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1.
AIDS Care ; 36(5): 652-660, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38295268

RESUMO

Alcohol use disorders (AUD) among people living with HIV (PLHIV) are associated with poor health outcomes. This cross-sectional study examined current alcohol use and AUD among 300 PLHIV on ART at four HIV care centres in Northwest Tanzania. Participants' data were collected using questionnaires. Alcohol use was assessed using Alcohol Use Disorders Identification Test (AUDIT). Logistic regression was used to examine associations between each outcome (current drinking and AUD) and sociodemographic and clinical factors. Association between alcohol use and ART adherence was also studied. The median age of participants was 43 years (IQR 19-71) and 41.3% were male. Twenty-two (7.3%) participants failed to take ART at least once in the last seven days. The prevalence of current drinking was 29.3% (95% CI 24.2-34.8%) and that of AUD was 11.3% (8.2%-15.5%). Males had higher odds of alcohol use (OR 3.03, 95% CI 1.79-5.14) and AUD (3.89, 1.76-8.60). Alcohol use was associated with ART non-adherence (OR = 2.78, 1.10-7.04). There was a trend towards an association between AUD and non-adherence (OR = 2.91, 0.92-9.21). Alcohol use and AUD were common among PLHIV and showed evidence of associations with ART non-adherence. Screening patients for alcohol use and AUD in HIV clinics may increase ART adherence.


Assuntos
Alcoolismo , Fármacos Anti-HIV , Infecções por HIV , Humanos , Masculino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Alcoolismo/complicações , Alcoolismo/epidemiologia , Administração de Caso , Estudos Transversais , Tanzânia/epidemiologia , Fármacos Anti-HIV/uso terapêutico , Adesão à Medicação
2.
Euro Surveill ; 29(7)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38362627

RESUMO

Many vaccine effectiveness (VE) analyses of severe disease outcomes such as hospitalisation and death include 'false' cases that are not actually caused by the infection or disease under study. While the inclusion of such false cases inflate outcome rates in both vaccinated and unvaccinated populations, it is less obvious how they affect estimates of VE. Illustrating the main points through simple examples, this article shows how VE is underestimated when false cases are included as outcomes. Depending how the outcome indicator is defined, estimates of VE against severe disease outcomes, whose definition allows for the inclusion of false cases, will be biased downwards and may in certain circumstances approximate the same level as the VE against infection. The bias is particularly pronounced for vaccines that offer high levels of protection against severe disease outcomes but poor protection against infection. Analysing outcomes that are measured with low sensitivity generally does not cause bias in VE studies; defining outcome indicators that minimise the number of false cases rather than the number of missed cases is preferable in VE studies.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Hospitalização , Eficácia de Vacinas , Sensibilidade e Especificidade , Vacinas contra COVID-19/administração & dosagem
3.
Trop Med Int Health ; 28(9): 720-730, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37496465

RESUMO

OBJECTIVE: HIV risk prediction tools are a critical component of efforts to end the HIV pandemic. We aimed to create and validate tools for identifying individuals at highest risk of prevalent and incident HIV in an African setting. METHODS: We used Logistic regression and Poisson regression to determine risk factors for HIV prevalence and incidence in a multi-country HIV vaccine trial preparedness cohort study among individuals at high risk of HIV, and used the identified factors to create and validate tools that predict HIV risk. We also assessed the performance of the VOICE risk score in predicting HIV incidence among women in the cohort. RESULTS: The prevalent HIV prediction tool created had good predictive ability [area under the curve (AUC) = 0.70, 95% CI 0.66-0.74]. It included the following participant variables: age, sex, recreational drug use, unprotected male-to-male anal sex, a sexual partner who had other partners, transactional sex and having a partner who was a long-distance truck driver/miner. It was not possible to create a valid HIV incidence prediction tool. Participants with high VOICE risk scores (≥7) had slightly higher HIV incidence but this tool performed poorly within our study (AUC = 0.58, 95% CI 0.51-0.64: Harrell's concordance index = 0.59). CONCLUSION: We created a prevalent HIV prediction tool that could be used to increase efficiency in diagnosis of HIV and linkage to care in sub-Saharan Africa. Existing incident HIV prediction tools may need modification to include context-specific predictors such as calendar period, participant occupation, study site, before adoption in settings different from those in which they were developed.


