The reliability of diagnostic coding and laboratory data to identify tuberculosis and nontuberculous mycobacterial disease among rheumatoid arthritis patients using anti-tumor necrosis factor therapy

Nationwide Increasing Incidence of Nontuberculous Mycobacterial Diseases Among Adults in Denmark: Eighteen Years of Follow-Up

BACKGROUND

The epidemiology of nontuberculous mycobacteria (NTM) infections is not well described. In this study, we sought to determine the incidence and prevalence of NTM infections and focus on social risk factors. In addition, we describe people with pulmonary and extrapulmonary NTM.

RESEARCH QUESTION

What are the incidence and prevalence of NTM in Denmark, and what are the characteristics of the affected patients?

STUDY DESIGN AND METHODS

This is a nationwide retrospective register-based cohort study in Denmark. Adult patients in the Danish national registers who received a diagnosis of NTM disease from 2000 to 2017 were classified as having either pulmonary or extrapulmonary NTM disease.

RESULTS

We identified 1,146 adults with an NTM diagnosis. Of these, 661 patients had pulmonary NTM, of whom 50.4% were male, whereas 485 had extrapulmonary NTM, of whom 59.6% were male. The median age (interquartile range) was 66 (18) years and 57 (32) years, respectively. The yearly incidence rate per 100,000 increased between 2000 and 2017 for both pulmonary NTM (0.4 to 1.3) and extrapulmonary NTM (0.3 to 0.6). The annual prevalence per 100,000 inhabitants increased from 0.4 to 3.5 for pulmonary NTM and from 0.3 to 1.0 for extrapulmonary NTM. The incidence rate increased with age. The incidence of pulmonary NTM was highest among those who were aged 70 years or older (19.3 per 100,000 inhabitants). Compared with patients with pulmonary NTM, patients with extrapulmonary NTM were more likely to be employed and had a higher educational level.

INTERPRETATION

This study indicates that the prevalence of NTM disease in Denmark increased between 2000 and 2017. We found that patients with pulmonary NTM and patients with extrapulmonary NTM represent two distinct groups that differ in age, sex, education, and employment status. Increased suspicion of pulmonary NTM disease is warranted in older adults after exclusion of more common lung infections.

Reductions in hospitalisations and emergency department visits with early antibiotic initiation in nontuberculous mycobacterial lung disease

Background

While antibiotics are recommended for treatment of nontuberculous mycobacterial lung disease (NTMLD), the impact of early antibiotic initiation on healthcare resource utilisation is unclear. This study compared healthcare resource utilisation with early versus delayed antibiotic initiation in NTMLD.

Methods

A retrospective, claims database study (Merative MarketScan) of patients diagnosed with NTMLD between 1 July 2015 and 30 June 2019. Patients were divided into early antibiotic initiation, i.e. ≤3 months after the first medical claim for NTMLD (index date), and delayed antibiotic initiation groups. Hospitalisations and outpatient visits during a 2-year post-index period were compared to baseline per treatment group; a difference-in-difference analysis compared early and delayed antibiotic initiation groups adjusting for confounding.

Results

Out of 481 NTMLD treated patients, 364 (76%) and 117 (24%) comprised the early and delayed antibiotic initiation groups, respectively. The early antibiotic initiation group showed significant reductions from baseline in hospitalisations (all-cause, respiratory) and emergency department (ED) visits at follow-up. A significant increase from baseline in mean number of hospitalisations per patient was observed in the delayed antibiotic initiation group in year 1 post-index. Compared to delayed antibiotic initiation, the early antibiotic initiation group showed significantly greater reductions in all-cause hospitalisations in years 1 and 2 post-index (relative risk 0.62 (95% CI 0.41-0.95) and 0.62 (95% CI 0.39-0.98), respectively), and in respiratory-related hospitalisations.

Conclusions

The early antibiotic initiation group showed significant reductions from baseline in hospitalisations and ED visits over time. Compared to delayed antibiotic initiation, early antibiotic initiation was associated with significantly greater reductions in hospitalisations.

Tolerability Outcomes of American Thoracic Society/Infectious Diseases Society of America Guideline-Recommended Multidrug Antibiotic Treatment for Mycobacterium avium Complex Pulmonary Disease in US Medicare Beneficiaries With Bronchiectasis

BACKGROUND

Nontuberculous mycobacteria are environmental organisms that are increasingly causing chronic and debilitating pulmonary infections, of which Mycobacterium avium complex (MAC) is the most common pathogen. MAC pulmonary disease (MAC-PD) is often difficult to treat, often requiring long-term multidrug antibiotic therapy.

RESEARCH QUESTION

Is there an association between various guideline-based three-drug therapy (GBT) regimens and (1) therapy-associated adverse events or (2) regimen change/discontinuation, within 12 months of therapy initiation?

STUDY DESIGN AND METHODS

In a retrospective cohort study, we examined tolerability outcomes of GBT regimens for MAC-PD in 4,626 US Medicare beneficiaries with bronchiectasis, who were prescribed a GBT as initial antibiotic treatment for presumed MAC-PD during 2006 to 2014. Using multivariable Cox proportional hazard regression, we estimated adjusted hazard ratios (aHRs) to compare the risk of adverse events and regimen change/discontinuations within 12 months of therapy initiation in various GBT regimens.

RESULTS

The cohort had a mean age ± SD of 77.9 ± 6.1 years at treatment start, were mostly female (77.7%), and were mostly non-Hispanic White (87.2%). The risk of regimen change/discontinuation within 12 months of therapy was higher for clarithromycin-based regimens than azithromycin-based regimens (aHR, 1.12; 95% CI, 1.04-1.20 with rifampin; aHR, 1.11; 95% CI, 0.93-1.32 with rifabutin as the companion rifamycin), and for rifabutin-containing regimens than rifampin-containing regimens (aHR, 1.49; 95% CI, 1.33-1.68 with azithromycin; aHR, 1.47; 95% CI, 1.27-1.70 with clarithromycin as the companion macrolide). The aHR comparing regimen change/discontinuation with clarithromycin-ethambutol-rifabutin and azithromycin-ethambutol-rifampin was 1.64 (95% CI, 1.43-1.64).

INTERPRETATION

Overall, an azithromycin-based regimen was less likely to be changed or discontinued than a clarithromycin-based regimen, and a rifampin-containing regimen was less likely to be changed or discontinued than a rifabutin-containing regimen within 12 months of therapy start. Our work provides a population-based assessment on the tolerability of multidrug antibiotic regimens used for the treatment of MAC-PD.

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

Because epidemiologic and environmental risk factors for nontuberculous mycobacteria (NTM) have been reported only infrequently, little information exists about those factors. The state of Virginia, USA, requires certain ecologic features to be included in reports to the Virginia Department of Health, presenting a unique opportunity to study those variables. We analyzed laboratory reports of Mycobacterium avium complex (MAC) and M. abscessus infections in Virginia during 2021-2023. MAC/M. abscessus was isolated from 6.19/100,000 persons, and 2.37/100,000 persons had MAC/M. abscessus lung disease. M. abscessus accounted for 17.4% and MAC for 82.6% of cases. Saturated vapor pressure was associated with MAC/M. abscessus prevalence (prevalence ratio 1.414, 95% CI 1.011-1.980; p = 0.043). Self-supplied water use was a protective factor (incidence rate ratio 0.304, 95% CI 0.098-0.950; p = 0.041). Our findings suggest that a better understanding of geographic clustering and environmental water exposures could help develop future targeted prevention and control efforts.

Global Epidemiology of Nontuberculous Mycobacterial Pulmonary Disease: A Review

Nontuberculous mycobacterial (NTM) isolation and pulmonary disease (NTM-PD) have continued to increase in most regions of the world, driven mainly by Mycobacterium avium. Single-center studies also support increasing trends as well as a persistent burden of undiagnosed NTM among persons suspected of having tuberculosis (TB), in countries with moderate-to-high TB prevalence. Cumulative exposure to water and soil presents an increased risk to susceptible hosts, and trace metals in water supply are recently recognized risk factors. Establishing standard case definitions for subnational and national surveillance systems with mandatory notification of NTM-PD are needed to allow comparisons within and across countries and regions.

Validity of claims-based diagnoses for infectious diseases common among immunocompromised patients in Japan

BACKGROUND

To validate Japanese claims-based disease-identifying algorithms for herpes zoster (HZ), Mycobacterium tuberculosis (MTB), nontuberculous mycobacteria infections (NTM), and Pneumocystis jirovecii pneumonia (PJP).

METHODS

VALIDATE-J, a multicenter, cross-sectional, retrospective study, reviewed the administrative claims data and medical records from two Japanese hospitals. Claims-based algorithms were developed by experts to identify HZ, MTB, NTM, and PJP cases among patients treated 2012-2016. Diagnosis was confirmed with three gold standard definitions; positive predictive values (PPVs) were calculated for prevalent (regardless of baseline disease-free period) and incident (preceded by a 12-month disease-free period for the target conditions) cases.

