Predicting Mortality in Patients with Tuberculous Destroyed Lung Receiving Mechanical Ventilation

Pulmonary tuberculosis in intensive care setting, with a focus on the use of severity scores, a multinational collaborative systematic review

Background and aim

Tuberculosis (TB) is associated with a high mortality in the intensive care unit (ICU), especially in subjects with Acute Respiratory Distress Syndrome (ARDS) requiring mechanical ventilation. Despite its global burden on morbidity and mortality, TB is an uncommon cause of ICU admission, however mortality is disproportionate to the advances in diagnosis and treatment made. Herein we report a systematic review of published studies.

Methods

Our Literature search was conducted to identify studies on outcomes of individuals with TB admitted to ICU. We report and review in-hospital mortality, predictors of poorer outcomes, usefulness of severity scoring systems and potential benefits of intravenous antibiotics. Searches from Pubmed, Embase, Cochrane and Medline were conducted from inception to March 2020. Only literature in English was included.

Results

Out of 529 potentially relevant articles, 17 were included. Mortality across all studies ranged from 29-95% with an average of 52.9%. All severity scores underestimated average mortality. The most common indication for ICU admission was acute respiratory failure (36.3%). Negative predictors of outcome included hospital acquired infections, need of mechanical ventilation and vasopressors, delay in initiation of anti-TB treatment, more than one organ failure and a higher severity score. Low income, high incidence countries showed a 23.4% higher mortality rate compared to high income, low TB incidence countries.

Conclusion

Mortality in individuals with TB admitted to ICU is high. Earlier detection and treatment initiation is needed.

Burden and clinical characteristics of high grade tuberculosis destroyed lung: a nationwide study

Background

Little clinical information on high grade tuberculosis destroyed lung (TDL) is available. The aim of this study was to investigate the characteristics and healthcare utilization of high grade TDL patients, and compared the differences between acute exacerbation and healthcare burden according to inhaler compliance.

Methods

This was an observational retrospective cohort study using the Korean Health Insurance Review and Assessment (HIRA) service database (2011-2015). Patients diagnosed with high grade TDL in 2011 were enrolled and reviewed for 5 years. The patients were further divided into adherent and non-adherent groups. Their socioeconomic outcomes according to treatment adherence in 2012 were analyzed.

Results

Among the 13,346 patients diagnosed with high grade TDL, 3,637 were assigned to the adherent group and 9,709 to the non-adherent group. Overall, 65.91% of the enrolled patients were male and the mean age of the study population was 64.68±10.06 years. All patients visited a tertiary hospital, but 99.04% and 69.74% also visited primary and secondary hospitals, respectively. The mean number of hospital admissions per year was 1.38±2.03 times per patient. The average total annual per-patient cost was US$4,140.95±3,715.01 and each patient spent a total of 56.21±45.28 days per year using hospital services. The majority of the patients in the adherent group were male (80.09% vs. 60.60%, P<0.01), and were of older age (65.71±9.35 vs. 64.29±10.28, P<0.01) than the non-adherent group. The frequencies of visiting a tertiary hospital (96.87 vs. 90.12%, P<0.01), the total mean healthcare utilization costs (US$4,151.77±4,084.76 vs. US$3,592.54±4,229.93, P<0.01), and the frequencies of exacerbations (0.72±2.03 vs. 0.46±1.51, P<0.01) were higher in the adherent group. However, healthcare services were used on significantly fewer days in the adherent group (52.96±50.87 vs. 56.67±50.81, P<0.01).

Conclusions

High grade TDL imposes a high socioeconomic burden in Korea. Estimated medical costs and exacerbation event rate were higher in the adherent group whereas number of days of healthcare usage was significantly lower.

Clinical characteristics and economic burden of tuberculous-destroyed lung in Korea: a National Health Insurance Service-National Sample Cohort-based study

Background

Tuberculous destroyed lung (TDL) contributes to patient mortality via acute exacerbation and combined medical comorbidities. This study characterized the clinical characteristics and economic burden of patients with TDL using large scale database, Health Insurance Review and Assessment Service (HIRA) data.

Methods

We searched the HIRA national database to identify patients diagnosed with TDL from January 01, 2011 to December 31, 2015. The clinical characteristics of the patients were collected and the 5-year claims data were analyzed.

Results

In total, 645,031 patients (55% male, mean age, 59.6 years) were enrolled over the 5 years. During the study period, 98.5% of the patients visited a primary care clinic and 71.1% and 93.2% visited secondary and tertiary hospitals, respectively. Patients spent a median of 5 days for inpatient services, and were admitted to the hospital a median of 0.62±1.2 times per person annually. Annual total cost per person was $1,838 and half of the total cost was expended for inpatient services. About 68.9% of the patients were prescribed respiratory medications, and $12 million was paid. Oral bronchodilators (46.5%) and methylxanthine (35.2%) were used more frequently than inhaled corticosteroids (ICSs)/long-acting β2 agonist (LABA) combination agents (11.6%) or inhaled long-acting muscarinic antagonists (LAMAs) (7.5%).

Conclusions

TDL imposes a high medical economic burden in Korea. The estimated economic costs were mainly made up of inpatient services and outpatient medication prescriptions. Interventions to prevent acute disease exacerbations and progression of comorbid conditions should be accompanied to alleviate the clinical and economic burden of TDL.

Effect of tiotropium inhaler use on mortality in patients with tuberculous destroyed lung: based on linkage between hospital and nationwide health insurance claims data in South Korea

Background

Although bronchodilator inhaler therapy can improve lung function in patients with tuberculous destroyed lung (TDL), its effect on mortality has not been studied. We evaluated the effect of tiotropium inhaler therapy on mortality in patients with TDL.

Methods

A retrospective cohort of 963 patients with TDL was followed for up to ten years by linking hospital and nationwide health insurance claims data. We compared patients receiving tiotropium inhaler with patients without tiotropium after matching with propensity scores. In addition, we elucidated the risk factors of mortality using Cox proportional hazards model.

Results

After the propensity score matching, the baseline characteristics were balanced in both the tiotropium group (n = 105) and the non-tiotropium group (n = 105); including mean age (63.9 vs. 64.4 years, P = 0.715), mean forced expiratory volume in 1 s (FEV₁) (45.0 vs. 45.3%, P = 0.903), and others. After the propensity score matching, the tiotropium group showed better survival than the non-tiotropium group (median survival period: not reached for the tiotropium group vs. 7.24 years for the non-tiotropium group, Prentice-Wilcoxon test, P = 0.008). Multivariate Cox proportional hazard analysis revealed that tiotropium inhaler usage was associated with lower risk of mortality in the multivariate analysis (HR, 0.560; 95% CI, 0.380–0.824; P = 0.003) after adjusting age, sex, BMI, smoking history, mMRC dyspnea score, Charlson Comorbidity Index, concomitant COPD diagnosis, FEV₁, X-ray severity score, and home oxygen usage.

Conclusions

Our results suggest that tiotropium inhaler is associated with decreased all-cause mortality in TDL. Further prospective study is required for validation.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1055-5) contains supplementary material, which is available to authorized users.