Use ofInternational Classification of Diseases, Ninth RevisionCodes for Obesity: Trends in the United States from an Electronic Health Record-Derived Database

Abstract

Obesity is a potentially modifiable risk factor for many diseases, and a better understanding of its impact on health care utilization, costs, and medical outcomes is needed. The ability to accurately evaluate obesity outcomes depends on a correct identification of the population with obesity. The primary objective of this study was to determine the prevalence and accuracy of International Classification of Diseases, Ninth Revision (ICD-9) coding for overweight and obesity within a US primary care electronic health record (EHR) database compared against actual body mass index (BMI) values from recorded clinical patient data; characteristics of patients with obesity who did or did not receive ICD-9 codes for overweight/obesity also were evaluated. The study sample included 5,512,285 patients in the database with any BMI value recorded between January 1, 2014, and June 30, 2014. Based on BMI, 74.6% of patients were categorized as being overweight or obese, but only 15.1% of patients had relevant ICD-9 codes. ICD-9 coding prevalence increased with increasing BMI category. Among patients with obesity (BMI ≥30 kg/m2), those coded for obesity were younger, more often female, and had a greater comorbidity burden than those not coded; hypertension, dyslipidemia, type 2 diabetes mellitus, and gastroesophageal reflux disease were the most common comorbidities. Key findings: US outpatients with overweight or obesity are not being reliably coded, making ICD-9 codes undependable sources for determining obesity prevalence and outcomes. BMI data available within EHR databases offer a more accurate and objective means of classifying overweight/obese status.

Association between shared medical appointments and weight loss outcomes and anti‐obesity medication use in patients with obesity

“…In addition, the use of coding to identify patients with obesity in the non‐SMA group has limitations; in that, it cannot be confirmed with absolute certainty that robust discussions around weight management occurred between providers and these patients. However, given evidence that in the United States, only 28% of patients with a BMI≥30 kg m −2 are coded for obesity, it is clear that this is not a common practice and thus, is likely to indicate, that some level of focused discussion about weight management did occur at that visit.…”

The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome

“…For example, ICD codes are valid (95% sensitivity; 96% specificity) for identifying patients with knee or hip replacement in the Veterans Health Administration system [55]. Although there can be false-positives, they tend to underestimate the rate in other conditions such as obesity (15.1% of true obesity rates were identified) [56] or psoriasis (81% valid case ascertainment) [57]. The sensitivity for identifying 32 different conditions using ICD-9 codes varied from 9.3 to 83.1% [58].…”

The Association Between Switching from Synthroid® and Clinical Outcomes: US Evidence from a Retrospective Database Analysis

“…Results from multivariable logistic regression models of clinical outcomes associations with number of switches including controls for patients' demographics (age, sex, region of residence, and insurance type), index dose and copayment of levothyroxine prescription, pre-period Charlson Comorbidity Index score, pre-period visit to endocrinologist, and lagged dependent variable CI confidence interval, TSH thyroid-stimulating hormone statistically significant differences that existed at baseline. Further, obesity has been recognized as a condition that has historically been unreliably recorded in claims data which may lead to bias in the current study's result for this condition [23].…”