RESUMO
OBJECTIVES: To investigate how differential access to key interventions to reduce STIs, HIV and their sequelae changed during the COVID-19 pandemic. METHODS: British participants (18-59 years) completed a cross-sectional web survey 1 year (March-April 2021) after the initial lockdown in Britain. Quota-based sampling and weighting resulted in a quasi-representative population sample. We compared Natsal-COVID data with Natsal-3, a household-based probability sample cross-sectional survey (16-74 years) conducted in 2010-2012. Reported unmet need for condoms because of the pandemic and uptake of chlamydia testing/HIV testing/cervical cancer screening were analysed among sexually experienced participants (18-44 years) (n=3869, Natsal-COVID; n=8551, Natsal-3). ORs adjusted for age and other potential confounders describe associations with demographic and behavioural factors. RESULTS: In 2021, 6.9% of women and 16.2% of men reported unmet need for condoms because of the pandemic. This was more likely among participants: aged 18-24 years, of black or black British ethnicity, and reporting same-sex sex (past 5 years) or one or more new relationships (past year). Chlamydia and HIV testing were more commonly reported by younger participants, those reporting condomless sex with new sexual partners and men reporting same-sex partners; a very similar distribution to 10 years previously (Natsal-3). However, there were differences during the pandemic, including stronger associations with chlamydia testing for men reporting same-sex partners; with HIV testing for women reporting new sexual partners and with cervical screening among smokers. CONCLUSIONS: Our study suggests differential access to key primary and secondary STI/HIV prevention interventions continued during the first year of the COVID-19 pandemic. However, there was not strong evidence that differential access has changed during the pandemic when compared with 2010-2012. While the pandemic might not have exacerbated inequalities in access to primary and secondary prevention, it is clear that large inequalities persisted, typically among those at greatest STI/HIV risk.
Assuntos
Síndrome da Imunodeficiência Adquirida , COVID-19 , Chlamydia , Infecções por HIV , Infecções Sexualmente Transmissíveis , Neoplasias do Colo do Útero , Masculino , Humanos , Feminino , Preservativos , Detecção Precoce de Câncer , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Pandemias/prevenção & controle , Reino Unido/epidemiologia , Estudos Transversais , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Comportamento Sexual , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle , Síndrome da Imunodeficiência Adquirida/epidemiologia , Teste de HIV , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controleRESUMO
BACKGROUND/AIMS: Sharing trial results with participants is an ethical imperative but often does not happen. Show RESPECT (ISRCTN96189403) tested ways of sharing results with participants in an ovarian cancer trial (ISRCTN10356387). Sharing results via a printed summary improved patient satisfaction. Little is known about staff experience and the costs of communicating results with participants. We report the costs of communication approaches used in Show RESPECT and the views of site staff on these approaches. METHODS: We allocated 43 hospitals (sites) to share results with trial participants through one of eight intervention combinations (2 × 2 × 2 factorial; enhanced versus basic webpage, printed summary versus no printed summary, email list invitation versus no invitation). Questionnaires elicited data from staff involved in sharing results. Open- and closed-ended questions covered resources used to share results and site staff perspectives on the approaches used. Semi-structured interviews were conducted. Interview and free-text data were analysed thematically. The mean additional site costs per participant from each intervention were estimated jointly as main effects by linear regression. RESULTS: We received questionnaires from 68 staff from 41 sites and interviewed 11 site staff. Sites allocated to the printed summary had mean total site costs of sharing results £13.71/patient higher (95% confidence interval (CI): -3.19, 30.60; p = 0.108) than sites allocated no printed summary. Sites allocated to the enhanced webpage had mean total site costs £1.91/patient higher (95% CI: -14, 18.74; p = 0.819) than sites allocated to the basic webpage. Sites allocated to the email list had costs £2.87/patient lower (95% CI: -19.70, 13.95; p = 0.731) than sites allocated to no email list. Most of these costs were staff time for mailing information and handling patients' queries. Most site staff reported no concerns about how they had shared results (88%) and no challenges (76%). Most (83%) found it easy to answer queries from patients about the results and thought the way they were allocated to share results with participants would be an acceptable standard approach (76%), with 79% saying they would follow the same approach for future trials. There were no significant effects of the randomised interventions on these outcomes. Site staff emphasised the importance of preparing patients to receive the results, including giving opt-in/opt-out options, and the need to offer further support, particularly if the results could confuse or distress some patients. CONCLUSIONS: Adding a printed summary to a webpage (which significantly improved participant satisfaction) may increase costs to sites by ~£14/patient, which is modest in relation to the cost of trials. The Show RESPECT communication interventions were feasible to implement. This information could help future trials ensure they have sufficient resources to share results with participants.
