Revision of the International Classification of Diseases to include standardized descriptions of multiple injuries and injury severity

Performance of International Classification of Diseases-based injury severity measures used to predict in-hospital mortality and intensive care admission among traumatic brain-injured patients

BACKGROUND

The International Classification of Diseases (ICD) is the main classification system used for population-based traumatic brain injury (TBI) surveillance activities but does not contain direct information on injury severity. International Classification of Diseases-based injury severity measures can be empirically derived or mapped to the Abbreviated Injury Scale, but no single approach has been formally recommended for TBI.

OBJECTIVE

The aim of this study was to compare the accuracy of different ICD-based injury severity measures for predicting in-hospital mortality and intensive care unit (ICU) admission in TBI patients.

METHODS

We conducted a population-based retrospective cohort study. We identified all patients 16 years or older with a TBI diagnosis who received acute care between April 1, 2006, and March 31, 2013, from the Quebec Hospital Discharge Database. The accuracy of five ICD-based injury severity measures for predicting mortality and ICU admission was compared using measures of discrimination (area under the receiver operating characteristic curve [AUC]) and calibration (calibration plot and the Hosmer-Lemeshow goodness-of-fit statistic).

RESULTS

Of 31,087 traumatic brain-injured patients in the study population, 9.0% died in hospital, and 34.4% were admitted to the ICU. Among ICD-based severity measures that were assessed, the multiplied derivative of ICD-based Injury Severity Score (ICISS-Multiplicative) demonstrated the best discriminative ability for predicting in-hospital mortality (AUC, 0.858; 95% confidence interval, 0.852-0.864) and ICU admissions (AUC, 0.813; 95% confidence interval, 0.808-0.818). Calibration assessments showed good agreement between observed and predicted in-hospital mortality for ICISS measures. All severity measures presented high agreement between observed and expected probabilities of ICU admission for all deciles of risk.

CONCLUSIONS

The ICD-based injury severity measures can be used to accurately predict in-hospital mortality and ICU admission in TBI patients. The ICISS-Multiplicative generally outperformed other ICD-based injury severity measures and should be preferred to control for differences in baseline characteristics between TBI patients in surveillance activities or injury research when only ICD codes are available.

LEVEL OF EVIDENCE

Prognostic study, level III.

Anxiety and Depression in Patients with Traumatic Spinal Cord Injury: A Nationwide Population-Based Cohort Study

Background

Traumatic spinal cord injury (tSCI) may involve new-onset anxiety and depression post-discharge. However, long-term population-based studies have lacked access to follow-up conditions in terms of new-onset anxiety and depression. The objective of this study was to estimate the long-term risk of new-onset anxiety and depression post-discharge.

Methods

The Longitudinal Health Insurance Database 2000 (LHID2000) from Taiwan’s National Health Insurance Research Database was used in this study. Individuals with tSCI were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes of 806 and 952 from 1999–2008. The comparison cohort (other health conditions group) was randomly selected from the LHID2000 and was 1:1 matched by age, sex, index year, and comorbidities to reduce the selection bias. All study participants were retrospectively followed for a maximum of 3 years until the end of follow-up, death, or new-onset anxiety (ICD-9-CM: 309.2–309.4) or depression (ICD-9-CM: 296.2, 296.5, 296.82, 300.4, 309.0–309.1, and 311). Persons who were issued a catastrophic illness card for tSCI were categorized as having a severe level of SCI (Injury Severity Score [ISS] ≥16). Poisson regression was used to estimate the incidence rate ratios of anxiety or depression between patients with tSCI and other health conditions. The relative risk of anxiety or depression was estimated using a Cox regression analysis, which was adjusted for potential confounding factors.

Results

Univariate analyses showed that the tSCI patients (n = 3556) had a 1.33 times greater incidence of new-onset anxiety or depression (95% confidence interval [CI]: 1.12–1.57) compared to the other health conditions group (n = 3556). After adjusting for potential risk factors, the tSCI patients had a significant 1.29-fold increased risk of anxiety or depression compared to the group with other health conditions (95% CI: 1.09–1.53). Individuals with tSCI, including patients who were under the age of 35, patients who were males, patients who had a low income, and patients without a Charlson Comorbidity Index score, all had a higher long-term risk of anxiety or depression than the other health conditions group (IRRs: 1.84, 1.63, 1.29, and 1.39, respectively). For all tSCI patients, those with an Injury Severity Score (ISS) ≥16 had an almost 2-fold higher risk of anxiety or depression (adjusted Hazard Ratio: 1.85; 95% CI: 1.17–2.92) compared to those with ISS <16.

