Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-17 (of 17 Records) |
Query Trace: Chen MP[original query] |
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Estimating county-level vaccination coverage using small area estimation with the National Immunization Survey-Child
Seeskin ZH , Ganesh N , Maitra P , Herman P , Wolter KM , Copeland KR , English N , Chen MP , Singleton JA , Santibanez TA , Yankey D , Elam-Evans LD , Sterrett N , Smith CS , Gipson K , Meador S . Vaccine 2023 The National Immunization Survey-Child (NIS-Child) provides annual vaccination coverage estimates in the United States for children aged 19 through 35 months, nationally, for each state, and for select local areas and territories. There is a need for vaccination coverage estimates for smaller geographic areas to support local authority planning and identify counties with potentially low vaccination coverage for possible further intervention. We describe small area estimation methods using 2008-2018 NIS-Child data to generate county-level estimates for children up to two years of age born 2007-2011 and 2012-2016. We applied an empirical best linear unbiased prediction method to combine direct estimates of vaccination coverage with model-based prediction using county-level predictors regarding health and demographic characteristics. We review the predictors commonly selected for the small area models and note multiple predictors related to barriers to vaccination. |
Symptoms and systemic drug reactions in persons receiving weekly rifapentine plus isoniazid (3HP) treatment for latent tuberculosis infection
Sadowski C , Belknap R , Holland DP , Moro RN , Chen MP , Wright A , Millet JP , Cayla JA , Scott NA , Borisov A , Gandhi NR . Clin Infect Dis 2023 76 (12) 2090-2097 BACKGROUND: Three months of weekly rifapentine plus isoniazid (3HP) therapy for latent tuberculosis infections (LTBI) is recommended worldwide. The development of symptoms and systemic drug reactions (SDR) on 3HP have not been fully characterized. We aimed to determine the patterns of symptom development and identify SDR and associated factors in patients on 3HP. METHODS: We analyzed symptoms data in participants undergoing 3HP in Tuberculosis Trials Consortium's (TBTC) iAdhere study (Study 33). We examined the patterns of symptom reporting across participants from baseline and four monthly visits. Bivariate analyses and multivariable regression models were used to identify factors associated with SDR. Risk ratios and 95% confidence intervals (CI) were calculated. RESULTS: Among 1,002 participants receiving 3HP, 768 (77%) reported at least one symptom; 97% of these symptoms were grade 1 (79%) or grade 2 (18%). Most symptoms developed in the first month and resolved. 111 (11%) participants had symptoms that met criteria for SDR; however, 53 (48%) of these participants completed therapy. Factors associated with SDR and discontinuation included female sex (RR 2.05, CI: 1.19-3.54), age ≥45 years (RR 1.99, CI: 1.19-3.31), and use of concomitant medications (RR 2.26, CI: 1.15-4.42). CONCLUSIONS: Although most patients receiving 3HP reported symptoms, most were mild, occurred early, and resolved without stopping treatment. Among patients experiencing SDR, nearly half were able to complete therapy. Patient and provider education should focus on differentiating severe reactions where 3HP should be stopped from minor symptoms that will resolve. |
Multidrug-resistant tuberculosis in the United States, 2011-2016: patient characteristics and risk factors
Chen MP , Miramontes R , Kammerer JS . Int J Tuberc Lung Dis 2020 24 (1) 92-99 OBJECTIVE: To determine risk factors for multidrug-resistant tuberculosis (MDR-TB) and describe MDR-TB according to three characteristics: previous TB disease, recent transmission of MDR-TB, and reactivation of latent MDR-TB infection.SETTING and DESIGN: We used 2011-2016 surveillance data from the US National Tuberculosis Surveillance System and National Tuberculosis Genotyping Service and used logistic regression models to estimate risk factors associated with MDR-TB.RESULTS: A total of 615/45 209 (1.4%) cases were confirmed as MDR-TB; 111/615 (18%) reported previous TB disease; 41/615 (6.7%) were attributed to recent MDR-TB transmission; and 449/615 (73%) to reactivation. Only 12/41 (29%) patients with TB attributed to recent transmission were known to be contacts of someone with MDR-TB. For non-US-born patients, the adjusted odds ratios of having MDR-TB were 32.6 (95%CI 14.6-72.6) among those who were known to be contacts of someone with MDR-TB and 6.5 (95%CI 5.1-8.3) among those who had had previous TB disease.CONCLUSION: The majority of MDR-TB cases in the United States were associated with previous TB disease or reactivation of latent MDR-TB infection; only a small proportion of MDR-TB cases were associated with recent transmission. |
Isoniazid- and Rifampin-Resistance Mutations Associated with Resistance to Second-line Drugs and with Sputum Culture Conversion.