Assuntos
Neoplasias Ovarianas , Feminino , Humanos , Estudos de Viabilidade , Inquéritos e Questionários , Análise Custo-BenefícioRESUMO
OBJECTIVES: Physical restrictions imposed to combat COVID-19 dramatically altered sexual lifestyles but the specific impacts on sexual behaviour are still emerging. We investigated physical and virtual sexual activities, sexual frequency and satisfaction in the 4 months following lockdown in Britain in March 2020 and compared with pre-lockdown. METHODS: Weighted analyses of web panel survey data collected July/August 2020 from a quota-based sample of 6654 people aged 18-59 years in Britain. Multivariable regression took account of participants' opportunity for partnered sex, gender and age, to examine their independent associations with perceived changes in sexual frequency and satisfaction. RESULTS: Most participants (86.7%) reported some form of sex following lockdown with physical activities more commonly reported than virtual activities (83.7% vs 52.6%). Altogether, 63.2% reported sex with someone ('partnered sex') since lockdown, three-quarters of whom were in steady cohabiting relationships. With decreasing relationship formality, partnered sex was less frequently reported, while masturbation, sex toy use and virtual activities were more frequently reported. Around half of all participants perceived no change in partnered sex frequency compared with the 3 months pre-lockdown, but this was only one-third among those not cohabiting, who were more likely to report increases in non-partnered activities than those cohabiting. Two-thirds of participants perceived no change in sexual satisfaction; declines were more common among those not cohabiting. Relationship informality and younger age were independently associated with perceiving change, often declines, in sexual frequency and satisfaction. CONCLUSIONS: Our quasi-representative study of the British population found a substantial minority reported significant shifts in sexual repertoires, frequency and satisfaction following the introduction of COVID-19 restrictions. However, these negative changes were perceived by some more than others; predominantly those not cohabiting and the young. As these groups are most likely to experience adverse sexual health, it is important to monitor behaviour as restrictions ease to understand the longer term consequences, including for health services.
Assuntos
COVID-19 , Humanos , Reino Unido/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Comportamento Sexual , Parceiros SexuaisRESUMO
BACKGROUND: Sharing trial results with participants is an ethical imperative but often does not happen. We tested an Enhanced Webpage versus a Basic Webpage, Mailed Printed Summary versus no Mailed Printed Summary, and Email List Invitation versus no Email List Invitation to see which approach resulted in the highest patient satisfaction with how the results were communicated. METHODS AND FINDINGS: We carried out a cluster randomised, 2 by 2 by 2 factorial, nonblinded study within a trial, with semistructured qualitative interviews with some patients (ISRCTN96189403). Each cluster was a UK hospital participating in the ICON8 ovarian cancer trial. Interventions were shared with 384 ICON8 participants who were alive and considered well enough to be contacted, at 43 hospitals. Hospitals were allocated to share results with participants through one of the 8 intervention combinations based on random permutation within blocks of 8, stratified by number of participants. All interventions contained a written plain English summary of the results. The Enhanced Webpage also contained a short video. Both the Enhanced Webpage and Email contained links to further information and support. The Mailed Printed Summary was opt-out. Follow-up questionnaires were sent 1 month after patients had been offered the interventions. Patients' reported satisfaction was measured using a 5-point scale, analysed by ordinal logistic regression estimating main effects for all 3 interventions, with random effects for site, restricted to those who reported receiving the results and assuming no interaction. Data collection took place in 2018 to 2019. Questionnaires were sent to 275/384 randomly selected participants and returned by 180: 90/142 allocated Basic Webpage, 90/133 Enhanced Webpage; 91/141 no Mailed Printed Summary, 89/134 Mailed Printed Summary; 82/129 no Email List Invitation, 98/146 Email List Invitation. Only 3 patients opted out of receiving the Mailed Printed Summary; no patients signed up to the email list. Patients' satisfaction was greater at sites allocated the Mailed Printed Summary, where 65/81 (80%) were quite or very satisfied compared to sites with no Mailed Printed Summary 39/64 (61%), ordinal odds ratio (OR) = 3.15 (1.66 to 5.98, p < 0.001). We found no effect on patient satisfaction from the Enhanced Webpage, OR = 1.47 (0.78 to 2.76, p = 0.235) or Email List Invitation, OR = 1.38 (0.72 to 2.63, p = 0.327). Interviewees described the results as interesting, important, and disappointing (the ICON8 trial found no benefit). Finding out the results made some feel their trial participation had been more worthwhile. Regardless of allocated group, patients who received results generally reported that the information was easy to understand and find, were glad and did not regret finding out the results. The main limitation of our study is the 65% response rate. CONCLUSIONS: Nearly all respondents wanted to know the results and were glad to receive them. Adding an opt-out Mailed Printed Summary alongside a webpage yielded the highest reported satisfaction. This study provides evidence on how to share results with other similar trial populations. Further research is needed to look at different results scenarios and patient populations. TRIAL REGISTRATION: ISRCTN: ISRCTN96189403.
