Cost analysis of a nucleic acid amplification test in the diagnosis of pulmonary tuberculosis at an urban hospital with a high prevalence of TB/HIV

Measurement of diabetes, prediabetes and their associated risk factors in Myanmar 2014

BACKGROUND

Myanmar, a low-income Southeast Asia country with an estimated population of 53.9 million, is currently facing an increasing burden of noncommunicable diseases. Research that systematically measures and reports the national prevalence of diabetes and prediabetes within Myanmar represents a gap in the literature. This study, a national survey, was conducted with the objectives of 1) measuring diabetic population, 2) measuring the prediabetic population, and 3) finding out the risk factors leading to diabetes and prediabetes in Myanmar.

METHOD

Multistage sampling was applied in proportional cluster approach to recruit a nationally representative sample of 8,575 participants from 52 townships selected to represent 332 townships across the country. The Ethical Committee of the Department of Medical Research (Lower Myanmar) approved the current study. Fasting plasma glucose and the level of glucose 2 hours after 75 g glucose load were applied, to screen for diabetes and prediabetes. Interviewer-administered questionnaires were carried out to investigate demographic and lifestyle behaviors. Stadiometer, weighing scale, measuring tape, and Omron blood pressure monitor measuring devices were used for the anthropometric measurements. Survey data analysis used STATA version 13 and application of descriptive statistics with multinomial logistic regression.

RESULT

Prevalence of diabetes in Myanmar was 10.8%: 11.5% in males and 9.2% in females. Overall prevalence of prediabetes was 19.7%: 16.5% in males and 23% in females. Increasing age, urban residence, big waist circumference, and high triglyceride level were significant factors associated with diabetes and prediabetes. Many people with diabetes were found to lack knowledge and awareness of diabetes.

CONCLUSION

Diabetes prevalence in Myanmar is high, and relatively higher than that reported in many Association of Southeast Asian Nations countries. The study findings call for urgent nationwide public health action in Myanmar such as screening people at risk of diabetes and prevention of the disease. The findings can also assist the health authority in Myanmar with the preparation and allocation of resources for diabetes prevention.

A scoping review on the field validation and implementation of rapid diagnostic tests for vector-borne and other infectious diseases of poverty in urban areas

BACKGROUND

Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings. There is a need to know what rapid diagnostic technologies are available, have been properly assessed, and are being implemented to improve control of these diseases in the urban context. This paper characterizes evidence on the field validation and implementation in urban areas of rapid diagnostics for vector-borne diseases and other diseases of poverty.

MAIN BODY

A scoping review was conducted. Peer-reviewed and grey literature were searched using terms describing the targeted infectious diseases, diagnostics evaluations, rapid tests, and urban setting. The review was limited to studies published between 2000 and 2016 in English, Spanish, French, and Portuguese. Inclusion and exclusion criteria were refined post hoc to identify relevant literature regardless of study design and geography. A total of 179 documents of the 7806 initially screened were included in the analysis. Malaria (n = 100) and tuberculosis (n = 47) accounted for the majority of studies that reported diagnostics performance, impact, and implementation outcomes. Fewer studies, assessing mainly performance, were identified for visceral leishmaniasis (n = 9), filariasis and leptospirosis (each n = 5), enteric fever and schistosomiasis (each n = 3), dengue and leprosy (each n = 2), and Chagas disease, human African trypanosomiasis, and cholera (each n = 1). Reported sensitivity of rapid tests was variable depending on several factors. Overall, specificities were high (> 80%), except for schistosomiasis and cholera. Impact and implementation outcomes, mainly acceptability and cost, followed by adoption, feasibility, and sustainability of rapid tests are being evaluated in the field. Challenges to implementing rapid tests range from cultural to technical and administrative issues.

CONCLUSIONS

Rapid diagnostic tests for vector-borne and other diseases of poverty are being used in the urban context with demonstrated impact on case detection. However, most evidence comes from malaria rapid diagnostics, with variable results. While rapid tests for tuberculosis and visceral leishmaniasis require further implementation studies, more evidence on performance of current tests or development of new alternatives is needed for dengue, Chagas disease, filariasis, leptospirosis, enteric fever, human African trypanosomiasis, schistosomiasis and cholera.

