Validation of methods to identify people with idiopathic inflammatory myopathies using hospital episode statistics

Validity of Diagnosis Codes to Identify a Dermatomyositis Cohort from Electronic Health Records

INTRODUCTION

Dermatomyositis (DM) is an uncommon idiopathic inflammatory myopathy resulting in characteristic patterns of cutaneous lesions and myositis. Observational evidence related to the disease is limited by small case cohorts. We aimed to evaluate the validity of specialist-specific diagnostic coding for DM in an outpatient clinical database.

METHODS

Adults having an outpatient encounter between January 1, 2010, and June 30, 2023, at a US regional health system with ICD-9/-10 coding for DM were identified. We randomly sampled 156 patients with ≥1 code applied by a dermatologist or rheumatologist. The primary reference standard for case adjudication was a confirmed diagnosis of DM by the treating physician in the medical chart. Fulfilment of the 2017 European Alliance of Associations for Rheumatology/American College of Rheumatology (EULAR/ACR) criteria for "probable" or "definite" DM was used as a secondary, more stringent reference standard. Positive predictive values (PPVs) for several case definitions were calculated with 95% confidence intervals.

RESULTS

Among eligible patients, the median age was 51.5 years, and 81% were female. Using the treating physician's diagnosis as reference, PPVs of ≥1 and ≥2 codes applied by a dermatologist were 93.2% (95% CI 82.0-98.3%) and 96.4% (82.2-99.8%), respectively. The PPVs of ≥1 and ≥2 codes from a rheumatologist were 82.0% (77.1-86.9%) and 85.8% (80.6-91.1%), respectively. At least one and at least two codes from a rheumatologist or dermatologist had PPVs of 82.1% (77.3-86.8%) and 85.7% (80.7-90.8%), respectively. The rate of confirmed cases based on EULAR/ACR criteria ranged from 44.9% to 57.1%.

CONCLUSION

All tested algorithms yielded an accurate case cohort with high PPV. Studies prioritizing sensitivity may use ≥1 code by dermatology or rheumatology to identify patients with DM.

Design of a randomised controlled hybrid trial of nintedanib in patients with progressive myositis-associated interstitial lung disease

BACKGROUND

The Myositis Interstitial Lung Disease Nintedanib Trial (MINT) is a hybrid trial, which is enrolling patients both at local sites and remotely via a decentralised site. The trial will investigate the efficacy and safety of nintedanib in patients with progressive myositis-associated interstitial lung disease (MA-ILD).

METHODS/DESIGN

MINT is an exploratory, prospective randomised placebo-controlled trial. Eligible patients will have myositis and evidence of fibrosing ILD on high-resolution computed tomography (HRCT), be taking standard of care medications for myositis, and meet criteria for ILD progression within the prior 24 months based on decline in FVC, worsened fibrosis on HRCT, and/or worsened dyspnoea. Patients will be randomised 1:1 to receive nintedanib 150 mg twice daily or placebo for 12 weeks then open-label nintedanib for 12 weeks. Patients will be enrolled at local sites and a decentralised site. Most study visits will be completed remotely using telemedicine or digital health technologies. The primary endpoint is the change in Living with Pulmonary Fibrosis (L-PF) questionnaire dyspnoea domain score at week 12. Other endpoints include changes in other L-PF questionnaire domains, lung function, imaging, and physical activity, and assessment of adverse events. Data collected using remote versus clinic enrolment, and using home versus clinic spirometry, will be compared.

DISCUSSION

MINT is an innovative, hybrid trial that will evaluate the effects of nintedanib on symptoms, quality of life, and ILD progression in patients with progressive MA-ILD and provide valuable information on the utility of decentralised recruitment and remote data collection in clinical trials.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05799755 (date of registration: 05/04/2023).

Incidence and outcomes for children with idiopathic inflammatory myopathy in Western Australia-a long-term population-based study

AIM

To determine the incidence and health outcomes for juvenile idiopathic inflammatory myopathy (JIIM) in a long-term whole-population study.

METHODS

We included patients under 18 years hospitalized in Western Australia (WA) from 1985 and 2015 with incident JIIM as defined by pertinent diagnostic codes for dermatomyositis (JDM) polymyositis (JPM), other JIIM and overlap myositis (JOM). We compared clinical outcomes and modified Charlson comorbidity scores with age and gender matched (2:1 ratio) patients with new onset juvenile idiopathic arthritis (JIA). Trends over time for annual incidence rate per million child-population (AIR) were analyzed by least square regression and survival by Kaplan-Meier curves.

RESULTS

We included 40 patients with JIIM (63% female, median age 8.5 years) for an average AIR of 2.52 per million (CI 1.09-5.57). AIR was stable over time leading to a point prevalence of 52.61 (CI 40.57-67.06) in 2015. Most patients (80%) were classified as JDM with an AIR for JDM of 2.02 (CI 1.09-5.58) and AIR for the combined other JIIM at 0.51 (CI 0.24-1.15). There was female preponderance (62.5%) in both JIIM groups, but no evidence of seasonality. Over a median follow-up of 13 years, one- and ten-year survival was 94.1%. Compared to JIA patients, readmission (80.4 vs. 63.7, p = .02) and infection rates (15.2 vs. 9.6, p < .01) per 100 person-years were higher for JIIM, with similar frequency of interstitial lung disease, fractures, and thrombotic events. At last observation, nearly all patients in both JIIM cohorts (97.5 vs. 92.5%) had accrued some form of comorbidity.

