The prevalence of tuberculosis infection among foreign-born Canadians: a modelling study

BACKGROUND

The prevalence of tuberculosis infection is critical to the design of tuberculosis prevention strategies, yet is unknown in Canada. We estimated the prevalence of tuberculosis infection among Canadian residents born abroad.

METHODS

We estimated the prevalence of tuberculosis infection by age and year of migration to Canada for people from each of 168 countries by constructing country-specific and calendar year-specific trends for annual risk of infection using a previously developed model. We combined country-specific prevalence estimates with Canadian Census data from 2001, 2006, 2011, 2016 and 2021 to estimate the overall prevalence of tuberculosis infection among foreign-born Canadian residents.

RESULTS

The estimated overall prevalence of tuberculosis infection among foreign-born people in Canada was 25% (95% uncertainty interval [UI] 20%-35%) for census year 2001, 24% (95% UI 20%-33%) for 2006, 23% (95% UI 19%-30%) for 2011, 22% (95% UI 19%-28%) for 2016 and 22% (95% UI 19%-27%) for 2021. The prevalence increased with age at migration and incidence of tuberculosis in the country of origin. In 2021, the estimated prevalence of infection among foreign-born residents was lowest in Quebec (19%, 95% UI 16%-24%) and highest in Alberta (24%, 95% UI 21%-28%) and British Columbia (24%, 95% UI 20%-30%). Among all foreign-born Canadian residents with tuberculosis infection in 2021, we estimated that only 1 in 488 (95% UI 185-1039) had become infected within the 2 preceding years.

INTERPRETATION

About 1 in 4 foreign-born Canadian residents has tuberculosis infection, but very few were infected within the 2 preceding years (the highest risk period for progression to tuberculosis disease). These data may inform future tuberculosis infection screening policies.

Incidence of and Risk Factors for Active Tuberculosis Disease in Individuals With Glomerular Disease: A Canadian Cohort Study

RATIONALE & OBJECTIVE

Kidney failure is an established risk factor for active tuberculosis (TB) but the risk of TB has not been reported in specific kidney diseases. We sought to determine the incidence of and risk factors for active TB in patients with glomerular disease.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

A provincial kidney pathology registry (2000-2012) was used to identify 3,079 adult patients with IgA nephropathy, focal segmental glomerulosclerosis (FSGS), antineutrophil cytoplasmic antibody (ANCA)-related glomerulonephritis, lupus nephritis, membranous nephropathy, minimal change disease, or "other" glomerular diseases in British Columbia, Canada.

EXPOSURE

Predictors included demographics, immigration status, comorbidities, immunosuppression use, estimated glomerular filtration rate (eGFR), and proteinuria.

OUTCOME

A diagnosis of active TB was ascertained using administrative data linkages and defined based on (1) the dispensation of 1 or more unique combinations of medications used to treat active TB, or (2) physician or hospital visits for active TB.

ANALYTICAL APPROACH

The definition of TB was validated in an external cohort linked to the Provincial TB registry at the BC Centre for Disease Control (BCCDC). Standardized incidence ratios were calculated using the age-matched general population. Risk factors for active TB were identified using Cox proportional hazards regression analysis.

RESULTS

The sensitivity and specificity of the outcome definition of active TB were 87.6% and 99.5%, respectively. During a median follow-up of 6.2 years, 41 patients developed active TB with an incidence of 197 of 100,000 person-years, approximately 23 times as high as the general population and>6 times higher than the threshold of 30 per 100,000 used to define high TB incidence. A high incidence was observed in all glomerular diseases (range, 110-403 per 100,000), in both Canadian- and foreign-born patients (range, 124-424 per 100,000), and in patients exposed or not to immunosuppression (282 vs 147 per 100,000). Factors associated with higher TB risk included immigration from a high-incidence country (HR, 3.90 [95% CI, 1.75-8.68]), diminished eGFR (HR, 2.81 [95% CI, 1.18-6.69]), higher levels of proteinuria (HR, 1.15 [95% CI, 1.04-1.27]), lupus nephritis (HR, 2.79 [95% CI, 1.37-5.68]), and immunosuppression use (HR, 2.13 [95% CI, 1.13-4.03]).

LIMITATIONS

A relatively low number of events contributed to uncertainty in risk estimates.

CONCLUSIONS

Patients with glomerular disease have a high incidence of active TB irrespective of disease type, demographics, or use of immunosuppression. Prospective studies are needed to evaluate the utility of screening for latent TB infection in this population.

PLAIN-LANGUAGE SUMMARY

Patients with kidney failure are at high risk of developing tuberculosis (TB), a major infection that can be prevented by identifying and treating patients who have had prior exposure to TB. The risk of TB in specific kidney diseases is unknown. In this Canadian study of 3,079 patients with glomerular disease, a group of autoimmune kidney conditions, the rate of TB was 23 times higher than in the general population. The rate was high irrespective of the use of immunosuppressive drugs or whether patients had immigrated to Canada from another country. These findings suggest that screening patients with glomerular disease for prior TB exposure may be beneficial; however, this needs to be evaluated in a prospective study.

Risk of Tuberculosis Disease in People With Chronic Kidney Disease Without Kidney Failure: A Systematic Review and Meta-analysis

BACKGROUND

Kidney failure is an established risk factor for tuberculosis (TB), but little is known about TB risk in people with chronic kidney disease (CKD) who have not initiated kidney replacement therapy (CKD without kidney failure). Our primary objective was to estimate the pooled relative risk of TB disease in people with CKD stages 3-5 without kidney failure compared with people without CKD. Our secondary objectives were to estimate the pooled relative risk of TB disease for all stages of CKD without kidney failure (stages 1-5) and by each CKD stage.

METHODS

This review was prospectively registered (PROSPERO CRD42022342499). We systematically searched MEDLINE, Embase, and Cochrane databases for studies published between 1970 and 2022. We included original observational research estimating TB risk among people with CKD without kidney failure. Random-effects meta-analysis was performed to obtain the pooled relative risk.

RESULTS

Of the 6915 unique articles identified, data from 5 studies were included. The estimated pooled risk of TB was 57% higher in people with CKD stages 3-5 than in people without CKD (adjusted hazard ratio: 1.57; 95% CI: 1.22-2.03; I2 = 88%). When stratified by CKD stage, the pooled rate of TB was highest in stages 4-5 (incidence rate ratio: 3.63; 95% CI: 2.25-5.86; I2 = 89%).

CONCLUSIONS

People with CKD without kidney failure have an increased relative risk of TB. Further research and modeling are required to understand the risks, benefits, and CKD cutoffs for screening people for TB with CKD prior to kidney replacement therapy.

Distinct healthcare utilization profiles of high healthcare use tuberculosis survivors: A latent class analysis

BACKGROUND

Recent data have demonstrated that healthcare use after treatment for respiratory tuberculosis (TB) remains elevated in the years following treatment completion. However, it remains unclear which TB survivors are high healthcare users and whether any variation exists within this population. Thus, the primary objective of this study was to identify distinct profiles of high healthcare-use TB survivors to help inform post-treatment support and care.

METHODS

Using linked health administrative data from British Columbia, Canada, we identified foreign-born individuals who completed treatment for incident respiratory TB between 1990 and 2019. We defined high healthcare-use TB survivors as those in the top 10% of annual emergency department visits, hospital admissions, or general practitioner visits among the study population during the five-year period immediately following TB treatment completion. We then used latent class analysis to categorize the identified high healthcare-use TB survivors into subgroups.