Click ES , Kurbatova E , Alexander H , Dalton TL , Chen MP , Posey JE , Ershova JJ , Cegielski P . J Infect Dis 2020 221 (12) 2072-2082 BACKGROUND: Mutations in the genes inhA, katG and rpoB confer resistance to anti-tuberculosis (TB) drugs isoniazid and rifampin. We questioned whether specific mutations in these genes were associated with different clinical and microbiological characteristics. METHODS: In a multi-country prospective cohort study of MDR-TB, we identified inhA, katG and rpoB mutations in sputum isolates using the Hain MTBDRplus line probe assay. For specific mutations, we performed bivariate analysis to determine relative risk of baseline or acquired resistance to other TB drugs. We compared time-to-sputum-culture-conversion (TSCC) using Kaplan-Meier curves and stratified Cox regression. RESULTS: In total, 447 participants enrolled January 2005-December 2008 from seven countries were included. Relative to rpoB S531L, isolates with rpoB D516V had less cross-resistance to rifabutin, increased baseline resistance to other drugs, and increased acquired fluoroquinolone resistance.Relative to mutation of katG only, mutation of inhA promoter and katG was associated with increased acquired fluoroquinolone resistance and slower TSCC (125.5 vs. 89.0 days). CONCLUSIONS: Specific mutations in inhA and katG are associated with differences in resistance to other drugs and TSCC. Molecular testing may make it possible to tailor treatment and assess additional drug resistance risk according to specific mutation profile. |
In reply
Castro KG , Marks SM , Hill AN , Chen MP , Miramontes R , Winston CA , LoBue PA . Int J Tuberc Lung Dis 2017 21 (1) 120-121 We agree with the excellent summary provided by Reves and Benjamin of the important, but insufficient, progress toward tuberculosis (TB) elimination (<1 case per million population) in the United States over the past two decades. Furthermore, we concur with the need to advance the argument in favor of additional investments required to eliminate TB by providing an estimate of future expected benefits. | | While we did not model future projected savings in our report,1 we have undertaken relatively simple retrospective modeling to estimate the reduction in TB cases and societal benefits had TB elimination been achieved in 1995 and sustained through 2014. From this we estimate that during 1995–2014 from 430 397 to 604 494 TB cases would have been averted (Figure 1), at estimated benefits of US $19.9 billion to $27.7 billion, including the value of deaths prevented and the costs to treat drug-resistant TB disease (Figure 2). Projected cases averted and cost savings for two decades into the future would also be anticipated to be substantial, although somewhat less, because even with a flat case rate the projected case counts for the next two decades would be less than those that actually occurred between 1995 and 2014. |
Self-administered versus directly observed once-weekly isoniazid and rifapentine treatment of latent tuberculosis infection: A randomized trial
Belknap R , Holland D , Feng PJ , Millet JP , Cayla JA , Martinson NA , Wright A , Chen MP , Moro RN , Scott NA , Arevalo B , Miro JM , Villarino ME , Weiner M , Borisov AS . Ann Intern Med 2017 167 (10) 689-697 Background: Expanding latent tuberculosis treatment is important to decrease active disease globally. Once-weekly isoniazid and rifapentine for 12 doses is effective but limited by requiring direct observation. Objective: To compare treatment completion and safety of once-weekly isoniazid and rifapentine by self-administration versus direct observation. Design: An open-label, phase 4 randomized clinical trial designed as a noninferiority study with a 15% margin. Seventy-five percent or more of study patients were enrolled from the United States for a prespecified subgroup analysis. (ClinicalTrials.gov: NCT01582711). Setting: Outpatient tuberculosis clinics in the United States, Spain, Hong Kong, and South Africa. Participants: 1002 adults (aged ≥18 years) recommended for treatment of latent tuberculosis infection. Intervention: Participants received once-weekly isoniazid and rifapentine by direct