Assuntos
Disseminação de Informação , Idoso , Análise por Conglomerados , Comunicação em Saúde , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Satisfação do Paciente , Seleção de PacientesRESUMO
There are sometimes cost, scientific, or logistical reasons to allocate individuals unequally in an individually randomized trial. In cluster randomized trials we can allocate clusters unequally and/or allow different cluster size between trial arms. We consider parallel group designs with a continuous outcome, and optimal designs that require the smallest number of individuals to be measured given the number of clusters. Previous authors have derived the optimal allocation ratio for clusters under different variance and/or intracluster correlations (ICCs) between arms, allowing different but prespecified cluster sizes by arm. We derive closed-form expressions to identify the optimal proportions of clusters and of individuals measured for each arm, thereby defining optimal cluster sizes, when cluster size can be chosen freely. When ICCs differ between arms but the variance is equal, the optimal design allocates more than half the clusters to the arm with the higher ICC, but (typically only slightly) less than half the individuals and hence a smaller cluster size. We also describe optimal design under constraints on the number of clusters or cluster size in one or both arms. This methodology allows trialists to consider a range for the number of clusters in the trial and for each to identify the optimal design. Except if there is clear prior evidence for the ICC and variance by arm, a range of values will need to be considered. Researchers should choose a design with adequate power across the range, while also keeping enough clusters in each arm to permit the intended analysis method.
Assuntos
Braço , Projetos de Pesquisa , Análise por Conglomerados , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Tamanho da AmostraRESUMO
BACKGROUND: Cluster randomised trials, like individually randomised trials, may benefit from a baseline period of data collection. We consider trials in which clusters prospectively recruit or identify participants as a continuous process over a given calendar period, and ask whether and for how long investigators should collect baseline data as part of the trial, in order to maximise precision. METHODS: We show how to calculate and plot the variance of the treatment effect estimator for different lengths of baseline period in a range of scenarios, and offer general advice. RESULTS: In some circumstances it is optimal not to include a baseline, while in others there is an optimal duration for the baseline. All other things being equal, the circumstances where it is preferable not to include a baseline period are those with a smaller recruitment rate, smaller intracluster correlation, greater decay in the intracluster correlation over time, or wider transition period between recruitment under control and intervention conditions. CONCLUSION: The variance of the treatment effect estimator can be calculated numerically, and plotted against the duration of baseline to inform design. It would be of interest to extend these investigations to cluster randomised trial designs with more than two randomised sequences of control and intervention condition, including stepped wedge designs.
Assuntos
Coleta de Dados , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Análise por Conglomerados , Humanos , Seleção de Pacientes , Estudos Prospectivos , Tamanho da AmostraRESUMO
BACKGROUND/AIMS: Published methods for sample size calculation for cluster randomised trials with baseline data are inflexible and primarily assume an equal amount of data collected at baseline and endline, that is, before and after the intervention has been implemented in some clusters. We extend these methods to any amount of baseline and endline data. We explain how to explore sample size for a trial if some baseline data from the trial clusters have already been collected as part of a separate study. Where such data aren't available, we show how to choose the proportion of data collection devoted to the baseline within the trial, when a particular cluster size or range of cluster sizes is proposed. METHODS: We provide a design effect given the cluster size and correlation parameters, assuming different participants are assessed at baseline and endline in the same clusters. We show how to produce plots to identify the impact of varying the amount of baseline data accounting for the inevitable uncertainty in the cluster autocorrelation. We illustrate the methodology using an example trial. RESULTS: Baseline data provide more power, or allow a greater reduction in trial size, with greater values of the cluster size, intracluster correlation and cluster autocorrelation. CONCLUSION: Investigators should think carefully before collecting baseline data in a cluster randomised trial if this is at the expense of endline data. In some scenarios, this will increase the sample size required to achieve given power and precision.