RESULTS

Of the 1,240 people who completed treatment for respiratory TB, 258 (20.8%) people were identified as high post- TB healthcare users. Latent class analysis results in a 2-class solution. Class 1 (n = 196; 76.0%) included older individuals (median age 71.0; IQR 59.8, 79.0) with a higher probability of pre-existing hypertension and diabetes (41.3% and 33.2%, respectively). Class 2 (n = 62; 24.0%) comprised of younger individuals (median age 31.0; IQR 27.0, 41.0) with a high probability (61.3%) of immigrating to Canada within five years of their TB diagnosis and a low probability (11.3%) of moderate to high continuity of primary care.

DISCUSSION

Our findings suggest that foreign-born high healthcare-use TB survivors in a high-resource setting may be categorized into distinct profiles to help guide the development of person-centred care strategies targeting the long-term health impacts TB survivors face.

Healthcare Utilization After Respiratory Tuberculosis: A Controlled Interrupted Time Series Analysis

BACKGROUND

Despite data suggesting elevated morbidity and mortality among people who have survived tuberculosis disease, the impact of respiratory tuberculosis on healthcare utilization in the years following diagnosis and treatment remains unclear.

METHODS

Using linked health administrative data from British Columbia, Canada, we identified foreign-born individuals treated for respiratory tuberculosis between 1990 and 2019. We matched each person with up to four people without a tuberculosis diagnosis from the same source cohort using propensity score matching. Then, using a controlled interrupted time series analysis, we measured outpatient physician encounters and inpatient hospital admissions in the 5 years following respiratory tuberculosis diagnosis and treatment.

RESULTS

We matched 1216 individuals treated for respiratory tuberculosis to 4864 non-tuberculosis controls. Immediately following the tuberculosis diagnostic and treatment period, the monthly rate of outpatient encounters in the tuberculosis group was 34.0% (95% confidence interval [CI]: 30.7%, 37.2%) higher than expected, and this trend was sustained for the duration of the post-tuberculosis period. The excess utilization represented an additional 12.2 (95% CI: 10.6, 14.9) outpatient encounters per person over the post-tuberculosis period, with respiratory morbidity a large contributor to the excess healthcare utilization. Results were similar for hospital admissions, with an additional 0.4 (95% CI: .3, .5) hospital admissions per person over the post-tuberculosis period.

CONCLUSIONS

Respiratory tuberculosis appears to have long-term impacts on healthcare utilization beyond treatment. These findings underscore the need for screening, assessment, and treatment of post-tuberculosis sequelae, as it may provide an opportunity to improve health and reduce resource use.

Medical Malpractice and the Neurologist: Specific Neurological Claims

This chapter highlights the most frequently encountered neurological malpractice claims. The format is designed to provide a rudimentary understanding of how lawsuits arise and thereby focus discussion on adapting practice patterns to improve patient care and minimize liability risk.

Medical Malpractice and the Neurologist: An Introduction

This article provides an overview of current malpractice trends in neurology as well as non-malpractice and forensic liability concerns. It is more important for clinicians to recognize the common patient care scenarios that are likely to precipitate lawsuits rather than memorize arcane legal principles. Therefore, this article offers an introduction to malpractice jurisprudence as well as a general overview of current litigation trends and a review of the role and duties of a neurologist serving as an expert witness. The next article highlights mitigation strategies for the most prevalent neurologic misadventures.

Global Neurology: The Good, the Bad, and the Ugly

Global health programs engaging in isolated or short-term medical missions can and do cause harm, reinforce health care disparities, and impede medical care in the regions where it is so desperately needed. Related ethical, medical, and legal concerns are reviewed in this article. The authors recommend abandoning these ill-considered missions and focusing attention and resources on advancing neurology through ethically congruent, multisectoral, collaborative partnerships to establish sustainable, self-sufficient training programs within low- and middle-income countries.

The association of SARS-CoV-2 infection and tuberculosis disease with unfavorable treatment outcomes: A systematic review

BACKGROUND

Whether SARS-CoV-2 infection and its management influence tuberculosis (TB) treatment outcomes is uncertain. We synthesized evidence on the association of SARS-CoV-2 coinfection (Coinfection Review) and its management (Clinical Management Review) on treatment outcomes among people with tuberculosis (TB) disease.

METHODS

We systematically searched the literature from 1 January 2020 to 6 February 2022. Primary outcomes included: unfavorable (death, treatment failure, loss-to-follow-up) TB treatment outcomes (Coinfection and Clinical Management Review) and/or severe or critical COVID-19 or death (Clinical Management Review). Study quality was assessed with an adapted Newcastle Ottawa Scale. Data were heterogeneous and a narrative review was performed. An updated search was performed on April 3, 2023.

FINDINGS

From 9,529 records, we included 11 studies and 7305 unique participants. No study reported data relevant to our review in their primary publication and data had to be contributed by study authors after contact. Evidence from all studies was low quality. Eight studies of 5749 persons treated for TB (286 [5%] with SARS-CoV-2) were included in the Coinfection Review. Across five studies reporting our primary outcome, there was no significant association between SARS-CoV-2 coinfection and unfavorable TB treatment outcomes. Four studies of 1572 TB patients-of whom 291 (19%) received corticosteroids or other immunomodulating treatment-were included in the Clinical Management Review, and two addressed a primary outcome. Studies were likely confounded by indication and discordant findings existed among studies. When updating our search, we still did not identify any study reporting data relevant to this review in their primary publication.

INTERPRETATION

No study was designed to answer our research questions of interest. It remains unclear whether TB/SARS-CoV-2 and its therapeutic management are associated with unfavorable outcomes. Research is needed to improve our understanding of risk and optimal management of persons with TB and SARS-CoV-2 infection.

TRIAL REGISTRATION

Registration: PROSPERO (CRD42022309818).

Comparing Mycobacterium tuberculosis transmission reconstruction models from whole genome sequence data

Genomic epidemiology is routinely used worldwide to interrogate infectious disease dynamics. Multiple computational tools exist that reconstruct transmission networks by coupling genomic data with epidemiological models. Resulting inferences can improve our understanding of pathogen transmission dynamics, and yet the performance of these tools has not been evaluated for tuberculosis (TB), a disease process with complex epidemiology including variable latency and within-host heterogeneity. Here, we performed a systematic comparison of six publicly available transmission reconstruction models, evaluating their accuracy when predicting transmission events in simulated and real-world Mycobacterium tuberculosis outbreaks. We observed variability in the number of transmission links that were predicted with high probability (P ≥ 0.5) and low accuracy of these predictions against known transmission in simulated outbreaks. We also found a low proportion of epidemiologically supported case-contact pairs were identified in our real-world TB clusters. The specificity of all models was high, and a relatively high proportion of the total transmission events predicted by some models were true links, notably with TransPhylo, Outbreaker2, and Phybreak. Our findings may inform the choice of tools in TB transmission analyses and underscore the need for caution when interpreting transmission networks produced using probabilistic approaches.