RESULTS

Of patients identified using claims-based algorithms, a random sample of 377 cases was included: HZ (n = 95 [55 incident cases]); MTB (n = 100 [58]); NTM (n = 82 [50]); and PJP (n = 100 [84]). PPVs ranged from 67.4-70.5% (HZ), 67.0-90.0% (MTB), 18.3-63.4% (NTM), and 20.0-45.0% (PJP) for prevalent cases, and 69.1-70.9% (HZ), 58.6-87.9% (MTB), 10.0-56.0% (NTM), and 22.6-51.2% (PJP) for incident cases, across definitions. Adding treatment to the algorithms increased PPVs for HZ, with a small increase observed for prevalent cases of NTM.

CONCLUSIONS

VALIDATE-J demonstrated moderate to high PPVs for disease-identifying algorithms for HZ and MTB using Japanese claims data.

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

Non-tuberculous mycobacterial (NTM) disease has increased in prevalence in the USA, however, little is known on NTM in the population with end-stage renal disease (ESRD). Thus, we investigated patients with ESRD to determine risk factors for NTM disease and mortality. We queried the United States Renal Data System from 2005 to 2015 using International Classification of Diseases (ICD)-9/ICD-10 codes to identify NTM and risk factors. Logistic regression was used to examine the association of risk factors with NTM and Cox proportional hazards modeling was used to assess the association of NTM with mortality. Of 1,068,634 included subjects, 3232 (0.3%) individuals were identified with any NTM diagnosis. Hemodialysis versus peritoneal dialysis (OR=0.10, 95% CI=0.08 to 0.13) was protective for NTM, whereas black (OR=1.27, 95% CI=1.18 to 1.37) or other race compared with white race (OR=1.39, 95% CI=1.21 to 1.59) increased the risk of NTM. HIV (OR=15.71, 95% CI=14.24 to 17.33), history of any transplant (OR=4.25, 95% CI=3.93 to 4.60), kidney transplant (OR=3.00, 95% CI=2.75 to 3.27), diabetes (OR=1.32, 95% CI=1.23 to 1.43), rheumatologic disease (OR=1.92, 95% CI=1.77 to 2.08), and liver disease (OR=2.09, 95% CI=1.91 to 2.30) were associated with increased risk for NTM diagnosis. In multivariable analysis, there was a significant increase in mortality with any NTM diagnosis (HR=1.83, 95% CI=1.76 to 1.91, p≤0.0001). Controlling for relevant demographic and clinical risk factors, there was an increased risk of mortality associated with any diagnosis of NTM. Early diagnosis and treatment of NTM infection may improve survival in patients with ESRD.

Identifying potentially undiagnosed nontuberculous mycobacterial lung disease among patients with chronic obstructive pulmonary disease: Development of a predictive algorithm using claims data

BACKGROUND: Nontuberculous mycobacterial lung disease (NTMLD) is a debilitating disease. Chronic obstructive pulmonary disease (COPD) is the leading comorbidity associated with NTMLD in the United States. Their similarities in symptoms and overlapping radiological findings may delay NTMLD diagnosis in patients with COPD. OBJECTIVE: To develop a predictive model that identifies potentially undiagnosed NTMLD among patients with COPD. METHODS: This retrospective cohort study developed a predictive model of NTMLD using US Medicare beneficiary claims data (2006 - 2017). Patients with COPD with NTMLD were matched 1:3 to patients with COPD without NTMLD by age, sex, and year of COPD diagnosis. The predictive model was developed using logistic regression modeling risk factors such as pulmonary symptoms, comorbidities, and health care resource utilization. The final model was based on model fit statistics and clinical inputs. Model performance was evaluated for both discrimination and generalizability with c-statistics and receiver operating characteristic curves. RESULTS: There were 3,756 patients with COPD with NTMLD identified and matched to 11,268 patients with COPD without NTMLD. A higher proportion of patients with COPD with NTMLD, compared with those with COPD without NTMLD, had claims for pulmonary symptoms and conditions, including hemoptysis (12.6% vs 1.4%), cough (63.4% vs 24.7%), dyspnea (72.5% vs 38.2%), pneumonia (59.2% vs 13.4%), chronic bronchitis (40.5% vs 16.3%), emphysema, (36.7% vs 11.1%), and lung cancer (15.7% vs 3.5%). A higher proportion of patients with COPD with NTMLD had pulmonologist and infectious disease (ID) specialist visits than patients with COPD without NTMLD (≥ 1 pulmonologist visit: 81.3% vs 23.6%, respectively; ≥ 1 ID visit: 28.3% vs 4.1%, respectively, P < 0.0001). The final model consists of 10 risk factors (≥ 2 ID specialist visits; ≥ 4 pulmonologist visits; the presence of hemoptysis, cough, emphysema, pneumonia, tuberculosis, lung cancer, or idiopathic interstitial lung disease; and being underweight during a 1-year pre-NTMLD period) predicting NTMLD with high sensitivity and specificity (c-statistic, 0.9). The validation of the model on new testing data demonstrated similar discrimination and showed the model was able to predict NTMLD earlier than the receipt of the first diagnostic claim for NTMLD. CONCLUSIONS: This predictive algorithm uses a set of criteria comprising patterns of health care use, respiratory symptoms, and comorbidities to identify patients with COPD and possibly undiagnosed NTMLD with high sensitivity and specificity. It has potential application in raising timely clinical suspicion of patients with possibly undiagnosed NTMLD, thereby reducing the period of undiagnosed NTMLD. DISCLOSURES: Dr Wang and Dr Hassan are employees of Insmed, Inc. Dr Chatterjee was an employee of Insmed, Inc, at the time of this study. Dr Marras is participating in multicenter clinical trials sponsored by Insmed, Inc, has consulted for RedHill Biopharma, and has received a speaker's honorarium from AstraZeneca. Dr Allison is an employee of Statistical Horizons, LLC. This study was funded by Insmed Inc.

Evaluation of Mycobacterium Avium Complex Pulmonary Disease Treatment Completion and Adherence to ATS/IDSA Guidelines

BACKGROUND

Nontuberculous mycobacteria are environmental organisms that cause infections leading to chronic, debilitating pulmonary disease, among which Mycobacterium avium complex (MAC) is the most common species.

METHODS

We described patterns of macrolide-based multidrug antibiotic therapies for MAC pulmonary disease (MAC-PD) in US Medicare beneficiaries with bronchiectasis between January 2006 and December 2014. MAC therapy was defined as a multidrug regimen containing a macrolide plus ≥1 other drug targeting MAC-PD (rifamycin, ethambutol, fluoroquinolone, or amikacin) prescribed concomitantly for >28 days.

RESULTS

We identified 9189 new MAC therapy users, with a mean age (standard deviation) of 74 (6 years) at the start of therapy; 75% female and 87% non-Hispanic white. A guideline-based regimen (a macrolide, ethambutol, and rifamycin, with or without amikacin) was prescribed for 51% of new MAC therapy users at treatment start, of whom 41% were continuing guideline-based therapy at 6 months, and only 18% at 12 months. Of all new MAC therapy users, by 18 months only 11% were still receiving MAC treatment, 55% had discontinued therapy, and 34% were censored owing to death or the end of the study period.

CONCLUSIONS

Overall, nearly half of new MAC therapy users were prescribed a non-guideline-recommended macrolide-based therapy, including regimens commonly associated with promoting macrolide resistance. Treatment discontinuation was common, and once discontinued, only a few beneficiaries resumed therapy at a later time. Our study adds important data to the current literature on treatment patterns for MAC-PD among older US populations. Future research should examine treatment patterns using more contemporary data sources.

Mortality association of nontuberculous mycobacterial infection requiring treatment in Taiwan: a population-based study

Background:

Infection due to nontuberculous mycobacteria (NTM) is an emerging issue worldwide, and we aimed to address the epidemiology and mortality association of NTM infection requiring treatment in Taiwan.

Methods:

We used the 2003–2018 data of 2 million representative individuals in Taiwan’s National Health Insurance Research Database. We identified patients with newly diagnosed NTM infection and received treatment as NTM cases. Age- and sex-matched (1:40) as well as propensity score-matched (PSM) (1:2) non-NTM individuals were selected as non-NTM controls. We used a Cox proportional hazard model to determine hazard ratios (HRs) with 95% confidence intervals (CIs).

Results:

We identified 558 patients with NTM infection requiring treatment. The mean age was 62.5 ± 15.4 years, and 57.5% of them were male. The incidence increased from 0.54 per 100,000 person-year in 2003 to 3.35 per 100,000 person-year in 2018. The overall mortality was 35.2%, with a mean follow-up duration of 4.1 ± 3.6 years. We found that NTM infection was independently associated with a greater risk of mortality (HR: 1.71; 95% CI: 1.47–1.98) compared with age- and sex-matched controls, and the association remained consistent (HR: 1.44; 95% CI: 1.19–1.75) compared with propensity-matched controls. We also found that old age, male, high Charlson comorbidity index, and the use of steroids or anti-neoplastic agents/immunosuppressants were associated with mortality risk.

Conclusion:

In conclusion, we found a steady increase in patients with NTM infection requiring treatment in Taiwan and further demonstrated that NTM infection was associated with greater risk of mortality using two comparable non-NTM control subjects.

Retrospective Cohort Study Comparing Infliximab-dyyb and Infliximab in Biologic-Naive Patients With Inflammatory Bowel Disease in the United States

Background

Real-world assessments of biosimilars are needed to understand their effectiveness and safety in practice settings that may differ from those seen in clinical trials or healthcare systems in different countries. To assess the effectiveness and safety of a biosimilar (infliximab-dyyb) and its reference product (infliximab) in patients with inflammatory bowel disease (IBD) in the United States.

