scholarly journals Smoothing age/time structure of HIV prevalence, for optimal use in synthetic cohort based incidence estimation

2021 ◽  
Author(s):  
Laurette Mhlanga ◽  
Grebe Eduard ◽  
Alex Welte
Keyword(s):  
Survey Design ◽  
Cohort Analysis ◽  
Large Population ◽  
Hiv Prevalence ◽  
Time Structure ◽  
Sampling Density ◽  
Synthetic Cohort ◽  
Incidence Estimate ◽  
Incidence And Mortality ◽  
Incidence Estimation

Abstract BackgroundPopulation-based surveys which ascertain HIV status are conducted in heavily affected countries, with the estimation of incidence being a primary goal. Numerous methods exist under the umbrella of ‘synthetic cohort analysis’, by which we mean estimating incidence from the age/time structure of prevalence (given knowledge on mortality). However, not enough attention has been given to how serostatus data is ‘smoothed’ into a time/age-dependent prevalence, so as to optimise the estimation of incidence.MethodsTo support this and other related investigations, we developed a comprehensive simulation environment in which we simulate age/time structured SI type epidemics and surveys. Scenarios are flexibly defined by demographic rates (fertility, incidence and mortality – dependent, as appropriate, on age, time, and time-since-infection) without any reference to underlying causative processes/parameters. Primarily using 1) a simulated epidemiological scenario inspired by what is seen in the hyper-endemic HIV affected regions, and 2) pairs of cross-sectional surveys, we explored A) options for extracting the age/time structure of prevalence so as to optimise the use of the formal incidence estimation framework of Mahiane et al, and B) aspects of survey design such as the interaction of epidemic details, sample-size/sampling-density and inter-survey interval.ResultsMuch as in our companion piece which crucially investigated the use of ‘recent infection’ (whereas the present analysis hinges fundamentally on the estimation of the prevalence gradient) we propose a ‘one size fits most’ process for conducting ‘synthetic cohort’ analyses of large population survey data sets, for HIV incidence estimation: fitting a generalised linear model for prevalence, separately for each age/time point where an incidence estimate is desired, using a ‘moving window’ data inclusion rule. Overall, even in very high incidence settings, sampling density requirements are onerous.ConclusionThe general default approach we propose for fitting HIV prevalence to data as a function of age and time appears to be broadly stable over various epidemiological stages. Particular scenarios of interest, and the applicable options for survey design and analysis, can readily be more closely investigated using our approach. We note that it is often unrealistic to expect even large household based surveys to provide meaningful incidence estimates outside of priority groups like young women, where incidence is often particularly high.

scholarly journals Smoothing age/time structure of HIV prevalence, for optimal use in synthetic cohort based incidence estimation

2021 ◽  
Author(s):  
Laurette Mhlanga ◽  
Grebe Eduard ◽  
Alex Welte
Keyword(s):  
Survey Design ◽  
Cohort Analysis ◽  
Large Population ◽  
Hiv Prevalence ◽  
Time Structure ◽  
Sampling Density ◽  
Synthetic Cohort ◽  
Incidence Estimate ◽  
Incidence And Mortality ◽  
Incidence Estimation