Role of latent tuberculosis infection on elevated risk of cardiovascular disease: a population-based cohort study of immigrants in British Columbia, Canada, 1985-2019

We investigated cardiovascular disease (CVD) risk associated with latent tuberculosis infection (LTBI) (Aim-1) and LTBI therapy (Aim-2) in British Columbia, a low-tuberculosis-incidence setting. 49,197 participants had valid LTBI test results. Cox proportional hazards model was fitted, adjusting for potential confounders. Compared with the participants who tested LTBI negative, LTBI positive was associated with an 8% higher CVD risk in complete case data (adjusted hazard ratio (HR): 1.08, 95% CI: 0.99-1.18), a statistically significant 11% higher risk when missing confounder values were imputed using multiple imputation (HR: 1.11, 95% CI: 1.02-1.20), and 10% higher risk when additional proxy variables supplementing known unmeasured confounders were incorporated in the highdimensional disease risk score technique to reduce residual confounding (HR: 1.10, 95% CI: 1.01-1.20). Also, compared with participants who tested negative, CVD risk was 27% higher among people who were LTBI positive but incomplete LTBI therapy (HR: 1.27, 95% CI: 1.04-1.55), whereas the risk was similar in people who completed LTBI therapy (HR: 1.04, 95% CI: 0.87-1.24). Findings were consistent in different sensitivity analyses. We concluded that LTBI is associated with an increased CVD risk in low-tuberculosis-incidence settings, with a higher risk associated with incomplete LTBI therapy and attenuated risk when therapy is completed.

Multimorbidity prevalence and chronic disease patterns among tuberculosis survivors in a high-income setting

OBJECTIVES

Multimorbidity is the presence of two or more chronic health conditions. Tuberculosis (TB) survivors are known to have higher prevalence of multimorbidity, although prevalence estimates from high-income low-TB incidence jurisdictions are not available and potential differences in the patterns of chronic disease among TB survivors with multimorbidity are poorly understood. In this study, we aimed to (1) compare the prevalence of multimorbidity among TB survivors with matched non-TB controls in a high-income setting; (2) assess the robustness of aim 1 analyses to different modelling strategies, unmeasured confounding, and misclassification bias; and (3) among people with multimorbidity, elucidate chronic disease patterns specific to TB survivors.

METHODS

A population-based cohort study of people immigrating to British Columbia, Canada, 1985-2015, using health administrative data. Participants were divided into two groups: people diagnosed with TB (TB survivors) and people not diagnosed with TB (non-TB controls) in British Columbia. Coarsened exact matching (CEM) balanced demographic, immigration, and socioeconomic covariates between TB survivors and matched non-TB controls. Our primary outcome was multimorbidity, defined as ≥2 chronic diseases from the Elixhauser comorbidity index.

RESULTS

In the CEM-matched sample (n=1962 TB survivors; n=1962 non-TB controls), we estimated that 21.2% of TB survivors (n=416), compared with 12% of non-TB controls (n=236), had multimorbidity. In our primary analysis, we found a double-adjusted prevalence ratio of 1.74 (95% CI: 1.49-2.05) between TB survivors and matched non-TB controls for multimorbidity. Among people with multimorbidity, differences were observed in chronic disease frequencies between TB survivors and matched controls.

CONCLUSION

TB survivors had a 74% higher prevalence of multimorbidity compared with CEM-matched non-TB controls. TB-specific multimorbidity patterns were observed through differences in chronic disease frequencies between the matched samples. These findings suggest a need for TB-specific multimorbidity interventions in high-income settings such as Canada. We suggest TB survivorship as a framework for developing person-centred interventions for multimorbidity among TB survivors.

Tuberculosis and risk of cancer: A systematic review and meta-analysis

INTRODUCTION

Cancer is a major cause of death among people who experience tuberculosis (TB), but little is known about its timing and incidence following TB treatment. Our primary objectives were to estimate the pooled risk of all and site-specific malignancies in people with TB compared to the general population or suitable controls. Our secondary objective was to describe the pooled risk of cancer at different time points following TB diagnosis.

METHODS

This study was prospectively registered (PROSPERO: CRD42021277819). We systematically searched MEDLINE, Embase, and the Cochrane Database for studies published between 1980 and 2021. We included original observational research articles that estimated cancer risk among people with TB compared to controls. Studies were excluded if they had a study population of fewer than 50 individuals; used cross-sectional, case series, or case report designs; and had a follow-up period of less than 12 months. Random-effects meta-analysis was used to obtain the pooled risk of cancer in the TB population.

RESULTS

Of the 5,160 unique studies identified, data from 17 studies were included. When compared to controls, the pooled standardized incidence ratios (SIR) of all cancer (SIR 1.62, 95% CI 1.35-1.93, I2 = 97%) and lung cancer (SIR 3.20, 95% CI 2.21-4.63, I2 = 90%) was increased in the TB population. The pooled risk of all cancers and lung cancer was highest within the first year following TB diagnosis (SIR 4.70, 95% CI 1.80-12.27, I2 = 99%) but remained over five years of follow-up.

CONCLUSIONS

People with TB have an increased risk of both pulmonary and non-pulmonary cancers. Further research on cancer following TB diagnosis is needed to develop effective screening and early detection strategies. Clinicians should have a high index of suspicion for cancer in people with TB, particularly in the first year following TB diagnosis.

A scoping review of interventions to mitigate common non-communicable diseases among people with TB

BACKGROUND: Recommendations have been made to integrate screening for common non-communicable diseases (NCDs) within TB programs. However, we must ensure screening is tied to evidence-based interventions before scale-up. We aimed to map the existing evidence regarding interventions that address NCDs that most commonly affect people with TB.METHODS: We systematically searched PubMed, Medline, and Embase for studies that evaluated interventions to mitigate respiratory disease, cardiovascular disease, alcohol and substance use disorder, and mental health disorders among people with TB. We excluded studies that only screened for comorbidity but resulted in no further intervention. We also excluded studies focusing on smoking cessation interventions for which evidence-based guidelines are well established.RESULTS: The search identified 20 studies that met our inclusion criteria. The most commonly evaluated intervention was referral for diabetes care (6 studies). Other interventions included pulmonary rehabilitation (5 studies), care programs for alcohol use disorder (4 studies), and psychosocial support or individual counselling (5 studies).CONCLUSION: There is limited robust evidence to support identified interventions in changing individual outcomes, and a significant knowledge gap remains on the long-term durability of the interventions´ clinical benefit, reach, and effectiveness. Implementation research demonstrating feasibility and effectiveness is needed before scaling up.

Costs of Tuberculosis at 3 Treatment Centers, Canada, 2010-2016

We estimated costs of managing different forms of tuberculosis (TB) across Canada by conducting a retrospective chart review and cost assessment of patients treated for TB infection, drug-susceptible TB (DS TB), isoniazid-resistant TB, or multidrug-resistant TB (MDR TB) at 3 treatment centers. We included 90 patients each with TB infection and DS TB, 71 with isoniazid-resistant TB, and 62 with MDR TB. Median per-patient costs for TB infection (in 2020 Canadian dollars) were $804 (interquartile range [IQR] $587-$1,205), for DS TB $12,148 (IQR $4,388-$24,842), for isoniazid-resistant TB $19,319 (IQR $7,117-$41,318), and for MDR TB $119,014 (IQR $80,642-$164,015). Compared with costs for managing DS TB, costs were 11.1 (95% CI 9.1-14.3) times lower for TB infection, 1.7 (95% CI 1.3-2.1) times higher for isoniazid-resistant TB, and 8.1 (95% CI 6.1-10.6) times higher for MDR TB. Broadened TB infection treatment could avert high costs associated with managing TB disease.