Assuntos
Infecções por HIV , Humanos , Masculino , Feminino , Infecções por HIV/diagnóstico , Estudos de Coortes , Fatores de Risco , Comportamento Sexual , Parceiros Sexuais
4.
Trop Med Int Health ; 28(3): 237-246, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36717965

RESUMO

OBJECTIVES: This cross-sectional survey aimed to explore associations between age of menarche, early sexual debut and high-risk sexual behaviour among urban Tanzanian schoolgirls. METHODS: Secondary schoolgirls aged 17-18 years from Mwanza, Tanzania, participated in structured face-to-face questionnaire-based interviews, conducted by nurses and clinicians. Age of menarche was evaluated in categories of 11-12, 13-14, 15-16 or ≥17 years. Primary outcome measures were self-reported early sexual debut (first vaginal sex at <16 years) and high-risk sexual behaviour, including non-use of condoms, having sex for gifts/money, having older sexual partners and/or other risky behaviours. RESULTS: Of 401 girls enrolled, 174 (43.4%) reported prior vaginal sex. Prevalence of early sexual debut was 14.2% but pressured/forced sex and risky sexual behaviours were common. Adjusted for potential confounding, younger age at menarche was associated with early sexual debut (adjusted odds ratio for linear trend: 1.88 per category, 95% confidence interval: 1.21-2.92, p = 0.005). This association remained after excluding girls with first sex at <8 years or experiencing pressure or force at first sex. Further, adjusted for potential confounding (including ever experiencing forced sex), early sexual debut was associated with high-risk sexual behaviour (adjusted odds ratio: 2.85, 95% confidence interval: 1.38-5.88, p = 0.004). CONCLUSIONS: Among urban Tanzanian school girls, younger age of menarche was associated with early sexual debut, and early sexual debut was associated with high-risk sexual behaviour. Researchers and public health professionals developing and delivering interventions aimed at preventing adverse sexual health outcomes should consider the impact of these early biological and sexual exposures.


Assuntos
Menarca , Comportamento Sexual , Feminino , Humanos , Estudos Transversais , Tanzânia/epidemiologia , Parceiros Sexuais
5.
PLoS Med ; 19(11): e1004037, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36413551

RESUMO

BACKGROUND: Individuals with a prior Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection have a moderate to high degree of protection against reinfection, though seemingly less so when the Omicron variant of SARS-CoV-2 started to circulate. The aim of this study was to evaluate the vaccine effectiveness (VE) against SARS-CoV-2 reinfection, Coronavirus Disease 2019 (COVID-19)-related hospitalization, and COVID-19-related death, in individuals with prior SARS-CoV-2 infection, and to assess the effect of time since vaccination during periods with different dominant SARS-CoV-2 variants. METHODS AND FINDINGS: This study used a nationwide cohort design including all individuals with a confirmed SARS-CoV-2 infection, who were alive, and residing in Denmark between 1 January 2020 and 31 January 2022. Using Danish nationwide registries, we obtained information on SARS-CoV-2 infections, COVID-19 vaccination, age, sex, comorbidity, staying at hospital, and country of origin. The study population included were individuals with prior SARS-CoV-2 infection. Estimates of VE against SARS-CoV-2 reinfection with 95% confidence intervals (CIs) were calculated using a Poisson regression model and adjusted for age, sex, country of origin, comorbidity, staying at hospital, calendar time, and test incidence using a Cox regression model. The VE estimates were calculated separately for three periods with different dominant SARS-CoV-2 variants (Alpha (B.1.1.7), Delta (B.1.617.2), or Omicron (B.1.1.529)) and by time since vaccination using unvaccinated as the reference. In total, 148,527 person-years and 44,192 SARS-CoV-2 infections were included for the analysis regarding reinfections. The study population comprised of 209,814 individuals infected before or during the Alpha period, 292,978 before or during the Delta period, and 245,530 before or during the Omicron period. Of these, 40,281 individuals had completed their primary vaccination series during the Alpha period (19.2%), 190,026 during the Delta period (64.9%), and 158,563 during the Omicron period (64.6%). VE against reinfection following any COVID-19 vaccine type administered in Denmark, peaked at 71% (95% CI: -Inf to 100%) at 104 days or more after vaccination during the Alpha period, 94% (95% CI: 92% to 96%) 14 to 43 days after vaccination during the Delta period, and 60% (95% CI: 58% to 62%) 14 to 43 days after vaccination during the Omicron period. Waning immunity following vaccination was observed and was most pronounced during the Omicron period. Due to too few events, it was not possible to estimate VE for hospitalization and death. Study limitations include potentially undetected reinfections, differences in health-seeking behavior, or risk behavior between the compared groups. CONCLUSIONS: This study shows that in previously infected individuals, completing a primary vaccination series was associated with a significant protection against SARS-CoV-2 reinfection compared with no vaccination. Even though vaccination seems to protect to a lesser degree against reinfection with the Omicron variant, these findings are of public health relevance as they show that previously infected individuals still benefit from COVID-19 vaccination in all three variant periods.