Methods

We conducted a retrospective cohort study of biologic-naive patients with IBD who started treatment with infliximab-dyyb or infliximab. The study included 3206 patients identified through electronic health records in a US integrated healthcare delivery system. The effectiveness outcome was a composite of IBD-related surgery, IBD-related emergency room visit, and IBD-related hospitalization within 12 months of initiation. Safety outcomes included incidence of any or serious infection, cancer, acute liver dysfunction, and tuberculosis. We used a non-inferiority test with an upper-limit margin of 10% to analyze effectiveness. Doubly robust methods incorporating Cox proportional hazard regression with standardized inverse probability of treatment weighting were used to analyze both effectiveness and safety outcomes.

Results

The composite effectiveness outcome occurred in 107 of 870 patients (12.3%) in the infliximab-dyyb and 379 of 2336 patients (16.2%) in the infliximab groups. Infliximab-dyyb was non-inferior (P < .01) and was not different (hazard ratio [HR] 0.81; confidence interval [CI] 0.65-1.01; P = .06) to infliximab. Safety outcomes were not different between infliximab-dyyb and infliximab for any infections (HR 1.01; CI 0.86-1.17; P = .95), serious infections (HR 0.83; CI 0.54-1.26; P = .38), cancers (HR 0.83; CI 0.44-1.54; P = .55), and tuberculosis (HR 0.59; CI 0.10-3.55; P = .57).

Conclusions

Initiation of infliximab-dyyb was non-inferior to infliximab among biologic-naive patients with IBD in an US integrated healthcare delivery system.

Hospitalization Risk for Medicare Beneficiaries With Nontuberculous Mycobacterial Pulmonary Disease

Background

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is an uncommon mycobacterial infection characterized by worsening lung function and increased health care resource utilization; however, the overall risk for hospitalization among patients with NTM-PD remains unclear.

Research Question

What is the hospitalization risk among older adults with NTM-PD?

Study Design and Methods

A retrospective, nested, case-control study was conducted by using the Medicare claims database. Cases were defined as patients with ≥ 2 NTM-PD claims ≥ 30 days apart between January 1, 2007, and December 31, 2015. The study included individuals aged ≥ 65 years with ≥ 12 months of continuous enrollment in both Parts A and B before the first NTM-PD diagnosis. Cases were matched 1:2 to Medicare beneficiaries without NTM-PD (control subjects) according to age and sex. Hospitalizations following the first NTM-PD claim were compared between case and control subjects by using univariate and multivariate analyses.

Results

A total of 35,444 case subjects and 65,467 matched control subjects (mean age, 76.6 years; 70% female; ≥ 87% White) were identified. Baseline comorbidities, particularly pulmonary comorbidities, were more common in case subjects than in control subjects (81.1% vs 17.7% for COPD; 44.6% vs 0.6% for bronchiectasis). All-cause hospitalization was observed in 65.7% of case subjects and 44.9% of control subjects. Unadjusted annual hospitalization rates were significantly (P < .05) greater among case subjects than control subjects. Case subjects also had a significantly shorter time to hospitalization than control subjects. The increased burden due to hospitalization was reflected in multivariate analysis adjusting for baseline comorbidities. All-cause hospitalization in patients with NTM-PD relative to control subjects was 1.2 times more likely (relative risk, 1.23; 95% CI, 1.21-1.25; P < .0001) with a 46% greater hazard (hazard ratio, 1.46; 95% CI, 1.43-1.50; P < .0001).

Interpretation

Patients with NTM-PD were significantly more likely to be hospitalized, had greater annualized hospitalization rates, and had shorter time to hospitalization than age- and sex-matched control subjects without NTM-PD. These findings highlight the significantly increased burden of hospitalizations among patients with NTM-PD.

The epidemiology of nontuberculous mycobacterial pulmonary disease in the Netherlands

Background

Nontuberculous mycobacteria (NTM) are emerging opportunistic pathogens of humans. Because NTM pulmonary disease (PD) is not a notifiable disease in Europe, the epidemiology of NTM-PD is not well known. However, the prevalence of NTM-PD is thought to be increasing, particularly in countries where tuberculosis rates have decreased. Here we aim to determine the prevalence of NTM-PD in the Netherlands.

Methods

Annual prevalence estimates of NTM-PD in the Netherlands (2012-2019) were derived from four separate databases, including two drug dispensing databases, an ICD-10 code database and a hospitalisation database. Databases covered a fraction of the Dutch population and were extrapolated. In addition, annual NTM-PD prevalence was also estimated by means of a pulmonologist survey.

Results

The estimated annual prevalence of NTM-PD using databases is between 2.3 and 5.9 patients per 100 000 inhabitants. Prevalence estimates derived from the drug dispensing databases, the hospitalisation database and the claims database were 2.3, 5.9, 3.5 and 4.5 per 100 000 inhabitants, respectively. The annual prevalence estimated in the pulmonologist survey was between 6.2 and 9.9 per 100 000 inhabitants. The annual prevalence remained stable over the included period.

Conclusion

The estimated annual prevalence of NTM-PD using databases was between 2.3 and 5.9 patients per 100 000 inhabitants. Due to the possible presence of tuberculosis patients and low coverage in one dispensing database, we believe an annual prevalence of between 2.3 and 4.5 patients per 100 000 inhabitants is more probable, which still renders NTM-PD a serious health threat. This estimate is lower than the estimate from the pulmonologist survey, indicating physicians likely overestimate prevalence.

Validity of Diagnosis Code-Based Claims to Identify Pulmonary NTM Disease in Bronchiectasis Patients

Nontuberculous mycobacteria infection is increasing in incidence and can lead to chronic, debilitating pulmonary disease. We investigated the accuracy of diagnosis code–based nontuberculous mycobacteria lung disease claims among Medicare beneficiaries in the United States. We observed that these claims have moderate validity, but given their low sensitivity, incidence might be underestimated.

Reduction in Expected Survival Associated With Nontuberculous Mycobacterial Pulmonary Disease

BACKGROUND

Nontuberculous mycobacteria (NTM) are opportunistically pathogenic bacteria that are found abundantly in the soil and water. Susceptible individuals exposed to NTM-containing aerosols from environmental sources may develop NTM pulmonary disease (NTM-PD). Reported survival after NTM-PD diagnosis varies widely among existing studies. Prior work has suggested that mortality among persons with NTM-PD is primarily driven by comorbidities rather than NTM-PD.

METHODS

We retrospectively identified a cohort of patients in the Duke University Health System who were diagnosed with NTM-PD between 1996 and 2015. Hospitalizations and survival were compared among patients with NTM-PD with and without other comorbidities. Additionally, survival among patients with NTM-PD was compared with standardized mortality data for a similar cohort of the general population.

RESULTS

Patients with NTM-PD without other comorbidities had 0.65 hospitalizations/1000 patient-days compared with 1.37 hospitalizations/1000 patient-days for patients with other comorbidities. Compared with a cohort of the general population, expected survival decreased by approximately 4 years for a diagnosis of NTM-PD without comorbidities and 8.6 years for a diagnosis of NTM-PD with comorbidities. Mortality 5 years after diagnosis was 25.0% and 44.9% among NTM patients without and with comorbidities, respectively, compared with 5.7% in the general-population cohort.

CONCLUSIONS

NTM-PD was associated with significant morbidity that was worse in patients with comorbidities. Patients with NTM-PD, even without comorbidities, had worse survival than expected.

Validity of ICD-10-CM diagnoses to identify hospitalizations for serious infections among patients treated with biologic therapies

PURPOSE

Identifying hospitalizations for serious infections among patients dispensed biologic therapies within healthcare databases is important for post-marketing surveillance of these drugs. We determined the positive predictive value (PPV) of an ICD-10-CM-based diagnostic coding algorithm to identify hospitalization for serious infection among patients dispensed biologic therapy within the FDA's Sentinel Distributed Database.

METHODS

We identified health plan members who met the following algorithm criteria: (1) hospital ICD-10-CM discharge diagnosis of serious infection between July 1, 2016 and August 31, 2018; (2) either outpatient/emergency department infection diagnosis or outpatient antimicrobial treatment within 7 days prior to hospitalization; (3) inflammatory bowel disease, psoriasis, or rheumatological diagnosis within 1 year prior to hospitalization, and (4) were dispensed outpatient biologic therapy within 90 days prior to admission. Medical records were reviewed by infectious disease clinicians to adjudicate hospitalizations for serious infection. The PPV (95% confidence interval [CI]) for confirmed events was determined after further weighting by the prevalence of the type of serious infection in the database.

RESULTS

Among 223 selected health plan members who met the algorithm, 209 (93.7% [95% CI, 90.1%-96.9%]) were confirmed to have a hospitalization for serious infection. After weighting by the prevalence of the type of serious infection, the PPV of the ICD-10-CM algorithm identifying a hospitalization for serious infection was 80.2% (95% CI, 75.3%-84.7%).

CONCLUSIONS

The ICD-10-CM-based algorithm for hospitalization for serious infection among patients dispensed biologic therapies within the Sentinel Distributed Database had 80% PPV for confirmed events and could be considered for use within pharmacoepidemiologic studies.