Diagnostic accuracy of nucleic acid amplification tests (NAATs) in urine for genitourinary tuberculosis: a systematic review and meta-analysis

BACKGROUND

Genitourinary tuberculosis is the third most common form of extrapulmonary tuberculosis. Diagnosis is difficult because of unspecific clinical manifestations and low accuracy of conventional tests. Unfortunately, the delayed diagnosis impacts the urinary tract severely. Nucleic acid amplification tests yield fast results, and among these, new technologies can also detect drug resistance. There is lack of consensus regarding the use of these tests in genitourinary tuberculosis; we therefore aimed to assess the accuracy of nucleic acid amplification tests in the diagnosis of genitourinary tuberculosis and to evaluate the heterogeneity between studies.

METHODS

We did a systematic review and meta-analysis of research articles comparing the accuracy of a reference standard and a nucleic acid amplification test for diagnosis of urinary tract tuberculosis. We searched Medline, EMBASE, Web of Science, LILACS, Cochrane Library, and Scopus for articles published between Jan 1, 1990, and Apr 14, 2016. Two investigators identified eligible articles and extracted data for individual study sites. We analyzed data in groups with the same index test. Then, we generated pooled summary estimates (95% CIs) for sensitivity and specificity by use of random-effects meta-analysis when studies were not heterogeneous.

RESULTS

We identified eleven relevant studies from ten articles, giving information on PCR, LCR and Xpert MTB/RIF tests. All PCR studies were "in-house" tests, with different gene targets and had several quality concerns therefore we did not proceed with a pooled analysis. Only one study used LCR. Xpert studies were of good quality and not heterogeneous, pooled sensitivity was 0·87 (0·66-0·96) and specificity was 0·91 (0·84-0·95).

CONCLUSION

PCR studies were highly heterogeneous. Among Xpert MTB/RIF studies, specificity was favorable with an acceptable confidence interval, however new studies can update meta-analysis and get more precise estimates. Further high-quality studies are urgently needed to improve diagnosis of genitourinary tuberculosis.

PROTOCOL REGISTRATION

PROSPERO CRD42016039020.

Clinical Impact of Nucleic Acid Amplification Testing in the Diagnosis of Mycobacterium Tuberculosis: A 10-Year Longitudinal Study

BACKGROUND

Nucleic acid amplification (NAA) testing for Mycobacterium tuberculosis (MTB) offers improved diagnostic accuracy, compared with smear microscopy, in differentiating MTB from other mycobacteria. We aimed to evaluate the reliability and projected impact of NAA testing in patients with acid-fast bacilli (AFB) smear-positive respiratory samples.

METHODS

We identified a retrospective cohort of all patients with AFB smear-positive respiratory specimens at Henry Ford Hospital from January 1, 2001 through December 31, 2011. We examined the association between patients' sociodemographic factors and clinical comorbidities with the likelihood of being diagnosed with MTB. We evaluated the projected change in duration of airborne isolation and unnecessary MTB treatment with introducing NAA testing into clinical decision making for AFB smear-positive patients.

RESULTS

One hundred thirty patients had AFB smear-positive respiratory specimens, 80 of these patients had a positive NAA test result, and 82 patients grew MTB on culture. Nucleic acid amplification testing had a sensitivity and specificity of 97.6% and 100%, respectively. Integrating NAA testing into clinical decision making for patients with AFB-positive smears was associated with a significantly shorter time in airborne isolation (6.0 ± 7.6 vs 23.1 ± 38.0, P < .001) and 9.5 ± 11.32 fewer days of unnecessary MTB treatment in patients with negative NAA test.

CONCLUSIONS

Nucleic acid amplification testing provided a rapid and accurate test in the diagnosis of MTB while significantly reducing the duration of isolation and unnecessary medications in patients with negative NAA test.

Clinical Impact and Cost-effectiveness of Xpert MTB/RIF Testing in Hospitalized Patients With Presumptive Pulmonary Tuberculosis in the United States

Background

Microscopic examination of acid-fast-stained sputum smears is the current standard of care in the United States to determine airborne infection isolation (AII) of inpatients with presumptive pulmonary tuberculosis (PTB). However, nucleic acid amplification testing (NAAT) with the Xpert MTB/RIF assay (Xpert) may be more efficient and less costly.

Methods

This prospective observational cohort study enrolled a consecutive sample of 318 AII-eligible inpatients from a public hospital in Seattle, Washington, from March 2012 to October 2013. Sputum samples were collected from each inpatient and analyzed using smear microscopy, culture, drug susceptibility testing, and NAAT. The performance, clinical utility (AII duration and survival), and cost-effectiveness from an institutional perspective were compared for 5 testing strategies.

