Diagnostic Accuracy of Health Care Administrative Diagnosis Codes to Identify Nontuberculous Mycobacteria Disease: A Systematic Review

Abstract

Background Health care administrative database research frequently uses standard medical codes to identify diagnoses or procedures. The aim of this review was to establish the diagnostic accuracy of codes used in administrative data research to identify nontuberculous mycobacterial (NTM) disease, including lung disease (NTMLD). Methods We searched Ovid Medline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from inception to April 2019. We included studies assessing the diagnostic accuracy of International Classification of Diseases, 9th edition, Clinical Modification (ICD-9-CM) diagnosis codes to identify NTM disease and NTMLD. Studies were independently assessed by 2 researchers, and the Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess bias and quality. Results We identified 5549 unique citations. Of the 96 full-text articles reviewed, 7 eligible studies of moderate quality (3730 participants) were included in our review. The diagnostic accuracy of ICD-9-CM diagnosis codes to identify NTM disease varied widely across studies, with positive predictive values ranging from 38.2% to 100% and sensitivity ranging from 21% to 93%. For NTMLD, 4 studies reported diagnostic accuracy, with positive predictive values ranging from 57% to 64.6% and sensitivity ranging from 21% to 26.9%. Conclusions Diagnostic accuracy measures of codes used in health care administrative data to identify patients with NTM varied across studies. Overall the positive predictive value of ICD-9-CM diagnosis codes alone is good, but the sensitivity is low; this method is likely to underestimate case numbers, reflecting the current limitations of coding systems to capture NTM diagnoses.

Geographic Variation and Environmental Predictors of Nontuberculous Mycobacteria in Laboratory Surveillance, Virginia, USA, 2021–20231

“…Multiple studies have demonstrated the limitations of using diagnostic billing (International Classification of Diseases [ICD]) codes to identify rates of NTM disease. Barriers include lack of clinician familiarity with NTM diagnostic characteristics and variable rates of need for active antimicrobial therapy, which might not be necessary for treatment of NTM lung disease, unlike for many other infectious diseases ( 20 , 21 ). Several additional recent studies have evaluated laboratory-based surveillance of NTM, including 1 study from a CDC surveillance program ( 22 ).…”

Non-tuberculous mycobacterial infections in patients with end-stage renal disease: Prevalence, risk factors, and mortality

“…Cases in this study were selected based on the presence of a single diagnostic code for NTM. Prior studies attempting to validate the use of diagnostic codes in identifying NTM cases have demonstrated that the presence of a diagnostic code for NTM has moderate sensitivity but a very high positive predictive value (PPV) for identifying a true case 33. Attempts to add further qualifiers to the search such as the use of fluoroquinolones within a specific time range of the diagnosis code served to improve PPV only somewhat but further decreased sensitivity 34.…”

“…Prior studies attempting to validate the use of diagnostic codes in identifying NTM cases have demonstrated that the presence of a diagnostic code for NTM has moderate sensitivity but a very high positive predictive value (PPV) for identifying a true case. 33 Attempts to add further qualifiers to the search such as the use of fluoroquinolones within a specific time range of the diagnosis code served to improve PPV only somewhat but further decreased sensitivity. 34 When the literature review is expanded to include those studies assessing pulmonary NTM disease alone, the use of a single diagnosis code to identify cases becomes more commonplace.…”

Incremental mortality associated with nontuberculous mycobacterial lung disease among US Medicare beneficiaries with chronic obstructive pulmonary disease

“…There are inherent limitations in retrospective claims-based epidemiologic studies, including variations in coding practices and the potential for coding inaccuracy (overcoding, undercoding, miscoding) [ 6 , 46 ]. Case ascertainment methodology similar to that used in our investigation has reported a positive predictive value of 72% and a sensitivity of 42% for identifying NTMLD among patients with bronchiectasis, supporting that this method is valid for identifying NTMLD; the relatively low sensitivity suggested that NTMLD was often underdiagnosed or miscoded in claims-based epidemiologic research [ 35 ].…”