Increasing NTM Infections Cause Significant Cost Burden in South Korea

Adults in South Korea with diagnosed nontuberculous mycobacterial (NTM) infections have significantly higher rates of health care use and medical costs than those without NTM, according to study findings published in Therapeutic Advances in Respiratory Disease.

The global prevalence and incidence of NTM infections are increasing. In South Korea, the age-adjusted prevalence of NTM rose from 1.2 per 100,000 in 2003 to 33.3 per 100,000 in 2017. Investigators therefore sought to examine the economic burden of health care use and medical costs among people in South Korea with NTM infections.

The researchers conducted a retrospective cohort study using data from the National Health Insurance Service-National Sample Cohort database from 2002 to 2015. Participants included 798 deidentified adults diagnosed with NTM infection (mean [SD] age, 56.0 [16.6] years; 57.9% female) and a control group of 3192 adults (mean age, 55.7 [16.9] years). Participants were propensity-score matched 1:4 by sex, Charlson Comorbidity Index (CCI), age, and year of diagnosis.

Gastroesophageal reflux disease (GERD), hypertension, and chronic obstructive pulmonary disease (COPD) were the most common comorbidities in the NTM group. Mean follow-up was 3.6 years. Between-group differences were not significant for sex, age, or CCI score; however, the cohorts were not well matched for asthma, bronchiectasis, COPD, GERD, or cancer.

Investigators found patients infected with NTM vs those in the control group had significantly higher rates of respiratory disease costs (ie, 4.5 times greater) and medical costs (1.5 times greater) (P <.05). The highest medical costs incurred by individuals diagnosed with NTM occurred in the 6 months before diagnosis (inpatient visits/year with NTM infection, 0.79 vs without NTM infection, 0.61; and outpatient visits/year with NTM infection, 30.63 vs without NTM infection, 24.58; all P <.0001).

Total medical costs during the entire follow-up period for individuals with NTM infection were $6449.23 vs $5112.25 (both in US dollars) for individuals without NTM infection. The inpatient cost in individuals with NTM infection was 1.6 times that of the outpatient cost. Hospitalization due to respiratory diseases accounted for 58% of the inpatient cost. The investigators found no significant difference in total health care use and cost between those with or without NTM infection during the 12- to 36-month period prior to the index date. The level of health care use and medical costs during the 12 months prior to NTM infection diagnosis was significantly higher than in those without NTM infection.

Significant study limitations include the study’s retrospective design; potential errors from basing NTM diagnoses on insurance claims and ICD-10 codes; unaccounted-for inflation and changes in the won-dollar exchange rate; unaccounted for varying regional and institutional costs; and unaccounted-for indirect health care costs.

“NTM infection increases the economic burden on Korean adults. Appropriate

diagnostic tests and treatment plans for NTM infections are needed to reduce the burden of the disease caused by such infection,” the study authors concluded.