observation, self-administration with monthly monitoring, or self-administration with weekly text message reminders and monthly monitoring. Measurements: The primary outcome was treatment completion, defined as 11 or more doses within 16 weeks and measured using clinical documentation and pill counts for direct observation, and self-reports, pill counts, and medication event-monitoring devices for self-administration. The main secondary outcome was adverse events. Results: Median age was 36 years, 48% of participants were women, and 77% were enrolled at the U.S. sites. Treatment completion was 87.2% (95% CI, 83.1% to 90.5%) in the direct-observation group, 74.0% (CI, 68.9% to 78.6%) in the self-administration group, and 76.4% (CI, 71.3% to 80.8%) in the self-administration-with-reminders group. In the United States, treatment completion was 85.4% (CI, 80.4% to 89.4%), 77.9% (CI, 72.7% to 82.6%), and 76.7% (CI, 70.9% to 81.7%), respectively. Self-administered therapy without reminders was noninferior to direct observation in the United States; no other comparisons met noninferiority criteria. A few drug-related adverse events occurred and were similar across groups. Limitation: Persons with latent tuberculosis infection enrolled in South Africa would not routinely be treated programmatically. Conclusion: These results support using self-administered, once-weekly isoniazid and rifapentine to treat latent tuberculosis infection in the United States, and such treatment could be considered in similar settings when direct observation is not feasible. Primary Funding Source: Centers for Disease Control and Prevention. |
Three months of weekly rifapentine and isoniazid for treatment of Mycobacterium tuberculosis infection in HIV-coinfected persons
Sterling TR , Scott NA , Miro JM , Calvet G , La Rosa A , Infante R , Chen MP , Benator DA , Gordin F , Benson CA , Chaisson RE , Villarino ME . AIDS 2016 30 (10) 1607-15 OBJECTIVE: Compare the effectiveness, tolerability, and safety of 3 months of weekly rifapentine and isoniazid under direct observation (3HP) versus 9 months of daily isoniazid (9H) in HIV-infected persons. DESIGN: Prospective, randomized, and open-label noninferiority trial. SETTING: The United States , Brazil, Spain, Peru, Canada, and Hong Kong. PARTICIPANTS: HIV-infected persons who were tuberculin skin test positive or close contacts of tuberculosis cases. INTERVENTION: 3HP versus 9H. MAIN OUTCOME MEASURES: The effectiveness endpoint was tuberculosis; the noninferiority margin was 0.75%. The tolerability endpoint was treatment completion; the safety endpoint was drug discontinuation because of adverse drug reaction. RESULTS: Median baseline CD4 cell counts were 495 (IQR 389-675) and 538 (IQR 418-729) cells/mul in the 3HP and 9H arms, respectively (P = 0.09). In the modified intention-to-treat analysis, there were two tuberculosis cases among 206 persons [517 person-years (p-y) of follow-up] in the 3HP arm (0.39 per 100 p-y) and six tuberculosis cases among 193 persons (481 p-y of follow-up) in the 9H arm (1.25 per 100 p-y). Cumulative tuberculosis rates were 1.01 versus 3.50% in the 3HP and 9H arms, respectively (rate difference: -2.49%; upper bound of the 95% confidence interval of the difference: 0.60%). Treatment completion was higher with 3HP (89%) than 9H (64%) (P < 0.001), and drug discontinuation because of an adverse drug reaction was similar (3 vs. 4%; P = 0.79) in 3HP and 9H, respectively. CONCLUSION: Among HIV-infected persons with median CD4 cell count of approximately 500 cells/mul, 3HP was as effective and safe for treatment of latent Mycobacterium tuberculosis infection as 9H, and better tolerated. |
Estimating tuberculosis cases and their economic costs averted in the United States over the past two decades