Assuntos
Coleta de Dados/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Tamanho da Amostra , Análise por Conglomerados , Estudos Transversais , Interpretação Estatística de Dados , Determinação de Ponto Final , Feminino , Humanos , Masculino , Modelos Estatísticos , Distribuição Aleatória , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Projetos de PesquisaRESUMO
BACKGROUND: Anogenital warts are the second most common sexually transmitted infection diagnosed in sexual health services in England. About 90% of genital warts are caused by human papillomavirus (HPV) types 6 or 11, and half of episodes diagnosed are recurrences. The best and most cost-effective treatment for patients with anogenital warts is unknown. The commonly used treatments are self-administered topical agents, podophyllotoxin (0.15% cream) or imiquimod (5% cream), or cryotherapy with liquid nitrogen. Quadrivalent HPV (qHPV) vaccination is effective in preventing infection, and disease, but whether it has any therapeutic effect is not known. METHODS AND DESIGN: To investigate the efficacy of clearance and prevention of recurrence of external anogenital warts by topical treatments, podophyllotoxin 0.15% cream or imiquimod 5% cream, in combination with a three-dose regimen of qHPV or control vaccination. 500 adult patients presenting with external anogenital warts with either a first or subsequent episode of anogenital warts will be entered into this randomised, controlled partially blinded 2 × 2 factorial trial. DISCUSSION: The trial is expected to provide the first high-quality evidence of the comparative efficacy and cost-effectiveness of the two topical treatments in current use, as well as investigate the potential benefit of HPV vaccination, in the management of anogenital warts. TRIAL REGISTRATION: The trial was registered prior to starting recruitment under the following reference numbers: International Standard Randomized Controlled Trial Number (ISRCTN) Registry - ISRCTN32729817 (registered 25 July 2014); European Union Clinical Trials Register (EudraCT) - 2013-002951-14 (registered 26 June 2013).
Assuntos
Imiquimode/uso terapêutico , Papillomaviridae/efeitos dos fármacos , Infecções por Papillomavirus/tratamento farmacológico , Vacinas contra Papillomavirus/uso terapêutico , Podofilotoxina/uso terapêutico , Adulto , Quimioterapia Combinada , Feminino , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Masculino , Papillomaviridae/imunologia , Papillomaviridae/fisiologia , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/imunologia , Recidiva , Resultado do Tratamento , VacinaçãoRESUMO
BACKGROUND: Clinical trials of PI monotherapy indicate that most participants maintain viral suppression and emergent protease resistance is rare. However, outcomes among patients receiving PI monotherapy for clinical reasons, such as toxicity or adherence issues, are less well studied. METHODS: An observational study of patients attending an HIV treatment centre in London, UK, who had received PI monotherapy between 2004 and 2013, was conducted using prospectively collected clinical data and genotypic resistance reports. Survival analysis techniques were used to examine the times to virological failure and treatment discontinuation. RESULTS: Ninety-five patients had PI monotherapy treatment for a median duration of 126 weeks. Virological failure occurred during 64% of episodes and 8% of patients developed emergent protease mutations. We estimate failure occurs in half of episodes within 2 years following initiation. Where PI monotherapy was continued following virological failure, 68% of patients achieved viral re-suppression. Despite a high incidence of virological failure, many patients continued PI monotherapy and 79% of episodes were ongoing at the end of the study. The type of PI used, the presence of baseline protease mutations and the plasma HIV RNA at initiation did not have a significant impact on treatment outcomes. CONCLUSIONS: There was a higher incidence of virological failure and emerging resistance in our UK clinical setting than described in PI monotherapy clinical trials and other European observational studies. Despite this, many patients continued PI monotherapy and regained viral suppression, indicating this strategy remains a viable option in certain individuals following careful clinical evaluation.
Assuntos
Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/uso terapêutico , Adolescente , Adulto , Farmacorresistência Viral , Feminino , HIV-1/isolamento & purificação , Humanos , Incidência , Londres , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Carga Viral , Adulto JovemRESUMO
BACKGROUND: In the context of widespread opportunistic chlamydia screening among young adults, we aimed to quantify chlamydia testing and diagnosis among 16-24 year olds in Britain in relation to risk factors for prevalent chlamydia infection. METHODS: Using data from sexually experienced (≥1 lifetime sexual partner) 16-year-old to 24-year-old participants in Britain's third National Survey of Sexual Attitudes and Lifestyles (conducted 2010-2012), we explored socio-demographic and behavioural factors associated with prevalent chlamydia infection (detected in urine; n=1832), self-reported testing and self-reported diagnosis in the last year (both n=3115). RESULTS: Chlamydia prevalence was 3.1% (95% CI 2.2% to 4.3%) in women and 2.3% (1.5% to 3.4%) in men. A total of 12.3% of women and 5.3% men had a previous chlamydia diagnosis. Factors associated with prevalent infection were also associated with testing and diagnosis (eg, increasing numbers of sexual partners), with some exceptions. For example, chlamydia prevalence was higher in women living in more deprived areas, whereas testing was not. In men, prevalence was higher in 20-24 than 16-19 year olds but testing was lower. Thirty per cent of women and 53.7% of men with ≥2 new sexual partners in the last year had not recently tested. CONCLUSIONS: In 2010-2012 in Britain, the proportion of young adults reporting chlamydia testing was generally higher in those reporting factors associated with chlamydia. However, many of those with risk factors had not been recently tested, leaving potential for undiagnosed infections. Greater screening and prevention efforts among individuals in deprived areas and those reporting risk factors for chlamydia may reduce undiagnosed prevalence and transmission.