Measuring health-care delays among privately insured patients with tuberculosis in the USA: an observational cohort study

BACKGROUND

A high index of suspicion is needed to initiate appropriate testing for tuberculosis due to its protean symptoms, yet health-care providers in low-incidence settings are becoming less familiar with the disease as rates decline. We aimed to estimate delays in tuberculosis diagnosis and treatment at the US national level between 2008 and 2016.

METHODS

In this retrospective observational cohort study, we repurposed private insurance claims data provided by Aetna (Connecticut, USA), to measure health-care delays in tuberculosis diagnosis in the USA in 2008-16. Active tuberculosis was determined by diagnosis codes and the filling of anti-tuberculosis treatment prescriptions. Health-care delays were defined as the duration between the first health-care visit for a tuberculosis symptom and the initiation of anti-tuberculosis treatment. We assessed if delays varied over time, and by patient and system variables, using multivariable regression. We estimated household tuberculosis transmission and respiratory complications after treatment initiation.

FINDINGS

We confirmed 738 active tuberculosis cases (incidence 1·45 per 100 000 person-years) with a median health-care delay of 24 days (IQR 10-45). Multivariable regression analysis showed that longer delays were associated with older age (8·4% per 10 year increase [95% CI 4·0 to 13·1]; p<0·0086) and non-HIV immunosuppression (19·2% [15·1 to 60·0]; p=0·0432). Presenting with three or more symptoms was associated with a shorter delay (-22·5% [-39·1 to -2·0]; p=0·0415), relative to presenting with one symptom, as did use of chest imaging (-24·9% [-37·9 to -8·9]; p<0·0098), tuberculosis nucleic acid amplification tests (-19·2% [-32·7 to -3·1]; p=0·0241), and care by a tuberculosis specialist provider (-17·2% [-33·1 to -22·3]; p<0·0087). Longer delays were associated with an increased rate of respiratory complications even after controlling for patient characteristics, and an increased rate of secondary tuberculosis among dependents.

INTERPRETATION

In the USA, the median health-care delay for privately insured patients with tuberculosis exceeds WHO-recommended levels of 21 days (3 weeks). The results suggest the need for health-care provider education on best practices in tuberculosis diagnosis, including the use of molecular tests and the maintenance of a high index of suspicion for the disease.

FUNDING

US National Institutes of Health.

Incidence, duration and risk factors associated with delayed and missed diagnostic opportunities related to tuberculosis: a population-based longitudinal study

OBJECTIVES

Missed opportunities to diagnose tuberculosis are costly to patients and society. In this study, we (1) estimate the frequency and duration of diagnostic delays among patients with active pulmonary tuberculosis and (2) determine the risk factors for experiencing a diagnostic delay.

DESIGN

A retrospective cohort study of patients with tuberculosis using longitudinal healthcare encounters prior to diagnosis.

SETTING

Commercially insured enrollees from the Commercial Claims and Encounters or Medicare Supplemental IBM Marketscan Research Databases, 2001-2017.

PARTICIPANTS

All patients diagnosed with, and receiving treatment for, pulmonary tuberculosis, enrolled at least 365 days prior to diagnosis.

PRIMARY AND SECONDARY OUTCOME MEASURES

We estimated the number of visits with tuberculosis-related symptoms prior to diagnosis that would be expected to occur in the absence of delays and compared this estimate to the observed pattern. We computed the number of visits representing a delay and used a simulation-based approach to estimate the number of patients experiencing a delay, number of missed opportunities per patient and duration of delays (ie, time between diagnosis and earliest missed opportunity). We also explored risk factors for missed opportunities.

RESULTS

We identified 3371 patients diagnosed and treated for active tuberculosis that could be followed up for 1 year prior to diagnosis. We estimated 77.2% (95% CI 75.6% to 78.7%) of patients experienced at least one missed opportunity; of these patients, an average of 3.89 (95% CI 3.65 to 4.14) visits represented a missed opportunity, and the mean duration of delay was 31.66 days (95% CI 28.51 to 35.11). Risk factors for delays included outpatient or emergency department settings, weekend visits, patient age, influenza season presentation, history of chronic respiratory symptoms and prior fluoroquinolone use.

CONCLUSIONS

Many patients with tuberculosis experience multiple missed diagnostic opportunities prior to diagnosis. Missed opportunities occur most commonly in outpatient settings and numerous patient-specific, environment-specific and setting-specific factors increase risk for delays.

Incidence and Prevalence of Nontuberculous Mycobacterial Lung Disease in a Large U.S. Managed Care Health Plan, 2008-2015

Rationale: Estimating the annual incidence and prevalence of nontuberculous mycobacterial (NTM) lung disease may assist in improving understanding of the public health and economic impacts of this disease and its treatment.

Objective: To estimate the yearly incidence and prevalence of administrative claims–based NTM lung disease between 2008 and 2015 in a U.S. managed care claims database.

Methods: We used a national managed care claims database (Optum Clinformatics Data Mart) representing a geographically diverse population of approximately 27 million members annually. All medical claims from January 1, 2007, to June 30, 2016, were scanned for diagnosis codes for NTM lung disease (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 031.0 or ICD-10-CM code A31.0). We defined a case of NTM lung disease as having at least two medical claims with a code of 031.0 or A31.0 that were dated at least 30 days apart. Annual incidence and prevalence were estimated for each calendar year from 2008 to 2015.

Results: From 2008 to 2015, the annual incidence of NTM lung disease increased from 3.13 (95% confidence interval [CI], 2.88–3.40) to 4.73 (95% CI, 4.43–5.05) per 100,000 person-years, and the annual prevalence increased from 6.78 (95% CI, 6.45–7.14) to 11.70 (95% CI, 11.26–12.16) per 100,000 persons. The average annual changes in incidence and prevalence were +5.2% (95% CI, 4.0–6.4%; P < 0.01) and +7.5% (95% CI, 6.7–8.2%; P < 0.01), respectively. For women, the annual incidence increased from 4.16 (95% CI, 3.76–4.60) to 6.69 (95% CI, 6.19–7.22) per 100,000 person-years, and the annual prevalence increased from 9.63 (95% CI, 9.08–10.22) to 16.78 (95% CI, 16.04–17.55) per 100,000 persons. For individuals aged 65 years or older, the annual incidence increased from 12.70 (95% CI, 11.46–14.07) to 18.37 (95% CI, 16.98–19.87) per 100,000 person-years, and the annual prevalence increased from 30.27 (95% CI, 28.41–32.24) to 47.48 (95% CI, 45.37–49.67) per 100,000 persons. The incidence and prevalence of NTM lung disease increased in most U.S. states and overall at the national level.

Conclusions: The incidence and prevalence of NTM lung disease appears to be increasing in the United States, particularly among women and older age groups.

Predictive modeling of nontuberculous mycobacterial pulmonary disease epidemiology using German health claims data

OBJECTIVES

Administrative claims data are prone to underestimate the burden of non-tuberculous mycobacterial pulmonary disease (NTM-PD).

METHODS

We developed machine learning-based algorithms using historical claims data from cases with NTM-PD to predict patients with a high probability of having previously undiagnosed NTM-PD and to assess actual prevalence and incidence. Adults with incident NTM-PD were classified from a representative 5% sample of the German population covered by statutory health insurance during 2011-2016 by the International Classification of Diseases, 10th revision code A31.0. Pre-diagnosis characteristics (patient demographics, comorbidities, diagnostic and therapeutic procedures, and medications) were extracted and compared to that of a control group without NTM-PD to identify risk factors.

RESULTS

Applying a random forest model (area under the curve 0.847; total error 19.4%) and a risk threshold of >99%, prevalence and incidence rates in 2016 increased 5-fold and 9-fold to 19 and 15 cases/100,000 population, respectively, for both coded and non-coded vs. coded cases alone.

CONCLUSIONS

The use of a machine learning-based algorithm applied to German statutory health insurance claims data predicted a considerable number of previously unreported NTM-PD cases with high probabilty.

Epidemiology of nontuberculous mycobacterial pulmonary disease in Europe and Japan by Delphi estimation

BACKGROUND

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is an emerging opportunistic infection, but basic epidemiological data are lacking in most regions. We have investigated epidemiology and diagnostic and treatment practices in five EU countries (United Kingdom, Spain, Italy, France, Germany; EU5) and Japan.

STUDY DESIGN

and methods: Annual prevalence in each country was established using a 2-round Delphi method in combination with a regional prevalence-estimation model that incorporated data obtained from a blinded physician screening survey (3154 physicians) and a real-world NTM-PD treating-physician/patient-chart observational study (619 physicians - 1429 patient charts).

RESULTS

The annual prevalence of NTM-PD was estimated at 6.2/100,000 in the EU5 and 24.9/100,000 in Japan. Overall prevalence between the EU5 was comparable, while differences in regional prevalence were found to be pronounced in France and The United Kingdom. Regional differences were also found in Japan, with the majority of cases in Chubu and Kanto regions.

CONCLUSION

This new methodology for obtaining often missing regional-level epidemiological data reveals dramatic variations in NTM-PD annual prevalence and helps pinpoint areas that may merit special preventative and treatment focus.