Castro KG , Marks SM , Chen MP , Hill AN , Becerra JE , Miramontes R , Winston CA , Navin TR , Pratt RH , Young KH , LoBue PA . Int J Tuberc Lung Dis 2016 20 (7) 926-33 BACKGROUND: Following a concerted public health response to the resurgence of tuberculosis (TB) in the United States in the late 1980s, annual TB incidence decreased substantially. However, no estimates exist of the number and cost savings of TB cases averted. METHODS: TB cases averted in the United States during 1995-2014 were estimated: Scenario 1 used a static 1992 case rate; Scenario 2 applied the 1992 rate to foreign-born cases, and a pre-resurgence 5.1% annual decline to US-born cases; and a statistical model assessed human immunodeficiency virus and TB program indices. We applied the cost of illness to estimate the societal benefits (costs averted) in 2014 dollars. RESULTS: During 1992-2014, 368 184 incident TB cases were reported, and cases decreased by two thirds during that period. In the scenarios and statistical model, TB cases averted during 1995-2014 ranged from approximately 145 000 to 319 000. The societal benefits of averted TB cases ranged from US$3.1 to US$6.7 billion, excluding deaths, and from US$6.7 to US$14.5 billion, including deaths. CONCLUSIONS: Coordinated efforts in TB control and prevention in the United States yielded a remarkable number of TB cases averted and societal economic benefits. We illustrate the value of concerted action and targeted public health funding. |
Risk factors for transmission of tuberculosis among United States-born African Americans and Whites
Pagaoa MA , Royce RA , Chen MP , Golub JE , Davidow AL , Hirsch-Moverman Y , Marks SM , Teeter LD , Thickstun PM , Katz DJ . Int J Tuberc Lung Dis 2015 19 (12) 1485-92 SETTING: Tuberculosis (TB) patients and their contacts enrolled in nine states and the District of Columbia from 16 December 2009 to 31 March 2011. OBJECTIVE: To evaluate characteristics of TB patients that are predictive of tuberculous infection in their close contacts. DESIGN: The study population was enrolled from a list of eligible African-American and White TB patients from the TB registry at each site. Information about close contacts was abstracted from the standard reports of each site. RESULTS: Close contacts of African-American TB patients had twice the risk of infection of contacts of White patients (adjusted risk ratio [aRR] 2.1, 95%CI 1.3-3.4). Close contacts of patients whose sputum was positive for acid-fast bacilli on sputum smear microscopy had 1.6 times the risk of tuberculous infection compared to contacts of smear-negative patients (95%CI 1.1-2.3). TB patients with longer (>3 months) estimated times to diagnosis did not have higher proportions of infected contacts (aRR 1.2, 95%CI 0.9-1.6). CONCLUSION: African-American race and sputum smear positivity were predictive of tuberculous infection in close contacts. This study did not support previous findings that longer estimated time to diagnosis predicted tuberculous infection in contacts. |
Multidrug-resistant tuberculosis treatment outcomes in relation to treatment, initial and acquired second-line drug resistance
Cegielski JP , Kurbatova E , van der Walt M , Brand J , Ershova J , Tupasi T , Campos Caoili J , Dalton T , Contreras C , Yagui M , Bayona J , Kvasnovsky C , Leimane V , Kuksa L , Chen MP , Via LE , Hwang SH , Wolfgang M , Volchenkov GV , Somova T , Smith SE , Akksilp S , Wattanaamornkiet W , Kim HJ , Kim CK , Kazennyy BY , Khorosheva T , Kliiman K , Viiklepp P , Jou R , Huang AS , Vasilyeva IA , Demikhova OV . Clin Infect Dis 2015 62 (4) 418-430 BACKGROUND: Resistance to second-line drugs (SLD) develops during treatment of multidrug-resistant (MDR) tuberculosis (TB), but the impact on treatment outcome has not been determined. OBJECTIVES: To determine the relationship with treatment outcomes of (1) initial versus acquired drug resistance and (2) treatment regimens. METHODS: MDR-TB patients starting SLD treatment were enrolled in a prospective cohort study. Sputum cultures were analyzed at a central reference laboratory. We compared subjects with successful and poor treatment outcomes in terms of (1) initial and acquired resistance to fluoroquinolones and second-line injectables (SLI), and (2) treatment regimens. RESULTS: Of 1,244 MDR-TB patients, 973 (78.2%) had known outcomes and 232 (18.6%) were lost to follow-up. Among those with known outcomes, treatment succeeded in 85.8% with plain MDR-TB, 69.7% with initial resistance to either a fluoroquinolone or SLI, 37.5% with acquired resistance to a fluoroquinolone or SLI, 29.3% with