High-dose rifamycins in the treatment of TB: a systematic review and meta-analysis

BACKGROUND

There is growing interest in using high-dose rifamycin (HDR) regimens in TB treatment, but the safety and efficacy of HDR regimens remain uncertain. We performed a systematic review and meta-analysis comparing HDR to standard-dose rifamycin (SDR) regimens.

METHODS

We searched MEDLINE, Embase, CENTRAL, Cochrane Database of Systematic Reviews and clinicaltrials.gov for prospective studies comparing daily therapy with HDRs to SDRs. Rifamycins included rifampicin, rifapentine and rifabutin. Our primary outcome was the rate of severe adverse events (SAEs), with secondary outcomes of death, all adverse events, SAE by organ and efficacy outcomes of 2-month culture conversion and relapse. This study was prospectively registered in the International Prospective Register of Systematic Reviews (CRD42020142519).

RESULTS

We identified 9057 articles and included 13 studies with 6168 participants contributing 7930 person-years (PY) of follow-up (HDR: 3535 participants, 4387 PY; SDR: 2633 participants, 3543 PY). We found no significant difference in the pooled incidence rate ratio (IRR) of SAE between HDR and SDR (IRR 1.00, 95% CI 0.82 to 1.23, I ²=41%). There was no significant difference when analysis was limited to SAE possibly, probably or likely medication-related (IRR 1.07, 95% CI 0.82 to 1.41, I ²=0%); studies with low risk of bias (IRR 0.98, 95% CI 0.79 to 1.20, I ²=44%); or studies using rifampicin (IRR 1.00, 95% CI 0. 0.75-1.32, I ²=38%). No significant differences were noted in pooled outcomes of death, 2-month culture conversion and relapse.

CONCLUSIONS

HDRs were not associated with a significant difference in SAEs, 2-month culture conversion or death. Further studies are required to identify specific groups who may benefit from HDR.

Ethical challenges in the treatment of non-refugee migrants with tuberculosis in Canada

While attention to the ethical issues that migrants face in accessing tuberculosis care has increased in the last few years, most of the attention has focused on challenges that refugees face when emigrating. Less attention has been given to ethical challenges that arise in the context of providing tuberculosis treatment and care to non-refugee migrants in high-income countries (HIC), particularly those that do not face immediate danger or violence. In this paper, we analyze some of the ethical challenges associated with treating migrants with tuberculosis in the Canadian context. In particular, we will discuss (i) inter- and intra-jurisdictional issues that challenge quotidian public health governance structures, and (ii) the ethical imperative for the Canadian government and its provinces to clearly differentiate access to healthcare from a person's immigration status to help overcome power imbalances that may exist between public health workers and their clients. The arguments presented herein could potentially apply to other HIC with some form of universal health coverage.

How Well Does TSTin3D Predict Risk of Active Tuberculosis in the Canadian Immigrant Population? An External Validation Study

BACKGROUND

The online Tuberculin Skin Test/Interferon Gamma Release Assay (TST/IGRA) Interpreter V3.0 (TSTin3D), a tool for estimating the risk of active tuberculosis (TB) in individuals with latent TB infection (LTBI), has been in use for more than a decade, but its predictive performance has never been evaluated.

METHODS

People with a positive TST or IGRA result from 1985 to 2015 were identified using a health data linkage that involved migrants to British Columbia, Canada. Comorbid conditions at the time of LTBI testing were identified from physician claims, hospitalizations, vital statistics, outpatient prescriptions, and kidney and HIV databases. The risk of developing active TB within 2 and 5 years was estimated using TSTin3D. The discrimination and calibration of these estimates were evaluated.

RESULTS

A total of 37 163 individuals met study inclusion criteria; 10.4% were tested by IGRA. Generally, the TSTin3D algorithm assigned higher risks to demographic and clinical groups known to have higher active TB risks. Concordance estimates ranged from 0.66 to 0.68 in 2- and 5-year time frames. Comparing predicted to observed counts suggests that TSTin3D overestimates active TB risks and that overestimation increases over time (with relative bias of 3% and 12% in 2- and 5-year periods, respectively). Calibration plots also suggest that overestimation increases toward the upper end of the risk spectrum.

CONCLUSIONS

TSTin3D can discriminate adequately between people who developed and did not develop active TB in this linked database of migrants with predominately positive skin tests. Further work is needed to improve TSTin3D's calibration.

Changes in pulmonary function and patient-reported outcomes during COVID-19 recovery: a longitudinal, prospective cohort study

Objectives

The aim of this study was to compare respiratory and patient-reported outcome measures (PROMs) between 3 and 6 months after symptom onset and to identify features that predict these changes.

Methods

This was a consecutive prospective cohort of 73 patients who were hospitalised with coronavirus disease 2019 (COVID-19). We evaluated the changes in pulmonary function tests and PROMs between 3 and 6 months and then investigated the associations between outcomes (change in diffusing capacity of the lung for carbon monoxide (D _LCO), dyspnoea and quality of life (QoL)) and clinical and radiological features.

Results

There was improvement in forced vital capacity, total lung capacity and D _LCO between 3 and 6 months by 3.25%, 3.82% and 5.69%, respectively; however, there was no difference in PROMs. Reticulation and total computed tomography (CT) scores were associated with lower D _LCO % predicted at 6 months (coefficients; -8.7 and -5.3, respectively). The association between radiological scores and D _LCO were modified by time, with the degree of association between ground glass and D _LCO having decreased markedly over time. There was no association between other predictors and change in dyspnoea or QoL over time.

Conclusions

There is improvement in pulmonary function measurements between 3 and 6 months after COVID-19 symptom onset; however, PROMs did not improve. A higher reticulation and total CT score are negatively associated with D _LCO, but this association is attenuated over time. Lastly, there is a considerable proportion of patients with unexplained dyspnoea at 6 months, motivating further research to identify the underlying mechanisms.

Cerebral palsy litigation after fifty years: A hoax on you

The worldwide cerebral palsy (CP) litigation crisis is predicated on the hoax that electronic foetal monitoring (EFM) predicts and prevents CP. There are decades of research disproving this hoax, yet EFM continues to be performed in the vast majority of labours in developed countries with resultant harm to mothers and babies alike through unnecessary caesarean sections with all of the attendant complications and ramifications of that procedure. This article reviews the history and evolution of EFM, explores the reasons for its misuse, discusses how obstetricians have abandoned their ethical mandate by failing to obtain informed consent for EFM, and proposes a realistic, practical solution that would effectively change the standard of care.

Using Whole-genome Sequencing to Determine the Timing of Secondary Tuberculosis in British Columbia, Canada

Combined with epidemiological data, whole-genome sequencing (WGS) can help better resolve individual tuberculosis (TB) transmission events to a degree not possible with traditional genotyping. We combine WGS data with patient-level data to calculate the timing of secondary TB among contacts of people diagnosed with active TB in British Columbia, Canada.

Tuberculosis-associated depression: a population-based cohort study of people immigrating to British Columbia, Canada, 1985-2015

PURPOSE

To estimate the risk of tuberculosis (TB)-associated depression. A second aim was to estimate the extent to which any increased risk of depression among TB patients may be mediated by the length of hospital length stay (LOS) METHODS: Retrospective cohort study of linked healthcare claims and public health surveillance data. Our primary outcome, time-to-depression, was analyzed using Cox proportional hazards (PH) regressions. Causal mediation analysis was used to estimate the natural direct and indirect effect of TB mediated by hospital LOS.

