Evaluation of code-based algorithms to identify pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients in large administrative databases

Racial disparities in treatment patterns, healthcare resource use, and outcomes in patients with pulmonary arterial hypertension in the United States

OBJECTIVE

This retrospective study using claims data compared demographics, clinical characteristics, treatment patterns, healthcare resource utilization, and clinical outcomes in Black and White patients with pulmonary arterial hypertension (PAH) in the United States.

METHODS

Patients (aged ≥18 years) had ≥1 pharmacy claim for PAH medication, ≥6 months' continuous healthcare plan enrollment, ≥1 inpatient/outpatient medical claim with a pulmonary hypertension diagnosis ≤6 months before first PAH medication, and race recorded.

RESULTS

This analysis included 836 Black and 2896 White patients. Black patients were younger, with lower levels of education and annual household income, and higher comorbidity scores versus White patients. Only ∼14% of Black and White patients received index combination therapy. Lower adherence to index treatment was observed in Black patients. Although adjusted regression analysis in the overall population showed no differences in outcomes between groups, Black patients <65 years were 36% less likely to receive index combination therapy (odds ratio [OR] 0.64; 95% confidence interval [CI] 0.41-0.99), and 46% less likely to adhere to index treatment (OR 0.54; 95% CI 0.33-0.90). Other disparities included 24% higher all-cause health care resource utilization, 75% higher all-cause costs, and higher risk of clinical composite outcome. Social determinants of health (education, income, health insurance plan) partially mediated these race effects.

CONCLUSIONS

Differences in demographics, clinical characteristics, and treatment patterns between Black and White patients with PAH were observed. Disparities between Black and White patients <65 years were only partially mediated through social determinants of health variables, suggesting other factors may be involved.

Development and validation of a code-based algorithm using in-hospital medical records to identify patients with pulmonary arterial hypertension in a French healthcare database

Introduction

Pulmonary arterial hypertension (PAH) is a rare and severe disease for which most of the evidence about prognostic factors, evolution and treatment efficacy comes from cohorts, registries and clinical trials. We therefore aimed to develop and validate a new PAH identification algorithm that can be used in the French healthcare database "Système National des Données de Santé (SNDS)".

Methods

We developed and validated the algorithm using the Grenoble Alpes University Hospital medical charts. We first identified PAH patients following a previously validated algorithm, using in-hospital ICD-10 (10th revision of the International Statistical Classification of Diseases) codes, right heart catheterisation procedure and PAH-specific treatment dispensing. Then, we refined the latter with the exclusion of chronic thromboembolic pulmonary hypertension procedures and treatment, the main misclassification factor. Second, we validated this algorithm using a gold standard review of in-hospital medical charts and calculated sensitivity, specificity, positive and negative predictive value (PPV and NPV) and accuracy. Finally, we applied this algorithm in the French healthcare database and described the characteristics of the identified patients.

Results

In the Grenoble University Hospital, we identified 252 unique patients meeting all the algorithm's criteria between 1 January 2010 and 30 June 2022, and reviewed all medical records. The sensitivity, specificity, PPV, NPV and accuracy were 91.0%, 74.3%, 67.9%, 93.3% and 80.6%, respectively. Application of this algorithm to the SNDS yielded the identification of 9931 patients with consistent characteristics compared to PAH registries.

Conclusion

Overall, we propose a new PAH identification algorithm developed and adapted to the French specificities that can be used in future studies using the French healthcare database.

Clinical evaluation of code-based algorithms to identify patients with pulmonary arterial hypertension in healthcare databases

Pulmonary arterial hypertension (PAH) is a rare subgroup of pulmonary hypertension (PH). Claims and administrative databases can be particularly important for research in rare diseases; however, there is a lack of validated algorithms to identify PAH patients using administrative codes. We aimed to measure the accuracy of code-based PAH algorithms against the true clinical diagnosis by right heart catheterization (RHC). This study evaluated algorithms in patients who were recorded in two linkable data assets: the Stanford Healthcare administrative electronic health record database and the Stanford Vera Moulton Wall Center clinical PH database (which records each patient's RHC diagnosis). We assessed the sensitivity and specificity achieved by 16 algorithms (six published). In total, 720 PH patients with linked data available were included and 558 (78%) of these were PAH patients. Algorithms consisting solely of a P(A)H-specific diagnostic code classed all or almost all PH patients as PAH (sensitivity >97%, specificity <12%) while multicomponent algorithms with well-defined temporal sequences of procedure, diagnosis and treatment codes achieved a better balance of sensitivity and specificity. Specificity increased and sensitivity decreased with increasing algorithm complexity. The best-performing algorithms, in terms of fewest misclassified patients, included multiple components (e.g., PH diagnosis, PAH treatment, continuous enrollment for ≥6 months before and ≥12 months following index date) and achieved sensitivities and specificities of around 95% and 38%, respectively. Our findings help researchers tailor their choice and design of code-based PAH algorithms to their research question and demonstrate the importance of including well-defined temporal components in the algorithms.