Assuntos
COVID-19 , Vacinas Virais , Humanos , SARS-CoV-2 , Reinfecção/epidemiologia , Reinfecção/prevenção & controle , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Eficácia de Vacinas , Dinamarca/epidemiologia
6.
PLoS Med ; 19(9): e1003992, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36048766

RESUMO

BACKGROUND: The continued occurrence of more contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants and waning immunity over time require ongoing reevaluation of the vaccine effectiveness (VE). This study aimed to estimate the effectiveness in 2 age groups (12 to 59 and 60 years or above) of 2 or 3 vaccine doses (BNT162b2 mRNA or mRNA-1273) by time since vaccination against SARS-CoV-2 infection and Coronavirus Disease 2019 (COVID-19) hospitalization in an Alpha-, Delta-, or Omicron-dominated period. METHODS AND FINDINGS: A Danish nationwide cohort study design was used to estimate VE against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha, Delta, or Omicron variant. Information was obtained from nationwide registries and linked using a unique personal identification number. The study included all previously uninfected residents in Denmark aged 12 years or above (18 years or above for the analysis of 3 doses) in the Alpha (February 20 to June 15, 2021), Delta (July 4 to November 20, 2021), and Omicron (December 21, 2021 to January 31, 2022) dominated periods. VE estimates including 95% confidence intervals (CIs) were calculated (1-hazard ratio∙100) using Cox proportional hazard regression models with underlying calendar time and adjustments for age, sex, comorbidity, and geographical region. Vaccination status was included as a time-varying exposure. In the oldest age group, VE against infection after 2 doses was 90.7% (95% CI: 88.2; 92.7) for the Alpha variant, 82.3% (95% CI: 75.5; 87.2) for the Delta variant, and 39.9% (95% CI: 26.3; 50.9) for the Omicron variant 14 to 30 days since vaccination. The VE waned over time and was 73.2% (Alpha, 95% CI: 57.1; 83.3), 50.0% (Delta, 95% CI: 46.7; 53.0), and 4.4% (Omicron, 95% CI: -0.1; 8.7) >120 days since vaccination. Higher estimates were observed after the third dose with VE estimates against infection of 86.1% (Delta, 95% CI: 83.3; 88.4) and 57.7% (Omicron, 95% CI: 55.9; 59.5) 14 to 30 days since vaccination. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 98.1% or above for the Alpha and Delta variants. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 95.5% or above for the Omicron variant. The main limitation of this study is the nonrandomized study design including potential differences between the unvaccinated (reference group) and vaccinated individuals. CONCLUSIONS: Two vaccine doses provided high protection against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha and Delta variants with protection, notably against infection, waning over time. Two vaccine doses provided only limited and short-lived protection against SARS-CoV-2 infection with Omicron. However, the protection against COVID-19 hospitalization following Omicron SARS-CoV-2 infection was higher. The third vaccine dose substantially increased the level and duration of protection against infection with the Omicron variant and provided a high level of sustained protection against COVID-19 hospitalization among the +60-year-olds.


Assuntos
COVID-19 , Vacinas Virais , Vacina BNT162 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Estudos de Coortes , Dinamarca/epidemiologia , Hospitalização , Humanos , SARS-CoV-2/genética , Eficácia de Vacinas
7.
Am J Transplant ; 22(11): 2627-2636, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35801493

RESUMO

The risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization and death, and the effects of SARS-CoV-2 vaccines in solid organ transplant recipients (SOTRs) is still debated. We performed a nationwide, population-based, matched cohort study, including all Danish SOTRs (n = 5184) and a matched cohort from the general population (n = 41 472). Cox regression analyses were used to calculate incidence rate ratios (IRRs). SOTRs had a slightly increased risk of SARS-CoV-2 infection and were vaccinated earlier than the general population. The overall risk of hospital contact with COVID-19, severe COVID-19, need for assisted respiration, and hospitalization followed by death was substantially higher in SOTRs (IRR: 32.8 95%CI [29.0-37.0], 9.2 [6.7-12.7], 12.5 [7.6-20.8], 12.4 [7.9-12.7]). The risk of hospitalization and death after SARS-CoV-2 infection decreased substantially in SOTRs after the emergence of the Omicron variant (IRR: 0.45 [0.37-0.56], 0.17 [0.09-0.30]). Three vaccinations reduced the risk of SARS-CoV-2 infection only marginally compared to two vaccinations, but SOTRs with three vaccinations had a lower risk of death (IRR: 022 [0.16-0.35]). We conclude that SOTRs have a risk of SARS-CoV-2 infection comparable to the general population, but substantially increased the risk of hospitalization and death following SARS-CoV-2 infection. A third vaccination only reduces the risk of SARS-CoV2 infection marginally, but SOTRs vaccinated 3 times have reduced mortality.