Abstract Population-based surveys which ascertain HIV status are conducted in heavily affected countries, with the estimation of incidence being a primary goal. Numerous methods exist under the umbrella of ‘synthetic cohort analysis’, by which we mean estimating incidence from the age/time structure of prevalence (given knowledge on mortality). However, not enough attention has been given to how serostatus data is ‘smoothed’ into a time/age-dependent prevalence, so as to optimise the estimation of incidence.To support this and other related investigations, we developed a comprehensive simulation environment in which we simulate age/time structured SI type epidemics and surveys. Scenarios are flexibly defined by demographic rates (fertility, incidence and mortality – dependent, as appropriate, on age, time, and time-since-infection) without any reference to underlying causative processes/parameters. Primarily using 1) a simulated epidemiological scenario inspired by what is seen in the hyper-endemic HIV affected regions, and 2) pairs of cross-sectional surveys, we explored A) options for extracting the age/time structure of prevalence so as to optimise the use of the formal incidence estimation framework of Mahiane et al, and B) aspects of survey design such as the interaction of epidemic details, sample-size/sampling-density and inter-survey interval.Much as in our companion piece which crucially investigated the use of ‘recent infection’ (whereas the present analysis hinges fundamentally on the estimation of the prevalence gradient) we propose a ‘one size fits most’ process for conducting ‘synthetic cohort’ analyses of large population survey data sets, for HIV incidence estimation: fitting a generalised linear model for prevalence, separately for each age/time point where an incidence estimate is desired, using a ‘moving window’ data inclusion rule. Overall, even in very high incidence settings, sampling density requirements are onerous.The general default approach we propose for fitting HIV prevalence to data as a function of age and time appears to be broadly stable over various epidemiological stages. Particular scenarios of interest, and the applicable options for survey design and analysis, can readily be more closely investigated using our approach. We note that it is often unrealistic to expect even large household based surveys to provide meaningful incidence estimates outside of priority groups like young women, where incidence is often particularly high.

P6293Assessment of testosterone/estradiol ratio, DHEA-S level and correlation with coronary inflammatory markers IL-1 & 6, TNF-1 and hsCRP predict 5 years risk of cardiovascular disease in men

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
N Sen ◽  
S Tanwar ◽  
A Jain ◽  
J Sharma ◽  
R K Gokhroo ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Inflammatory Markers ◽  
Cohort Analysis ◽  
Large Population ◽  
Fold Increase ◽  
Male Population ◽  
Adjusted Risk ◽  
Significant Difference ◽  
Group A ◽  
Group B

Abstract Background Previous data showed the adrenal sex hormone dehydroepiandrosterone (DHEA) which is present in serum mainly as the sulfate DHEA-S is the most abundant steroid hormone and another hormones like testosterone, estradiol are related to cardiovascular risk in men. Literatures revealed vascular and metabolic actions of DHEA/-S, evidence for an association between DHEA/-S levels and cardiovascular events is controversy. Objectives Our aim is to review and clear the contradictory point regarding cardiovascular risk and correlation of testeosterone/ estradiol ratio, DHEA-S level with coronary inflammatory markers in men. Methods Large population based cohort study done at multi centre of cardiology from 2013- 2018 in India. We enrolled total 23631 normal healthy male population age between 40 to 60 years and divided into two groups based on testosterone/estradiol ratio (Group A (n=2450) lower value of T/E ratio and Group B (n=21181) normal or higher T/E ratio. We did cohort analysis for 5 years and evaluated DHEA-S level and correlated it with coronary inflammatory markers and cardiovascular risk. Results In group A (low T/E ratio) we found low level of DHEA-S (98% of individual) and higher value of interleukins IL-1 (68%),IL-6 (74%) and tumor necrosis factor TNF-1 (71%) and high sensitive C-reactive protein (hsCRP) (73% of individual). Data revealed two fold increase of high blood pressure and LDL cholesterol level as compared to group B (normal or high T/E ratio and normal or high value of DHEA-S). 2.5 fold higher rate of coronary heart disease (CHD) found in group A versus in group B. We did not found as much significant difference in stroke, carotid and peripheral artery disease. T/E ratio and DHEA-S levels were inversely associated with the age-adjusted risk of a CHD event; the hazard ratios and 95% confidence intervals per standard deviation (SD) increase were 0.76 (0.66 to 0.91) and 0.82 (0.72 to 0.93), respectively. Conclusions Decrease ratio of testosterone/estradiol levels correlate decreased levels of DHEA-S which may increase the risk of CHD in men. For future aspect, correction of T/E ratio, DHEA-S and increase its awareness should be at mass level for prevention of CHD.

