Identifying monoclonal gammopathy of undetermined significance in electronic health data

Multimorbidity in patients with monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS), a precursor to multiple myeloma, is present in over 5% of adults aged 70 and older, a population with a high prevalence of multimorbidity. MGUS is often diagnosed incidentally when patients seek care for unrelated conditions. Our study sought to examine patterns of multimorbidity among MGUS patients, as overall health may impact patient care and the prioritization of MGUS surveillance. We examined patterns of comorbidities in 429 patients diagnosed with MGUS (2007-2015) and 1287 matched controls. Twenty-seven conditions were defined at diagnosis/index date using algorithms developed by the Centers for Medicare and Medicaid Chronic Conditions Warehouse. Patterns of common comorbidities were identified individually, in dyads and triads, and compared between MGUS cases and controls. We conducted a latent class analysis to identify comorbidity patterns among cases only. We also examined comorbidity patterns among a subset of 32 MGUS cases who progressed to cancer during the study period. The most common comorbidities among both MGUS cases and controls included hypertension and hyperlipidemia. Anemia (cases: 43%; controls: 16%) and chronic kidney disease (CKD; cases: 36%; controls: 18%), and dyads and triads containing those conditions, were more common among cases. Latent class analysis identified three classes of comorbidity among MGUS cases: hypertension-hyperlipidemia plus anemia and CKD (31%); low comorbidity burden (17%); and hypertension-hyperlipidemia alone (52%). The higher prevalence among cases of anemia and CKD, which may be involved in the pathogenesis of, or surveillance for, MGUS, warrants additional investigation.

Identifying monoclonal gammopathy of undetermined significance from electronic health records

BACKGROUND

Monoclonal gammopathy of undetermined significance (MGUS) precedes multiple myeloma (MM). Use of electronic health records may facilitate large-scale epidemiologic research to elucidate risk factors for the progression of MGUS to MM or other lymphoid malignancies.

AIMS

We evaluated the accuracy of an electronic health records-based approach for identifying clinically diagnosed MGUS cases for inclusion in studies of patient outcomes/ progression risk.

METHODS AND RESULTS

Data were retrieved from Kaiser Permanente Southern California's comprehensive electronic health records, which contain documentation of all outpatient and inpatient visits, laboratory tests, diagnosis codes and a cancer registry. We ascertained potential MGUS cases diagnosed between 2008 and 2014 using the presence of an MGUS ICD-9 diagnosis code (273.1). We initially excluded those diagnosed with MM within 6 months after MGUS diagnosis, then subsequently those with any lymphoid malignancy diagnosis from 2007 to 2014. We reviewed medical charts for 100 randomly selected potential cases for evidence of a physician diagnosis of MGUS, which served as our gold standard for case confirmation. To assess sensitivity, we also investigated the presence of the ICD-9 code in the records of 40 randomly selected and chart review-confirmed MGUS cases among patients with a laboratory report of elevated circulating monoclonal (M-) protein (a key test for MGUS diagnosis) and no subsequent lymphoid malignancy (as described above). The positive predictive value (PPV) for the ICD-9 code was 98%. All MGUS cases confirmed by chart review also had confirmatory laboratory test results. Of the confirmed cases first identified via M-protein test results, 88% also had the ICD-9 diagnosis code.

CONCLUSION

The diagnosis code-based approach has excellent PPV and likely high sensitivity for detecting clinically diagnosed MGUS. The generalizability of this approach outside an integrated healthcare system warrants further evaluation.

Multi-trajectory models of serum biomarkers among patients with monoclonal gammopathy of undetermined significance

Understanding the progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) is needed to identify patients who would benefit from closer clinical surveillance. Given that two of the defining criteria of MM are renal failure and anemia, we described the trajectories of creatinine (Cr) and hemoglobin (Hgb) over time in patients with a diagnosis of MGUS. Patients diagnosed with MGUS (n = 424) were identified by a previously validated case-finding algorithm using health claims and electronic health record data (2007-2015) and followed through 2018. Group-based trajectory modeling identified patients with distinct laboratory value trajectories of Cr (mg/dl) and Hgb (g/dl). Most patients were non-Hispanic White (97.6%) with a mean age of 75 years at MGUS diagnosis. Three multi-trajectory groups were identified: (1) Normal Cr/Hgb (n = 225; 53.1%)-stable serum Cr levels and decreasing, normal Hgb levels; (2) Normal Cr/lower-normal Hgb group (n = 188; 44.3%)-stable, slightly elevated levels of Cr and decreasing levels of Hgb; and (3) High Cr/borderline Hgb group (n = 11; 2.6%)-increased Cr levels and stable low levels of Hgb. Patients with MGUS in Group 2 were older than patients in other groups, and patients in group 3 had more comorbidities than participants in all other groups. Few patients developed MM during the study period. We were able to identify distinct biomarker trajectories in patients with MGUS over time. Future research should investigate how these trajectories may be related to the risk of progression to MM, including M-protein levels.

Differences in Hospital, Emergency Room and Outpatient Visits Among Adults With and Without Monoclonal Gammopathy of Undetermined Significance

INTRODUCTION

This study evaluated the impact of receiving a monoclonal gammopathy of undetermined significance (MGUS) diagnosis on healthcare utilization from patients at a community-based multispecialty provider organization.

METHODS

A cohort of patients with MGUS (n = 429) were matched on sex, age, and length of enrollment to a cohort of patients without MGUS (n = 1286). Healthcare utilization was assessed: 1-12 months before, 1 month before and after, and 1-12 months after diagnosis/index date. Multivariable conditional Poisson models compared change in utilization of each service in patients with and without MGUS.

RESULTS

During the 2 months around diagnosis/index date, the rates of emergency room, hospital and outpatient visits were higher for patients with MGUS than patients without MGUS. In the year before MGUS diagnosis, the association was still elevated, although attenuated.

CONCLUSION

Understanding the care of MGUS patients is important given that multiple myeloma patients with a pre-existing MGUS diagnosis may have a better prognosis.

Risk factors for monoclonal gammopathy of undetermined significance: a systematic review

Monoclonal gammopathy of undetermined significance (MGUS), precursor of multiple myeloma, is an asymptomatic plasma cell disorder that overproduces serum monoclonal protein. Older age, male sex, black race, and family history of MGUS increase the risk of MGUS, yet other risk factors are known. We systematically reviewed observational epidemiological studies that examined sociodemographic, clinical, and behavioral risk factors for the development of MGUS. The protocol for this study was registered on the PROSPERO registry for systematic reviews. We identified epidemiological studies from PubMed and Scopus. Articles were limited to those written in English and published before February 2019. Five case-control and three cohort studies were eligible for data extraction. Studies evaluating factors associated with MGUS risk are limited, with conflicting conclusions regarding risk associated with obesity. Despite the limited research, a significant elevated risk for being diagnosed with MGUS was associated with several specific prior infections, inflammatory disorders, and smoking. The sparse existing literature suggests an increased risk of MGUS associated with several risk factors related to immune function. Further research is needed to explore the potential mechanisms underlying the development of MGUS and to confirm risk factors, both modifiable and non-modifiable.