RESULTS

Among 755,836 participants (52.2% female, median age=35 years, median follow-up=8.75 years), 2295 were diagnosed with TB (exposure), and 128,963 were diagnosed with depression (outcome). We observed a covariate-adjusted hazard ratio (aHR) of 1.24 (95% CI, 1.14-1.34) for depression by TB. The total effect of TB on depression was decomposed into a natural direct effect of TB of aHR=1.11 (95% CI, 1.02-1.21) and an indirect effect through hospital LOS of aHR=1.11 (95% CI, 1.10-1.12), indicating that TB's total effect was mediated by 50% (95% CI, 35-82%) through hospital LOS.

CONCLUSIONS

TB patients had a 24% higher risk of developing depression. TB's effect was mediated substantially by hospital LOS, requiring further study. Depression screening among TB patients is warranted.

A prospective study of 12-week respiratory outcomes in COVID-19-related hospitalisations

The long-term respiratory morbidity of COVID-19 remains unclear. We describe the clinical, radiological and pulmonary function abnormalities that persist in previously hospitalised patients assessed 12 weeks after COVID-19 symptom onset, and identify clinical predictors of respiratory outcomes. At least one pulmonary function variable was abnormal in 58% of patients and 88% had abnormal imaging on chest CT. There was strong association between days on oxygen supplementation during the acute phase of COVID-19 and both DLCO-% (diffusion capacity of the lung for carbon monoxide) predicted and total CT score. These findings highlight the need to develop treatment strategies and the importance of long-term respiratory follow-up after hospitalisation for COVID-19.

Risk of active tuberculosis in migrants diagnosed with cancer: a retrospective cohort study in British Columbia, Canada

OBJECTIVES

To describe the association between types of cancer and active tuberculosis (TB) risk in migrants. Additionally, in order to better inform latent TB infection (LTBI) screening protocols, we assessed proportion of active TB cases potentially preventable through LTBI screening and treatment in migrants with cancer.

DESIGN

Population-based, retrospective cohort study.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

1 000 764 individuals who immigrated to Canada from 1985 to 2012 and established residency in BC at any point up to 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

Using linked health administrative databases and disease registries, data on demographics, comorbidities, cancer type, TB exposure and active TB diagnosis were extracted. Primary outcomes included: time to first active TB diagnoses, and risks of active TB following cancer diagnoses which were estimated using Cox extended hazard regression models. Potentially preventable TB was defined as active TB diagnosed >6 months postcancer diagnoses.

RESULTS

Active TB risk was increased in migrants with cancer ((HR (95% CI)) 2.5 (2.0 to 3.1)), after adjustment for age, sex, TB incidence in country of origin, immigration classification, contact status and comorbidities. Highest risk was observed with lung cancer (HR 11.2 (7.4 to 16.9)) and sarcoma (HR 8.1 (3.3 to 19.5)), followed by leukaemia (HR 5.6 (3.1 to 10.2)), lymphoma (HR 4.9 (2.7 to 8.7)) and gastrointestinal cancers (HR 2.7 (1.7 to 4.4)). The majority (65.9%) of active TB cases were diagnosed >6 months postcancer diagnosis.

CONCLUSION

Specific cancers increase active TB risk to varying degrees in the migrant population of BC, with approximately two-thirds of active TB cases identified as potentially preventable.

Post-tuberculosis airway disease: A population-based cohort study of people immigrating to British Columbia, Canada, 1985-2015

BACKGROUND

Current epidemiological evidence of post-TB airway disease is largely cross-sectional and derived from high-TB-incidence settings. We present the first cohort study of post-TB airway disease in a low-TB-incidence setting.

AIMS

(1) analyze the risk of airway disease by respiratory TB, (2) assess potential unmeasured confounding between TB and airway disease, and (3) investigate TB effect measure modification.

METHODS

A population-based cohort study using healthcare claims data for immigrants to British Columbia (BC), Canada, 1985-2015. Airway disease included chronic airway obstruction, asthma, bronchitis, bronchiolitis, and emphysema. Respiratory TB was defined from TB registry data. Cox proportional hazards (PH) regressions were used to analyze time-to-airway disease by respiratory TB. Sensitivity analyses included varying definitions of TB and airway disease. Potential unmeasured confounding by smoking was evaluated by E-value and hybrid least absolute shrinkage and selection operator (LASSO)-high-dimensional propensity score (hdPS).

FINDINGS

In our cohort (N = 1 005 328; n_TB=1141) there were 116 840 incident cases of airway disease during our 30-year study period (10.43 per 1,000 person-years of follow-up), with cumulative incidence of 42·5% among respiratory TB patients compared with 11·6% among non-TB controls. The covariate-adjusted hazard ratio (aHR) for airway disease by respiratory TB was 2·08 (95% CI: 1·91-2·28) with E-value=3·58. The LASSO-hdPS analysis produced aHR=2·26 (95% CI: 2·07-2·47).

INTERPRETATION

A twofold higher risk of airway disease was observed among immigrants diagnosed with respiratory TB, compared with non-TB controls, in a low-TB-incidence setting. Unmeasured confounding is unlikely to explain this relationship. Models of post-TB care are needed.

FUNDING

Canadian Institutes of Health Research.

Active case-finding in contacts of people with TB

BACKGROUND: Exposure to people with TB substantially elevates a person's risk of tuberculous infection and TB disease. Systematic screening of TB contacts enables the early detection and treatment of co-prevalent disease, and the opportunity to prevent future TB disease. However, scale-up of contact investigation in high TB transmission settings remains limited.METHODS: We undertook a narrative review to evaluate the evidence for contact investigation and identify strategies that TB programmes may consider when introducing contact investigation and management.RESULTS: Selection of contacts for priority screening depends upon their proximity and duration of exposure, along with their susceptibility to develop TB. Screening algorithms can be tailored to the target population, the availability of diagnostic tests and preventive therapy, and healthcare worker expertise. Contact investigation may be performed in the household or at communal locations. Local contact investigation policies should support vulnerable patients, and ensure that drop-out during screening can be mitigated. Ethical issues should be anticipated and addressed in each setting.CONCLUSION: Contact investigation is an important strategy for TB elimination. While its epidemiological impact will be greatest in lower-transmission settings, the early detection and prevention of TB have important benefits for contacts and their communities.

Post-tuberculosis mortality risk among immigrants to British Columbia, Canada, 1985-2015: a time-dependent Cox regression analysis of linked immigration, public health, and vital statistics data

OBJECTIVE

To compare non-tuberculosis (non-TB)-cause mortality risk overall and cause-specific mortality risks within the immigrant population of British Columbia (BC) with and without TB diagnosis through time-dependent Cox regressions.

METHODS

All people immigrating to BC during 1985-2015 (N = 1,030,873) were included with n = 2435 TB patients, and the remaining as non-TB controls. Outcomes were time-to-mortality for all non-TB causes, respiratory diseases, cardiovascular diseases, cancers, and injuries/poisonings, and were ascertained using ICD-coded vital statistics data. Cox regressions were used, with a time-varying exposure variable for TB diagnosis.

RESULTS

The non-TB-cause mortality hazard ratio (HR) was 4.01 (95% CI 3.57-4.51) with covariate-adjusted HR of 1.69 (95% CI 1.50-1.91). Cause-specific covariate-adjusted mortality risk was elevated for respiratory diseases (aHR = 2.96; 95% CI 2.18-4.00), cardiovascular diseases (aHR = 1.63; 95% CI 1.32-2.02), cancers (aHR = 1.40; 95% CI 1.13-1.75), and injuries/poisonings (aHR = 1.85; 95% CI 1.25-2.72).

