1. Evaluating The Accuracy Of International Classification Of Diseases 10TH Revision Codes For Venous Thromboembolism (VTE) And Major Bleeding (MB) in Emergency Room Discharges
Fatimah Al-Ani, Salimah Shariff, Lenicio Siqueira, Alejandro Lazo-Langner* Hematology and Epidemiology and Biostatistics, University of Western Ontario, and Institute for Clinical Evaluative Sciences, London ON Canada
Autores / Authors
Background
Results
A total of 300 patients were included, 100 with a VTE discharge code and 200 with a major bleeding.
Kappa statistics showed good agreement between the two chart reviewers for all the six groups (Table 1). Overall, ICD-10 codes showed reasonable accuracy for identifying major bleeding events with a PPV of 72% and a specificity of 78%.
Diagnostic codes performed particularly well for subarachnoid hemorrhage and intracranial bleeding (PPV 88% and 90%, respectively).
Diagnostic codes for upper and lower gastrointestinal bleeding codes performed less well (PPV 50% and 60%, respectively).
In contrast, ICD-10 codes for venous thromboembolism had a moderate to poor accuracy with an overall PPV of 49% and a specificity of 66%. Diagnostic codes for PE performed better than for DVT (Table 2).
Table 1: Kappa statistic results for diagnostic agreement between abstractors
Epidemiological studies evaluating venous thromboembolism (VTE) prevention and treatment consistently use thrombotic and bleeding events as outcomes of interest. The use of administrative databases to conduct epidemiological and health services research has steadily increased in recent years.
Since 2002, Canada has adopted the International Classification of Diseases, 10th revision (ICD-10) coding for all hospital encounters. Research dependent on administrative databases is thus reliant on the accuracy in the coding for the diagnoses of interest.
During the past decade, a significant change occurred in the standard of care for patients diagnosed with acute VTE, with a transition from inpatient to outpatient treatment for most patients.
Therefore, this study has focused on Emergency Room (ER) discharges to capture most of VTE events, and consequently major bleeding episodes. To date, validation studies of VTE and major bleeding have focused on ICD-9 coding that is no longer reflective of the current coding environment in Canada.
Diagnosis N
Kappa (95% CI)
DVT 50
0.756 (57-93) PE
0.918 (80-100)
SAH
0.811 (55-100)
ICH
0.669 (36-96)
UGIB
0.683 (48-87)
LGIB
0.750 (56-93)
Table 2: Diagnostic accuracy of ICD-10CM codes for venous thromboembolism and major bleeding categories
Aims
Conclusion Dx N TP TN FP FN
Spec. (95%CI)
PPV% (95% CI)
VTE
100 49 51
66 (58-73)
49 (39-58)
DVT 50 21 29
63(52-73)
42 (29-57) PE 28 22
69 (58-78)
56 (42-68) MB
200
144 56
78(72-82)
72 (65-77)
SAH 44 6
89 (78-95)
88 (76-94)
ICH 45 5
90 (80-96)
90 (78-95)
UGIB 25
66 (55-76)
50 (36-63)
LGIB 30 20
71 (59-80)
60 (46-72)
In this study, we sought to validate the accuracy of the ICD-10 codes for venous thromboembolism and major bleeding in ER discharges in a large hospital in Ontario, Canada.
Single ICD-10 code for VTE has limited predictive ability for identifying DVT and PE in ER discharges in our institution using the CIHI-NACRS database. In contrast, ICD-10 codes have a reasonable accuracy for identifying major bleeding events and it would be reasonable to use them for research purposes.
Patients/Methods
Retrospective chart re-abstraction study: Conducted at the London Health Sciences Centre, a university-associated teaching hospital in London, Ontario, Canada between July 1st 2002 and March 31st 2014.
Inclusion: Patients were adults with a VTE or a major bleeding code included in National Ambulatory Care Reporting System (NACRS) assessed in the ER of our institution.
Methods: VTE was defined using ICD-10 codes for deep venous thrombosis (DVT), and pulmonary embolism (PE), and major bleeding was defined using codes for intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), upper gastrointestinal (UGIB), and lower gastrointestinal bleeding (LGIB). A random sample of 50 patients was selected for each of DVT, PE, ICH, SAH and UGIB and LGIB groups. Bleeding group was used as negative controls for VTE group and vice versa. Two chart abstractors independently conducted data collection and diagnostic assessment in a blinded fashion. Discrepancies were resolved by consensus with a third reviewer.   
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Abbrv: Dx, diagnosis; N, number of patients; TP, true positive; TN, true negative; FP, false positive; FN, false negative; CI, confidence interval; PPV, positive predictive value