Assuntos
COVID-19 , Transplante de Órgãos , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Estudos de Coortes , RNA Viral , Vacinas contra COVID-19 , Transplante de Órgãos/efeitos adversos , Dinamarca/epidemiologia
8.
Lancet ; 397(10280): 1204-1212, 2021 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-33743221

RESUMO

BACKGROUND: The degree to which infection with SARS-CoV-2 confers protection towards subsequent reinfection is not well described. In 2020, as part of Denmark's extensive, free-of-charge PCR-testing strategy, approximately 4 million individuals (69% of the population) underwent 10·6 million tests. Using these national PCR-test data from 2020, we estimated protection towards repeat infection with SARS-CoV-2. METHODS: In this population-level observational study, we collected individual-level data on patients who had been tested in Denmark in 2020 from the Danish Microbiology Database and analysed infection rates during the second surge of the COVID-19 epidemic, from Sept 1 to Dec 31, 2020, by comparison of infection rates between individuals with positive and negative PCR tests during the first surge (March to May, 2020). For the main analysis, we excluded people who tested positive for the first time between the two surges and those who died before the second surge. We did an alternative cohort analysis, in which we compared infection rates throughout the year between those with and without a previous confirmed infection at least 3 months earlier, irrespective of date. We also investigated whether differences were found by age group, sex, and time since infection in the alternative cohort analysis. We calculated rate ratios (RRs) adjusted for potential confounders and estimated protection against repeat infection as 1 - RR. FINDINGS: During the first surge (ie, before June, 2020), 533 381 people were tested, of whom 11 727 (2·20%) were PCR positive, and 525 339 were eligible for follow-up in the second surge, of whom 11 068 (2·11%) had tested positive during the first surge. Among eligible PCR-positive individuals from the first surge of the epidemic, 72 (0·65% [95% CI 0·51-0·82]) tested positive again during the second surge compared with 16 819 (3·27% [3·22-3·32]) of 514 271 who tested negative during the first surge (adjusted RR 0·195 [95% CI 0·155-0·246]). Protection against repeat infection was 80·5% (95% CI 75·4-84·5). The alternative cohort analysis gave similar estimates (adjusted RR 0·212 [0·179-0·251], estimated protection 78·8% [74·9-82·1]). In the alternative cohort analysis, among those aged 65 years and older, observed protection against repeat infection was 47·1% (95% CI 24·7-62·8). We found no difference in estimated protection against repeat infection by sex (male 78·4% [72·1-83·2] vs female 79·1% [73·9-83·3]) or evidence of waning protection over time (3-6 months of follow-up 79·3% [74·4-83·3] vs ≥7 months of follow-up 77·7% [70·9-82·9]). INTERPRETATION: Our findings could inform decisions on which groups should be vaccinated and advocate for vaccination of previously infected individuals because natural protection, especially among older people, cannot be relied on. FUNDING: None.


Assuntos
Teste para COVID-19 , Reação em Cadeia da Polimerase , Reinfecção/epidemiologia , Reinfecção/imunologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Bases de Dados Factuais , Dinamarca/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
9.
Euro Surveill ; 27(30)2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35904059

RESUMO

By employing a common protocol and data from electronic health registries in Denmark, Navarre (Spain), Norway and Portugal, we estimated vaccine effectiveness (VE) against hospitalisation due to COVID-19 in individuals aged ≥ 65 years old, without previous documented infection, between October 2021 and March 2022. VE was higher in 65-79-year-olds compared with ≥ 80-year-olds and in those who received a booster compared with those who were primary vaccinated. VE remained high (ca 80%) between ≥ 12 and < 24 weeks after the first booster administration, and after Omicron became dominant.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Eletrônica , Hospitalização , Humanos , Projetos Piloto , Sistema de Registros , Eficácia de Vacinas
10.
Epidemiol Infect ; 150: e9, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34784997

RESUMO

Identification of societal activities associated with SARS-CoV-2 infection may provide an evidence base for implementing preventive measures. Here, we investigated potential determinants for infection in Denmark in a situation where society was only partially open. We conducted a national matched case-control study. Cases were recent RT-PCR test-positives, while controls, individually matched on age, sex and residence, had not previously tested positive for SARS-CoV-2. Questions concerned person contact and community exposures. Telephone interviews were performed over a 7-day period in December 2020. We included 300 cases and 317 controls and determined odds ratios (ORs) and 95% confidence intervals (95% CI) by conditional logistical regression with adjustment for household size and country of origin. Contact (OR 4.9, 95% CI 2.4-10) and close contact (OR 13, 95% CI 6.7-25) with a person with a known SARS-CoV-2 infection were main determinants. Contact most often took place in the household or work place. Community determinants included events with singing (OR 2.1, 95% CI 1.1-4.1), attending fitness centres (OR 1.8, 95% CI 1.1-2.8) and consumption of alcohol in a bar (OR 10, 95% CI 1.5-65). Other community exposures appeared not to be associated with infection, these included shopping at supermarkets, travel by public transport, dining at restaurants and private social events with few participants. Overall, the restrictions in place at the time of the study appeared to be sufficient to reduce transmission of disease in the public space, which instead largely took place following direct exposures to people with known SARS-CoV-2 infections.