initial XDR-TB, and 13.0% with acquired XDR-TB (P<0.0001 for trend). In contrast, among those with known outcomes, treatment success increased stepwise from 41.6% to 92.3% as the number of proven effective drugs increased from ≤1 to ≥5 (P<0.0001 for trend); while acquired drug resistance decreased from 12%-16% range, depending on the drug, down to 0%-2% (P<0.0001 for trend). In multivariable analysis, the adjusted odds of treatment success decreased 0.62-fold (CL 0.56,0.69) for each increment in drug resistance and increased 2.1-fold (1.40,3.18) for each additional effective drug, controlling for differences between programs and patients. Specific treatment, patient and program variables were also associated with treatment outcome. CONCLUSION: Increasing drug resistance was associated in a logical stepwise manner with poor treatment outcomes. Acquired resistance was worse than initial resistance to the same drugs. Increasing numbers of effective drugs, specific drugs, and specific program characteristics were associated with better outcomes and less acquired resistance. |
Reply to Soman et al, Alffenaar et al, Metcalfe et al, and Raoult
Cegielski JP , Chen MP , Tupasi TE , Leimane V , Volchenkov GV . Clin Infect Dis 2014 60 (6) 971-3 We thank Metcalfe et al, Alffenaar et al, Soman et al, and Raoult for their interest in our study [1]. Metcalfe et al raise 2 issues about the analysis and reporting of results [2]. Alffenaar and colleagues raise issues related to drug dosing [3]. Soman and colleagues raise concern about standardized treatment regimens [4]. Raoult refers to the potential utility of existing drugs that are not standard antituberculosis drugs [5]. We respond to each of these letters in turn. | Metcalfe and colleagues suggest that patients who remain culture negative after 1 month of treatment could not have acquired drug resistance and therefore might have been included in the denominator when calculating the proportion of patients with acquired drug resistance [2]. However, the reality and the math are more complicated for at least 3 reasons. First, we disagree that the target population “is presented as all patients with MDR [multidrug-resistant] tuberculosis starting treatment with [second-line drugs].” The target population for this analysis was patients with at least one positive follow-up cultures as displayed in our Figure 1 [1]. Second, we described the excluded subset of patients as having no positive follow-up cultures rather than as having all negative follow-up cultures because these are not the same: 20.8% of the excluded group of patients did not complete treatment (ie, were classified as defaulting) after a median of <12 months (interquartile range, 5–16 months). Because “default” is a World Health Organization (WHO)–defined standard outcome category [6], it was the endpoint in our follow-up of these patients, and we cannot know whether these patients had any subsequent positive cultures. However, the duration of treatment for this group of patients is inadequate. These patients would be at high risk for again becoming culture positive and for acquired drug resistance. Third, many of these patients already had baseline resistance to fluoroquinolones, second-line injectable drugs, or both. It would not be appropriate to include them in the denominator when calculating the frequency of acquired resistance to these same drugs. The exact percentages are uncertain because we did not receive baseline cultures for all these patients and did not recover viable mycobacteria from all cultures received. However, of the 340 viable baseline isolates we received among patients with no positive follow-up cultures, 6.8% had fluoroquinolone resistance, 8.5% had resistance to 1 or more second-line injectable drugs, 11.8% had resistance to either, and 3.5% had resistance to both. |
Extensive drug resistance acquired during treatment of multidrug-resistant tuberculosis
