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

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common comorbidity in patients with nontuberculous mycobacterial lung disease (NTMLD). Both conditions are associated with increased morbidity and mortality, but data are lacking on the additional burden associated with NTMLD among patients with COPD. Thus, the goal of this study was to assess the incremental mortality risk associated with NTMLD among older adults with COPD.

METHODS

A retrospective cohort study was conducted using the US Medicare claims database (2010-2017). Patients with preexisting COPD and NTMLD (cases) were matched 1:3 by age and sex with patients with COPD without NTMLD (control patients). Patients were followed up until death or data cutoff (December 31, 2017). Incremental risk of mortality was evaluated by comparing the proportions of death, annualized mortality rate, and mortality hazard rate between cases and control patients using both univariate and multivariate analyses adjusting for age, sex, comorbidities, and COPD severity.

RESULTS

A total of 4,926 cases were matched with 14,778 control patients. In univariate analyses, a higher proportion of cases (vs. control patients) died (41.5% vs. 26.7%; P < 0.0001), unadjusted annual mortality rates were higher among cases (158.5 vs. 86.0 deaths/1000 person-years; P < 0.0001), and time to death was shorter for cases. This increased mortality risk was also reflected in subsequent multivariate analyses. Patients with COPD and NTMLD were more likely to die (odds ratio [95% CI], 1.39 [1.27-1.51]), had higher mortality rates (rate ratio [95% CI], 1.36 [1.28-1.45]), and had higher hazard of death (hazard ratio [95% CI], 1.37 [1.28-1.46]) than control patients.

CONCLUSIONS

The substantial incremental mortality burden associated with NTMLD in patients with COPD highlights the importance of developing interventions targeting this high-risk group and may indicate an unmet need for timely and appropriate management of NTMLD.

Dipeptidyl peptidase IV inhibitors and the risk of mycobacterial pulmonary infections in type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (DM) is a risk factor for mycobacterial pulmonary infections (MPI), including tuberculosis (TB) and nontuberculous mycobacterial lung disease (NTM-LD). Dipeptidyl peptidase IV inhibitor (DPP4i), a common DM medication, has an immune-modulation effect that raises concerns about developing MPI. However, there is scarce research on the topic.

METHODS

This retrospective study was conducted in a tertiary-referral center in Taiwan from 2009 to 2016. Patients with type 2 DM who were receiving any DM medication were enrolled. TB and NTM-LD were defined by microbiological criteria. We analyzed the risk of MPI in DPP4i users using Cox proportional hazard regression with adjusted inverse probability of treatment weighting.

RESULTS

A total of 9963 patients were included. Among them, 3931 were classified as DPP4i users, and 6032 patients were DPP4i nonusers. DPP4i users had no increase in incidences of MPI (604 vs. 768 per 100,000 person-years, p = 0.776), NTM-LD (174 vs. 255 per 100,000 person-years, p = 0.228), and TB (542 vs. 449 per 100,000 person-years, p = 0.663) relative to those of DPP4i nonusers. After adjustment, the adjusted hazard ratios for MPI (aHR: 1.07, 95% CI: 0.79-1.45), TB (aHR: 1.15, 95% CI: 0.81-1.64) and NTM-LD (aHR: 0.85, 95% CI: 0.49-1.47) were not significantly increased relative to those of nonusers. The subgroup analysis also showed that DPP4i use did not increase the risk of MPI in different DM severities and comorbidities.

CONCLUSIONS

According to our large cohort study, DPP4i use is safe for patients with type 2 DM and might not increase the risk of MPI.

Real-world treatment patterns in patients with nontuberculous mycobacterial lung disease in the Netherlands based on medication dispensing data

PURPOSE

Real-world data on antibiotic management of nontuberculous mycobacterial lung disease (NTM-LD) is limited for many countries. This study aimed to evaluate real-world treatment practices of NTM-LD in the Netherlands using medication dispensing data.

METHODS

A retrospective longitudinal real-world study was conducted using IQVIA's Dutch pharmaceutical dispensing database. The data are collected monthly and include approximately 70% of all outpatient prescriptions in the Netherlands. Patients initiated on specific NTM-LD treatment regimens between October 2015 and September 2020 were included. The main areas of investigation were initial treatment regimens, persistence on treatment, treatment switching, treatment compliance in terms of medication possession rate (MPR) and restarts of treatment.