Assuntos
COVID-19/epidemiologia , Atividades Humanas/estatística & dados numéricos , Adulto , Estudos de Casos e Controles , Dinamarca/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quarentena/organização & administração , Adulto Jovem
11.
BMC Public Health ; 20(1): 353, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32183759

RESUMO

BACKGROUND: Immediate uptake of antiretroviral therapy (ART) after an HIV-positive diagnosis (Test and Treat) is now being implemented in Uganda. Data are limited on lost to follow-up (LTFU) in high-risk cohorts that have initiated 'Test and Treat'. We describe LTFU in a cohort of women of high-risk sexual behaviour who initiated ART under "Test and Treat". METHODS: We performed a retrospective cohort study of participant records at the Good Health for Women Project (GHWP) clinic, a clinic in Kampala for women at high-risk of HIV-infection. We included HIV positive women ≥18 years who initiated ART at GHWP between August 2014 and March 2018. We defined LTFU as not taking an ART refill for ≥3 months from the last clinic appointment among those not registered as dead or transferred to another clinic. We used the Kaplan-Meier technique to estimate time to LTFU after ART initiation. Predictors of LTFU were assessed using a multivariable Cox proportional hazards model. RESULTS: The mean (±SD) age of the 293 study participants was 30.3 (± 6.5) years, with 274 (94%) reporting paid sex while 38 (13%) had never tested for HIV before enrolment into GHWP. LTFU within the first year of ART initiation was 16% and the incidence of LTFU was estimated at 12.7 per 100 person-years (95%CI 9.90-16.3). In multivariable analysis, participants who reported sex work as their main job at ART initiation (Adjusted Hazards Ratio [aHR] =1.95, 95%CI 1.10-3.45), having baseline WHO clinical stage III or IV (aHR = 2.75, 95% CI 1.30-5.79) were more likely to be LTFU. CONCLUSION: LTFU in this cohort is high. Follow up strategies are required to support women on Test and Treat to remain on treatment, especially those who engage in sex work and those who initiate ART at a later stage of disease.


Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Perda de Seguimento , Trabalho Sexual/estatística & dados numéricos , Adulto , Feminino , Infecções por HIV/epidemiologia , Humanos , Adesão à Medicação/estatística & dados numéricos , Avaliação de Programas e Projetos de Saúde , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Uganda/epidemiologia
13.
Emerg Themes Epidemiol ; 15: 11, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30123310

RESUMO

BACKGROUND: Information on the size of populations is crucial for planning of service and resource allocation to communities in need of health interventions. In resource limited settings, reliable census data are often not available. Using publicly available Google Earth Pro and available local household survey data from fishing communities (FC) on Lake Victoria in Uganda, we compared two simple methods (using average population density) and one simple linear regression model to estimate populations of small rural FC in Uganda. We split the dataset into two sections; one to obtain parameters and one to test the validity of the models. RESULTS: Out of 66 FC, we were able to estimate populations for 47. There were 16 FC in the test set. The estimates for total population from all three methods were similar, with errors less than 2.2%. Estimates of individual FC populations were more widely discrepant. CONCLUSIONS: In our rural Ugandan setting, it was possible to use a simple area based model to get reasonable estimates of total population. However, there were often large errors in estimates for individual villages.

14.
Pharm Stat ; 17(6): 854-865, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30215881

RESUMO

It is often unclear what specific adaptive trial design features lead to an efficient design which is also feasible to implement. Before deciding on a particular design, it is generally advisable to carry out a simulation study to characterise the properties of candidate designs under a range of plausible assumptions. The implementation of such pre-trial simulation studies presents many challenges and requires considerable statistical programming effort and time. Despite the scale and complexity, there is little existing literature to guide the implementation of such projects using commonly available software. This Teacher's Corner article provides a practical step-by-step guide to implementing such simulation studies including how to specify and fit a Bayesian model in WinBUGS or OpenBUGS using SAS, and how results from the Bayesian analysis may be pulled back into SAS and used for adaptation of allocation probabilities before simulating subsequent stages of the trial. The interface between the two software platforms is described in detail along with useful tips and tricks. A key strength of our approach is that the entire exercise can be defined and controlled from within a single SAS program.


Assuntos
Teorema de Bayes , Ensaios Clínicos como Assunto , Guias de Prática Clínica como Assunto , Simulação por Computador , Humanos
15.
J Neurol Neurosurg Psychiatry ; 86(3): 295-301, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24935983

RESUMO

OBJECTIVE: Somatic symptoms unexplained by disease are common in all medical settings. The process of identifying such patients requires a clinical assessment often supported by clinical tests. Such assessments are time-consuming and expensive. Consequently the observation that such patients tend to report a greater number of symptom has led to the use of self-rated somatic symptom counts as a simpler and cheaper diagnostic aid and proxy measure for epidemiological surveys. However, despite their increasing popularity there is little evidence to support their validity. METHODS: We tested the score on a commonly used self-rated symptom questionnaire- the Patient Health Questionnaire (PHQ 15) (plus enhanced iterations including an additional 10 items on specific neurological symptoms and an additional 5 items on mental state) for diagnostic sensitivity and specificity against a medical assessment (with 18 months follow-up) in a prospective cohort study of 3781 newly attending patients at neurology clinics in Scotland, UK. RESULTS: We found 1144/3781 new outpatients had symptoms that were unexplained by disease. The patients with symptoms unexplained by disease reported higher symptoms count scores (PHQ 15: 5.6 (95% CI 5.4 to 5.8) vs 4.2 (4.1 to 4.4) p<0.0001). However, the PHQ15 performed little better than chance in its ability to identify patients with symptoms unexplained by disease. The findings with the enhanced scales were similar. CONCLUSIONS: Self-rated symptom count scores should not be used to identify patients with symptoms unexplained by disease.


