Together, the five national lupus registries funded by the Centers for Disease Control and Prevention provide important information about lupus in populations totaling over 6.5 million from four states and three selected Indian Health Service regions, including mixed urban and rural areas. Studies of this magnitude hold great value because case definitions and case ascertainment methodologies have been standardized, and they incorporate capture-recapture analyses to estimate the completeness of case finding.
It should be noted that in all of the studies, when a different definition for lupus was applied, there were significant changes in incidence and prevalence estimates highlighting a lack of precision when there is no gold standard.
With better clarity around the definition of lupus that covers more of the spectrum without losing specificity for the pathology and a broader and more refined approach to case ascertainment, our understanding of the real burden of disease in the United States will only improve.
Susan Manzi, MD, is with the department of medicine at the Allegheny Health Network, Pittsburgh, and Joan Merrill, MD, is with the department of arthritis and clinical immunology at the Oklahoma Medical Research Foundation, Oklahoma City. These comments are taken from an accompanying editorial (Arthritis Rheumatol. 2017 Sep 11. doi: 10.1002/art.40190). No conflicts of interest were available.