SSA Studies Correlation Patterns Between Diagnosis Codes

Empire Justice Center July 31, 2018

A recently released Working Paper from the Social Security Administration’s (SSA’s) Office of Economic Analysis and Comparative Studies (ORES No. 113, by Javier Meseguer, released June 2018), examines the association between primary and secondary impairments in disability claims.  Advocates who review SSA evidence files will be familiar with the SSA-831 Disability Determination and Transmittal form, which reports the primary and secondary diagnosis, diagnostic group, and impairment code related to the claimant’s disability.  Upon issuing a disability determination, disability examiners (DEs) and state agency medical consultants (SAMCs) assign primary and secondary diagnosis codes most relevant to the determination, choosing among listed impairments that approximately follow the taxonomy established by the International Classification of Diseases, 9th Revision (ICD-9).  The 4-digit codes often provide the only medical information available to most researchers and are among the most reliable predictors of the resulting initial disability determination outcome.


Overall, the percentage of initial SSDI claimants (including those concurrently applying for SSI) with an assigned secondary diagnosis has steadily increased over time. In 1997, a little over half of qualified claimants had a secondary diagnosis code (56.3%).  By 2010, that percentage had increased to 71.4%.  The paper finds evidence of strong impairment comorbidity patterns among individuals filing initial claims to Social Security disability programs in 2009.


Understanding which combinations of impairments in disability claims tend to appear together, and which are infrequently linked, can be useful for numerous reasons.  For example, it is common practice in disability research to ignore the secondary diagnosis codes, which can result in a distorted picture of diagnostic incidence and can thereby complicate the analysis of determination outcomes.


In recent decades, there has been growing interest in the study of multimorbidity, which involves the concurrence of multiple disorders in the same person (“comorbidity,” a subset of multimorbidity, refers to cases of two impairments only).  Multimorbidity occurs among a majority of the elderly and will likely become increasingly prevalent as the population ages (Marengoni and others 2011; Sinnige and others 2015).  Co-existing multiple disorders can have a synergistic effect on health and disability that goes beyond the additive effect of the individual impairments.  Thus, the traditional single-disease paradigm in medicine may not provide an adequate picture of health or disability status.


Many studies have found a significant effect of multimorbidity on the likelihood of disability, poor quality of life, and high health care costs.  Accordingly, a better understanding of multimorbidity could have enormous implications for early intervention and cost containment.  In context of this study, the sheer volume of administrative data could prove a valuable alternative source of information to epidemiological researchers.  Additionally, the correlation estimates between the diagnoses may help identify outliers or unusual trends that could merit further scrutiny.  Over time, such changes in the correlation between primary and secondary impairments could signal events of interest to policymakers.  Thus, a better understanding of impairment comorbidity in SSDI and SSI is important and worthwhile.


See full study here: https://www.ssa.gov/policy/docs/workingpapers/wp113.html


Thanks to Empire Justice Center paralegal Keith Jensen for summarizing this and other articles for us.  We wish Keith well as he heads off to CUNY Law School!