Secular trends in incidence and mortality of bladder cancer in China, 1990–2017: A joinpoint and age-period-cohort analysis

2019 ◽  
Vol 61 ◽  
pp. 95-103 ◽  
Author(s):  
Xiaoxue Liu ◽  
Junfeng Jiang ◽  
Chuanhua Yu ◽  
Yongbo Wang ◽  
Yi Sun ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cohort Analysis ◽  
Secular Trends ◽  
Incidence And Mortality

scholarly journals Incidence and Outcomes of Desmoplastic Small Round Cell Tumor: Results from the Surveillance, Epidemiology, and End Results Database

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Christina K. Lettieri ◽  
Pamela Garcia-Filion ◽  
Pooja Hingorani
Keyword(s):  
Radiation Therapy ◽  
Cohort Analysis ◽  
Large Population ◽  
Incidence Rates ◽  
Cell Tumor ◽  
Round Cell ◽  
Round Cell Tumor ◽  
Small Round Cell Tumor ◽  
Small Round Cell ◽  
Significant Difference

Desmoplastic small round cell tumor (DSRCT) is a rare but highly fatal malignancy. Due to the rarity of this neoplasm, no large population based studies exist.Procedure. This is a retrospective cohort analysis. Incidence rates were calculated based on sex and ethnicity and compared statistically. Gender-, ethnicity-, and treatment- based survival were calculated using the Kaplan-Meier method.Results. A total of 192 cases of DSRCT were identified. Peak incidence age was between 20 and 24 years. Age-adjusted incidence rate for blacks was 0.5 cases/million and for whites was 0.2 cases/million (P=0.037). There was no statistically significant difference in survival based on gender or ethnicity. When adjusted for age, there was no statistically significant difference in survival amongst patients who received radiation therapy compared to those who did not (HRadj = 0.73; 95% CI 0.49, 1.11). There was a statistically significant survival advantage for patients who received radiation after surgery compared to those who did not (HR 0.49; 95% CI 0.30, 0.79).Conclusion. DSRCT is more common in males and in people of African-American descent. Although overall survival remains poor, radiation therapy following surgery seems to improve outcome in these patients.

The determinants of income inequality in Thailand: A synthetic cohort analysis

2014 ◽  
Vol 31-32 ◽  
pp. 10-21 ◽  
Author(s):  
Sasiwimon Warunsiri Paweenawat ◽  
Robert McNown
Keyword(s):  
Income Inequality ◽  
Cohort Analysis ◽  
Synthetic Cohort

scholarly journals Management of adult spontaneous spondylodiscitis and its rising incidence

2015 ◽  
Vol 97 (6) ◽  
pp. 451-455 ◽  
Author(s):  
A Sur ◽  
K Tsang ◽  
M Brown ◽  
N Tzerakis
Keyword(s):  
Case Series ◽  
Intravenous Antibiotic ◽  
Case Presentation ◽  
Reactive Protein ◽  
Incidence Estimate ◽  
Management Guidance ◽  
Incidence Estimation ◽  
Rising Incidence ◽  
The Mean ◽  
Developed World

Introduction Spondylodiscitis refers to the infection of the intervertebral disc and osteomyelitis of the adjacent endplates, and it is uncommon in the developed world. Broad consensus indicates its incidence is on the rise. Methods The aim of this retrospective study was twofold. First, we sought to give an up-to-date incidence estimate by comparing case presentation over two time periods (1995–1999 and 2008–2011). Data from the England and Wales census in 2001 and 2011 were used for incidence estimation. The second part of this study aimed to generate management guidance from data from medical and radiographic records of the 2008–2011 patient cohort. Results The incidence of adult spontaneous spondylodiscitis in the local region between 2008 and 2011 was 3.67/100,000 per year, representing a 150% increase from the incidence in 1995–1999. Our data demonstrate that methicillin sensitive Staphylococcus aureus remains the most common offending pathogen of spontaneous spondylodiscitis. The mean C-reactive protein (CRP) level remained at >30mg/l after a month of starting antibiotic treatment in both medically and surgically managed groups. Conclusions Evidence suggests that the incidence of spondylodiscitis is on the rise. A review of our case series has demonstrated the effectiveness of intravenous antibiotic therapy. While no official guidance exists for when to switch from intravenous to oral antibiotics, our study shows that CRP at 1 month is >30mg/l and we recommend 6 weeks of intravenous therapy, followed by 6 further weeks of oral therapy.