Unmasking a Silent Threat: Improving Pulmonary Hypertension Screening Methods for Interstitial Lung Disease Patients

This article provides a comprehensive overview of the latest literature on the diagnostics and treatment of pulmonary hypertension (PH) associated with interstitial lung disease (ILD). Heightened suspicion for PH arises when the advancement of dyspnoea in ILD patients diverges from the expected pattern of decline in pulmonary function parameters. The complexity of PH associated with ILD (PH-ILD) diagnostics is emphasized by the limitations of transthoracic echocardiography in the ILD population, necessitating the exploration of alternative diagnostic approaches. Cardiac magnetic resonance imaging (MRI) emerges as a promising tool, offering insights into hemodynamic parameters and providing valuable prognostic information. The potential of biomarkers, alongside pulmonary function and cardiopulmonary exercise tests, is explored for enhanced diagnostic and prognostic precision. While specific treatments for PH-ILD remain limited, recent studies on inhaled treprostinil provide new hope for improved patient outcomes.

A claims-based, machine-learning algorithm to identify patients with pulmonary arterial hypertension

Many patients with pulmonary arterial hypertension (PAH) experience substantial delays in diagnosis, which is associated with worse outcomes and higher costs. Tools for diagnosing PAH sooner may lead to earlier treatment, which may delay disease progression and adverse outcomes including hospitalization and death. We developed a machine-learning (ML) algorithm to identify patients at risk for PAH earlier in their symptom journey and distinguish them from patients with similar early symptoms not at risk for developing PAH. Our supervised ML model analyzed retrospective, de-identified data from the US-based Optum® Clinformatics® Data Mart claims database (January 2015 to December 2019). Propensity score matched PAH and non-PAH (control) cohorts were established based on observed differences. Random forest models were used to classify patients as PAH or non-PAH at diagnosis and at 6 months prediagnosis. The PAH and non-PAH cohorts included 1339 and 4222 patients, respectively. At 6 months prediagnosis, the model performed well in distinguishing PAH and non-PAH patients, with area under the curve of the receiver operating characteristic of 0.84, recall (sensitivity) of 0.73, and precision of 0.50. Key features distinguishing PAH from non-PAH cohorts were a longer time between first symptom and the prediagnosis model date (i.e., 6 months before diagnosis); more diagnostic and prescription claims, circulatory claims, and imaging procedures, leading to higher overall healthcare resource utilization; and more hospitalizations. Our model distinguishes between patients with and without PAH at 6 months before diagnosis and illustrates the feasibility of using routine claims data to identify patients at a population level who might benefit from PAH-specific screening and/or earlier specialist referral.

Time to diagnosis of pulmonary hypertension and diagnostic burden: A retrospective analysis of nationwide US healthcare data

The main aim of this analysis was to investigate time from symptom onset (chronic unexplained dyspnoea [CUD]) to diagnosis of Group 1 pulmonary hypertension (PH)-pulmonary arterial hypertension (PAH)-and to characterize healthcare resource utilization leading up to diagnosis using a nationwide US claims and an electronic health record (EHR) database from Optum^©. Eligible patients were ≥18 years old at first CUD diagnosis (index event) and had a PAH diagnosis on or after index date. Based on administrative codes, PAH was defined as right heart catheterization (RHC), ≥ 2 PAH diagnoses (1 within a year of RHC), and ≥1 post-RHC prescription for PAH treatment. All values are median (1st quartile-3rd quartile) unless otherwise stated. Of 854,722 patients with CUD in the claims database, 582 (0.1%) had PAH. Time from CUD to PAH diagnosis was 2.26 (0.73-4.22) years. PAH patients experienced 3 (2-4) transthoracic echocardiograms (TTEs), 6 (3-12) specialist visits, and 2 (1-4) hospitalizations during the diagnostic interval. Almost one-third of patients (29%) waited 10 months or more to have a TTE. Findings from the EHR database were broadly similar. Resource utilization during the diagnostic interval was also analyzed in an overall PH cohort: findings were generally similar to the PAH cohort (2 [1-3] TTEs, 4 [2-9] specialist visits and 2 [1-4] hospitalizations). These data indicate a delay in the diagnostic pathway for PAH, and illustrate the burden associated with PAH diagnosis.