CONCLUSIONS

In any given year, if an immigrant to BC was diagnosed with TB, their risk of non-TB mortality was 69% higher than if they were not diagnosed with TB. Healthcare providers should consider multiple potential threats to the long-term health of TB patients during and after TB treatment. TB guidelines in high-income settings should address TB survivor health.

Discovery and validation of a personalized risk predictor for incident tuberculosis in low transmission settings

The risk of tuberculosis (TB) is variable among individuals with latent Mycobacterium tuberculosis infection (LTBI), but validated estimates of personalized risk are lacking. In pooled data from 18 systematically identified cohort studies from 20 countries, including 80,468 individuals tested for LTBI, 5-year cumulative incident TB risk among people with untreated LTBI was 15.6% (95% confidence interval (CI), 8.0-29.2%) among child contacts, 4.8% (95% CI, 3.0-7.7%) among adult contacts, 5.0% (95% CI, 1.6-14.5%) among migrants and 4.8% (95% CI, 1.5-14.3%) among immunocompromised groups. We confirmed highly variable estimates within risk groups, necessitating an individualized approach to risk stratification. Therefore, we developed a personalized risk predictor for incident TB (PERISKOPE-TB) that combines a quantitative measure of T cell sensitization and clinical covariates. Internal-external cross-validation of the model demonstrated a random effects meta-analysis C-statistic of 0.88 (95% CI, 0.82-0.93) for incident TB. In decision curve analysis, the model demonstrated clinical utility for targeting preventative treatment, compared to treating all, or no, people with LTBI. We challenge the current crude approach to TB risk estimation among people with LTBI in favor of our evidence-based and patient-centered method, in settings aiming for pre-elimination worldwide.

Patient-reported outcome measures after COVID-19: a prospective cohort study

Patient reported outcome measures (PROMs) are standardised validated questionnaires completed by patients to provide information on their perceived functional well-being and health status [1]. These questionnaires can address various aspects of health including symptoms, quality of life, functionality, and physical, mental and social well-being. PROMs play an important role in increasing patient engagement, improving health systems, and ensuring that clinical care and research is person-centred.

Over 75% of patients admitted to hospital with COVID-19 have abnormal patient-reported outcome measures 3 months after symptom onset, with a third of patients reporting at least moderate impairment in major dimensions of quality of lifehttps://bit.ly/32QMMgw

Chest x-ray analysis with deep learning-based software as a triage test for pulmonary tuberculosis: a prospective study of diagnostic accuracy for culture-confirmed disease

BACKGROUND

Deep learning-based radiological image analysis could facilitate use of chest x-rays as triage tests for pulmonary tuberculosis in resource-limited settings. We sought to determine whether commercially available chest x-ray analysis software meet WHO recommendations for minimal sensitivity and specificity as pulmonary tuberculosis triage tests.

METHODS

We recruited symptomatic adults at the Indus Hospital, Karachi, Pakistan. We compared two software, qXR version 2.0 (qXRv2) and CAD4TB version 6.0 (CAD4TBv6), with a reference of mycobacterial culture of two sputa. We assessed qXRv2 using its manufacturer prespecified threshold score for chest x-ray classification as tuberculosis present versus not present. For CAD4TBv6, we used a data-derived threshold, because it does not have a prespecified one. We tested for non-inferiority to preset WHO recommendations (0·90 for sensitivity, 0·70 for specificity) using a non-inferiority limit of 0·05. We identified factors associated with accuracy by stratification and logistic regression.

FINDINGS

We included 2198 (92·7%) of 2370 enrolled participants. 2187 (99·5%) of 2198 were HIV-negative, and 272 (12·4%) had culture-confirmed pulmonary tuberculosis. For both software, accuracy was non-inferior to WHO-recommended minimum values (qXRv2 sensitivity 0·93 [95% CI 0·89-0·95], non-inferiority p=0·0002; CAD4TBv6 sensitivity 0·93 [0·90-0·96], p<0·0001; qXRv2 specificity 0·75 [0·73-0·77], p<0·0001; CAD4TBv6 specificity 0·69 [0·67-0·71], p=0·0003). Sensitivity was lower in smear-negative pulmonary tuberculosis for both software, and in women for CAD4TBv6. Specificity was lower in men and in those with previous tuberculosis, and reduced with increasing age and decreasing body mass index. Smoking and diabetes did not affect accuracy.

INTERPRETATION

In an HIV-negative population, these software met WHO-recommended minimal accuracy for pulmonary tuberculosis triage tests. Sensitivity will be lower when smear-negative pulmonary tuberculosis is more prevalent.

FUNDING

Canadian Institutes of Health Research.

Estimated Impact of World Health Organization Latent Tuberculosis Screening Guidelines in a Region With a Low Tuberculosis Incidence: Retrospective Cohort Study

BACKGROUND

Latent tuberculosis infection (LTBI) screening and treatment is a key component of the World Health Organization (WHO) EndTB Strategy, but the impact of LTBI screening and treatment at a population level is unclear. We aimed to estimate the impact of LTBI screening and treatment in a population of migrants to British Columbia (BC), Canada.

METHODS

This retrospective cohort included all individuals (N = 1 080 908) who immigrated to Canada as permanent residents between 1985 and 2012 and were residents in BC at any time up to 2013. Multiple administrative databases were linked to identify people with risk factors who met the WHO strong recommendations for screening: people with tuberculosis (TB) contact, with human immunodeficiency virus, on dialysis, with tumor necrosis factor-alpha inhibitors, who had an organ/haematological transplant, or with silicosis. Additional TB risk factors included immunosuppressive medications, cancer, diabetes, and migration from a country with a high TB burden. We defined active TB as preventable if diagnosed ≥6 months after a risk factor diagnosis. We estimated the number of preventable TB cases, given optimal LTBI screening and treatment, based on these risk factors.

RESULTS

There were 16 085 people (1.5%) identified with WHO strong risk factors. Of the 2814 people with active TB, 118 (4.2%) were considered preventable through screening with WHO risk factors. Less than half (49.4%) were considered preventable with expanded screening to include people migrating from countries with high TB burdens, people who had been prescribed immunosuppressive medications, or people with diabetes or cancer.

CONCLUSIONS

The application of WHO LTBI strong recommendations for screening would have minimally impacted the TB incidence in this population. Further high-risk groups must be identified to develop an effective LTBI screening and treatment strategy for low-incidence regions.

Latent Tuberculosis Therapy Outcomes in Dialysis Patients: A Retrospective Cohort

RATIONALE & OBJECTIVES

Maintenance dialysis patients are at an increased risk for active tuberculosis (TB). In 2012, British Columbia, Canada, began systematically screening maintenance dialysis patients for latent TB infection (LTBI) and treating people with evidence of LTBI when appropriate. We examined LTBI treatment outcomes and compared treatment outcomes before and after rollout of the systematic screening program.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

The study comprised 365 people in British Columbia, Canada, initiating at least 90 days of dialysis from January 1, 2001, to May 31, 2017, and starting LTBI therapy: 290 (79.5%) people in the recent cohort and 75 (20.5%) in the historical cohort. People starting LTBI therapy from January 1, 2012, onward were classified as the recent cohort, whereas people starting LTBI therapy before January 1, 2012, were classified as the historical cohort.