Assuntos
Infecções por Chlamydia/epidemiologia , Infecções por Chlamydia/prevenção & controle , Adolescente , Fatores Etários , Atitude , Bacteriúria/microbiologia , Infecções por Chlamydia/diagnóstico , Análise por Conglomerados , Feminino , Humanos , Entrevistas como Assunto , Estilo de Vida , Modelos Logísticos , Masculino , Prevalência , Fatores de Risco , Comportamento Sexual , Fatores Sociológicos , Reino Unido/epidemiologia , Adulto JovemRESUMO
OBJECTIVES: To describe the prevalence of medication use to assist sexual performance in Britain and to identify associated factors. METHODS: Cross-sectional probability sample, undertaken in 2010-2012, of 15â 162 people aged 16-74â years, resident in Britain, of whom, 5617 men and 8095 women reported sexual experience (ever) and 4817 men were sexually-active (reported sex in the last year). RESULTS: Ever use of medication to assist sexual performance (medicated sex) was more commonly reported by men than women (12.9% (95% CI 11.9% to 13.9%) vs 1.9% (95% CI 1.7% to 2.3%)) and associated with older age in men and younger age in women. It was associated with reporting smoking, and use of alcohol and recreational drugs, as well as unsafe sex (≥2 partners and no condom use in the last year) in both men and women. Among men, the proportion reporting medicated sex in the last year was higher among those reporting erectile difficulties (ED) than those not doing so (28.4% (95% CI 24.4% to 32.8%) vs 4.1% (95% CI 3.4% to 4.9%)). In all men, medicated sex was associated with more frequent sexual activity, meeting a partner on the internet, unsafe sex and recent sexually transmitted infections diagnosis; associations that persisted after adjusting for same-sex behaviour and ED. However, there were significant interactions with reporting ED, indicating that among men with ED, medicated sex is not associated with same-sex behaviour and ever use of recreational drugs. CONCLUSIONS: A substantial minority of people in Britain report medicated sex, and the association between medicated sex and risky sexual behaviour is not confined to high-risk groups.
Assuntos
Metanfetamina/administração & dosagem , Inibidores da Fosfodiesterase 5/administração & dosagem , Comportamento Sexual/efeitos dos fármacos , Infecções Sexualmente Transmissíveis/prevenção & controle , Citrato de Sildenafila/administração & dosagem , Testosterona/administração & dosagem , Sexo sem Proteção/efeitos dos fármacos , Adolescente , Adulto , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Assunção de Riscos , Parceiros Sexuais , Reino Unido/epidemiologiaRESUMO
OBJECTIVE: To examine sociodemographic and behavioural differences between men who have sex with men (MSM) participating in recent UK convenience surveys and a national probability sample survey. METHODS: We compared 148 MSM aged 18-64â years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010-2012, with men in the same age range participating in contemporaneous convenience surveys of MSM: 15â 500 British resident men in the European MSM Internet Survey (EMIS); 797 in the London Gay Men's Sexual Health Survey; and 1234 in Scotland's Gay Men's Sexual Health Survey. Analyses compared men reporting at least one male sexual partner (past year) on similarly worded questions and multivariable analyses accounted for sociodemographic differences between the surveys. RESULTS: MSM in convenience surveys were younger and better educated than MSM in Natsal-3, and a larger proportion identified as gay (85%-95% vs 62%). Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Compared with Natsal-3, MSM in convenience surveys were more likely to report gonorrhoea diagnoses and HIV testing (both past year). Differences between the samples were reduced when restricting analysis to gay-identifying MSM. CONCLUSIONS: National probability surveys better reflect the population of MSM but are limited by their smaller samples of MSM. Convenience surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviours. Because both sampling strategies have strengths and weaknesses, methods are needed to triangulate data from probability and convenience surveys.
