Rheumatology Network News Roundup: Lupus

In this video, Dr. Anastasiou discusses the study in greater length, including final takeaways and recommendations for physicians.

Dr. Anastasiou: My name is Christine Anastasiou. Thank you for having me. I am a rheumatologist at the University of California San Francisco. I perform research in systemic lupus erythematosus, rheumatoid arthritis, and the inflammatory myopathies.

Rheumatology Network:Welcome to Rheumatology Network. I appreciate your time today. We’re here to discuss a study that you recently published. You were the lead author on this study that focused on mortality in lupus. Would you mind summarizing the findings.

Dr. Anastasiou: We performed this research study with the goal of answering three questions. First, How has mortality for U.S. hospitalized individuals with SLE changed over a time period which we chose as 2006 and 2016 when compared to the general population. Second, did in-hospital mortality risk vary by race and ethnicity. And, third, among hospitalized individuals with SLE what factors were associated with a higher mortality?

These questions are important for multiple reasons. We know that SLE can lead to life-threatening organ damage and premature death and advances in therapy have decreased the rate of organ damage and mortality for patients with SLE over the past century. However, recent studies have evaluating hospital outcomes for patients with SLE are limited. The most recent multi year national evaluation of mortality for hospitalized U.S. SLE patients of which we are aware was conducted from 1998-2002. We needed a more recent evaluation of the progress that we’ve had in areas for potential improvement. In addition, most studies evaluating lupus mortality are based on patient cohorts which are invaluable research tools, but they capture only a relatively small number of total deaths and may not represent the general lupus population. And, most prior research also did not investigate whether there were in-hospital mortality differences for patients with SLE based on their race and ethnicity. So, we know that race and ethnicity are important in lupus. Previous cohort and population-based studies of SLE mortality have consistently shown increased damage accrual and mortality among black patients compared to whites. And, most studies also suggested that Hispanic ethnicity was associated with more active SLE and higher mortality. Population-based U.S. studies conducted in the 1970s and 1980s have described mortality rated of three to five times greater among Asians or Pacific Islanders as compared to whites. And, a study in the early 1990s showed a higher odds and mortality among hospitalized Asians compared to white. So, this is an important topic to include.

We analyzed data from the national in-patient sample, which is also called the Nationwide In-Patient Sample, and it’s useful for performing large scale longitudinal analyses. In 2016, the NIS yielded weighted national estimates for more than 35 million hospitalizations which represents over 97 percent of U.S. community hospital discharges.

So, during the study time frame that we included, there approximately 1.9 hospitalizations for adults with a discharge diagnosis of SLE included in our analysis.

Our findings were the following:Compared to the general hospitalized population, hospitalized individuals with SLE were younger, more likely to be female, black of Hispanic, live in a low-income area, and they had on average a higher comorbidity index score. I would say that these characteristics are what we would expect because based on prior research that wasn’t anything new.

In answer to those three questions I brought up at the beginning:

All-cause yearly in-patient mortality in our adjusted analysis decreased by approximately 30 percent among admissions for individuals with SLE from 2.2 percent in 2006 to 1.5 percent in 2016. The mortality rate for admitted individuals with SLE started higher than that of the general hospitalized population and decreased between 2006 and 2008. After that time point the mortality rate for SLE patients were statically similar to that of the general hospitalized population and remained stable for the rest of the years analyzed. We also found that hospitalizations for blacks, Hispanics and Asian Pacific Islanders with SLE were more likely to end in death compared to hospitalizations for people of the same racial or ethnic group without SLE. They were also more likely to end of death compared to hospitalizations for whites with SLE.

Interestingly, we found that hospitalized Asian Pacific Islanders with lupus had a 43 percent higher risk of death compared to those without SLE, and a 79 percent higher risk of death compared to hospitalizations with SLE.

In contrast to what we just discussed for the other racial ethnic groups, the hospitalizations among whites with SLE were less likely to end in death compared to those without SLE.

We also performed an analysis to assess factors associated with death among lupus hospitalizations, and similar to prior studies, our results showed that men with lupus a higher risk of in-hospital mortality and as expected, increasing age and higher comorbidity index score were also associated with a higher mortality.

Importantly, though, we found that hospitalizations for SLE patients without insurance were also associated with a higher mortality when compared to those for patients covered by Medicare. So I would say those are all of the main results of our study.”

The most important takeaway points are that 1) SLE hospitalizations were more likely to end in death at the beginning of the time frame we studied and mortality rate decreased to a point where over the last few years of the study, it was similar to the general population and it was remaining relatively stable over time. The second primary takeaway point, is that despite advances in overall all-cause mortality among patients with SLE, the U.S. hospitalized blacks, Hispanics, Asians they have a higher rate of in-patient death compared to patients of the same racial and ethnic group without SLE and to whites with SLE.

Our results suggest that interventions to reduce all cause in-hospital mortality and interventions that are primarily targeting patients with SLE, such as a broader array of immunosuppressant medications, may have successfully improved in-hospital survival over one decade. So that’s fantastic news. We also noted that among hospitalized patients with SLE, self-pay status, which means the person did not have insurance, was associated with higher mortality. So future work could potentially investigate whether this higher mortality risk is reproduceable and if so, what are some ways we could intervene. Some hypotheses for why these hospitalizations have worse outcomes could include limited primary preventive care that may be driving differences in outcomes. Maybe self-pay SLE patients receive a different quality of in-patient care. Or, maybe this higher mortality per admission is just a reflection of these patients themselves or treating physicians have a higher threshold of illness severity for them to be admitted to the hospital compared to individuals who have insurance.

In terms of hospital mortality overall for lupus, it’s great news that we see improvements in mortality and the data also suggests that we need to increase our efforts to eliminate racial and ethnic disparities in outcomes through early recognition, treatment, and long-term management of the disease.

Our research study was the first large-scale population based study in over 20 years to evaluate U.S. Asian Pacific Islander in-hospital mortality among individuals with SLE. Our results show the importance of considering this population (U.S. Asian and Pacific islanders) as potentially hidden risks for poor outcomes. So, future studies should include them when possible and future studies may benefit from investigating for potential reasons for persistent inequalities in outcomes among all of the racial and ethnic groups.

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REFERENCE

Christine Anastasiou,Laura Trupin,David V. Glidden,Jing Li,Milena Gianfrancesco,Stephen Shiboski,Gabriela Schmajuk,Jinoos Yazdany. "Mortality among Hospitalized Individuals with Systemic Lupus Erythematosus in the United States between 2006 and 2016," Arthritis Care and Research. First published June 17, 2020.https://doi.org/10.1002/acr.24356