This is an examination of how the utilization of ICD-10 codes may have an impact on mortality reduction.
The utilization of ICD-10 (International Classification of Diseases), 10th Revision is a major milestone in specifying greater precision in diagnostic descriptions. Utilization of ICD-10 in the United States (USA) has been mandated by the Centers for Medicare and Medicaid (CMS) with implementation targeted for the near future. The advantage is that the ‘USA ICD-10 Clinical Modifications (CM) has some 68,000 codes. The USA ICD-10 Procedure Code System (PCS) also has a procedure code system not used by other countries that contains 76,000 codes’.[i]
Logically, we can understand that utilization of codes with greater specificity will reduce the number of potential errors by reducing confusion regarding diagnostic determinations, allowing for improvements in treatment. Specifically, logic indicates that greater precision in codes translates into more immediate and accurate medical treatment along the continuum of care, reducing interpretative errors or lags in time related to assessing imprecise codes and then rendering treatment.
ICD-10 was not intended as a mechanism to directly assist in mortality reduction and, as such, it is a by-product of improved descriptive codes. Only recently has a focus been placed on ICD-10 in improving survivability, with the bulk (if not all) of that information (at least that which is published) being from regions that have adopted and institutionalized ICD-10, which generally means outside the USA. The following summarizes selected case studies, available as of mid-2012.
England & Wales.“…the impact of the introduction of ICD-10 on mortality from circulatory diseases in England and Wales. The article examines changes to specific types of circulatory disease, focusing on ischemic heart disease (IHD) and cerebrovascular disease (stroke). The main changes are highlighted and the article explains how data can be adjusted to take account of these changes so that trends over time can be analyzed. The article then looks at the impact of the changes on baselines for Government targets to reduce mortality from circulatory diseases. The number of deaths assigned to circulatory diseases increases by 3-4 per cent as a result of the introduction of ICD-10, replacing ICD-9. For cerebrovascular diseases specifically, the increase is 9 per cent for females and 13 per cent for males. Trends in mortality from IHD are unaffected by the introduction of ICD-10. However, the number of deaths assigned to acute myocardial infarction, which forms part of IHD, decreases by around 10 per cent when ICD-10 is used instead of ICD-9.”[ii]
Massachusetts, USA. In another study of influenza deaths, the classification using ICD-9 and ICD-10 noted that using a “comparability modified” categorization, no statistically discernible variance was noted, as shown below:
“Comparability ratios are used to make comparisons between data classified under the new system with data classified under the old system. For example, in 1998, there were 2,897 deaths classified as influenza and pneumonia using ICD-9 (ICD-9 codes: 480-487). However, changes in the classification and coding of underlying causes of deaths using ICD-10 reduce the assignment of influenza and pneumonia as an underlying cause of death. The comparability ratio for influenza and pneumonia is 0.6982. Applying the comparability ratio to the 1998 number yields 2,023 deaths that would have been classified as influenza and pneumonia deaths in 1998, had the ICD-10 classification system and coding rules been in place. We can now compare that comparability modified number for 1998 (2,023 deaths) with the actual number of influenza and pneumonia deaths in 1999 (2,176 deaths). In 1999, there was a slight increase in influenza and pneumonia from what we would have expected if the same classification system was used for 1998. [iii]
However, the primary utilization of ICD-10 generally appears to be greater precision in recording the reasons for mortality among a population. There exist a wide range of benefits from such precision, not the least of which is accurate deployment of healthcare resources, such as in rural/agrarian populations. For example, in 2006 in Mozambique, “ICD-10 was adopted by the system and four pilot projects were implemented to provide facility-based mortality and morbidity data for public health use. Lists of selected diseases, included in paper forms for aggregated data, are used for hospital morbidity and mortality surveillance. The system is highly accepted by practitioners, is easy to use and implementable nationwide. Data are used to improve hospital management and to elaborate health facility profile reports.”[iiii]
Thus, the current state-of-ICD-10 in directly reducing mortality has little empirical evidence to support a relationship between ICD-10 codes and statistically valid improvement in mortality, as of mid-2012. However, as a tool to improve care delivery and reduce ambiguity of diagnoses, ICD-10 offers tremendous potential. What studies that have been conducted to date are predominately from countries other than USA, largely due to the lagging adoption of ICD-10 in the USA.
Once ICD-10 becomes commonly utilized within the USA, we anticipate that a range of studies will demonstrate that ICD-10 is a valid tool in preemptively reducing mortality. However, this will necessarily wait upon broad adoption of ICD-10 and a period of elapsed time between ICD-9 cessation and ICD-10 utilization, such that statistically valid results can be drawn.
Carl C. Jaekel, MS, CPHIMS, ACHE
Strategic Advisory Services
Santa Rosa Consulting
carljaekel@SantaRosaConsulting.com
[i]Wikipedia Online Dictionary (http://en.wikipedia.org/wiki/ICD-10)
[ii] Giffiths C, Brock A, Rooney C. – Office for National Statistics, “The impact of introducing ICD-10 on trends in mortality from circulatory diseases in England and Wales.”, Health Statistics Quarterly, 2004 Summer;(22):14-20. (www.ncbi.nlm.nih.gov/pubmed/15704390)
[iii]Massachusetts Deaths 1999,Massachusetts Department of Public Health, Bureau of Health Statistics Research and Evaluation (www.mass.gov/eohhs/docs/dph/research-epi/death-faq-diseases.doc)
[iiii]Roberta Pastore, Alessandro Campione, Bernardina Gonçalves, Armando Melo, Celia Goncalves, Carla Silva Matos, and Marcelino Mugai – “Use of ICD-10 for morbidity and mortality notification for in-patients, in recourse limited settings. The experience of Mozambique using reduced disease lists.” ANNUAL WHO FAMILY OF INTERNATIONAL CLASSIFICATIONS NETWORK MEETING, Seoul, Korea 2009 (http://www.who.int/classifications/network/WHOFIC2009_D050p_Pastone.pdf)