Assuntos
Inquéritos Epidemiológicos , Homossexualidade Masculina/estatística & dados numéricos , Saúde Reprodutiva/estatística & dados numéricos , Adolescente , Adulto , Atitude Frente a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos de Amostragem , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Reino Unido/epidemiologia , Sexo sem Proteção/estatística & dados numéricos , Adulto JovemRESUMO
Longitudinal data are widely analysed using linear mixed models, with 'random slopes' models particularly common. However, when modelling, for example, longitudinal pre-treatment CD4 cell counts in HIV-positive patients, the incorporation of non-stationary stochastic processes such as Brownian motion has been shown to lead to a more biologically plausible model and a substantial improvement in model fit. In this article, we propose two further extensions. Firstly, we propose the addition of a fractional Brownian motion component, and secondly, we generalise the model to follow a multivariate-t distribution. These extensions are biologically plausible, and each demonstrated substantially improved fit on application to example data from the Concerted Action on SeroConversion to AIDS and Death in Europe study. We also propose novel procedures for residual diagnostic plots that allow such models to be assessed. Cohorts of patients were simulated from the previously reported and newly developed models in order to evaluate differences in predictions made for the timing of treatment initiation under different clinical management strategies. A further simulation study was performed to demonstrate the substantial biases in parameter estimates of the mean slope of CD4 decline with time that can occur when random slopes models are applied in the presence of censoring because of treatment initiation, with the degree of bias found to depend strongly on the treatment initiation rule applied. Our findings indicate that researchers should consider more complex and flexible models for the analysis of longitudinal biomarker data, particularly when there are substantial missing data, and that the parameter estimates from random slopes models must be interpreted with caution.
Assuntos
Contagem de Linfócito CD4/estatística & dados numéricos , Infecções por HIV/epidemiologia , Análise Multivariada , Infecções por HIV/imunologia , Infecções por HIV/terapia , Humanos , Funções Verossimilhança , Modelos Lineares , Estudos Longitudinais , Modelos Estatísticos , Processos Estocásticos , Resultado do TratamentoRESUMO
BACKGROUND: There has been some debate in the literature as to whether baseline values of a measurement of interest at treatment initiation should be treated as an outcome variable as part of a model for longitudinal change or instead used as a predictive variable with respect to the response to treatment. We develop a new approach that involves a combined statistical model for all pre- and post-treatment observations of the biomarker of interest, in which the characteristics of response to treatment are treated as a function of the 'true' value of the biomarker at treatment initiation. METHODS: The modelling strategy developed is applied to a dataset of CD4 counts from patients in the UK Register of HIV Seroconverters (UKR) cohort who initiated highly active antiretroviral therapy (HAART). The post-HAART recovery in CD4 counts for each individual is modelled as following an asymptotic curve in which the speed of response to treatment and long-term maximum are functions of the 'true' underlying CD4 count at initiation of HAART and the time elapsed since seroconversion. Following previous research in this field, the models developed incorporate non-stationary stochastic process components, and the possibility of between-patient differences in variability over time was also considered. RESULTS: A variety of novel models were successfully fitted to the UKR dataset. These provide reinforcing evidence for findings that have previously been reported in the literature, in particular that there is a strong positive relationship between CD4 count at initiation of HAART and the long-term maximum in each patient, but also reveal potentially important features of the data that would not have been easily identified by other methods of analysis. CONCLUSION: Our proposed methodology provides a unified framework for the analysis of pre- and post-treatment longitudinal biomarker data that will be useful for epidemiological investigations and simulations in this context. The approach developed allows use of all relevant data from observational cohorts in which many patients are missing pre-treatment measurements and in which the timing and number of observations vary widely between patients.
Assuntos
Infecções por HIV/diagnóstico , Algoritmos , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Biomarcadores , Contagem de Linfócito CD4 , Interpretação Estatística de Dados , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Humanos , Funções Verossimilhança , Estudos Longitudinais , Análise de Regressão , Resultado do TratamentoRESUMO
OBJECTIVES: Gram-stained urethral smear (GSUS), the standard point-of-care test for non-gonococcal urethritis (NGU) is operator dependent and poorly specific. The performance of rapid automated urine flow cytometry (AUFC) of first void urine (FVU) white cell counts (UWCC) for predicting Mycoplasma genitalium and Chlamydia trachomatis urethral infections was assessed and its application to asymptomatic infection was evaluated. METHODS: Receiver operating characteristic curve analysis, determining FVU-UWCC threshold for predicting M. genitalium or C. trachomatis infection was performed on 208 'training' samples from symptomatic patients and subsequently validated using 228 additional FVUs obtained from prospective unselected patients. RESULTS: An optimal diagnostic threshold of >29â UWC/µL gave sensitivities and specificities for either infection of 81.5% (95% CI 65.1% to 91.6%) and 85.8% (79.5% to 90.4%), respectively, compared with 86.8% (71.1% to 95%) and 64.7% (56.9% to 71.7%), respectively, for GSUS, using the training set samples. FVU-UWCC demonstrated sensitivities and specificities of 69.2% (95% CI 48.1% to 84.9%) and 92% (87.2% to 95.2%), respectively, when using validation samples. In asymptomatic patients where GSUS was not used, AUFC would have enabled more infections to be detected compared with clinical considerations only (71.4% vs 28.6%; p=0.03). The correlation between UWCC and bacterial load was stronger for M. genitalium compared with C. trachomatis (τ=0.426, p≤0.001 vs τ=0.295, p=0.022, respectively). CONCLUSIONS: AUFC offers improved specificity over microscopy for predicting C. trachomatis or M. genitalium infection. Universal AUFC may enable non-invasive diagnosis of asymptomatic NGU at the PoC. The degree of urethral inflammation exhibits a stronger association with pathogen load for M. genitalium compared with C. trachomatis.