Assuntos
Doenças do Sistema Nervoso/diagnóstico , Transtornos Somatoformes/diagnóstico , Adolescente , Adulto , Idoso , Assistência Ambulatorial , Estudos de Coortes , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/psicologia , Exame Neurológico , Valor Preditivo dos Testes , Estudos Prospectivos , Encaminhamento e Consulta , Autorrelato , Transtornos Somatoformes/psicologia , Inquéritos e Questionários , Adulto Jovem
16.
Lancet Oncol ; 15(10): 1168-76, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25175097

RESUMO

BACKGROUND: The management of depression in patients with poor prognosis cancers, such as lung cancer, creates specific challenges. We aimed to assess the efficacy of an integrated treatment programme for major depression in patients with lung cancer compared with usual care. METHODS: Symptom Management Research Trials (SMaRT) Oncology-3 is a parallel-group, multicentre, randomised controlled trial. We enrolled patients with lung cancer and major depression from three cancer centres and their associated clinics in Scotland, UK. Participants were randomly assigned in a 1:1 ratio to the depression care for people with lung cancer treatment programme or usual care by a database software algorithm that used stratification (by trial centre) and minimisation (by age, sex, and cancer type) with allocation concealment. Depression care for people with lung cancer is a manualised, multicomponent collaborative care treatment that is systematically delivered by a team of cancer nurses and psychiatrists in collaboration with primary care physicians. Usual care is provided by primary care physicians. The primary outcome was depression severity (on the Symptom Checklist Depression Scale [SCL-20], range 0-4) averaged over the patient's time in the trial (up to a maximum of 32 weeks). Trial statisticians and data collection staff were masked to treatment allocation, but patients and clinicians could not be masked to the allocations. Analyses were by intention to treat. This trial is registered with Current Controlled Trials, number ISRCTN75905964. FINDINGS: 142 participants were recruited between Jan 5, 2009, and Sept 9, 2011; 68 were randomly allocated to depression care for people with lung cancer and 74 to usual care. 43 (30%) of 142 patients had died by 32 weeks, all of which were cancer-related deaths. No intervention-related serious adverse events occurred. 131 (92%) of 142 patients provided outcome data (59 in the depression care for people with lung cancer group and 72 in the usual care group) and were included in the intention-to-treat primary analysis. Average depression severity was significantly lower in patients allocated to depression care for people with lung cancer (mean score on the SCL-20 1·24 [SD 0·64]) than in those allocated to usual care (mean score 1·61 [SD 0·58]); difference -0·38 (95% CI -0·58 to -0·18); standardised mean difference -0·62 (95% CI -0·94 to -0·29). Self-rated depression improvement, anxiety, quality of life, role functioning, perceived quality of care, and proportion of patients achieving a 12-week treatment response were also significantly better in the depression care for people with lung cancer group than in the usual care group. INTERPRETATION: Our findings suggest that major depression can be treated effectively in patients with a poor prognosis cancer; integrated depression care for people with lung cancer was substantially more efficacious than was usual care. Larger trials are now needed to estimate the effectiveness and cost-effectiveness of this care programme in this patient population, and further adaptation of the treatment will be necessary to address the unmet needs of patients with major depression and even shorter life expectancy. FUNDING: Cancer Research UK and Chief Scientist Office of the Scottish Government.


Assuntos
Prestação Integrada de Cuidados de Saúde , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/terapia , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/psicologia , Equipe de Assistência ao Paciente/organização & administração , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antidepressivos/uso terapêutico , Comorbidade , Transtorno Depressivo Maior/diagnóstico , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Prognóstico , Psicoterapia/métodos , Medição de Risco , Fatores Sexuais , Análise de Sobrevida , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Reino Unido
17.
Lancet Infect Dis ; 24(9): 964-973, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38761806

