard intravenous antibiotics alone.Methods: We performed a retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System linked dataset. People with CF were included if they were hospitalized for PEx between 2006 and 2016 and 6 to 21 years of age. Lung function outcomes were assessed by linear mixed effect modeling and generalized estimating equations. The time to next PEx was assessed by Cox proportional hazards regression. To estimate independent causal effects while accounting for indication bias and other confounders, inverse probabilities of treatment weights were calculated based on covariates believed to influence the likelihood of inhaled antibiotic use during PEx treatment.Results: A total of 3,253 children and adolescents contributed 9,040 PEx events for analysis. Inhaled antibiotics were used in 23% of PEx events but were not associated with better pre- to post-PEx percent predicted forced expiratory volume in 1 second responses (mean difference, -1.11%; 95% confidence interval [CI], -1.83 to -0.38; P = 0.003), higher odds of returning to lung function baseline (odds ratio, 0.94; 95% CI, 0.82 to 1.07; P = 0.34), or longer time to next PEx (hazard ratio, 1.05; 95% CI, 0.99 to 1.12; P = 0.098).Conclusions: The addition of inhaled antibiotics to standard intravenous antibiotic PEx treatment was not associated with improved lung function outcomes or a longer time to next PEx.

Effect of Concomitant Azithromycin and Tobramycin Use on Cystic Fibrosis Pulmonary Exacerbation Treatment

Rationale: Pulmonary exacerbations (PExs) are associated with significant morbidity in people with cystic fibrosis (CF). Severe PExs are treated with intravenous antibiotics, including tobramycin. CF care guidelines recommend continuing chronic maintenance medications during PEx treatment. Azithromycin (AZM) is one of the most widely prescribed chronic medications for CF in the United States. Recent evidence has identified a potential antagonistic relationship between AZM and tobramycin.Objectives: To determine whether, among PEx treated with intravenous tobramycin, concomitant AZM use is associated with worse clinical outcomes.Methods: Retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System (CFFPR-PHIS)-linked dataset. People with CF age 6-21 years were included if they were hospitalized between 2006 and 2016 for a PEx. Inverse probability of treatment weighing was used to minimize the effects of confounders, including indication bias. Associations of concomitant treatment with AZM and lung function outcomes were determined using linear mixed-effect models and generalized estimating equations. Cox proportional hazard regression models were used to evaluate associations with time to next PEx.Results: Among the 10,660 people with CF included in the CFFPR-PHIS-linked dataset, 2,294 children and adolescents with 5,022 PExs that had intravenous tobramycin use were identified. A little less than half (n = 2,247; 45%) of all PExs were treated concomitantly with AZM and intravenous tobramycin. AZM use both at the most recent outpatient clinic encounter and during PEx treatment in combination with intravenous tobramycin was associated with a significantly lower absolute improvement in percentage-predicted forced expiratory volume in 1 second (ppFEV₁) (-0.93%; 95% confidence interval [CI], -1.78 to -0.07; P = 0.033), a lesser odds of returning to 90% or more of baseline ppFEV₁ (odds ratio, 0.79; 95% CI, 0.68-0.93; P = 0.003), and a shorter time to next PEx requiring intravenous antibiotics (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < 0.001) compared with intravenous tobramycin use without concomitant AZM.Conclusions: Concomitant AZM and intravenous tobramycin use for in-hospital PEx treatment was associated with poorer clinical outcomes than treatment with intravenous tobramycin without AZM. These results support the hypothesis that an antagonistic relationship between these two medications might exist.

Association Between Number of Intravenous Antipseudomonal Antibiotics and Clinical Outcomes of Pediatric Cystic Fibrosis Pulmonary Exacerbations

BACKGROUND

Pulmonary exacerbations (PEx) in people with cystic fibrosis (PwCF) are associated with significant morbidity. While standard PEx treatment for PwCF with Pseudomonas aeruginosa infection includes two IV antipseudomonal antibiotics, little evidence exists to recommend this approach. This study aimed to compare clinical outcomes of single versus double antipseudomonal antibiotic use for PEx treatment.

METHODS

Retrospective cohort study using the linked CF Foundation Patient Registry-Pediatric Health Information System dataset. PwCF were included if hospitalized between 2007-2018 and 6-21 years of age. Regression modeling accounting for repeated measures was used to compare lung function outcomes between single versus double IV antipseudomonal antibiotic regimens using propensity-score weighting to adjust for relevant confounding factors.

RESULTS

Among 10,660 PwCF in the dataset, we analyzed 2,578 PEx from 1,080 PwCF, of which 455 and 2,123 PEx were treated with 1 versus 2 IV antipseudomonal antibiotics, respectively. We identified no significant differences between PEx treated with 1 versus 2 IV antipseudomonal antibiotics either in change between pre- and post-PEx percent predicted forced expiratory volume in one second (ppFEV1) (-0.84%, [95% CI -2.25, 0.56]; p=0.24), odds of returning to ≥90% of baseline ppFEV1 within 3 months following PEx (Odds Ratio 0.83, [95% CI 0.61, 1.13]; p=0.24) or time to next PEx requiring IV antibiotics (Hazard Ratio 1.04, [95% CI 0.87, 1.24]; p=0.69).

CONCLUSION

Use of 2 IV antipseudomonal antibiotics for PEx treatment in young PwCF was not associated with greater improvements in measured respiratory and clinical outcomes compared to treatment with 1 IV antipseudomonal antibiotic.