RESULTS

The database included 465 unique patients initiated on triple- or dual-drug regimens for the treatment of NTM-LD. Treatment switches were common and occurred approximately 1.6 per quarter throughout the treatment period. The average MPR of patients initiated on triple-drug therapy was 90%. The median time on therapy for these patients was 119 days; after six months and one year, 47% and 20% of the patients, respectively, were still on antibiotic therapy. Of 187 patients initiated on triple-drug therapy, 33 (18%) patients restarted antibiotic therapy after the initial treatment had been stopped.

CONCLUSION

When on therapy, patients were compliant with the NTM-LD treatment; however, many patients stopped their therapy prematurely, treatment switches often occurred, and part of patients had to restart their therapy after a longer treatment gap. NTM-LD management should be improved through greater guideline adherence and appropriate involvement of expert centers.

Distinguishing nontuberculous mycobacterial lung disease and Mycobacterium tuberculosis lung disease on X-ray images using deep transfer learning

BACKGROUND

Nontuberculous mycobacterial lung disease (NTM-LD) and Mycobacterium tuberculosis lung disease (MTB-LD) have similar clinical characteristics. Therefore, NTM-LD is sometimes incorrectly diagnosed with MTB-LD and treated incorrectly. To solve these difficulties, we aimed to distinguish the two diseases in chest X-ray images using deep learning technology, which has been used in various fields recently.

METHODS

We retrospectively collected chest X-ray images from 3314 patients infected with Mycobacterium tuberculosis (MTB) or nontuberculosis mycobacterium (NTM). After selecting the data according to the diagnostic criteria, various experiments were conducted to create the optimal deep learning model. A performance comparison was performed with the radiologist. Additionally, the model performance was verified using newly collected MTB-LD and NTM-LD patient data.

RESULTS

Among the implemented deep learning models, the ensemble model combining EfficientNet B4 and ResNet 50 performed the best in the test data. Also, the ensemble model outperformed the radiologist on all evaluation metrics. In addition, the accuracy of the ensemble model was 0.85 for MTB-LD and 0.78 for NTM-LD on an additional validation dataset consisting of newly collected patients.

CONCLUSIONS

In previous studies, it was known that it was difficult to distinguish between MTB-LD and NTM-LD in chest X-ray images, but we have successfully distinguished the two diseases using deep learning methods. This study has the potential to aid clinical decisions if the two diseases need to be differentiated.

Impact of initiation of amikacin liposome inhalation suspension on hospitalizations and other healthcare resource utilization measures: a retrospective cohort study in real-world settings

BACKGROUND

Mycobacterium avium complex lung disease (MAC-LD) is an infection that is increasing in frequency, associated with substantial disease burden, and often refractory to treatment. Amikacin liposome inhalation suspension (ALIS) is the first therapy approved for refractory MAC-LD. In the CONVERT study of adult patients with refractory MAC-LD, adding ALIS to a multidrug background regimen showed evidence of MAC infection elimination in sputum by month 6, which was maintained in most patients through the end of treatment (≤ 12 months post-conversion). This study assessed changes in healthcare resource utilization (HCRU) among patients initiating ALIS in real-world settings.

METHODS

This retrospective cohort study of the All-Payer Claims Database (October 2018-April 2020) included patients aged ≥ 18 years with ≥ 1 pharmacy claim for ALIS and ≥ 12 months of continuous health plan enrollment pre- and post-ALIS initiation. Respiratory disease-related (and all-cause) HCRU (hospitalizations, length of stay [LOS], emergency department [ED] visits, and outpatient office visits) were compared 12 months pre- and post-ALIS initiation. Outcomes were reported at 6-month intervals; 0-6 months pre-ALIS initiation was the reference period for statistical comparisons.

RESULTS

A total of 331 patients received ALIS, with HCRU highest in the 6 months pre-ALIS initiation. Compared with 26.9% during the reference period, respiratory-related hospitalizations decreased to 19.3% (P < 0.01) and 15.4% (P < 0.0001) during 0-6 and 7-12 months post-ALIS initiation, respectively. Mean number of respiratory disease-related hospitalizations per patient/6-month period decreased from 1.0 (reference period) to 0.6 (P < 0.0005) at both timepoints post-ALIS initiation. A similar pattern was observed for all-cause hospitalizations and hospitalizations per patient/6-month period (both P < 0.005). Reductions in all-cause and respiratory disease-related LOS post-ALIS initiation were significant (both P < 0.05). ED visits were few and unchanged during the study. Significant reductions per patient/6-month period in all-cause and respiratory-related outpatient office visits were observed post-ALIS initiation (all P < 0.01).

