View source for Incidence and prevalence of idiopathic inflammatory myopathies among commercially insured, Medicare supplemental insured, and Medicaid enrolled populations: an administrative claims analysis

A review of the article by Smoyer-Tomic et al., ‘Incidence and prevalence of idiopathic inflammatory myopathies among commercially insured, Medicare supplemental insured, and Medicaid enrolled populations: an administrative claims analysis' <ref name=“Smoyer-Tomic 2012”> Smoyer-Tomic 2012. Incidence and prevalence of idiopathic inflammatory myopathies among commercially insured, Medicare supplemental insured, and Medicaid enrolled populations: an administrative claims analysis http://www-ncbi-nlm-nih-gov.ezproxyhost.library.tmc.edu/pubmed/22703603 </ref>

==Introduction==
Autoimmune idiopathic inflammatory myopathies (IIMs) have the following common characteristics: Auto-immune disorder, no known cause, muscle inflammation, and muscle weakness and consist of three types: polymyositis, dermatomyositis, and sporadic inclusion body myositis. Many studies have not examined IIM, however using data gathered from commercial insurance, Medicaid and Medicare, this study examined how common and frequent IIM is. 

==Methods== 
Data from 2004 - 2008 was gathered from:
# 130 unique commercial insurance companies for outpatient pharmacy claims for people under 65 (14 million enrollees annually) 
# Medicare supplemental insurance paid for by employers for retired and working-age recipients (1.6 million individuals)
# Pooled Medicaid healthcare information from 10 states (28 million)
The data was filtered for patients over the age of 18 with an IIM treatment and patients who had a muscle biopsy; incidence and prevalence was then calculated. 

==Results==
The study identified 2,990 incident cases with 2,477 (83%) were from the commercially insured/Medicare supplemental databases and 513 (17%) were from the Medicaid database with 1,072 had dermatomyositis, 1,784 had polymyositis, and .476 had interstitial myositis. The study also identified 7,155 prevalent patients 39.1% had dermatomyositis, 58.9% had polymyositis, and 9.8% had interstitial myositis. 

==Discussion==
The data showed that IIM incidence for 2004–2008 for commercial/ Medicare supplemental groups was 4.27 cases per 100,000 py, and 5.23 cases per 100,000 py for Medicaid, with the  highest incidence among the polymyositis type (2.46 commercial/Medicare supplemental and 3.53 Medicaid new cases per 100,000 py). Overall, the study shows that in the U.S., IIM incidence will likely range from 3 to 7 new cases per 100,000 py and prevalence for IIM treatment will range from 32,000 to 68,000 per year.

==Conclusion==
Overall, the study did identify higher IIM incidence than historically reported. However, additional studies will need to be completed in order to confirm the incidence and prevalence of IIM findings from this study. 

===Comments===
I chose to review this article because of the large datasets the fact that the authors chose to use both Medicare and Medicaid data. The Medicaid data from 10 states covering 28 million people, Medicare data from 1.6 million retirees and working-age adults, and commercial insurance data from pharmacy claims for 130 different insurers covering 14 million people is an extraordinary amount of information and data to use to study IIM. And of those large databases, data from 2,990 incident cases and 7,155 prevalent patients was used in this study to identify that a higher incidence than previously reported existed. However, even with these three massive datasets, the authors suggest further research and studies are needed to confirm their findings and narrow down the incidence and prevalence range estimates. I would have liked the authors to provide additional information on the types of claims data they would have preferred be available for future studies.

== References ==

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[[Category: Reviews]]
[[Category: Databases, Big Data, and Data Quality‏]]