Cegielski JP , Dalton T , Yagui M , Wattanaamornkiet W , Volchenkov GV , Via LE , Van Der Walt M , Tupasi T , Smith SE , Odendaal R , Leimane V , Kvasnovsky C , Kuznetsova T , Kurbatova E , Kummik T , Kuksa L , Kliiman K , Kiryanova EV , Kim H , Kim CK , Kazennyy BY , Jou R , Huang WL , Ershova J , Erokhin VV , Diem L , Contreras C , Cho SN , Chernousova LN , Chen MP , Caoili JC , Bayona J , Akksilp S . Clin Infect Dis 2014 59 (8) 1049-63 INTRODUCTION: Increasing access to drugs for the treatment of multidrug-resistant (MDR) tuberculosis (TB) is crucial but could lead to increasing resistance to these same drugs. In 2000, the international Green Light Committee (GLC) initiative began to increase access while attempting to prevent acquired resistance. SUBJECTS AND METHODS: To assess the GLC's impact, we followed adults with pulmonary MDRTB from the start to the end of treatment with monthly sputum cultures, drug susceptibility testing, and genotyping. We compared the frequency and predictors of acquired resistance to second-line drugs (SLD) in nine countries that volunteered to participate, five countries that met GLC criteria and four countries that did not apply to the GLC. RESULTS: In total, 832 subjects were enrolled. Of those without baseline resistance to specific SLDs, 68 (8.9%) acquired extensively drug-resistant (XDR) TB, 79 (11.2%) acquired fluoroquinolone (FQ) resistance, and 56 (7.8%) acquired resistance to second-line injectable drugs (SLI). The relative risk (95% confidence interval) of acquired resistance was lower at GLC-approved sites: 0.27 (0.16,0.47) for XDRTB, 0.28 (0.17,0.45) for FQ, and 0.15 (0.06,0.39) to 0.60 (0.34,1.05) for three different SLI. The risk increased as the number of potentially effective drugs decreased. Controlling for baseline drug resistance and differences between sites, the odds ratios were 0.21 (0.07,0.62) for acquired XDRTB and 0.23 (0.09,0.59) for acquired FQ resistance. CONCLUSIONS: Treatment of MDRTB involves substantial risk of acquired resistance to SLD, increasing as baseline drug resistance increases. The risk was significantly lower in programs documented by the GLC to meet specific standards. |
Patterns of treatment interruption among patients with multidrug-resistant TB (MDR TB) and association with interim and final treatment outcomes
Podewils LJ , Gler MT , Quelapio MI , Chen MP . PLoS One 2013 8 (7) e70064 BACKGROUND: The reasons that patients with multidrug-resistant tuberculosis (MDR TB) miss treatment are multi-factorial and complex. Identifying patterns of treatment interruption that predict poor outcomes can be used to target program activities aiming to improve treatment adherence. OBJECTIVE: To characterize patterns of treatment interruption among MDR TB patients and determine the association between patterns and treatment outcomes. METHODS: Retrospective analysis of MDR TB patients. A treatment interruption was defined as any time that a patient missed a prescribed dose of treatment for at least 1 day but for a period of less than 2 consecutive months. Patients were characterized by the number, length and variability of interruptions, variability of time between interruptions, and percent of missed doses. Final treatment outcome was dichotomized as a successful (cured or completed) or poor outcome (defaulted, failed, or died). Risk ratios were calculated to determine the association between characteristics of treatment interruption and treatment outcomes. All analyses were conducted in 6 month treatment intervals. RESULTS: Only 7.0% of 583 patients completed treatment without interruption. Of the remaining 542 patients, the median time to the first interruption was 2 (1/2) months (70 days). In multivariate analysis, patients who had longer interruptions with sporadic variability during the 6-12 month or the 12-18 month treatment period had a significantly increased risk for poor outcomes compared to patients who had short, regular interruptions (RRadj 4.37, 95% CI 1.2-15.8; = 0.03 and RRadj 3.38, 95% CI 1.6-7.1; p = 0.001, respectively). In addition, missing 10% or more of the prescribed doses during any 6 month period in the initial 18 months of therapy significantly increased the risk for poor outcomes (RRadj range 1.55-2.35; p-value range 0.01-0.005). CONCLUSION: Patients that miss more consecutive days of treatment with sporadic interruption patterns or a greater proportion of treatment are at an increased risk for poor treatment outcomes. |
