Coding algorithms for identifying patients with cirrhosis and hepatitis B or C virus using administrative data

Validation of methods for assessing cardiovascular disease using electronic health data in a cohort of Veterans with diabetes

BACKGROUND

Electronic health data are routinely used to conduct studies of cardiovascular disease in the setting of the Veterans Health Administration (VA). Previous studies have estimated the positive predictive value (PPV) of International Classification of Disease, Ninth Revision (ICD-9) codes for acute myocardial infarction (MI), but the sensitivity of these codes for all true events and the accuracy of coding algorithms for prevalent disease status at baseline are largely unknown.

METHODS

We randomly sampled 180 Veterans from the VA Puget Sound Health Care System who initiated diabetes treatment. The full electronic medical record was reviewed to identify prevalent conditions at baseline and acute MI events during follow-up. The accuracy of various coding algorithms was assessed.

RESULTS

Algorithms for previous acute events at baseline had high PPV (previous MI: 97%; previous stroke: 81%) but low sensitivity (previous MI: 38%; previous stroke: 52%). Algorithms for chronic conditions at baseline had high PPV (heart failure: 72%; coronary heart disease [CHD]: 85%) and high sensitivity (heart failure: 90%, CHD: 84%). For current smoking status at baseline, ICD-9 codes with pharmacy data had a PPV of 77% and sensitivity of 73%. The coding algorithm for acute MI events during follow-up had high PPV (80%) and sensitivity (89%).

CONCLUSIONS

ICD-9 codes for acute MI events during follow-up had high PPV and sensitivity. The sensitivity of ICD-9 codes for previous acute events at baseline was low, but a composite variable for baseline CHD had good accuracy.

Hepatocellular carcinoma surveillance rates in commercially insured patients with noncirrhotic chronic hepatitis B

American association for the study of liver diseases (AASLD) and European Association for the Study of the Liver (EASL) guidelines recommend biannual hepatocellular carcinoma (HCC) screening for noncirrhotic patients with chronic hepatitis B infection (HBV), yet there are no data estimating surveillance rates or factors associated with surveillance. We performed a retrospective cohort study of US patients using the Truven Health Analytics databases from 2006 to 2010 and identified patients with noncirrhotic chronic HBV. Surveillance patterns were characterized using categorical and continuous outcomes, with the continuous measure of the proportion of time 'up to date' with surveillance (PUTDS), with the 6-month interval following each ultrasound categorized as 'up to date'. During a median follow-up of 26.0 (IQR: 16.2-40.0) months among 4576 noncirrhotic patients with chronic HBV (median age: 44 years, IQR: 36-52), only 306 (6.7%) had complete surveillance (one ultrasound every 6-month interval), 2727 (59.6%) incomplete (≥1 ultrasound) and 1543 (33.7%) none. The mean PUTDS was 0.34 ± 0.29, and the median was 0.32 (IQR: 0.03-0.52). In multinomial logistic regression models, patients diagnosed by a nongastroenterologist were significantly less likely to have complete surveillance (P < 0.001), as were those coinfected with HBV/HIV (P < 0.001). In linear regression models, nongastroenterologist provider, health insurance subtype, HBV/HIV coinfection, rural status and metabolic syndrome were independently associated with decreased surveillance. Patients with HIV had an absolute decrease in the PUTDS of 0.24, while patients in less populated rural areas had an absolute decrease of 0.10. HCC surveillance rates in noncirrhotic patients with chronic HBV in the United States are poor and lower than reported rates of HCC surveillance in cirrhotic patients.