CONCLUSIONS

In this first real-world study of ALIS, respiratory disease-related (and all-cause) hospitalizations and outpatient visits were reduced in the 12 months following ALIS initiation. The results of this study provide HCRU-related information to better understand the impact of initiating ALIS treatment.

TRIAL REGISTRATION

Not appliable.

Is the Leicester Cough Questionnaire useful for nontuberculous mycobacterial lung disease?

BACKGROUND

Although the incidence of nontuberculous mycobacterial lung disease (NTM-LD) is increasing worldwide, there is no established standard of care leading to eradication. Therefore, research on health-related quality of life (HRQOL) is important for patients with NTM-LD. HRQOL is commonly evaluated using the St. George's Respiratory Questionnaire (SGRQ), developed for chronic obstructive pulmonary disease (COPD). However, NTM-LD differs from COPD in that few patients complain of dyspnea or wheezing, and cough and sputum are their main symptoms. The Leicester Cough Questionnaire (LCQ) is an HRQOL questionnaire dedicated to cough, but few studies have used it for NTM-LD. This study evaluated HRQOL in patients with NTM-LD using the SGRQ and LCQ and clarified the usefulness of the LCQ.

METHODS

Information on age, height, weight, lung function, percent ideal body weight, laboratory data, radiological scores, exercise capacity, SGRQ, and LCQ were collected from the medical records of 81 patients. Correlations between SGRQ and LCQ domains were assessed using Spearman's rank correlation coefficients. Multivariate analysis was performed with SGRQ and LCQ total scores.

RESULTS

Statistically significant correlations were observed between all domains, and the correlation between the total scores was -0.67 (p < 0.01). Multivariate analysis with total scores as the dependent variable showed that the explanatory variables were lung function (p < 0.05) and radiological score (p < 0.05) in the SGRQ, and radiological score (p < 0.05) and C-reactive protein level (p < 0.05) in the LCQ.

CONCLUSION

The LCQ, which evaluates an inflammatory response involved in the diagnosis of NTM-LD, may be useful to assess HRQOL in patients with NTM-LD.

Real-world treatment patterns in patients with nontuberculous mycobacterial lung disease in general and pneumologist practices in Germany

Background

Nontuberculous mycobacterial lung disease (NTMLD) is a rare, progressive disease with an increasing incidence worldwide.

Aims

The aim of this retrospective study was to analyze the baseline characteristics and management of NTMLD in general and pneumologist practices in Germany.

Methods

This retrospective study included patients with a culture-confirmed diagnosis of NTMLD documented between October 1, 2014 and September 30, 2019 by 125 general practitioners (GP) and 31 office-based pulmonologists from the IMS Disease Analyzer Database (IQVIA).

Results

A total of 159 patients managed by German GPs (mean age 59 ± 19 years, 51% female) and 236 patients managed by pulmonologists (mean age 62 ± 14 years, 58% female) were analyzed. In total, 45% (72/159) and 40% (94/236) of patients managed by GPs and pulmonologists respectively received antibiotic therapy for NTMLD. This therapy lasted for ≥ 6 months in 42%, for ≥ 12 months in 24%, and ≥ 18 months in 8% of patients. The average therapy duration was longer in patients treated by pulmonologists (241 ± 196 days) than in patients treated by GPs (113 ± 152 days). A total of 27% of patients managed by GPs and 45% of those managed by pulmonologists respectively received guideline-based therapy (GBT), defined as combination therapy with macrolide (azi-/ clarithromycin) + ethambutol + rifabutin/rifampicin, at least once; however, almost all patients (100% in the GP group, 96% in the pulmonologist group) also received non-GBT regimens intermediately.

Conclusions

A considerable number of patients with NTMLD were not managed in accordance with the German guidelines and a substantial proportion also discontinue therapy prematurely. NTMLD management should be improved through appropriate referral pathways and collaboration between expert centers and primary or secondary care physicians.