Conclusions

Our findings indicated that tSCI patients have a high risk of anxiety or depression post-discharge, especially among the younger tSCI patients (age <50 years), compared with the other health conditions group. This information could help physicians understand the long-term risk of new-onset anxiety or depression in tSCI patients post-discharge.

Development of an expert based ICD-9-CM and ICD-10-CM map to AIS 2005 update 2008

OBJECTIVE

This article describes how maps were developed from the clinical modifications of the 9th and 10th revisions of the International Classification of Diseases (ICD) to the Abbreviated Injury Scale 2005 Update 2008 (AIS08). The development of the mapping methodology is described, with discussion of the major assumptions used in the process to map ICD codes to AIS severities. There were many intricacies to developing the maps, because the 2 coding systems, ICD and AIS, were developed for different purposes and contain unique classification structures to meet these purposes.

METHODS

Experts in ICD and AIS analyzed the rules and coding guidelines of both injury coding schemes to develop rules for mapping ICD injury codes to the AIS08. This involved subject-matter expertise, detailed knowledge of anatomy, and an in-depth understanding of injury terms and definitions as applied in both taxonomies. The official ICD-9-CM and ICD-10-CM versions (injury sections) were mapped to the AIS08 codes and severities, following the rules outlined in each coding manual. The panel of experts was composed of coders certified in ICD and/or AIS from around the world. In the process of developing the map from ICD to AIS, the experts created rules to address issues with the differences in coding guidelines between the 2 schemas and assure a consistent approach to all codes.

RESULTS

Over 19,000 ICD codes were analyzed and maps were generated for each code to AIS08 chapters, AIS08 severities, and Injury Severity Score (ISS) body regions. After completion of the maps, 14,101 (74%) of the eligible 19,012 injury-related ICD-9-CM and ICD-10-CM codes were assigned valid AIS08 severity scores between 1 and 6. The remaining 4,911 codes were assigned an AIS08 of 9 (unknown) or were determined to be nonmappable because the ICD description lacked sufficient qualifying information for determining severity according to AIS rules. There were also 15,214 (80%) ICD codes mapped to AIS08 chapter and ISS body region, which allow for ISS calculations for patient data sets.

CONCLUSION

This mapping between ICD and AIS provides a comprehensive, expert-designed solution for analysts to bridge the data gap between the injury descriptions provided in hospital codes (ICD-9-CM, ICD-10-CM) and injury severity codes (AIS08). By applying consistent rules from both the ICD and AIS taxonomies, the expert panel created these definitive maps, which are the only ones endorsed by the Association for the Advancement of Automotive Medicine (AAAM). Initial validation upheld the quality of these maps for the estimation of AIS severity, but future work should include verification of these maps for MAIS and ISS estimations with large data sets. These ICD-AIS maps will support data analysis from databases with injury information classified in these 2 different systems and open new doors for the investigation of injury from traumatic events using large injury data sets.

The science of clinical practice: disease diagnosis or patient prognosis? Evidence about "what is likely to happen" should shape clinical practice

BACKGROUND

Diagnosis is the traditional basis for decision-making in clinical practice. Evidence is often lacking about future benefits and harms of these decisions for patients diagnosed with and without disease. We propose that a model of clinical practice focused on patient prognosis and predicting the likelihood of future outcomes may be more useful.

DISCUSSION

Disease diagnosis can provide crucial information for clinical decisions that influence outcome in serious acute illness. However, the central role of diagnosis in clinical practice is challenged by evidence that it does not always benefit patients and that factors other than disease are important in determining patient outcome. The concept of disease as a dichotomous 'yes' or 'no' is challenged by the frequent use of diagnostic indicators with continuous distributions, such as blood sugar, which are better understood as contributing information about the probability of a patient's future outcome. Moreover, many illnesses, such as chronic fatigue, cannot usefully be labelled from a disease-diagnosis perspective. In such cases, a prognostic model provides an alternative framework for clinical practice that extends beyond disease and diagnosis and incorporates a wide range of information to predict future patient outcomes and to guide decisions to improve them. Such information embraces non-disease factors and genetic and other biomarkers which influence outcome.

