Background/Purpose:  Mortality rates are higher in SLE patients compared to the general population, and research on SLE mortality is ongoing. The majority of mortality studies have relied on death certificates to identify SLE patients. However, this approach may misclassify cases and include both false positives and negatives. The rate of misclassification on death certificates is unclear. Using a large population-based registry of validated SLE patients, we sought to ascertain the accuracy of death certificates in identifying SLE patients.

Methods:   The Georgia Lupus Registry (GLR) is a population-based registry of validated SLE patients living in Atlanta, GA from 2002-04. The state HIPAA exemption for surveillance allowed health care providers and facilities to provide access to protected health information without written patient consent. Patients were validated by meeting ≥4 ACR criteria or 3 ACR criteria with a final diagnosis of SLE by a board-certified rheumatologist. These patients were matched to the Georgia Office of Vital Records death certificates through 2013. The primary, secondary, tertiary, and contributing causes of death were identified on the death certificates using ICD-10 codes.

Results:   State death certificates matched with 321 SLE patients from the GLR through 2013.  Only 24.6% (79/321) of patients had SLE listed on the death certificate. Characteristics of the deceased SLE patients are listed in the below table. While there were no significant differences with race and sex, SLE patients captured in death certificates were much younger at SLE diagnosis and died at a younger age.

Conclusion:   In a population-based registry with many high-risk black SLE patients, SLE was recorded on the death certificates of only 24.6% of deaths. SLE was listed more often on the death certificates of those who were younger at SLE diagnosis and death, perhaps indicating more severe disease or increased awareness by the caring providers. Death certificates do not accurately capture the full spectrum of SLE patients. Reliance on death certificates to obtain SLE mortality data will underestimate the burden of the disease.