Adherence and treatment patterns of disease-specific drugs among patients with pulmonary arterial hypertension: A nationwide, new-user cohort study

Background: Pulmonary arterial hypertension (PAH) is an incurable pulmonary disease that might result in right heart failure and death. Treatment guidelines recommend upfront or sequential combination therapy for patients with PAH. Recently, several PAH-targeted medications have been approved in Taiwan. This study aimed to investigate treatment patterns and medication adherence in real-world settings. Method: This was a new-user design study on patients treated with PAH-specific medication between 1 January 2014, and 31 December 2019. Data were extracted from the National Health Insurance Research Database. Medication adherence was evaluated by the proportion of days covered (PDC). Adherence was defined as PDC ≥ .8. Statistical analyses were performed to compare the study outcomes. Logistic regression analysis was performed to identify the association between baseline characteristics and adherence. P < .05 indicated statistical significance. Results: A total of 1,900 patients with PAH were identified, and 75.3% of them were females. The mean (standard deviation (SD)) age was 57.2 (17.5) years. Only 23 (1.2%) patients began the initial combination therapy. A total of 148 (7.8%) patients switched their initial treatment to another treatment, and 159 (8.4%) patients had sequential combination therapy. The most common combination therapy was endothelin receptor antagonist (ERA) plus phosphodiesterase-5 inhibitor (PDE5i), mostly macitentan plus sildenafil, for initial or sequential combination. The mean (SD) PDC was .71 (.33), and 1,117 (58.8%) patients were adherent. A significant difference in mean PDC was observed between initial ERA users and PDE5i users (p < .0001). No factor was significantly associated with medication adherence. Conclusion: Patients with PAH mostly initiated sildenafil as monotherapy, and macitentan was added as a sequential combination therapy. The initial ERA and combination groups showed higher medication adherence. Further investigations are needed to identify other factors associated with adherence.

Medication use by US patients with pulmonary hypertension associated with chronic obstructive pulmonary disease: a retrospective study of administrative data

BACKGROUND

Pulmonary hypertension (PH) is a serious complication of chronic obstructive pulmonary disease (COPD). While clinical guidelines recommend specific drug therapies for pulmonary arterial hypertension (PAH), these drug therapies are not recommended for PH due to lung disease.

METHODS

This was a retrospective cohort study using the Optum® Clinformatics® Data Mart from January 2009-September 2019. An algorithm was designed to identify adults with ≥ 2 ICD-9-CM or ICD-10-CM diagnosis codes for PH and with ≥ 2 diagnosis codes for COPD. Sensitivity analyses were conducted among subgroups of patients with evidence of a right heart catheterization (RHC) or pulmonary function test (PFT). Patient characteristics, medications used, and durations of use of PAH and COPD medications were analyzed.

RESULTS

A total of 25,975 patients met the study inclusion criteria. Their mean age was 73.5 (SD 10.0) years and 63.8% were female. Medications targeting PAH were prescribed to 643 (2.5%) patients, most frequently a phosphodiesterase-5 inhibitor (2.1%) or an endothelin receptor antagonist (0.75%). Medications for COPD were prescribed to 17,765 (68.4%) patients, most frequently an inhaled corticosteroid (57.4%) or short-acting beta agonist (50.4%). The median durations of use ranged from 4.9 to 12.8 months for PAH medications, and from 0.4 to 5.9 months for COPD medications. Of the subgroup of patients with RHC (N = 2325), 257 (11.1%) were prescribed a PAH medication and 1670 (71.8%) used a COPD medication. Of the subgroup with a PFT (N = 2995), 58 (1.9%) were prescribed a PAH medication and 2100 (70.1%) a COPD medication.

CONCLUSIONS

Patients with PH associated with COPD were identified in a US administrative claims database. Very few of these patients received any of the medications recommended for PAH, and only about two thirds received medications for COPD.