Costs Associated with Nontuberculous Mycobacteria Infection, Ontario, Canada, 2001-2012

To determine incidence-based healthcare costs attributable to nontuberculous mycobacterial (NTM) pulmonary disease (PD) and NTM pulmonary isolation (PI), from the healthcare payer perspective, we conducted a population-based matched cohort study in Ontario, Canada. We established cohorts of patients with incident NTM-PD and NTM-PI during 2001–2012 by using individually linked laboratory data and health administrative data, matched to unexposed persons from the general population. To estimate attributable costs for acute and long-term illness, we used a phase-of-care approach. Costs were stratified by age, sex, and healthcare resource, and reported in 2018 Canadian dollars (CAD) and US dollars (USD), standardized to 10 days. Costs were highest during the before-death phase (NTM-PD CAD $1,352 [USD $1,044]; NTM-PI CAD $731 [USD $565]). The cumulative mean attributable 1-year costs were CAD $14,953 (USD $11,541) for NTM-PD and CAD $8,729 (USD $6,737) for NTM-PI. Costs for patients with NTM-PD and NTM-PI were higher than those for unexposed persons.

An Integrated Analysis of the Safety of Tofacitinib in Psoriatic Arthritis across Phase III and Long-Term Extension Studies with Comparison to Real-World Observational Data

INTRODUCTION

Tofacitinib is an oral Janus kinase inhibitor for the treatment of psoriatic arthritis (PsA).

OBJECTIVE

Our objective was to compare the incidence rates (IRs) of adverse events in tofacitinib clinical trials and real-world observational data for alternative treatments.

METHODS

The tofacitinib "dose-comparison cohort" included months 0-12 of two phase III studies (tofacitinib 5 [n = 238] and 10 [n = 236] mg twice daily [BID]); the "all-tofacitinib comparison cohort" (n = 783) included two phase III and one ongoing long-term extension study (data cutoff May 2016). An "observational comparison cohort" (n = 5799) comprised patients initiating a conventional synthetic disease-modifying antirheumatic drug (DMARD), biologic DMARD, or apremilast in the US Truven MarketScan database from 2010 to 2015. IRs for serious infections (SIEs; requiring hospitalization), herpes zoster (HZ), malignancies (excluding non-melanoma skin cancer [NMSC]), NMSC, and major adverse cardiovascular events (MACE) across cohorts were qualitatively compared.

RESULTS

IRs (patients with events/100 patient-years) for SIEs were similar between the tofacitinib dose-comparison cohort (5 mg BID: 1.3; 10 mg BID: 2.0) and the observational comparison cohort (1.1-7.9; treatment dependent). The tofacitinib dose-comparison cohort had a higher rate of HZ (5 mg BID: 2.0; 10 mg BID: 2.7) than did the observational comparison cohort (0.8-2.0). IRs for NMSC were generally lower in the all-tofacitinib comparison cohort (0.5) than in the observational comparison cohort (0.4-6.0). IRs for MACE, malignancies excluding NMSC, and NMSC were similar between cohorts.

CONCLUSION

In patients with PsA, tofacitinib had a safety profile similar to that of other systemic therapies in real-world settings, except for the risk of HZ, a known risk of tofacitinib.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01877668; NCT01882439; NCT01976364.

Relative risk of all-cause mortality in patients with nontuberculous mycobacterial lung disease in a US managed care population

RATIONALE

The risk of all-cause mortality of nontuberculous mycobacterial lung disease (NTMLD) in the United States (US) population is not well established.

OBJECTIVES

This study aims to assess the public health burden of NTMLD in the US by comparing the relative risk of all-cause mortality in the NTMLD population with an age- and sex-matched cohort from the general population.

METHODS

Patients with physician claims for NTMLD (ICD-9 0.031; ICD-10 A31.0) were identified between 2007 and 2016 from a large US national managed care insurance plan covering approximately 15-18 million members annually. A control group with no NTMLD ICD-9 or 10 codes was randomly selected from the general population and matched 3:1 to the NTMLD sample according to birth year, gender, and insurance benefit coverage. The date of first NTMLD diagnosis of each patient was assigned to the matched controls as the index date. The Cox proportional hazard method compared survival between cohorts, adjusting for demographic factors and baseline comorbidities.

RESULTS

A total of 2005 patients with NTMLD and 6014 controls were identified, with a mean follow-up duration of 3.4 years and 3.7 years, respectively. The NTMLD group had substantially higher proportions of patients with asthma (23.3% versus 3.5%), bronchiectasis (36.5% versus 0.1%), COPD (52.0% versus 5.9%), arrhythmia (22.6% versus 6.5%), coronary artery disease (18.5% versus 6.6%), heart failure (11.9% versus 4.1%), and cancer (18.5% versus 5.0%). The unadjusted rate of all-cause mortality from the index date was 20.7 per 1000 person-years in the NTMLD group vs 5.6 per 1000 person-years in the control group (rate ratio = 3.73; 95% CI: 2.93-4.75). Multivariable Cox regression, adjusted for the above variables as well as all other important baseline covariates, showed a doubling risk of all-cause mortality (hazard ratio [HR] = 2.06; CI: 1.52-2.79; P < 0.001) in the NTMLD vs control group.

CONCLUSIONS

All-cause mortality, adjusted for other factors, more than doubled with NTMLD compared with an age-sex-matched control group in a large US national managed care insurance plan.

Characteristics and Health-care Utilization History of Patients With Bronchiectasis in US Medicare Enrollees With Prescription Drug Plans, 2006 to 2014

BACKGROUND

Bronchiectasis is an increasingly common chronic inflammatory airway disease. There is an urgent need to understand the epidemiology of bronchiectasis in older adults. We describe the prevalence and characteristics of patients with bronchiectasis within the US Medicare population.

METHODS

Among the 40% of Medicare enrollees with prescription drug plans from 2006 to 2014, we identified patients ≥ 65 years of age with bronchiectasis by International Classification of Diseases, Ninth Revision, Clinical Modification claims (494.0 or 494.1) from a pulmonologist and no claim for cystic fibrosis. We calculated the prevalence from 2012 to 2014. Incident or newly diagnosed patients were those enrolled in Medicare at least 12 months prior to the first bronchiectasis diagnosis. We described clinical and health-care utilization characteristics for this cohort during the prior 12-month (baseline) period, and explored differences between those with and without a COPD diagnosis.

RESULTS

We identified 252,362 patients with bronchiectasis meeting all eligibility criteria. The average annual prevalence from 2012 to 2014 was 701 per 100,000 persons. Newly diagnosed patients were a mean age of 76 years, predominately women (65%), and predominately white, non-Hispanic (84%). During the baseline period, 12% were hospitalized for respiratory infections. Fifty-one percent had a dual diagnosis of COPD. Newly diagnosed patients with bronchiectasis and COPD had significantly different characteristics and utilization, for example were more likely hospitalized for respiratory infections during the baseline period (16% vs 7%) and to have a smoking history (46% vs 17%) compared with those without a dual COPD diagnosis, respectively.

CONCLUSIONS

We confirmed a high prevalence of bronchiectasis in the United States and significant heterogeneity in patients with bronchiectasis with and without COPD that should be further explored.

Geographic Distribution of Nontuberculous Mycobacterial Species Identified among Clinical Isolates in the United States, 2009-2013

RATIONALE

Nontuberculous mycobacteria are an important cause of morbidity in the United States, although patient outcomes vary greatly by species. Currently, nationally representative data on the distribution of mycobacterial species from clinical isolates are limited.

OBJECTIVES

Using a national hospitalization database capturing microbiologic data for nearly 6 million patient encounters, we describe the geographic distribution of, and patient demographic features associated with, clinical mycobacterial isolates in the United States.

METHODS

Linked demographic and microbiologic data from the Premier Healthcare Database were extracted for all patient encounters from 2009 to 2013. Patients with at least one positive potentially pathogenic nontuberculous mycobacterial culture were identified as cases. The period prevalence was calculated, and patient-, encounter-, and hospital-level factors were analyzed. Regional differences in species distribution were analyzed; a subanalysis was conducted among patients with International Classification of Diseases, Ninth Revision, codes for pulmonary nontuberculous mycobacterial disease. Significant differences were assessed (P < 0.05).

RESULTS

Of 5,928,830 unique patients included during the 5-year study period, 7,812 (0.13%) had at least one positive nontuberculous mycobacterial culture. The mean age of cases was 64 years (range, <1-89 yr), and most were female (52%) and white (70%). Hospitals with cases were more often labeled "urban" (96%), "teaching" (56%), and had at least 500 beds (78%). Species distribution differed significantly by geographic area. Mycobacterium avium complex ranged from 61 to 91% of isolates and were most frequent in the South and Northeast regions; M. abscessus/M. chelonae ranged from 2 to 18% of isolates and were most frequent in the West; and other species, including M. fortuitum and M. kansasii, ranged from 7 to 26% and were also most frequent in the West.

CONCLUSIONS

Significant geographic variation exists in the distribution of nontuberculous mycobacterial species in the United States. Whereas M. avium complex was the most common species isolated in the South, M. abscessus/M. chelonae was proportionately higher in the West. Greater clinical awareness in regions with increased levels of harder-to-treat mycobacteria are needed, given differences in treatment options and implications for patient outcomes.