Assuntos
Automação Laboratorial/métodos , Infecções por Chlamydia/diagnóstico , Citometria de Fluxo/métodos , Microscopia/métodos , Infecções por Mycoplasma/diagnóstico , Uretrite/diagnóstico , Urina/citologia , Adulto , Humanos , Contagem de Leucócitos/métodos , Masculino , Curva ROC , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: The objective of this study was to compare the costs and outcomes of two sexually transmitted infection (STI) screening interventions targeted at men in football club settings in England, including screening promoted by team captains. METHODS: A comparison of costs and outcomes was undertaken alongside a pilot cluster randomised control trial involving three trial arms: (1) captain-led and poster STI screening promotion; (2) sexual health advisor-led and poster STI screening promotion and (3) poster-only STI screening promotion (control/comparator). For all study arms, resource use and cost data were collected prospectively. RESULTS: There was considerable variation in uptake rates between clubs, but results were broadly comparable across study arms with 50% of men accepting the screening offer in the captain-led arm, 67% in the sexual health advisor-led arm and 61% in the poster-only control arm. The overall costs associated with the intervention arms were similar. The average cost per player tested was comparable, with the average cost per player tested for the captain-led promotion estimated to be £88.99 compared with £88.33 for the sexual health advisor-led promotion and £81.87 for the poster-only (control) arm. CONCLUSIONS: Costs and outcomes were similar across intervention arms. The target sample size was not achieved, and we found a greater than anticipated variability between clubs in the acceptability of screening, which limited our ability to estimate acceptability for intervention arms. Further evidence is needed about the public health benefits associated with screening interventions in non-clinical settings so that their cost-effectiveness can be fully evaluated.
Assuntos
Atletas , Testes Diagnósticos de Rotina/estatística & dados numéricos , Custos de Cuidados de Saúde , Programas de Rastreamento/economia , Programas de Rastreamento/métodos , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/transmissão , Adolescente , Adulto , Testes Diagnósticos de Rotina/economia , Inglaterra , Futebol Americano , Pesquisa sobre Serviços de Saúde , Humanos , Masculino , Infecções Sexualmente Transmissíveis/prevenção & controle , Adulto JovemRESUMO
BACKGROUND: Uptake of chlamydia screening by men in England has been substantially lower than by women. Non-traditional settings such as sports clubs offer opportunities to widen access. Involving people who are not medically trained to promote screening could optimise acceptability. METHODS: We developed two interventions to explore the acceptability and feasibility of urine-based sexually transmitted infection (STI) screening interventions targeting men in football clubs. We tested these interventions in a pilot cluster randomised control trial. Six clubs were randomly allocated, two to each of three trial arms: team captain-led and poster STI screening promotion; sexual health adviser-led and poster STI screening promotion; and poster-only STI screening promotion (control/comparator). Primary outcome was test uptake. RESULTS: Across the three arms, 153 men participated in the trial and 90 accepted the offer of screening (59%, 95% CI 35% to 79%). Acceptance rates were broadly comparable across the arms: captain-led: 28/56 (50%); health professional-led: 31/46 (67%); and control: 31/51 (61%). However, rates varied appreciably by club, precluding formal comparison of arms. No infections were identified. Process evaluation confirmed that interventions were delivered in a standardised way but the control arm was unintentionally 'enhanced' by some team captains actively publicising screening events. CONCLUSIONS: Compared with other UK-based community screening models, uptake was high but gaining access to clubs was not always easy. Use of sexual health advisers and team captains to promote screening did not appear to confer additional benefit over a poster-promoted approach. Although the interventions show potential, the broader implications of this strategy for UK male STI screening policy require further investigation.