Nonpharmacological treatment for patients with nontuberculous mycobacterial lung disease

Patients with nontuberculous mycobacterial lung disease (NTM-LD) often have significant exercise intolerance and poorer health-related quality of life (HRQL). The goals of treatment for NTM-LD should include reducing the severity of symptoms, improving HRQL, and reducing acute exacerbations. Nonpharmacological treatment, including pulmonary rehabilitation program and optimal nutritional strategy, should be one part of treatment for NTM-LD. A pulmonary rehabilitation (PR) program can comprise education, airway clearance techniques instruction, exercise training program, and inspiratory muscle training (IMT). Airway clearance techniques can improve the volume of sputum expectorated, cough symptom, breathlessness, and HRQL. Exercise training can improve exercise capacity and HRQL, and reduce acute exacerbations and dyspnea. Clinical benefits of IMT remain controversial but high-intensity IMT has been shown to be effective in increasing respiratory muscle strength with concurrent improvement of HRQL and exercise capacity. Body weight and muscle mass loss are common in patients with NTM-LD. An adequate protein and caloric diet combined with antioxidant nutrients might be the most appropriate dietary strategy. Comprehensive treatment for NTM-LD should include the combination of both pharmacological and nonpharmacological treatments. The management programs should be tailored to the individual's condition.

Clinical features and treatment outcomes of Mycobacterium chimaera lung disease and antimicrobial susceptibility of the mycobacterial isolates

BACKGROUND

Mycobacterium chimaera, one of the Mycobacterium avium complex (MAC) members, was recently identified using modern gene sequencing analysis. Unlike M. avium and M. intracellulare, little is known about the clinical features, antimicrobial susceptibilities, and treatment outcomes of M. chimaera lung disease.

METHODS

This study was conducted in a medical center from December 2012 to July 2015. Patients who fulfilled the 2007 ATS/IDSA diagnostic criteria for nontuberculous mycobacterial lung disease were enrolled. M. chimaera isolates were identified based on the findings of sequencing of rpoB gene, the internal transcribed spacer (ITS) region of the 16S-23S rRNA gene, and the heat-shock protein 65 gene (hsp65). Minimum inhibitory concentrations (MICs) of 13 antimicrobial agents were determined.

RESULTS

During the study period, 247 patients with MAC lung disease were identified, and 11.3% (28/247) of the patients had lung disease caused by M. chimaera. Among these patients, 17 (60.7%) were female, and their median age was 72.5 (40-100) years. All M. chimaera isolates were susceptible to clarithromycin and rifabutin. All the isolates were resistant to moxifloxacin and only 10 (35.7%) and 2 (7.1%) were susceptible to amikacin and linezolid, respectively. Of the nine patients who received macrolide-based regimens, more achieved radiographic resolution than those treated with non-macrolide-based regimens (66.7% vs. 15.8%, P = 0.013), and they tended to have better survival (P = 0.10).

CONCLUSIONS

A substantial portion (11.3%) of MAC lung disease cases were caused by M. chimaera, and treatment with macrolide-based regimens resulted in better clinical outcomes for patients with M. chimaera lung disease.

Change in lung function in never-smokers with nontuberculous mycobacterial lung disease: A retrospective study

Purpose

Never-smokers account for a large proportion of subjects in general population studies on nontuberculous mycobacteria lung disease (NTM-LD). However, the influence of NTM infection on the lung function of never-smokers has not yet been evaluated. The aim of this study was to determine how NTM-LD impairs the lung function in never-smokers, and whether there are an association between successful NTM-LD treatment in radiologic outcomes and improvement in lung function of never-smokers with NTM-LD or not.

Methods

We performed a retrospective study of patients (1) who have never smoked during their lifetime; (2) with at least two respiratory specimens from sputum, one bronchial washing sample, or one lung tissue that were culture positive for the same NTM species; and (3) who underwent at least two pulmonary function tests. We enrolled healthy never-smokers as the control group.

Results

In 22 never-smokers with NTM-LD, the median forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) at baseline was lower than those in 9 healthy never-smokers [1800 vs 2080 ml (p = 0.23) and 2230 vs 2620 ml (p = 0.06)], respectively. The median change in FEV₁ in never-smokers with NTM-LD was lower than that in healthy never-smokers [−70 vs 20 ml per year (p = 0.07), respectively]. On univariate analysis, baseline %-predicted FEV₁ in never-smokers with NTM-LD was associated with changes in FVC (p = 0.026) and FEV₁ (p = 0.013). Anti-NTM treatment was administered for at least 1 year in 19 patients (86.4%). The relationship between worsening chest CT findings and rapid progressive decline in both FVC (p = 0.66) and FEV₁ (p = 0.23) were not significant.

Conclusion

Never-smokers with NTM-LD showed lung function decline. There was no association between successful NTM-LD treatment in radiologic outcomes and improvement in lung function of never-smokers.