No association between initiation of phosphodiesterase-5 inhibitors and risk of incident Alzheimer's disease and related dementia: results from the Drug Repurposing for Effective Alzheimer's Medicines study

We evaluated the hypothesis that phosphodiesterase-5 inhibitors, including sildenafil and tadalafil, may be associated with reduced incidence of Alzheimer's disease and related dementia using a patient-level cohort study of Medicare claims and cell culture-based phenotypic assays. We compared incidence of Alzheimer's disease and related dementia after phosphodiesterase-5 inhibitor initiation versus endothelin receptor antagonist initiation among patients with pulmonary hypertension after controlling for 76 confounding variables through propensity score matching. Across four separate analytic approaches designed to address specific types of biases including informative censoring, reverse causality, and outcome misclassification, we observed no evidence for a reduced risk of Alzheimer's disease and related dementia with phosphodiesterase-5 inhibitors;hazard ratio (95% confidence interval): 0.99 (0.69-1.43), 1.00 (0.71-1.42), 0.67 (0.43-1.06), and 1.15 (0.57-2.34). We also did not observe evidence that sildenafil ameliorated molecular abnormalities relevant to Alzheimer's disease in most cell culture-based phenotypic assays. These results do not provide support to the hypothesis that phosphodiesterase-5 inhibitors are promising repurposing candidates for Alzheimer's disease and related dementia.

Comparison of Healthcare Encounters and Drug Persistence in Patients With Pulmonary Arterial Hypertension Receiving Oral Selexipag, Inhaled Iloprost, or Parenteral Treprostinil: A Retrospective Database Analysis

Background: Agents targeting the prostacyclin (PGI₂) pathway are important in managing pulmonary arterial hypertension (PAH). No head-to-head clinical trials have compared outcomes between the 3 different PGI₂-pathway drugs most commonly available in countries with advanced healthcare: oral selexipag, inhaled iloprost, and parenteral (subcutaneous or intravenous) treprostinil. Objectives: To conduct retrospective database analyses to describe characteristics of patients with PAH initiating therapy with these agents and compare the rate and risk of healthcare facility encounters and drug persistence. Methods: Data were obtained from the Optum™ Clinformatics® Data Mart and Truven™ Health Analytics® MarketScan® Commercial Claims and Encounters databases from July 1, 2008, to September 30, 2020 (Optum™), or October 31, 2020 (Truven™). Patients were categorized into index-drug cohorts based on first pharmacy claims for selexipag, inhaled iloprost, or parenteral treprostinil. Eligible patients were ≥18 years of age with ≥1 ICD-9-CM or ICD-10-CM diagnosis code indicating pulmonary hypertension and no diagnosis code suggesting Group 3-5 pulmonary hypertension. Rates of hospitalization (inpatient admissions), emergency room visits, or outpatient visits per person-year were calculated. Drug persistence was measured as time to discontinuation of index drug. Multivariable analyses were performed to compare outcomes with selexipag vs inhaled iloprost and parenteral treprostinil, adjusting for baseline characteristics using inverse probability of treatment weighting. Results: Overall, 583 patients were included in the Optum™ sample and 482 in the Truven™ sample. Mean (SD) age was 61.7 (14.5) and 49.3 (11.3) years, respectively; 74.4% and 75.7% of patients, respectively, were women. In the pooled samples, after adjustment for baseline characteristics, selexipag had a lower risk than inhaled iloprost or parenteral treprostinil for hospitalization (relative rate ratio [95% CI], 0.40 [0.22, 0.75], and 0.26 [0.17, 0.39]) and outpatient visits (0.66 [0.56, 0.78] and 0.76 [0.66, 0.88]). Trends toward lower risk of emergency room visits did not attain statistical significance. Drug discontinuation risk was 16% and 36% lower with selexipag vs parenteral treprostinil and inhaled iloprost, respectively. Conclusions: In real-world use, selexipag appears to be associated with lower rates of hospitalization and outpatient visits than inhaled iloprost or parenteral treprostinil. Further research is required to identify factors underlying these differences.

An algorithm to identify cases of pulmonary arterial hypertension from the electronic medical record

BACKGROUND

Study of pulmonary arterial hypertension (PAH) in claims-based (CB) cohorts may facilitate understanding of disease epidemiology, however previous CB algorithms to identify PAH have had limited test characteristics. We hypothesized that machine learning algorithms (MLA) could accurately identify PAH in an CB cohort.

METHODS

ICD-9/10 codes, CPT codes or PAH medications were used to screen an electronic medical record (EMR) for possible PAH. A subset (Development Cohort) was manually reviewed and adjudicated as PAH or "not PAH" and used to train and test MLAs. A second subset (Refinement Cohort) was manually reviewed and combined with the Development Cohort to make The Final Cohort, again divided into training and testing sets, with MLA characteristics defined on test set. The MLA was validated using an independent EMR cohort.