Confidence intervals and statistical testing for ratio measures of percent change
Winston CA , Hill AN , Chen MP , Shang N , Becerra JE . Stat Med 2012 31 (27) 3295-8 In public health and medical research, ratio measures of percent change relative to baseline are often used to express a change in disease incidence. Estimating variance becomes more complex when the comparison is to an expectation based on previous data (E), rather than to an observed value (O). In 2009, the decline in reported tuberculosis (TB) cases was the largest single-year decrease since national TB surveillance began in 1953. To investigate the 2009 TB decline compared with expected counts, we analyzed TB cases reported to the Center for Disease Control and Prevention's National Tuberculosis Surveillance System. We log-transformed case counts for 2000-2008, and performed linear regression stratified by patient and clinical characteristics. We calculated relative declines from expectation as (O - E) E for patient subgroups, and constructed 95% confidence intervals for TB declines. We then formulated a Z-score test statistic comparing declines across patient subgroups under the null hypothesis that the difference of the two ratio measures was zero. We illustrate our methods by comparing 2009 declines from expectation for US-born versus foreign-born patients. Predicted values and confidence intervals assessed the magnitude of unexpected TB declines within patient groups, while statistical tests comparing ratio measures evaluated relative TB declines across groups. (Copyright (c) 2012 John Wiley & Sons, Ltd.) |
A Bayesian analysis of the 2009 decline in tuberculosis morbidity in the United States
Chen MP , Shang N , Winston CA , Becerra JE . Stat Med 2012 31 (27) 3278-84 Although annual data are commonly used to model linear trends and changes in trends of disease incidence, monthly data could provide additional resolution for statistical inferences. Because monthly data may exhibit seasonal patterns, we need to consider seasonally adjusted models, which can be theoretically complex and computationally intensive. We propose a combination of methods to reduce the complexity of modeling seasonal data and to provide estimates for a change in trend when the timing and magnitude of the change are unknown. To assess potential changes in trend, we first used autoregressive integrated moving average (ARIMA) models to analyze the residuals and forecast errors, followed by multiple ARIMA intervention models to estimate the timing and magnitude of the change. Because the variable corresponding to time of change is not a statistical parameter, its confidence bounds cannot be estimated by intervention models. To model timing of change and its credible interval, we developed a Bayesian technique. We avoided the need for computationally intensive simulations by deriving a closed form for the posterior distribution of the time of change. Using a combination of ARIMA and Bayesian methods, we estimated the timing and magnitude of change in trend for tuberculosis cases in the United States. Copyright (c) 2012 John Wiley & Sons, Ltd. |
Unexpected decline in tuberculosis cases coincident with economic recession -- United States, 2009
Winston CA , Navin TR , Becerra JE , Chen MP , Armstrong LR , Jeffries C , Yelk Woodruff RS , Wing J , Starks AM , Hales CM , Kammerer JS , Mac Kenzie WR , Mitruka K , Miner MC , Price S , Scavotto J , Cronin AM , Griffin P , Lobue PA , Castro KG . BMC Public Health 2011 11 (1) 846 BACKGROUND: Since 1953, through the cooperation of state and local health departments, the U.S. Centers for Disease Control and Prevention (CDC) has collected information on incident cases of tuberculosis (TB) disease in the United States. In 2009, TB case rates declined -11.4%, compared to an average annual -3.8% decline since 2000. The unexpectedly large decline raised concerns that TB cases may have gone unreported. To address the unexpected decline, we examined trends from multiple sources on TB treatment initiation, medication sales, and laboratory and genotyping data on culture-positive TB. METHODS: We analyzed 