scholarly journals Implementation of a Web-Based Symptom Checker to Manage the Quarantine of the USS Theodore Roosevelt Crew Following a Shipboard Outbreak of SARS-CoV-2

2021 ◽  
Author(s):  
Robert L Fenequito ◽  
Daniel Houskamp ◽  
Vincent Siu ◽  
Jamal Rorie ◽  
Nikunj Bhatt ◽  
...  
Keyword(s):  
Medical Staff ◽  
Time Course ◽  
Cohort Analysis ◽  
Large Population ◽  
Medical Provider ◽  
Aircraft Carrier ◽  
Theodore Roosevelt ◽  
Web Based ◽  
Social Distancing ◽  
Positive Contact

Introduction: In late March 2020, the USS Theodore Roosevelt (TR), a nuclear-powered aircraft carrier, pulled into port in the US territory of Guam to assess the severity of a developing outbreak of COVID-19 aboard the ship. A small staff contingent of 60 personnel from US Naval Hospital (USNH) Guam was tasked with the medical care of 4,079 sailors who were placed in single room quarantine amongst 11 hotels across the island of Guam. With the assistance of the Defense Digital Service, the USNH Guam staff implemented a web-based symptom checker, which allowed for monitoring of developing COVID symptoms, and selective testing of symptomatic individuals. Materials and Methods: Sailors from the TR were placed in quarantine or isolation cohorts upon debarking the ship. Sailors not positive for COVID-19 were quarantined amongst 11 hotels on Guam. Sailors positive for COVID-19 were isolated aboard Naval Base Guam (NBG). A retrospective cohort analysis and subgroup analyses were performed on symptom data obtained from sailors in quarantine. The sailors recorded their symptoms and temperature in a web-based symptom checker that assigned a symptom severity score (SSS). Sailors with a SSS >50 were evaluated by a medical provider and re-tested. Data were collected from 4 April 2020 to 1 May 2020. Sailors required two negative tests to exit quarantine and re-embark the ship. The time course, and most common cluster of symptoms associated with a positive COVID-19 PCR test were determined retrospectively after data collection. Results: The web-based symptom checker was successful in establishing daily positive contact and symptom monitoring of susceptible individuals in quarantine. 4,079 sailors in quarantine maintained positive contact with medical staff via the symptom checker, with at least 81% of the sailors recording their symptoms on a daily basis. Individuals with high symptom scores were quickly identified and underwent further evaluation and repeat COVID-19 testing. A cohort of 331 sailors tested positive for COVID-19 while in quarantine and recorded symptoms in the symptom checker before and after a positive COVID-19 test. In this cohort, the most frequent symptoms reported prior to a positive test were headache, anosmia, followed by cough. The symptom of anosmia was reported more frequently in sailors positive for COVID-19, compared to a cohort of matched controls. A small medical staff was able to monitor developing symptoms in a large quarantined population, while efficiently allocating resources, preserving personal protective equipment (PPE), and maintaining isolation and social distancing protocols. Conclusions and Relevance: The application provided a tool for broad health surveillance over a large population while maintaining strict quarantine and social distancing protocols. Highly symptomatic sailors were quickly identified, triaged, and transferred to a higher level of care if indicated. The symptom checker and predictive model generated from the data can be utilized by military and civilian public health officials to triage large populations and make rapid decisions on isolation measures, resource allocation, selective testing.

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