Identifying children with Cystic Fibrosis in population-scale routinely collected data in Wales: A Retrospective Review

INTRODUCTION

The challenges in identifying a cohort of people with a rare condition can be addressed by routinely collected, population-scale electronic health record (EHR) data, which provide large volumes of data at a national level. This paper describes the challenges of accurately identifying a cohort of children with Cystic Fibrosis (CF) using EHR and their validation against the UK CF Registry.

OBJECTIVES

To establish a proof of principle and provide insight into the merits of linked data in CF research; to identify the benefits of access to multiple data sources, in particular the UK CF Registry data, and to demonstrate the opportunity it represents as a resource for future CF research.

METHODS

Three EHR data sources were used to identify children with CF born in Wales between 1st January 1998 and 31st August 2015 within the Secure Anonymised Information Linkage (SAIL) Databank. The UK CF Registry was later acquired by SAIL and linked to the EHR cohort to validate the cases and explore the reasons for misclassifications.

RESULTS

We identified 352 children with CF in the three EHR data sources. This was greater than expected based on historical incidence rates in Wales. Subsequent validation using the UK CF Registry found that 257 (73%) of these were true cases. Approximately 98.7% (156/158) of individuals identified as CF cases in all three EHR data sources were confirmed as true cases; but this was only the case for 19.8% (20/101) of all those identified in just a single data source.

CONCLUSION

Identifying health conditions in EHR data can be challenging, so data quality assurance and validation is important or the merit of the research is undermined. This retrospective review identifies some of the challenges in identifying CF cases and demonstrates the benefits of linking cases across multiple data sources to improve quality.

Finding the relevance of antimicrobial stewardship for cystic fibrosis

Antimicrobials have undoubtedly improved the lives of people with CF, but important antimicrobial-related toxicities and the emergence of antimicrobial-resistant bacteria associated with their use must be considered. Antimicrobial stewardship (AMS) is advocated across the spectrum of healthcare to promote the appropriate use of antimicrobials to preserve their current effectiveness and to optimise treatment, and it is clear that AMS strategies are applicable to and can benefit both non-CF and CF populations. This perspective explores the definition and components of an AMS program, the current evidence for AMS, and the reasons why AMS is a challenging concept in the provision of CF care. We also discuss the elements of CF care which align with AMS programs and principles and propose research priorities for AMS in CF.

Big Data in the Assessment of Pediatric Medication Safety

Big data (BD) in pediatric medication safety research provides many opportunities to improve the safety and health of children. The number of pediatric medication and device trials has increased in part because of the past 20 years of US legislation requiring and incentivizing study of the effects of medical products in children (Food and Drug Administration Modernization Act of 1997, Pediatric Rule in 1998, Best Pharmaceuticals for Children Act of 2002, and Pediatric Research Equity Act of 2003). There are some limitations of traditional approaches to studying medication safety in children. Randomized clinical trials within the regulatory context may not enroll patients who are representative of the general pediatric population, provide the power to detect rare safety signals, or provide long-term safety data. BD sources may have these capabilities. In recent years, medical records have become digitized, and cell phones and personal devices have proliferated. In this process, the field of biomedical science has progressively used BD from those records coupled with other data sources, both digital and traditional. Additionally, large distributed databases that include pediatric-specific outcome variables are available. A workshop entitled "Advancing the Development of Pediatric Therapeutics: Application of 'Big Data' to Pediatric Safety Studies" held September 18 to 19, 2017, in Silver Spring, Maryland, formed the basis of many of the ideas outlined in this article, which are intended to identify key examples, critical issues, and future directions in this early phase of an anticipated dramatic change in the availability and use of BD.

The use of antimicrobial susceptibility testing in pediatric cystic fibrosis pulmonary exacerbations

BACKGROUND

Although antimicrobial susceptibility testing (AST) frequently guides cystic fibrosis (CF) pulmonary exacerbation (PEx) management, its clinical utility is unclear. This study examined associations between AST and antimicrobial switching during PEx treatment and time and occurrence of next PEx as treatment outcomes.

METHODS

This retrospective cohort study utilized Pediatric Health Information System data. Children and adolescents aged 1-18 years admitted for a PEx from 2011 to 2016 were studied. Antimicrobial switching was defined as any intra-admission change in intravenous (IV), oral, and/or inhaled antimicrobials. Time to next PEx was defined as the time between index PEx hospital discharge and subsequent hospital admission requiring IV antimicrobials. Odds of antimicrobial switching ≥5 days after treatment initiation were determined by generalized linear mixed models, and associations between AST and time to next PEx were studied using Kaplan-Meier curves and Cox proportional hazards regression.

RESULTS

AST occurred in 2518 (39%) of 6451 PEx at 36 hospitals and was associated with increased odds of antimicrobial switching (OR 1.33, 95% CI 1.16-1.52; p = 0.001) and increased hazard of future PEx (HR 1.32, 95% CI 1.16-1.50; p < 0.001). However, antimicrobial switching was not associated with a longer time to next PEx.

CONCLUSIONS

AST was associated with both increased probability of antimicrobial regimen change and increased PEx hazard. There was no evidence that antimicrobial regimen change was associated with clinical benefit as assessed by time to next PEx. However, these results indicate residual indication bias remained after adjustment for available disease covariates. Additional studies of the clinical value of AST are warranted.