SUMMARY

Patient prognosis can provide the framework for modern clinical practice to integrate information from the expanding biological, social, and clinical database for more effective and efficient care.

The 2014 Academic College of Emergency Experts in India's INDO-US Joint Working Group (JWG) White Paper on "Developing Trauma Sciences and Injury Care in India"

It is encouraging to see the much needed shift in the understanding and recognition of the concept of “burden of disease” in the context of traumatic injury. Equally important is understanding that the impact of trauma burden rivals that of nontraumatic morbidities.

Subsequently, this paradigm shift reinstates the appeal for timely interventions as the standard for management of traumatic emergencies. Emergency trauma care in India has been disorganized due to inadequate sensitivity toward patients affected by trauma as well as the haphazard, nonuniform acceptance of standardization as the norm. Some of the major hospitals across various regions in the country do have trauma care units, but even those lack protocols to ensure that all trauma cases are handled by those units, largely owing to lack of structured referral system.

As a first step to reform the state of trauma care in the country, a detailed overview is needed to gain insight into the prevailing reality. The objectives of this paper are to thus weave a foundation based on the statistical and qualitative burden of trauma in the country; the available infrastructure of trauma care centers equipped to deal with trauma; the need and scope of standardized protocols for intervention; and most importantly, the application of these in shaping educational initiatives in advancing emergency trauma care in the country.

Adherence to published antimicrobial prophylaxis guidelines for wounded service members in the ongoing conflicts in Southwest Asia

In 2008, a clinical practice guideline (CPG) was developed for the prevention of infections among military personnel with combat-related injuries. Our analysis expands on a prior 6-month evaluation and assesses CPG adherence with respect to antimicrobial prophylaxis for U.S. combat casualties medically evacuated to Landstuhl Regional Medical Center over a 1-year period (June 2009 through May 2010), with an eventual goal of continuously monitoring CPG adherence and measuring outcomes as a function of compliance. We classified adherence to the CPG as receipt of recommended antimicrobials within 48 hours of injury. A total of 1106 military personnel eligible for CPG assessment were identified and 74% received antimicrobial prophylaxis. Overall, CPG compliance within 48 hours of injury was 75%. Lack of antimicrobial prophylaxis contributed 2 to 22% to noncompliance varying by injury category, whereas receipt of antibiotics other than preferred was 11 to 30%. For extremity injuries, antimicrobial prophylaxis adherence was 60 to 83%, whereas it was 80% for closed injuries and 68% for penetrating abdominal injuries. Overall, the results of our analysis suggest an ongoing need to improve adherence, monitor CPG compliance, and assess effectiveness.

Bridging classification for injury diagnoses that can be converted to both the International Classification of Diseases and the Abbreviated Injury Scale

Background

The International Statistical Classification of Diseases and Related Health Problems (ICD) is currently undergoing a revision process to develop the Eleventh Revision (ICD-11), but substantial modification of chapter 19 has not been proposed despite its known problems in describing injury severity and multiple injuries. Many facilities treating trauma patients perform duplicate coding for trauma diagnoses using two different classification systems, the ICD for administrative purposes and the Abbreviated Injury Scale (AIS) for trauma registry, because unambiguous conversion of codes between the ICD and AIS is not always possible due to structural differences.

Aim

We developed a new bridging classification system which can be unambiguously converted to both ICD and AIS.

Methods and Results

The bridging classification adopted multidimensional coding and addressed differences in granularity and classification boundaries by adopting the more detailed categorizations whenever the granularity and classification boundaries differed between the ICD and AIS. Then we showed that the bridging classification codes could unambiguously converted to both ICD and AIS.

Conclusion

Once injuries are coded using the bridging classification, the ICD and AIS codes are readily available. Integrating the new bridging classification into the ICD-11, possibly as a clinical modification, would eliminate the necessity of complicated procedures for code conversion and duplicate coding, and benefit users by building on the strengths of both the ICD and AIS.

Abbreviated Injury Scale: not a reliable basis for summation of injury severity in trauma facilities?

BACKGROUND

Injury severity is most frequently classified using the Abbreviated Injury Scale (AIS) as a basis for the Injury Severity Score (ISS) and the New Injury Severity Score (NISS), which are used for assessment of overall injury severity in the multiply injured patient and in outcome prediction. European trauma registries recommended the AIS 2008 edition, but the levels of inter-rater agreement and reliability of ISS and NISS, associated with its use, have not been reported.