142,174 incident TB cases reported to the U. S. National Tuberculosis Surveillance System (NTSS) during January 1, 2000-December 31, 2009; TB control program data from 59 public health reporting areas; self-reported data from 50 CDC-funded public health laboratories; monthly electronic prescription claims for new TB therapy prescriptions; and complete genotyping results available for NTSS cases. Accounting for prior trends using regression and time-series analyses, we calculated the deviation between observed and expected TB cases in 2009 according to patient and clinical characteristics, and assessed at what point in time the deviation occurred. RESULTS: The overall deviation in TB cases in 2009 was -7.9%, with -994 fewer cases reported than expected (P <.001). We ruled out evidence of surveillance underreporting since declines were seen in states that used new software for case reporting in 2009 as well as states that did not, and we found no cases unreported to CDC in our examination of over 5400 individual line-listed reports in 11 areas. TB cases decreased substantially among both foreign-born and U.S.-born persons. The unexpected decline began in late 2008 or early 2009, and may have begun to reverse in late 2009. The decline was greater in terms of case counts among foreign-born than U.S.-born persons; among the foreign-born, the declines were greatest in terms of percentage deviation from expected among persons who had been in the United States less than 2 years. Among U.S.-born persons, the declines in percentage deviation from expected were greatest among homeless persons and substance users. Independent information systems (NTSS, TB prescription claims, and public health laboratories) reported similar patterns of declines. Genotyping data did not suggest sudden decreases in recent transmission. CONCLUSIONS: Our assessments show that the decline in reported TB was not an artifact of changes in surveillance methods; rather, similar declines were found through multiple data sources. While the steady decline of TB cases before 2009 suggests ongoing improvement in TB control, we were not able to identify any substantial change in TB control activities or TB transmission that would account for the abrupt decline in 2009. It is possible that other multiple causes coincident with economic recession in the United States, including decreased immigration and delayed access to medical care, could be related to TB declines. Our findings underscore important needs in addressing health disparities as we move towards TB elimination in the United States. |
Treatment outcome of multidrug/extensively drug-resistant tuberculosis in Latvia, 2000-2004
Leimane V , Dravniece G , Riekstina V , Sture I , Kammerer S , Chen MP , Skenders G , Holtz TH . Eur Respir J 2010 36 (3) 584-93 In the present study, we characterised drug-resistance patterns, compared treatment outcome between extensively and nonextensively drug-resistant tuberculosis (non-XDR-TB) cases, and assessed risk factors for poor outcome in a high-prevalence country that screens all TB patients for first-line anti-TB drug resistance. We reviewed drug susceptibility test results among all pulmonary TB cases in Latvia diagnosed from 2000-2004, as well as demographic and clinical characteristics, drug-resistance patterns, and treatment outcomes. During the 5-yr period, 1,027 multidrug-resistant tuberculosis (MDR-TB) cases initiated treatment. Among all cases, the proportion that experienced an outcome of cure or completion increased from 66.2 to 70.2% (p = 0.06 for linear trend). Among the 48 (4.7%) XDR-TB cases, 18 (38%) were cured, four (8%) died, three (6%) defaulted, and treatment failed in 23 (48%). In proportional-hazards analysis, characteristics significantly associated with poor outcome included XDR-TB, being retired, presence of bilateral cavitation, and previous MDR-TB treatment history for those aged ≥55 yrs. Overall, treatment success among all MDR-TB cases increased over time. Strategies to prevent transmission of XDR-TB and to further improve treatment outcome are crucial for the future of TB control in Latvia. |
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