EXPOSURE

Systematic LTBI screening and therapy.

OUTCOMES

Proportion of people who experience grade 3 to 5 adverse events (AEs) or any grade rash and end-of-treatment outcomes.

ANALYTICAL APPROACH

Outcomes were reported using descriptive statistics. 2-sample test of proportions using χ² distribution was used to test for statistical significance between the recent and historical cohorts.

RESULTS

298 (81.6%) people successfully completed LTBI therapy. The proportion of people experiencing a grade 3 to 4 AE or any grade rash was 21.1%. Most AEs were related to gastrointestinal events, general malaise, or pruritus that resulted in regimen changes. 2 (0.5%) people were hospitalized for AEs related to LTBI therapy. No significant difference was found between the recent and historical cohorts in all outcomes of interest. No grade 5 AEs (deaths) were attributed to LTBI therapy.

LIMITATIONS

Retrospective data and generalizability outside low-TB-burden settings.

CONCLUSIONS

Our findings suggest that a high proportion of people receiving maintenance dialysis can complete LTBI therapy. The rate of grade 3 to 4 AEs was high and associated with frequent medication changes during therapy. LTBI therapy in maintenance dialysis may be safe but requires close monitoring.

Effectiveness of Latent TB Screening and Treatment in People Initiating Dialysis in British Columbia, Canada

Background:

People undergoing chronic dialysis are at an increased risk of active tuberculosis (TB). In 2012, the Canadian province of British Columbia began systematically screening people initiating dialysis for latent TB using interferon-gamma release assay (IGRA), and treating when appropriate.

Objective:

The objective of this study was to compare active TB rate in people who initiated dialysis and were screened using an IGRA compared with those not screened during the same period.

Design:

Retrospective cohort study.

Setting:

British Columbia (BC), a Canadian province of 5.0 million people with an active TB incidence of 5.1 per 100 000 population.

Participants:

All people in BC who initiated at least 90 days of dialysis between January 2012 and May 2017 were included in the study. People were excluded if they were <18 years of age or had a prior history of active TB diagnosis or treatment for latent TB.

Methods:

A retrospective cohort was created of British Columbians who initiated dialysis between 2012 and 2017. Individuals were stratified into a screened and nonscreened group. Multivariable Cox regression was used to determine the association between latent TB screening and the development of active TB. The primary outcome was incident active TB, either microbiologically confirmed or clinically diagnosed.

Results:

Of the 3190 people included in the study, 1790 (56.1%) were screened, of which 152 (8.5%) initiated latent TB treatment postscreening. During follow-up, incident active TB was diagnosed in 6 (0.3%) of the 1790 people screened, compared with 11 (0.8%) of the 1400 people who received no screening. In multivariable analysis, latent TB screening and treatment was associated with a significant reduction in the rate of active TB (adjusted hazard ratio = 0.3, 95% confidence interval = 0.1-0.8; P < .01).

Limitations:

This was an observational retrospective study and the potential for unmeasured confounding should be carefully assessed.

Conclusions:

These findings suggest that systematically screening and treating people initiating dialysis can significantly decrease the rate of active TB in this high-risk population. Given the importance of screening high-risk groups, the results from this analysis could inform scale-up of TB screening in dialysis programs in other low incidence regions. Trial registration is not applicable as this was a retrospective cohort analysis and not a randomized trial.

Cardiovascular morbidity and mortality among persons diagnosed with tuberculosis: A systematic review and meta-analysis

Introduction

The emerging epidemiological evidence of increased cardiovascular disease (CVD) risk among persons diagnosed with tuberculosis (TB) has not been systematically reviewed to date. Our aim was to review the existing epidemiological evidence for elevated risk of CVD morbidity and mortality among persons diagnosed with TB compared to controls.

Materials and methods

EMBASE, MEDLINE, and Cochrane databases were searched (inception to January 2020) for terms related to “tuberculosis” and “cardiovascular diseases”. Inclusion criteria: trial, cohort, or case-control study design; patient population included persons diagnosed with TB infection or disease; relative risk (RR) estimate and confidence interval reported for CVD morbidity or mortality compared to suitable controls. Exclusion criteria: no TB or CVD outcome definition; duplicate study; non-English abstract; non-human participants. Two reviewers screened studies, applied ROBINS-I tool to assess risk of bias, and extracted data independently. Random effects meta-analysis estimated a pooled RR of CVD morbidity and mortality for persons diagnosed with TB compared to controls.

Results

6,042 articles were identified, 244 full texts were reviewed, and 16 were included, meta-analyzing subsets of 8 studies’ RR estimates. We estimated a pooled RR of 1.51 (95% CI: 1.16–1.97) for major adverse cardiac events among those diagnosed with TB compared to non-TB controls (p = 0.0024). A ‘serious’ pooled risk of bias was found across studies with between-study heterogeneity (I2 = 75.3%).

Conclusions

TB appears to be a marker for increased CVD risk; however, the literature is limited and is accompanied by serious risk of confounding bias and evidence of publication bias. Further retrospective and prospective studies are needed. Pending this evidence, best practice may be to consider persons diagnosed with TB at higher risk of CVD as a precautionary measure.

Diagnostic accuracy of serological tests for covid-19: systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of serological tests for coronavirus disease-2019 (covid-19).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, bioRxiv, and medRxiv from 1 January to 30 April 2020, using subject headings or subheadings combined with text words for the concepts of covid-19 and serological tests for covid-19.

ELIGIBILITY CRITERIA AND DATA ANALYSIS

Eligible studies measured sensitivity or specificity, or both of a covid-19 serological test compared with a reference standard of viral culture or reverse transcriptase polymerase chain reaction. Studies were excluded with fewer than five participants or samples. Risk of bias was assessed using quality assessment of diagnostic accuracy studies 2 (QUADAS-2). Pooled sensitivity and specificity were estimated using random effects bivariate meta-analyses.

MAIN OUTCOME MEASURES

The primary outcome was overall sensitivity and specificity, stratified by method of serological testing (enzyme linked immunosorbent assays (ELISAs), lateral flow immunoassays (LFIAs), or chemiluminescent immunoassays (CLIAs)) and immunoglobulin class (IgG, IgM, or both). Secondary outcomes were stratum specific sensitivity and specificity within subgroups defined by study or participant characteristics, including time since symptom onset.

RESULTS

5016 references were identified and 40 studies included. 49 risk of bias assessments were carried out (one for each population and method evaluated). High risk of patient selection bias was found in 98% (48/49) of assessments and high or unclear risk of bias from performance or interpretation of the serological test in 73% (36/49). Only 10% (4/40) of studies included outpatients. Only two studies evaluated tests at the point of care. For each method of testing, pooled sensitivity and specificity were not associated with the immunoglobulin class measured. The pooled sensitivity of ELISAs measuring IgG or IgM was 84.3% (95% confidence interval 75.6% to 90.9%), of LFIAs was 66.0% (49.3% to 79.3%), and of CLIAs was 97.8% (46.2% to 100%). In all analyses, pooled sensitivity was lower for LFIAs, the potential point-of-care method. Pooled specificities ranged from 96.6% to 99.7%. Of the samples used for estimating specificity, 83% (10 465/12 547) were from populations tested before the epidemic or not suspected of having covid-19. Among LFIAs, pooled sensitivity of commercial kits (65.0%, 49.0% to 78.2%) was lower than that of non-commercial tests (88.2%, 83.6% to 91.3%). Heterogeneity was seen in all analyses. Sensitivity was higher at least three weeks after symptom onset (ranging from 69.9% to 98.9%) compared with within the first week (from 13.4% to 50.3%).

