Validation of the International Classification of Disease 10th Revision Codes for Kidney Transplant Rejection and Failure.

BACKGROUND

Clinical research requires that diagnostic codes captured from routinely collected health administrative data accurately identify individuals with a disease.

OBJECTIVE

In this study, we validated the International Classification of Disease 10th Revision (ICD-10) definition for kidney transplant rejection (T86.100) and for kidney transplant failure (T86.101).

DESIGN

Retrospective cohort study.

SETTING

A large, regional transplantation center in Ontario, Canada.

PATIENTS: All adult kidney transplant recipients from 2002 to 2018.

MEASUREMENTS: Chart review was undertaken to identify the first occurrence of biopsy-confirmed rejection and graft loss for all participants. For each observation, we determined the first date a single ICD-10 code T86.100 or T86.101 was recorded as a hospital encounter discharge diagnosis.

METHODS

Using chart review as the gold standard, we determined the sensitivity, specificity, and positive predictive value (PPV) for the ICD-10 codes T86.100 and T86.101.

RESULTS

Our study population comprised of 1,258 kidney transplant recipients. The prevalence of rejection and death-censored graft loss were 15.6 and 9.1%, respectively. For the ICD-10 rejection code (T86.100), sensitivity was 72.9% (95% confidence interval [CI], 66.6-79.2), specificity 97.5% (96.5-98.4), and PPV 83.8% (78.3-89.4). For the ICD-10 graft loss code (T86.101), sensitivity was 21.2% (95% CI, 13.2-29.3), specificity 86.3% (84.3-88.3), and PPV 11.7% (7.0-16.4).

LIMITATIONS: Single-center study which may limit generalizability of our findings.

CONCLUSIONS

A single ICD-10 code for kidney transplant rejection (T86.100) was present in 84% of true kidney transplant rejections and is an accurate way of identifying kidney transplant recipients with rejection using administrative health data. The ICD-10 code for graft failure (T86.101) performed poorly and should not be used for administrative health research.