RESUMO

BACKGROUND: During the 2023 Danish COVID-19 vaccination campaign, an updated monovalent mRNA vaccine targeting the SARS-CoV-2 omicron XBB.1.5 subvariant was administered. However, the rapid spread of a genetically divergent omicron BA.2.86 subvariant, JN.1, since September, 2023, poses potential challenges due to its rapid dominance and possible immune escape. Using national electronic health registry data from all regions of Denmark, we aimed to investigate whether the SARS-CoV-2 subvariant BA.2.86, and its descendant JN.1, differed from other circulating variants in terms of their ability to escape vaccine protection, the risk of infection leading to severe disease, and self-reported symptoms among infected people. METHODS: In this observational study, we included all residents of Denmark aged 65 years and older who tested positive for SARS-CoV-2 by PCR between Oct 1 and Dec 31, 2023, and for whom genomic data on the SARS-CoV-2 variant that had caused their infection were available. Data from clinical testing, sentinel, and self-sampling-based surveillance were linked with national electronic civil, vaccination, and hospitalisation registers. The relative protection of the XBB.1.5 updated COVID-19 vaccine against BA.2.86 infections versus infections with other variants was analysed in a case-only study, and the relative risk of hospitalisation in people infected with BA.2.86 versus other variants was analysed in a case-control study. Both analyses were adjusted for time, comorbidities, and previous vaccination history, among other potential confounders. Additionally, prevalence patterns in self-reported symptoms among people of all ages infected with SARS-CoV-2 were reported separately by subvariant. FINDINGS: Of the 7581 people in Denmark aged 65 years or older who tested positive for SARS-CoV-2 by PCR during the study period, 5882 (78%) samples were eligible for sequencing. 3862 (66%) of these passed quality control, were successfully sequenced, and the SARS-CoV-2 variant and subvariant identified, and these individuals were included in the study. Of these 3862 people, 2184 (57%) were infected with the BA.2.86 subvariant, including 1615 JN.1 infections. Participants infected with BA.2.86 had 1·52 (95% CI 1·25-1·86) times the odds, and those infected with JN.1 had 1·60 (1·27-2·02) times the odds, of having received the XBB.1.5 vaccine at least 7 days before their infection compared with participants infected with a non-BA.2.86 variant. The severity analysis showed no evidence of association between the infecting variant and the risk of COVID-19 hospitalisation (odds ratio 1·04 [95% CI 0·86-1·26] for BA.2.86 and 1·07 [0·85-1·34] for JN.1). Similarly, there was no evidence of differences in self-reported symptoms by variant strain. INTERPRETATION: Compared with other SARS-CoV-2 variants, BA.2.86 and the JN.1 sublineage were less sensitive to vaccine-induced immune protection from the XBB.1.5 updated COVID-19 vaccine; however, we found no evidence that infection with BA.2.86 or JN.1 resulted in increased disease severity or different symptom profiles. Although less effective against the new variants, XBB.1.5 vaccination remains protective and reduces the risk of infection and COVID-19 disease. FUNDING: The Danish Government and the EU's EU4Health programme.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/prevenção & controle , COVID-19/epidemiologia , COVID-19/virologia , Dinamarca/epidemiologia , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Idoso , Feminino , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Masculino , Idoso de 80 Anos ou mais , Índice de Gravidade de Doença , Vacinação
18.
PLoS One ; 18(7): e0281972, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37490451

RESUMO

BACKGROUND: The Danish national SARS-CoV-2 mass test system was among the most ambitious worldwide. We describe its set-up and analyse differences in patterns of testing per demography and time period in relation to the three waves of SARS-CoV-2 transmission in Denmark. METHODS: We included all reported PCR- and rapid antigen-tests performed between 27 February 2020 and 10 March 2022 among all residents aged 2 years or above. Descriptive statistics and Poisson regression models were used to analyse characteristics of individuals tested for SARS-CoV-2 using a national cohort study design. RESULTS: A total of 63.7 million PCR-tests and 60.0 million rapid antigen-tests were performed in the study period, testing 90.9% and 78.8% of the Danish population at least once by PCR or antigen, respectively. Female sex, younger age, Danish heritage and living in the capital area were all factors positively associated with the frequency of PCR-testing. The association between COVID-19 vaccination and PCR-testing changed from negative to positive over time. CONCLUSION: We provide details of the widely available, free-of-charge, national SARS-CoV-2 test system, which served to identify infected individuals, assist isolation of infectious individuals and contact tracing, and thereby mitigating the spread of SARS-CoV-2 in the Danish population. The test system was utilized by nearly the entire population at least once, and widely accepted across different demographic groups. However, demographic differences in the test uptake did exist and should be considered in order not to cause biases in studies related to SARS-CoV-2, e.g., studies of transmission and vaccine effectiveness.


Assuntos
COVID-19 , Humanos , Feminino , COVID-19/diagnóstico , COVID-19/epidemiologia , Vacinas contra COVID-19 , Estudos de Coortes , SARS-CoV-2 , Dinamarca/epidemiologia
19.
Infect Drug Resist ; 16: 301-312, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36683911