CONCLUSION

Higher quality clinical studies assessing the diagnostic accuracy of serological tests for covid-19 are urgently needed. Currently, available evidence does not support the continued use of existing point-of-care serological tests.

STUDY REGISTRATION

PROSPERO CRD42020179452.

Resource implications of the latent tuberculosis cascade of care: a time and motion study in five countries

BACKGROUND

The End TB Strategy calls for global scale-up of preventive treatment for latent tuberculosis infection (LTBI), but little information is available about the associated human resource requirements. Our study aimed to quantify the healthcare worker (HCW) time needed to perform the tasks associated with each step along the LTBI cascade of care for household contacts of TB patients.

METHODS

We conducted a time and motion (TAM) study between January 2018 and March 2019, in which consenting HCWs were observed throughout a typical workday. The precise time spent was recorded in pre-specified categories of work activities for each step along the cascade. A linear mixed model was fit to estimate the time at each step.

RESULTS

A total of 173 HCWs in Benin, Canada, Ghana, Indonesia, and Vietnam participated. The greatest amount of time was spent for the medical evaluation (median: 11 min; IQR: 6-16), while the least time was spent on reading a tuberculin skin test (TST) (median: 4 min; IQR: 2-9). The greatest variability was seen in the time spent for each medical evaluation, while TST placement and reading showed the least variability. The total time required to complete all steps along the LTBI cascade, from identification of household contacts (HHC) through to treatment initiation ranged from 1.8 h per index TB patient in Vietnam to 5.2 h in Ghana.

CONCLUSIONS

Our findings suggest that the time requirements are very modest to perform each step in the latent TB cascade of care, but to achieve full identification and management of all household contacts will require additional human resources in many settings.

Cost-effectiveness of Latent Tuberculosis Infection Screening before Immigration to Low-Incidence Countries

Prospective migrants to countries where the incidence of tuberculosis (TB) is low (low-incidence countries) receive TB screening; however, screening for latent TB infection (LTBI) before immigration is rare. We evaluated the cost-effectiveness of mandated and sponsored preimmigration LTBI screening for migrants to low-incidence countries. We used discrete event simulation to model preimmigration LTBI screening coupled with postarrival follow-up and treatment for those who test positive. Preimmigration interferon-gamma release assay screening and postarrival rifampin treatment was preferred in deterministic analysis. We calculated cost per quality-adjusted life-year gained for migrants from countries with different TB incidences. Our analysis provides evidence of the cost-effectiveness of preimmigration LTBI screening for migrants to low-incidence countries. Coupled with research on sustainability, acceptability, and program implementation, these results can inform policy decisions.

Demographic predictors of active tuberculosis in people migrating to British Columbia, Canada: a retrospective cohort study

BACKGROUND

Canadian tuberculosis (TB) guidelines recommend targeting postlanding screening for and treatment of latent tuberculosis infection (LTBI) in people migrating to Canada who are at increased risk for TB reactivation. Our objectives were to calculate robust longitudinal estimates of TB incidence in a cohort of people migrating to British Columbia, Canada, over a 29-year period, and to identify groups at highest risk of developing TB based on demographic characteristics at time of landing.

METHODS

We included all individuals (n = 1 080 908) who became permanent residents of Canada between Jan. 1, 1985, and Dec. 31, 2012, and were resident in BC at any time between 1985 and 2013. Multiple administrative databases were linked to the provincial TB registry. We used recursive partitioning models to identify populations with high TB yield.

RESULTS

Active TB was diagnosed in 2814 individuals (incidence rate 24.2/100 000 person-years). Demographic factors (live-in caregiver, family, refugee immigration classes; higher TB incidence in country of birth; and older age) were strong predictors of TB incidence in BC, with elevated rates continuing many years after entry into the cohort. Recursive partitioning identified refugees 18-64 years of age from countries with a TB incidence greater than 224/100 000 population as a high-yield group, with 1% developing TB within the first 10 years.

INTERPRETATION

These findings support recommendations in Canadian guidelines to target postlanding screening for and treatment of LTBI in adult refugees from high-incidence countries. Because high-yield populations can be identified at entry via demographic data, screening at this point may be practical and high-impact, particularly if the LTBI care cascade can be optimized.

Mobile phone short message service for adherence support and care of patients with tuberculosis infection: Evidence and opportunity

To attain the Global End Tuberculosis (TB) goals, the treatment of persons with TB requires advancements in coordinated approaches that are low-cost and highly accessible. Treating TB successfully requires prolonged medication regimens with good adherence, which in turn requires patients to be adequately supported. Furthermore, TB care-providers often wish to monitor treatment-taking by patients in order to track the success of their programs and ensure adequate completion of therapies by individuals. The standard-of-care for treatment monitoring in TB programs often includes directly observed therapy (DOT). Video observed therapy (VOT) has emerged as a method to mimic in-person visits or observations, especially in the smartphone era with internet data connections, but remains simply inaccessible to patients in areas where TB is most endemic. Both approaches may be considered more intensive than necessary for many patients, leaving an opportunity for more affordable and acceptable approaches. The rapid increase in mobile phone penetration provides an opportunity to reach patients between clinical visits. Short message services (SMS) are available on almost every mobile phone and are supported by first generation cellular communication networks, thus providing the farthest reach and penetration globally. Evidence from non-TB conditions suggests SMS, used in a variety of ways, may support outpatients for better medication adherence and quality of care but the evidence in TB remains limited. In this paper, we discuss how basic mobile phones and SMS-related services may be used in supporting global care of persons with TB, with a focus on patient-centered approaches.

Patient satisfaction with sleep study experience: findings from the Sleep Apnea Patient-Centered Outcomes Network

Study Objectives

Home sleep apnea testing (HSAT) is increasingly used as an alternative to laboratory-based polysomnography (PSG) for the diagnosis of obstructive sleep apnea. Patient satisfaction with sleep testing performed at home or in the lab has been sparsely assessed, despite its potentially pivotal role in determining patients' acceptance of sleep apnea treatment. We hypothesize that satisfaction in clinical practice may differ from what has been previously reported within the research setting.

Methods

We analyzed survey data including responses to questions regarding diagnostic sleep study type and sleep study experience satisfaction from 2563 sleep apnea patients enrolled in the Sleep Apnea Patient-Centered Outcomes Network.

Results

Patients (mean age 57 years; 54% male) who underwent in-lab PSG were more likely to be satisfied with their study experience than patients who had a HSAT (71% vs 60%; p < 0.01). Furthermore, the 38 per cent diminished odds of satisfaction in patients having HSAT (OR: 0.62; 95% CI: 0.49-0.77) persisted after adjustment for potential confounders (OR: 0.41, 95% CI; 0.27-0.63). Greater sleep apnea symptom burden and satisfaction with CPAP therapy were associated with greater study satisfaction. Effect modifications on study types by college degree education and tiredness as a study trigger were detected.

Conclusions

Patients receiving care in the community who underwent PSG reported greater satisfaction with study experience than patients who underwent HSAT in contrast to findings from randomized controlled trials. Our findings, based on data from contemporary "real-world" settings, suggest that assumptions about the generalizability of early reports comparing in-lab PSG to home-based paradigms need to be revisited.