Cohort Definition Name : Earliest Event of Multiple Sclerosis
Contributor name : Joel Swerdel’
Contributor OrcId :
Logic Description : Earliest occurrence of multiple sclerosis indexed on diagnosis date for the first time in persons history cohort exit is the end of continuous observation.
Recommended study application : target
Assertion statement : This cohort definition was executed on at least one real person-level observational health data source and resulted in a cohort with at least 1 person.
Target Clinical Description : Multiple sclerosis (MS) is a chronic disease affecting the central nervous system (the brain and spinal cord). MS occurs when the immune system attacks nerve fibers and myelin sheathing (a fatty substance which surrounds/insulates healthy nerve fibers) in the brain and spinal cord. This attack causes inflammation, which destroys nerve cell processes and myelin – altering electrical messages in the brain. The onset of MS patients is typically noted as occurring between 20 and 40 years of age. However, research utilizing claims data have reported mean ages of onset spanning from 42 to 52 years old. MS is 2-to-3 times more common in women then men and effects approximately 1 million Americans, with prevalence varying significantly by country. Besides age and sex, risk factors include, family history of disease, race, climate and geography, and certain infections and autoimmune diseases
"Evaluation conclusion : We developed a prevalent cohort definition for Multiple Sclerosis (MS) using a concept set of four concepts which incorporated all those found from the literature review and from the analysis of PHOEBE and orphan concepts in cohort diagnostics. We performed the evaluation across a network of claim data sources and 1 EHR US data source. The data sources are: IBM® MarketScan® Commercial Database (CCAE), Optum’s longitudinal EHR repository (Optum EHR), Optum’s Clinformatics® Data Mart (DOD), IBM® MarketScan® Multi-State Medicaid Database (MDCD), IBM® MarketScan® Medicare Supplemental Database (MDCR), Japan Claims Database (JMDC), Clinical Practice Research Datalink (CPRD) , IQVIA® Australia Longitudinal Patient Data (LPD) database (Australia), IQVIA® Disease Analyzer (DA) France database (France), QVIA® Disease Analyzer (DA) Germany database (Germany), IQVIA® Adjudicated Health Plan Claims Data (formerly PharMetrics Plus) - US database (PharMetrics), IQVIA® Ambulatory EMR (EMR). The algorithm retrieves subjects from all databases tested. We developed a more specific cohort requiring a second diagnosis code for MS in the time period 31-365 days after index. This cohort improves the specificity of the algorithm albeit at the expense of sensitivity as determined by PheValuator. It should be noted that there is a trade-off between the two cohorts in performance.
Performance characteristics were determined for 8 of the 11 databases. The remaining databases did not contain enough subjects to produce an accurate diagnostic model. Using this deffinition (one code) sensitivity ranged from about 53% in Germany to about 92% in PharMetrics while positive predictive value ranged from about 68% in JMDC to about 85% in Germany. Using a deffinition based on 2 codes, sensitivity decreased, ranging from about 13% in Germany to about 77% in JMDC while positive predictive value increased, ranging from 82% in JMDC to about 99% in CCAE, Optum EHR, and Optum SES.
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