RESULTS

194 PAH and 786 "not PAH" in the Development Cohort trained and tested the initial MLA. In the Final Cohort test set, the final MLA sensitivity was 0.88, specificity was 0.93, positive predictive value was 0.89, and negative predictive value was 0.92. Persistence and strength of PAH medication use and CPT code for right heart catheterization were principal MLA features. Applying the MLA to the EMR cohort using a split cohort internal validation approach, we found 265 additional non-confirmed cases of suspected PAH that exhibited typical PAH demographics, comorbidities, hemodynamics.

CONCLUSIONS

We developed and validated a MLA using only CB features that identified PAH in the EMR with strong test characteristics. When deployed across an entire EMR, the MLA identified cases with known features of PAH.

Assessment for residual disease after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension

Objectives

Pulmonary endarterectomy (PEA) is recommended for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH) and is potentially curative. However, persistent/recurrent CTEPH post-PEA can occur. Here we describe symptom and diagnostic assessment rates for residual disease post-PEA and longitudinal diagnostic patterns before and after riociguat approval for persistent/recurrent CTEPH after PEA.

Methods

This US retrospective cohort study analysed MarketScan data (1 January 2002–30 September 2018) from patients who underwent PEA following a CTEPH/pulmonary hypertension (PH) claim with at least 730 days of continuous enrolment post-PEA. Data on pre-specified PH symptoms and the types and timings of diagnostic assessments were collected.

Results

Of 103 patients (pre-riociguat approval, n=55; post-riociguat approval, n=48), residual PH symptoms >3 months after PEA were reported in 89% of patients. Overall, 89% of patients underwent one or more diagnostic tests (mean 4.6 tests/patient), most commonly echocardiography (84%), with only 5% of patients undergoing right heart catheterisation (RHC). In the post- versus pre-riociguat approval subgroup, assessments were more specific for CTEPH with an approximately two-fold increase in 6-min walk distance and N-terminal prohormone of brain natriuretic protein measurements and ventilation/perfusion scans, and a four-fold increase in RHCs.

Conclusions

Low RHC rates suggest that many patients with PH symptoms post-PEA are not being referred for full diagnostic workup. Changes to longitudinal diagnostic patterns may indicate increased recognition of persistent/recurrent CTEPH post-PEA; however, there remains a need for greater awareness around the importance of continued follow-up for patients with residual PH symptoms post-PEA.

Rates of residual PH symptoms are high after PEA but referral of patients with suspected persistent/recurrent CTEPH following PEA for CTEPH-specific diagnostic assessments is suboptimal, highlighting potential gaps in CTEPH patient care post-PEAhttps://bit.ly/3jfUZlO

Development and validation of a claims-based model to identify patients at risk of chronic thromboembolic pulmonary hypertension following acute pulmonary embolism

OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that often follows pulmonary embolism (PE). Screening for CTEPH is challenging, often delaying diagnosis and worsening prognosis. Predictive risk models for CTEPH could help identify at-risk patients, but existing models require multiple clinical inputs. We developed and validated a predictive risk model for CTEPH using health insurance claims that can be used by payers/quality-of-care organizations to screen patients post-PE.

METHODS

Adult patients newly diagnosed with acute PE (index date) were identified from the Optum De-identified Clinformatics Extended DataMart (January 2007-March 2018; development set) and IBM MarketScan (January 2008-June 2019; validation set) databases. Predictors were identified 12 months before or on the index PE. Risk of "likely CTEPH" was assessed post-PE based on CTEPH-related diagnoses and procedures since the CTEPH diagnosis code (ICD-10-CM: I27.24) was not available until 1 October 2017. Stepwise variable selection was used to build the model using the development set; model validation was subsequently conducted using the validation set.

RESULTS

The development set included 93,428 patients, of whom 11,878 (12.7%) developed likely CTEPH. Older age (odds ratios [OR] = 1.16-1.49), female (OR = 1.09), unprovoked PE (i.e. without thrombotic factors; OR = 1.14), hypertension (OR = 1.07), osteoarthritis (OR = 1.08), diabetes (OR = 1.07), chronic obstructive pulmonary disease (OR = 1.11), obesity (OR = 1.21) were associated with higher odds of likely CTEPH, and oral anticoagulants with lower odds (OR= 0.50, all p < .01). C-statistic was 0.77 in the development and validation sets.

CONCLUSION

A claims-based risk model reliably predicted the risk of CTEPH post-PE and could be used to identify high-risk patients who may benefit from focused monitoring.