CONCLUSIONS

The overall incidence of JIIM leading to hospitalization in WA was stable over 30 years. JIIM prognosis remains suboptimal due to early mortality and accrual of long-term comorbidity.

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia

OBJECTIVE

To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population.

METHODS

Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates.

RESULTS

The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM.

CONCLUSION

Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

The spectrum of idiopathic inflammatory myopathies in Western Australia: epidemiological characteristics and mortality over time

To determine long term overall and subgroup specific incidence rates and associated mortality for idiopathic inflammatory myopathies (IIM) in a population wide study. We included patients hospitalised between 1980 and 2015 with incident IIM as defined by relevant diagnostic codes for dermatomyositis (DM) polymyositis (PM), inclusion body myositis (IBM), other IIM and overlap myositis (OM) in the Western Australia Health Hospital Morbidity Data Collection (n = 846). Trends over time for annual incidence rate per million population (AIR) were analysed by least square regression and Kaplan-Meier survival and mortality rates (MR)/100 person years compared with a matched control group (n = 3681). The averaged AIR for all IIM was 19 (CI 10.4-27.5) and stable over time with point prevalence reaching 205.3 (CI 185.6-226.6) per million in 2015. Over time, the AIR for DM 5.0 (CI 0.6-9.4) and IBM 3.3 (CI 0.7-9.6) was stable, while AIR decreased for PM (p < 0.01) and increased for other IIM (p < 0.01) and OM (p < 0.01). IBM patients were eldest at diagnosis (68 years, CI 59-77) with male preponderance in IBM (53.4%) and other IIM (55.8%) groups. Crude mortality (54.5 vs 41.3%), MR ratio (6.65 vs 5.91) and 5 (65.8% vs 71.6%) and 10-year (52.5% vs 58.7%) survival were all worse for IIM patients (all p < 0.05). IBM patients had highest MR (10.1; CI 8.38-12.14) and lowest 10-year survival (39.2%). While cardiovascular disease and cancer were predominant causes of death, they were proportionally lower in IIM patients, where respiratory and rheumatic disease were more frequent causes of death. While the overall incidence of IIM in WA was stable over 35 years, the spectrum of IIM has changed significantly with increases especially in other IIM and OM. The overall prognosis with IIM remains guarded with 10-year survival just over 50%.

Low utilization of statins in patients with dermatomyositis/polymyositis and hyperlipidemia: a multicenter USA-based study (2013-2023)

OBJECTIVE

While the cardioprotective benefits of statins for rheumatoid arthritis (RA) patients are well-established, there might be a hesitation in recommending them for dermatomyositis/polymyositis (DM/PM) patients with hyperlipidemia (HLD), particularly with myopathy. We sought to contrast statin prescription patterns between DM/PM-HLD and RA-HLD patients and delve into the mortality variations among DM/PM-HLD statin users and non-users.

METHODS

We examined a decade's worth of anonymized US health data from the TriNetX database. Inclusion criteria were a subsequent HLD diagnosis after an initial DM/PM or RA diagnosis. We compared statin initiation rates and mortality outcomes, adjusting for demographics and cardiovascular risks through propensity score matching.

RESULTS

The analysis comprised 33,000 RA-HLD and 1079 DM/PM-HLD patients. RA-HLD patients exhibited higher statin initiation (27.4%) than DM/PM-HLD patients (17.91%, p < 0.0001). Notably, DM/PM-HLD statin users (n = 311) presented a reduced mortality rate (75 deaths/1000/year) compared to non-users (n = 661) with 147 deaths/1000/year (p = 0.0273, HR = 0.515, CI 0.28-0.93).

CONCLUSION

There is a marked disparity in statin initiation between DM/PM-HLD and RA-HLD patients, accompanied by elevated mortality in DM/PM-HLD non-users. It is imperative for further research to elucidate this discrepancy and formulate patient-centric cardiovascular guidelines for DM/PM-HLD patients. Key Points • Statin initiation among patients with DM/PM-HLD is significantly lower than that with RA-HLD. • Mortality rates within the statin initiator DM/PM-HLD were significantly lower compared to non-statin DM/PM-HLD initiators, spanning multiple time intervals.

Digital Approaches for Myositis

PURPOSE OF REVIEW

This article serves as a comprehensive review, focusing on digital approaches utilized in the diagnosis, monitoring, and treatment of patients with idiopathic inflammatory myopathies (IIM). The authors critically assess the literature published in the last three years, evaluating the advancements and progress achieved in this specific domain.

RECENT FINDINGS

Remarkable strides have been made in the realm of digital diagnostic support, particularly in image analysis and clinical prediction models, showing promise in aiding the diagnosis of IIM. The field of remote patient monitoring has also witnessed significant advancements, revolutionizing the care process by offering more convenient, data-driven, and continuous monitoring for IIM patients. Various digital tools, such as wearables, video- and voice consultations, and electronic patient-reported outcomes, have been extensively explored and implemented to enhance patient care. Survey studies consistently reveal a high acceptance of telehealth services among patients. Additionally, internet-based studies have facilitated the efficient and rapid recruitment of IIM patients for research purposes. Moreover, the integration of sensors and exoskeletons has shown great potential in significantly improving the functionality and quality of life for individuals with muscle weakness caused by IIM. The integration of digital health solutions in the care of IIM patients is steadily gaining attention and exploration. Although the existing evidence is limited, it does indicate that patients can be adequately and safely supported through digital means throughout their entire healthcare journey. The growing interest in digital health technologies holds the promise of improving the overall management and outcomes for individuals with idiopathic inflammatory myopathies.