Epidemiology of Nontuberculous Mycobacteriosis

Annual prevalence estimates for pulmonary nontuberculous mycobacterial (PNTM) disease in the contiguous United States range from 1.4 to 13.9 per 100,000 persons, while one study found an annual prevalence of up to 44 per 100,000 persons in Hawaii. PNTM prevalence varies by region, sex, and race/ethnicity, with higher prevalence among women and persons of Asian ancestry, as well as in the Southern United States and Hawaii. Studies consistently indicate that PNTM prevalence is increasing, with estimates ranging from 2.5 to 8% per year. Most PNTM disease is associated with Mycobacterium avium complex (MAC), although the proportion of disease attributed to MAC varies by region. Host factors identified as influencing disease risk include structural lung disease, immunomodulatory medication, as well as variants in connective tissue, mucociliary clearance, and immune genes. Environmental variables including measures of atmospheric moisture and concentrations of certain soil factors have also been shown to correlate with higher PNTM prevalence. Prevalence of extrapulmonary NTM disease is lower, stable, and associated with different risk factors, including primary immune deficiencies or HIV infection.

Pulmonary Nontuberculous Mycobacteria-Associated Deaths, Ontario, Canada, 2001-2013

Survival implications of nontuberculous mycobacterial pulmonary disease (NTM-PD) and NTM pulmonary isolation without disease (NTM-PI) are unclear. To study deaths associated with NTM-PD and NTM-PI and differences in survival between them, we conducted a population-based cohort study of persons with microbiologically defined NTM-PD or NTM-PI diagnosed during 2001–2013 in Ontario, Canada. We used propensity score matching and Cox proportional hazards models to compare survival. Among 9,681 NTM-PD patients and 10,936 NTM-PI patients, 87% and 91%, respectively, were successfully matched with unexposed controls. Both NTM-PD and NTM-PI were associated with higher rates of death for all species combined and for most individual species. Compared with NTM-PI, NTM-PD was associated with higher death rates for all species combined, Mycobacterium avium complex, and M. xenopi. NTM-PD and NTM-PI were significantly associated with death, NTM-PD more so than NTM-PI.

On the Reportability of Nontuberculous Mycobacterial Disease to Public Health Authorities

Nontuberculous mycobacteria (NTM) are environmental pathogens that are an increasingly common cause of pulmonary and extrapulmonary disease. Electronic laboratory-based reporting is a straightforward mechanism for identifying NTM infections and for monitoring trends in disease. Oregon was the first state to make NTM reportable, although at this time the reporting requirement is limited to extrapulmonary infection. This has assisted authorities in detecting outbreaks and healthcare-related infections. However, further consideration should be given to the reportability of pulmonary NTM disease. Pulmonary NTM disease is more common than tuberculosis in the United States and is of emerging public health concern. Although the direct public health action that would be triggered by a pulmonary NTM disease report is not clear, without surveillance, public health is missing an opportunity to better understand pulmonary NTM disease trends and reasons for its increasing recognition within our population. We believe state health authorities should conduct surveillance for pulmonary NTM, either by mandating reporting of laboratory isolates or by other mechanisms as we have done in Oregon.

Body habitus in patients with and without bronchiectasis and non-tuberculous mycobacteria

Background

Female gender, tall stature, presence of bronchiectasis are associated with pulmonary nontuberculous mycobacterial (NTM) infections. The biologic relationship between the body habitus and NTM infection is not well defined and the body habitus profile of the patients with NTM and concurrent bronchiectasis is completely unknown.

Methods

We conducted a case control study at the Miami VA Healthcare System and the University of Illinois Medical Center on patients with pulmonary NTM infections between 2010 and 2015. We compared pulmonary NTM subjects with and without bronchiectasis. NTM infection was confirmed by using the American Thoracic Society/ Infectious Disease Society of America criteria. Standard radiological criteria were used to define bronchiectasis in chest CT-scan.

Results

Two hundred twenty subjects with pulmonary NTM were enrolled in the study. Sixty six subjects (30%) had bronchiectasis on CT scan of the chest. Subjects in the bronchiectasis group included more women (p = 0.002) and were significantly older (p = 0.005). Those patients who had bronchiectasis tended to have a significantly lower weight (less than 50kg) and height ≤155 cm (p <0.0001 and p = 0.018, respectively). Kaplan–Meier analysis confirmed that subjects who had bronchiectasis were shorter and weighed less, after adjusting for gender.

Conclusions

This study defines a new sub-phenotype of NTM subjects with bronchiectasis who tend to be short with lower body weight. Further studies are needed to better understand and define the body habitus profiles of this new sub-phenotype and their clinical implications.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.

The Burden of Pulmonary Nontuberculous Mycobacterial Disease in the United States

RATIONALE

State-specific case numbers and costs are critical for quantifying the burden of pulmonary nontuberculous mycobacterial disease in the United States.

OBJECTIVES

To estimate and project national and state annual cases of nontuberculous mycobacterial disease and associated direct medical costs.

METHODS

Available direct cost estimates of nontuberculous mycobacterial disease medical encounters were applied to nontuberculous mycobacterial disease prevalence estimates derived from Medicare beneficiary data (2003-2007). Prevalence was adjusted for International Classification of Diseases, 9th Revision, undercoding and the inclusion of persons younger than 65 years of age. U.S. Census Bureau data identified 2010 and 2014 population counts and 2012 primary insurance-type distribution. Medical costs were reported in constant 2014 dollars. Projected 2014 estimates were adjusted for population growth and assumed a previously published 8% annual growth rate of nontuberculous mycobacterial disease prevalence.

MEASUREMENTS AND MAIN RESULTS

In 2010, we estimated 86,244 national cases, totaling to $815 million, of which 87% were inpatient related ($709 million) and 13% were outpatient related ($106 million). Annual state estimates varied from 48 to 12,544 cases ($503,000-$111 million), with a median of 1,208 cases ($11.5 million). Oceanic coastline states and Gulf States comprised 70% of nontuberculous mycobacterial disease cases but 60% of the U.S. population. Medical encounters among individuals aged 65 years and older ($562 million) were twofold higher than those younger than 65 years of age ($253 million). Of all costs incurred, medications comprised 76% of nontuberculous mycobacterial disease expenditures. Projected 2014 estimates resulted in 181,037 national annual cases ($1.7 billion).

CONCLUSIONS

For a relatively rare disease, the financial cost of nontuberculous mycobacterial disease is substantial, particularly among older adults. Better data on disease dynamics and more recent prevalence estimates will generate more robust estimates.

Tuberculosis and other opportunistic infections in tofacitinib-treated patients with rheumatoid arthritis

OBJECTIVES

To evaluate the risk of opportunistic infections (OIs) in patients with rheumatoid arthritis (RA) treated with tofacitinib.

METHODS

Phase II, III and long-term extension clinical trial data (April 2013 data-cut) from the tofacitinib RA programme were reviewed. OIs defined a priori included mycobacterial and fungal infections, multidermatomal herpes zoster and other viral infections associated with immunosuppression. For OIs, we calculated crude incidence rates (IRs; per 100 patient-years (95% CI)); for tuberculosis (TB) specifically, we calculated rates stratified by patient enrolment region according to background TB IR (per 100 patient-years): low (≤0.01), medium (>0.01 to ≤0.05) and high (>0.05).

RESULTS

We identified 60 OIs among 5671 subjects; all occurred among tofacitinib-treated patients. TB (crude IR 0.21, 95% CI of (0.14 to 0.30)) was the most common OI (n=26); median time between drug start and diagnosis was 64 weeks (range 15-161 weeks). Twenty-one cases (81%) occurred in countries with high background TB IR, and the rate varied with regional background TB IR: low 0.02 (0.003 to 0.15), medium 0.08 (0.03 to 0.21) and high 0.75 (0.49 to 1.15). In Phase III studies, 263 patients diagnosed with latent TB infection were treated with isoniazid and tofacitinib concurrently; none developed TB. For OIs other than TB, 34 events were reported (crude IR 0.25 (95% CI 0.18 to 0.36)).

CONCLUSIONS

Within the global tofacitinib RA development programme, TB was the most common OI reported but was rare in regions of low and medium TB incidence. Patients who screen positive for latent TB can be treated with isoniazid during tofacitinib therapy.

Health-related quality of life, comorbidities and mortality in pulmonary nontuberculous mycobacterial infections: A systematic review

Nontuberculous mycobacterial (NTM) infections are increasing in disease frequency worldwide. This systematic review examines health-related quality of life (HRQOL), comorbidities and mortality associated with pulmonary NTM disease. We searched MEDLINE, EMBASE, CINAHL, Scopus Life Sciences, conference proceedings and Google (earliest date available to February 2015) for primary studies. Eligible studies compared populations with and without pulmonary NTM disease in high-income jurisdictions. We excluded studies on HIV/AIDS. All languages were accepted. Two reviewers followed MOOSE and PRISMA reporting guidelines and independently appraised quality using STROBE. All studies were summarized qualitatively regardless of quality. Of 3193 citations screened, we included 17 studies mostly from Taiwan (n = 5) and the USA (n = 4). Two studies assessed HRQOL; one assessed comorbidities, 11 assessed mortality, and three assessed multiple outcomes. Populations with pulmonary NTM reported significantly worse or similar HRQOL than the general population, depending on the instruments used. Some suggested greater prevalence of having bronchiectasis (n = 2) and greater risk of developing pulmonary tuberculosis (n = 1). Most (n = 7) suggested no difference in mortality, although only one was age-matched and gender-matched to the general population. Four suggested NTM populations had higher mortality-two of which compared with the general population and were deemed of high quality, while two compared with non-NTM patients from hospital. High clinical heterogeneity in study design may explain discordant results. Bias assessments and controlling for confounding were carried out poorly. No consistent trends were observed although there is suggestion of an increased health burden from respiratory diseases and increased mortality associated with pulmonary NTM disease.