RESUMO

Background: Seroprevalence studies can be used to measure the progression of national COVID-19 epidemics. The Danish National Seroprevalence Survey of SARS-CoV-2 infections (DSS) was conducted as five separate surveys between May 2020 and May 2021. Here, we present results from the two last surveys conducted in February and May 2021. Methods: Persons aged 12 or older were randomly selected from the Danish Population Register and those having received COVID-19 vaccination subsequently excluded. Invitations to have blood drawn in local test centers were sent by mail. Samples were analyzed for whole Immunoglobulin by ELISA. Seroprevalence was estimated by sex, age and geography. Comparisons to vaccination uptake and RT-PCR test results were made. Results: In February 2021, we found detectable antibodies in 7.2% (95% CI: 6.3-7.9%) of the invited participants (participation rate 25%) and in May 2021 in 8.6% (95% CI: 7.6-9.5%) of the invited (participation rate: 14%). Seroprevalence did not differ by sex, but by age group, generally being higher among the <50 than 50+ year-olds. In May 2021, levels of seroprevalence varied from an estimated 13% (95% CI: 12-15%) in the capital to 5.2% (95% CI: 3.4-7.4%) in rural areas. Combining seroprevalence results with vaccine coverage, estimates of protection against infection in May 2021 varied from 95% among 65+ year-olds down to 10-20% among 12-40 year-olds. In March-May 2021, an estimated 80% of all community SARS-CoV-2 infections were diagnosed by RT-PCR and captured by surveillance. Conclusion: Seroprevalence estimates doubled during the 2020-21 winter wave of SARS-CoV-2 infections and then stabilized as vaccinations were rolled out. The epidemic affected large cities and younger people the most. Denmark saw comparatively low infections rates, but high test coverage; an estimated four out of five infections were detected by RT-PCR in March-May 2021.

20.
Lancet Infect Dis ; 23(2): 167-176, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36270311

RESUMO

BACKGROUND: Estimates of immunity and severity for the SARS-CoV-2 omicron subvariant BA.5 are important to assess the public health impact associated with its rapid global spread despite vaccination. We estimated natural and vaccine immunity and severity of BA.5 relative to BA.2 in Denmark, a country with high mRNA-vaccination coverage and free-of-charge RT-PCR testing. METHODS: This nation-wide population-based study in Denmark included residents aged 18 years or older who had taken an RT-PCR test between 10 April and 30 June, 2022 (ie, the outcome period), and who the national COVID-19 surveillance system identified as having information since February 2020 on RT-PCR tests, whole-genome sequencing, vaccinations, and hospitalisation with a positive RT-PCR test and COVID-19 as the main diagnosis. First, we used a case-control design, in which cases were people infected with BA.5 or BA.2 during the outcome period and controls were people who tested negative for SARS-CoV-2 infection during the outcome period. We calculated the protection provided by a previous PCR-confirmed omicron infection against BA.5 and BA.2 infection and hospitalisation among triple-vaccinated individuals. Second, we compared vaccination status in people infected with BA.5 versus BA.2 and estimated relative vaccine protection against each subvariant. Third, we compared rates of hospitalisation for COVID-19 among people infected with BA.5 versus BA.2. We estimated effects using logistic regression with adjustment for sex, age, region, PCR-test date, comorbidity and, as appropriate, vaccination and previous infection status. FINDINGS: A total of 210 (2·4%) of 8678 of BA.5 cases, 192 (0·7%) of 29 292 of BA.2 cases, and 33 972 (19·0%) of 178 669 PCR-negative controls previously had an omicron infection, which was estimated in the adjusted analyses to offer 92·7% (95% CI 91·6-93·7) protection against BA.5 infection and 97·1% (96·6-97·5) protection against BA.2 infection. We found similarly high amounts of protection against hospitalisation owing to infection with BA.5 (96·4% [95% CI 74·2-99·5]) and BA.2 (91·2% [76·3-96·7]). Vaccine coverage (three mRNA doses vs none) was 9307 (94·2%) of 9878 among BA.5 cases and 30 581 (94·8%) of 32 272 among BA.2 cases, although in the adjusted analysis, there was a trend towards slightly higher vaccination coverage among BA.5 cases than BA.2 cases (OR 1·18 [95% CI 0·99-1·42]; p=0·064), possibly suggesting marginally poorer vaccine protection against BA.5. The rate of hospitalisation due to COVID-19 was higher among the BA.5 cases (210 [1·9%] of 11 314) than among the BA.2 cases (514 [1·4%] of 36 805), with an OR of 1·34 (95% CI 1·14-1·57) and an adjusted OR of 1·69 (95% CI 1·22-2·33), despite low and stable COVID-19 hospitalisation numbers during the study period. INTERPRETATION: The study provides evidence that a previous omicron infection in triple-vaccinated individuals provides high amounts of protection against BA.5 and BA.2 infections. However, protection estimates greater than 90% might be too high if individuals with a previous infection were more likely than those without one to come forward for a test for reasons other than suspicion of COVID-19. Our analysis also showed that vaccine protection against BA.5 infection was similar to, or slightly weaker than, protection against BA.2 infection. Finally, there was evidence that BA.5 infections were associated with an increased risk of hospitalisation compared with BA.2 infections. FUNDING: There was no funding source for this study.


Assuntos
COVID-19 , Vacinas , Humanos , Reinfecção , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2/genética , RNA Mensageiro , Dinamarca/epidemiologia
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