METHODS

Nineteen Norwegian AIS-certified trauma registry coders were invited to score 50 real, anonymised patient medical records using AIS 2008. Rater agreements for ISS and NISS were analysed using Bland-Altman plots with 95% limits of agreement (LoA). A clinically acceptable LoA range was set at ± 9 units. Reliability was analysed using a two-way mixed model intraclass correlation coefficient (ICC) statistics with corresponding 95% confidence intervals (CI) and hierarchical agglomerative clustering.

RESULTS

Ten coders submitted their coding results. Of their AIS codes, 2189 (61.5%) agreed with a reference standard, 1187 (31.1%) real injuries were missed, and 392 non-existing injuries were recorded. All LoAs were wider than the predefined, clinically acceptable limit of ± 9, for both ISS and NISS. The joint ICC (range) between each rater and the reference standard was 0.51 (0.29,0.86) for ISS and 0.51 (0.27,0.78) for NISS. The joint ICC (range) for inter-rater reliability was 0.49 (0.19,0.85) for ISS and 0.49 (0.16,0.82) for NISS. Univariate linear regression analyses indicated a significant relationship between the number of correctly AIS-coded injuries and total number of cases coded during the rater's career, but no significant relationship between the rater-against-reference ISS and NISS ICC values and total number of cases coded during the rater's career.

CONCLUSIONS

Based on AIS 2008, ISS and NISS were not reliable for summarising anatomic injury severity in this study. This result indicates a limitation in their use as benchmarking tools for trauma system performance.

Trauma deserts: distance from a trauma center, transport times, and mortality from gunshot wounds in Chicago

OBJECTIVES

We examined whether urban patients who suffered gunshot wounds (GSWs) farther from a trauma center would have longer transport times and higher mortality.

METHODS

We used the Illinois State Trauma Registry (1999-2009). Scene address data for Chicago-area GSWs was geocoded to calculate distance to the nearest trauma center and compare prehospital transport times. We used multivariate regression to calculate the effect on mortality of being shot more than 5 miles from a trauma center.

RESULTS

Of 11,744 GSW patients during the study period, 4782 were shot more than 5 miles from a trauma center. Mean transport time and unadjusted mortality were higher for these patients (P < .001 for both). In a multivariate model, suffering a GSW more than 5 miles from a trauma center was associated with an increased risk of death (odds ratio = 1.23; 95% confidence interval = 1.02, 1.47; P = .03).

CONCLUSIONS

Relative "trauma deserts" with decreased access to immediate care were found in certain areas of Chicago and adversely affected mortality from GSWs. These results may inform decisions about trauma systems planning and funding.

A nationwide, population-based, long-term follow-up study of repeated self-harm in Taiwan

Background

Previous follow-up studies of repeated self-harm show that the cumulative risk of repeated self-harm within one year is 5.7%–15%, with females at greatest risk. However, relatively few studies have focused on the Far East. The objective of this study was to calculate the cumulative risk of repeated self-harm over different lengths of follow-up time (3 months, 6 months, and 1–8 years), to determine factors influencing repeated self-harm and to explore the interaction between gender and self-harm methods.

Methods

We used self-harm patient who hospitalized due to first-time self-harm between 2000 and 2007 from 1,230 hospitals in Taiwan. Hospitalization for repeated self-harm among members of this cohort was tracked after 3 months, 6 months, and 1–8 years. Tracking continued until December 31, 2008. We analyzed the cumulative risk and risk factors of repeated self-harm by using negative binomial regression.

Results

Of the 39,875 individual study samples, 3,388 individuals (8.50%) were found to have repeatedly self-harmed. The cumulative risk of repeated self-harm within three months was 7.19% and within one year was 8%. Within 8 years, it was 8.70%. Females were more likely to repeatedly self-harm than males (RR = 1.21, 95% CI = 1.15–1.76). The main method of self-harm was solid or liquid substances (RR = 1.88, 95% CI = 1.23–2.04) or cutting or piercing (RR = 1.36, 95% CI = 1.02–1.82), and in patients with psychiatric disorders were more likely to self-harm (RR = 1.61, 95% CI = 1.48–1.75).

Conclusions

The key time for intervention for repeated self-harm is within three months. Appropriate prevention programs should be developed based on gender differences.