A population-based study of infection-related hospital mortality in patients with dermatomyositis/polymyositis

OBJECTIVE

Dermatomyositis (DM) and polymyositis (PM) are debilitating inflammatory myopathies associated with significant mortality. We evaluated the relative contribution of infection to hospital mortality in a large population-based study of individuals with PM/DM.

METHODS

Data derive from the 2007 to 2011 Healthcare Cost and Utilization Project National Inpatient Samples and include all hospital discharges that met a validated administrative definition of PM/DM. The primary outcome was hospital mortality. Variables for infections and comorbidities were generated from discharge diagnoses using validated administrative definitions. Logistic regression was used to investigate the relationship between infection and mortality in individuals with PM/DM, adjusting for sociodemographics, utilization variables, and comorbidities. Relative risks (RRs) were calculated to compare the overall prevalence of specific infections and associated mortality in PM/DM hospitalizations with those seen in the general hospitalized population.

RESULTS

A total of 15,407 hospitalizations with PM/DM met inclusion criteria for this study and inpatient mortality was 4.5% (700 deaths). In adjusted logistic regression analyses, infection (odds ratio [OR] 3.4, 95% confidence interval [95% CI] 2.9-4.0) was the strongest predictor of hospital mortality among individuals with PM/DM. Bacterial infection (OR 3.5, 95% CI 3.0-4.1), comprised primarily of pneumonia and bacteremia, and opportunistic fungal infections (OR 2.5, 95% CI 1.5-4.0) were independently associated with hospital mortality. The overall burden of infection in hospitalizations with PM/DM was significantly increased in comparison with the general hospitalized population (RR 1.5, 95% CI 1.4-1.6).

CONCLUSION

Among hospitalized individuals with PM/DM, infection is the leading cause of mortality. Strategies to mitigate infection risk in both the clinic and hospital settings should be evaluated to improve disease outcomes.

Increased risk of mycobacterial infections associated with anti-rheumatic medications

RATIONALE

Anti-tumour necrosis factor (TNF) agents and other anti-rheumatic medications increase the risk of TB in rheumatoid arthritis (RA). Whether they increase the risk of infections with nontuberculous mycobacteria (NTM) is uncertain.

OBJECTIVES

To determine the effect of anti-TNF therapy and other anti-rheumatic drugs on the risk of NTM disease and TB in older patients with RA.

METHODS

Population-based nested case-control study among Ontario seniors aged ≥67 years with RA who were prescribed at least one anti-rheumatic medication between 2001 and 2011. We identified cases of TB and NTM disease microbiologically and identified drug exposures using linked prescription drug claims. We estimated ORs using conditional logistic regression, controlling for several potential confounders.

MEASUREMENTS AND MAIN RESULTS

Among 56 269 older adults with RA, we identified 37 cases of TB and 211 cases of NTM disease; each case was matched to up to 10 controls. Individuals with TB or NTM disease were both more likely to be using anti-TNF therapy (compared with non-use); adjusted ORs (95% CIs) were 5.04 (1.27 to 20.0) and 2.19 (1.10 to 4.37), respectively. Exposure to leflunomide and other anti-rheumatic drugs with high immunosuppressing potential also were associated with both TB and NTM disease, while oral corticosteroids and hydroxychloroquine were associated with NTM disease.

CONCLUSIONS

Anti-TNF use is associated with increased risk of both TB and NTM disease, but appears to be a relatively greater risk for TB. Several other anti-rheumatic drugs were also associated with mycobacterial infections.

Risk of mycobacterial infections associated with rheumatoid arthritis in Ontario, Canada

OBJECTIVE

Patients with rheumatoid arthritis (RA) are at increased risk of TB. Little is known about the risk of nontuberculous mycobacteria (NTM) disease in these patients. We sought to ascertain the rate of NTM infection and TB in all residents of Ontario, Canada, with and without RA.

METHODS

In a cohort study, all Ontarians aged ≥ 15 years in January 2001 were followed until December 2010. Individuals with RA were identified using a validated algorithm to search hospitalization and physician billing claims. We linked Public Health Ontario Laboratory data to identify all cases of laboratory-confirmed TB and NTM disease. Analysis was performed using Cox proportional hazards regression.

RESULTS

We identified 113,558 Ontarians with RA and 9,760,075 Ontarians without RA. Relative to the non-RA group, adjusted hazard ratios (HRs) and 95% CIs for TB (1.92, [1.50-2.47]) and NTM disease (2.07, [1.84-2.32]) demonstrated increased risks in the RA group. Among those with RA, per 100,000 person-years, NTM disease (HR, 41.6; 95% CI, 37.1-46.5) was more common than TB (HR, 8.5; 95% CI, 6.5-10.8). After full adjustment, people with RA who developed NTM disease were 1.81 times as likely to die than uninfected people with RA.

CONCLUSIONS

Mycobacterial infections are more common in Ontarians with RA, with NTM disease more likely than TB. NTM disease is associated with an increased risk of death in patients with RA. Given the rising rates of NTM disease worldwide, determining whether this risk is due to the use of immunosuppressive medications vs RA itself is an important objective for future research.

Epidemiology of human pulmonary infection with nontuberculous mycobacteria: a review

Population-based data have documented a worldwide increase in the prevalence of human nontuberculous mycobacterial (NTM) infections since 2000. Mycobacterium avium complex is predominant in North America and East Asia, whereas in regions within Europe, M kansasii, M xenopi, and M malmoense are more common. Host factors important to the current epidemiology of NTM pulmonary disease include thoracic skeletal abnormalities, rheumatoid arthritis, and use of immunomodulatory drugs. Clustering of disease within families suggests a heritable genetic predisposition to disease susceptibility. Warm, humid environments with high atmospheric vapor pressure contribute to population risk.

Infection risk in patients with rheumatoid arthritis treated with etanercept or adalimumab

OBJECTIVES

To compare the risk of infection for rheumatoid arthritis (RA) patients who took etanercept or adalimumab medication in a nationwide population.

METHODS

RA patients who took etanercept or adalimumab were identified in the Taiwan's National Health Insurance Research Database. The composite outcome of serious infections, including hospitalization for infection, reception of an antimicrobial injection, and tuberculosis were followed for 365 days. A Kaplan-Meier survival curve with a log-rank test and Cox proportional hazards regression were used to compare risks of infection between the two cohorts of tumor necrosis factor (TNF)-α antagonists users. Hazard ratios (HRs) were obtained and adjusted with propensity scores and clinical factors. Sensitivity analyses and subgroup analyses were also performed.

RESULTS

In total, 1660 incident etanercept users and 484 incident adalimumab users were eligible for the analysis. The unadjusted HR for infection of the etanercept users was significantly higher than that of the adalimumab users (HR: 1.93; 95% confidence interval (CI): 1.09-3.42; p=0.024). The HRs were 2.04 (95% CI: 1.14-3.65; p=0.016) and 2.02 (95% CI: 1.13-3.61; p=0.018) after adjusting for propensity scores and for propensity scores in addition to clinical factors, respectively. The subgroup analyses revealed that HRs for composite infection was significantly higher in patient subgroups of older age, female, as well as patients who did not have DM, COPD, and hospitalization history at the baseline.

CONCLUSION

In this head-to-head cohort study involving a nationwide population of patients with RA, etanercept users demonstrated a higher risk of infection than adalimumab users. Results of this study suggest the possible existence of an intra-class difference in infection risk among TNF-α antagonists.

A systematic review of validated methods for identifying patients with rheumatoid arthritis using administrative or claims data

PURPOSE

To review the evidence supporting the validity of billing, procedural, or diagnosis code, or pharmacy claim-based algorithms used to identify patients with rheumatoid arthritis (RA) in administrative and claim databases.

METHODS

We searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to RA and reference lists of included studies were searched. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria and extracted the data. Data collected included participant and algorithm characteristics.

RESULTS

Nine studies reported validation of computer algorithms based on International Classification of Diseases (ICD) codes with or without free-text, medication use, laboratory data and the need for a diagnosis by a rheumatologist. These studies yielded positive predictive values (PPV) ranging from 34 to 97% to identify patients with RA. Higher PPVs were obtained with the use of at least two ICD and/or procedure codes (ICD-9 code 714 and others), the requirement of a prescription of a medication used to treat RA, or requirement of participation of a rheumatologist in patient care. For example, the PPV increased from 66 to 97% when the use of disease-modifying antirheumatic drugs and the presence of a positive rheumatoid factor were required.

CONCLUSIONS

There have been substantial efforts to propose and validate algorithms to identify patients with RA in automated databases. Algorithms that include more than one code and incorporate medications or laboratory data and/or required a diagnosis by a rheumatologist may increase the PPV.