Results

Among the 318 admissions with presumptive PTB, 20 (6.3%) were culture-positive for Mycobacterium tuberculosis. The sensitivity of 1 Xpert, 2 Xperts, 2 smears, or 3 smears compared to culture was 0.85 (95% confidence interval [CI], .61–.96), 0.95 (95% CI, .73–1.0), 0.70 (95% CI, .46–.88), and 0.80 (95% CI, .56–.93), respectively. A cost-effectiveness analysis of the study results demonstrated that an Xpert test on 1 unconcentrated sputum sample (assuming equivalent results for unconcentrated and concentrated sputum samples) is the most cost-effective strategy (99.9% preferred at willingness-to-pay of US$50000) and on average would save 51.5 patient-hours in AII and up to $11466 relative to microscopy without a compromise in sensitivity.

Conclusions

In hospitalized patients with presumptive PTB in a low-burden setting, NAAT can reduce AII and is comparably sensitive, more specific, and more cost-effective than smear microscopy.

Cost–benefit analysis of Xpert MTB/RIF for tuberculosis suspects in German hospitals

Our objective was to assess the cost–benefit of enhancing or replacing the conventional sputum smear with the real-time PCR Xpert MTB/RIF method in the inpatient diagnostic schema for tuberculosis (TB).

Recent data from published per-case cost studies for TB/multidrug-resistant (MDR)-TB and from comparative analyses of sputum microscopy, mycobacterial culture, Xpert MTB/RIF and drug susceptibility testing, performed at the German National Reference Center for Mycobacteria, were used. Potential cost savings of Xpert MTB/RIF, based on test accuracy and multiple cost drivers, were calculated for diagnosing TB/MDR-TB suspects from the hospital perspective.

Implementing Xpert MTB/RIF as an add-on in smear-positive and smear-negative TB suspects saves on average €48.72 and €503, respectively, per admitted patient as compared with the conventional approach. In smear-positive and smear-negative MDR-TB suspects, cost savings amount to €189.56 and €515.25 per person, respectively. Full replacement of microscopy by Xpert MTB/RIF saves €449.98. In probabilistic Monte-Carlo simulation, adding Xpert MTB/RIF is less costly in 46.4% and 76.2% of smear-positive TB and MDR-TB suspects, respectively, but 100% less expensive in all smear-negative suspects. Full replacement by Xpert MTB/RIF is also consistently cost-saving.

Using Xpert MTB/RIF as an add-on to and even as a replacement for sputum smear examination may significantly reduce expenditures in TB suspects.

Diagnostic Value of Convex Probe Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Mediastinal Tuberculous Lymphadenitis: A Systematic Review and Meta-Analysis

Background

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been widely used in the diagnosis of mediastinal lymphadenopathies. Here, we performed a systematic review and meta-analysis to explore the diagnostic value of EBUS-TBNA in mediastinal tuberculous lymphadenopathy (TBLA).

Material/Methods

PubMed, EMBASE, and Sinoced were systematically searched for articles published in English or Chinese that reported the diagnostic yield of EBUS-TBNA in mediastinal TBLA. The quality of studies was assessed using the QualSyst tool. Using 95% confidence intervals (CI), the diagnostic yields of EBUS-TBNA were calculated for the individual studies, and the results were then pooled using a random-effects model. Heterogeneity and publication bias were also assessed.

Results

A total of 14 studies, consisting of 684 patients with mediastinal TBLA, were finally included. The pooled diagnostic yield of EBUS-TBNA for mediastinal TBLA was 80% (95% CI: 74–86%). Significant heterogeneity (I²=77.9%) and significant publication bias were detected (Begg’s test p=0.05 and Egger’s test p=0.02). From subgroup analyses, significant differences in the diagnostic yield of EBUS-TBNA were associated with Asian vs. European (UK) studies, retrospective vs. prospective studies, those employing rapid on-site cytological evaluation vs. not, those employing different anesthetic types, and those employing smear vs. culture. However, microbiological examination and the number of lymph node passes did not have a significant effect on the diagnostic yield of EBUS-TBNA. Fifteen minor complications for EBUS-TBNA were reported.

Conclusions

EBUS-TBNA appears to be an efficacious and safe procedure and should be used as an initial diagnostic tool for mediastinal TBLA.