Understanding the burden of tuberculosis among American Indians/Alaska Natives in the U.S.: a validation study

OBJECTIVE

We validated cases of active tuberculosis (TB) recorded in the Indian Health Service (IHS) National Patient Information Reporting System (NPIRS) and evaluated the completeness of TB case reporting from IHS facilities to state health departments.

METHODS

We reviewed the medical records of American Indian/Alaska Native (AI/AN) patients at IHS health facilities who were classified as having active TB using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes from 2006 to 2009 for clinical and laboratory evidence of TB disease. Individuals were reclassified as having active TB disease; recent latent TB infection (LTBI); past positive tuberculin skin test (TST) only; or as having no evidence of TB, LTBI, or a past positive TST. We compared validated active TB cases with corresponding state records to determine if they were reported.

RESULTS

The study included 596 patients with active TB as per ICD-9-CM codes. Based on chart review, 111 (18.6%) had active TB; 156 (26.2%) had LTBI; 104 (17.4%) had a past positive TST; and 221 (37.1%) had no evidence of TB disease, LTBI, or a past positive TST. Of the 111 confirmed cases of active TB, 89 (80.2%) resided in participating states; 81 of 89 (91.2%) were verified as reported TB cases.

CONCLUSIONS

ICD-9-CM codes for active TB disease in the IHS NPIRS do not accurately reflect the burden of TB among AI/ANs. Most confirmed active TB cases in the IHS health system were reported to the state; the national TB surveillance system may accurately represent the burden of TB in the AI/AN population.

Nontuberculous mycobacterial disease mortality in the United States, 1999-2010: a population-based comparative study

Background

Environmental nontuberculous mycobacteria (NTM) are ubiquitous organisms with which humans commonly interact. The epidemiologic characteristics of NTM diseases including mortality rate and its associated factors remain largely unknown. In this study, we explored the geographical area of exposure and mortality and comorbid conditions of affected persons to determine environment, host, and host-pathogen interactive factors.

Methods

We analyzed mortality related to nontuberculous mycobacterial infections from 1999 through 2010 by examining multiple-cause-of-death data from the National Center for Health Statistics. Among those who died with these diseases, we analyzed age-adjusted mortality rates, trends, associations with demographic variables, and comorbid conditions and correlated this information with similar data for tuberculosis-related mortality during the same time.

Measurements and Mean Results

From 1999 through 2010, nontuberculous mycobacterial disease was reported as an immediate cause of death in 2,990 people in the United States with a combined overall mean age-adjusted mortality rate of 0.1 per 100,000 person-years. A significant increase in the number of NTM related deaths was seen from 1999 through 2010 (R² = 0.72, p<0.0001), but it was not significant after adjustment for age. Persons aged 55 years and older, women, those living in Hawaii and Louisiana, and those of non-Hispanic, white ethnicity had higher mortality rates. Compared to tuberculosis-related mortality, chronic obstructive pulmonary disease, bronchiectasis, HIV, interstitial lung diseases, and tobacco use were significantly more common in persons with nontuberculous mycobacteria-related deaths.

Conclusions

Nontuberculous mycobacteria-related death numbers are rising and are unevenly distributed. The strong association of nontuberculous mycobacterial disease with age suggests that its prevalence will increase as the United States population ages.

Systematic review of validation studies of the use of administrative data to identify serious infections

OBJECTIVE

To conduct a systematic review of the literature on the validation of algorithms identifying infections in administrative data for future use in populations with rheumatic diseases.

METHODS

Medline and EMBase were searched using the themes "administrative data" and "infection" between 1950 and October 2012. Inclusion criteria consisted of validation studies of administrative data identifying infections in adult populations. Article quality was assessed using a validated tool.

RESULTS

A total of 5,941 articles were identified, 90 articles underwent detailed review, and 24 studies were included. The majority (17 of 24) examined bacterial infections and 9 examined opportunistic infections. Eighteen studies were from the US and all but 4 studies used International Classification of Diseases, Ninth Revision codes. Rheumatoid arthritis patients were studied in 6 of 24 articles. The studies on bacterial infections in general reported highly variable sensitivity and positive predictive value (PPV) for the diagnosis of infections using administrative data (sensitivity range 4.4-100%, PPV range 21.7-100%). Algorithms to identify opportunistic infections similarly had a highly variable sensitivity (range 20-100%) and PPV (range 1.3-100%). Thirteen studies compared the diagnostic accuracy of different algorithms, which revealed that strategies including a comprehensive algorithm using a greater number of diagnostic codes or codes in any position had the highest sensitivity for the diagnosis of infection. Algorithms that incorporated microbiologic or pharmacy data in combination with diagnostic codes had improved PPV for identification of tuberculosis.

CONCLUSION

Algorithms for identifying infections using administrative data should be selected based on the purpose of the study, with careful consideration as to whether a high sensitivity or PPV is required.

[Multiple sclerosis as an adverse effect of anti-tumor necrosis factor agents: an infrequent but important complication of infliximab in Crohn's disease]

Anti-tumor necrosis factor alpha (TNF-α) agents have been a great advantage in the treatment of inflammatory bowel disease. The safety profile of these agents is well-known and they can be considered safe when properly used. In clinical practice, the most important adverse events are infections. Other adverse effects are also possible but are much less frequent. However, because of the widespread use of these drugs, these uncommon adverse effects may also occur in clinical practice. We report one of these infrequent adverse events, multiple sclerosis, which is rare but important because of its severity. When neurological symptoms appear during treatment with anti-TNF-α, multiple sclerosis must be ruled out. The diagnosis and therapeutic management of this entity, led by a neurologist with our collaboration, required permanent cessation of anti-TNF-α therapy. Azathioprine, interferon, and even natalizumab, may be used as alternatives in patients who require therapy.

Infections and biologic therapy in rheumatoid arthritis: our changing understanding of risk and prevention

Patients with rheumatoid arthritis are at higher risk for serious infections and death from infection than the general public. Prednisone and biologic agents increase this risk, although the risk associated with biologics can be mitigated when such agents act as prednisone-sparing therapies. Some of the important causes of infectious morbidity in this setting are preventable with screening (eg, tuberculosis) or vaccination (eg, herpes zoster).

Spatial clusters of nontuberculous mycobacterial lung disease in the United States

RATIONALE

Prevalence of pulmonary nontuberculous mycobacterial (PNTM) disease varies by geographic region, yet the factors driving these differences remain largely unknown.

OBJECTIVES

To identify spatial clusters of PNTM disease at the county level and to describe environmental and sociodemographic factors predictive of disease.

METHODS

PNTM cases identified from a nationally representative sample of Medicare Part B beneficiaries from 1997 to 2007 were geocoded by county and state of residence. County-level PNTM case counts and Medicare population data were then uploaded into SaTScan to identify significant spatial clusters and low-risk areas of disease. High-risk and low-risk counties were then compared to identify significant sociodemographic and environmental differences.

MEASUREMENTS AND MAIN RESULTS

We identified seven significant (P < 0.05) clusters of PNTM cases. These high-risk areas encompassed 55 counties in 8 states, including parts of California, Florida, Hawaii, Louisiana, New York, Oklahoma, Pennsylvania, and Wisconsin. Five low-risk areas were also identified, which encompassed 746 counties in 23 states, mostly in the Midwest. Counties in high-risk areas were significantly larger, had greater population densities, and higher education and income levels than low-risk counties. High-risk counties also had higher mean daily potential evapotranspiration levels and percentages covered by surface water, and were more likely to have greater copper and sodium levels in the soil, although lower manganese levels.

CONCLUSIONS

Specific environmental factors related to soil and water exposure appear to increase the risk of PNTM infection. Still, given that environmental sources of NTM are ubiquitous and PNTM disease is rare, both host susceptibility and environmental factors must be considered in explaining disease development.

Accuracy of pharmacy and coded-diagnosis information in identifying tuberculosis in patients with rheumatoid arthritis

PURPOSE

Previous studies suggest that disease-modifying anti-rheumatic drugs (DMARDs) increase tuberculosis (TB) risk. The accuracy of pharmacy and coded-diagnosis information to identify persons with TB is unclear.

METHODS

Within a cohort of rheumatoid arthritis (RA) patients (2000-2005) enrolled in Tennessee Medicaid, we identified those with potential TB using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9-CM) diagnosis codes and/or pharmacy claims. Using the Tennessee TB registry as the gold standard for identification of TB, we estimated the sensitivity, specificity, predictive values, and the respective 95% confidence intervals for each TB case-ascertainment strategy.

RESULTS

Ten of 18,094 RA patients had confirmed TB during 61,461 person-years of follow-up (16.3 per 100,000 person-years). The sensitivity and positive predictive value (PPV) and respective 95% confidence intervals were low for confirmed TB based on ICD9-CM codes alone (60.0% (26.2-87.8) and 1.3% (0.5-2.9)), pharmacy data alone (20% (2.5-55.6) and 4.1% (0.5-14.3)), and both (20% (2.5-55.6) and 25.0% (3.2-65.1)).

CONCLUSIONS

Algorithms that use administrative data alone to identify TB have a poor PPV that results in a high false positive rate of TB detection.