Assuntos
Atletas , Terapia Comportamental/métodos , Testes Diagnósticos de Rotina/estatística & dados numéricos , Programas de Rastreamento/métodos , Infecções Sexualmente Transmissíveis/diagnóstico , Adolescente , Adulto , Inglaterra , Futebol Americano , Humanos , Masculino , Reino Unido , Adulto JovemRESUMO
BACKGROUND: In Britain, young people continue to bear the burden of sexually transmitted infections (STIs) so efforts are required, especially among men, to encourage STI testing. The SPORTSMART study trialled an intervention that sought to achieve this by offering chlamydia and gonorrhoea test-kits to men attending amateur football clubs between October and December 2012. With football the highest participation team sport among men in England, this paper examines the potential public health benefit of offering STI testing to men in this setting by assessing their sociodemographic characteristics, sexual behaviours, and healthcare behaviour and comparing them to men in the general population. METHODS: Data were collected from 192 (male) members of 6 football clubs in London, United Kingdom, aged 18-44 years via a 20-item pen-and-paper self-completion questionnaire administered 2 weeks after the intervention. These were compared to data collected from 409 men of a similar age who were resident in London when interviewed during 2010-2012 for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a national probability survey that used computer-assisted-personal-interviewing with computer-assisted-self-interview. Age standardisation and multivariable regression were used to account for sociodemographic differences between the surveys. RESULTS: Relative to men in the general population, SPORTSMART men were younger (32.8 % vs. 21.7 % aged under 25 y), and more likely to report (all past year) at least 2 sexual partners (adjusted odds ratio, AOR: 3.25, 95 % CI: 2.15-4.92), concurrent partners (AOR: 2.05, 95 % CI: 1.39-3.02), and non-use of condoms (AOR: 2.17, 95 % CI: 1.39-3.41). No difference was observed in STI/HIV risk perception (AOR for reporting "not at all at risk" of STIs: 1.25, 95 % CI: 0.76-2.04; of HIV: AOR: 1.54, 95 % CI: 0.93-2.55), nor in reporting STI testing in the past year (AOR: 0.83, 95 % CI: 0.44-1.54), which was reported by only one in six men. CONCLUSIONS: Relative to young men in the general population, football club members who completed the SPORTSMART survey reported greater sexual risk behaviour but similar STI/HIV risk perception and STI testing history. Offering STI testing in amateur football clubs may therefore widen access to STI testing and health promotion messages for men at higher STI risk, which, given the minority currently testing and the popularity of football in England, should yield both individual and public health benefit.
Assuntos
Programas de Rastreamento/métodos , Prática de Saúde Pública , Infecções Sexualmente Transmissíveis/diagnóstico , Adolescente , Adulto , Estudos Transversais , Humanos , Londres , Masculino , Assunção de Riscos , Comportamento Sexual , Infecções Sexualmente Transmissíveis/epidemiologia , Futebol , Reino Unido/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Sexual behaviour and relationships are key components of wellbeing and are affected by social norms, attitudes, and health. We present data on sexual behaviours and attitudes in Britain (England, Scotland, and Wales) from the three National Surveys of Sexual Attitudes and Lifestyles (Natsal). METHODS: We used a multistage, clustered, and stratified probability sample design. Within each of the 1727 sampled postcode sectors for Natsal-3, 30 or 36 addresses were randomly selected and then assigned to interviewers. To oversample individuals aged 16-34 years, we randomly allocated addresses to either the core sample (in which individuals aged 16-74 years were eligible) or the boost sample (in which only individuals aged 16-34 years were eligible). Interviewers visited all sampled addresses between Sept 6, 2010, and Aug 31, 2012, and randomly selected one eligible individual from each household to be invited to participate. Participants completed the survey in their own homes through computer-assisted face-to-face interviews and self-interview. We analysed data from this survey, weighted to account for unequal selection probabilities and non-response to correct for differences in sex, age group, and region according to 2011 Census figures. We then compared data from participants aged 16-44 years from Natsal-1 (1990-91), Natsal-2 (1999-2001), and Natsal-3. FINDINGS: Interviews were completed with 15,162 participants (6293 men, 8869 women) from 26,274 eligible addresses (57·7%). 82·1% (95% CI 81·0-83·1%) of men and 77·7% (76·7-78·7%) of women reported at least one sexual partner of the opposite sex in the past year. The proportion generally decreased with age, as did the range of sexual practices with partners of the opposite sex, especially in women. The increased sexual activity and diversity reported in Natsal-2 in individuals aged 16-44 years when compared with Natsal-1 has generally been sustained in Natsal-3, but in men has generally not risen further. However, in women, the number of male sexual partners over the lifetime (age-adjusted odds ratio 1·18, 95% CI 1·08-1·28), proportion reporting ever having had a sexual experience with genital contact with another woman (1·69, 1·43-2·00), and proportion reporting at least one female sexual partner in the past 5 years (2·00, 1·59-2·51) increased in Natsal-3 compared with Natsal-2. While reported number of occasions of heterosexual intercourse in the past 4 weeks had reduced since Natsal-2, we recorded an expansion of heterosexual repertoires--particularly in oral and anal sex--over time. Acceptance of same-sex partnerships and intolerance of non-exclusivity in marriage increased in men and women in Natsal-3. INTERPRETATION: Sexual lifestyles in Britain have changed substantially in the past 60 years, with changes in behaviour seeming greater in women than men. The continuation of sexual activity into later life--albeit reduced in range and frequency--emphasises that attention to sexual health and wellbeing is needed throughout the life course. FUNDING: Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and the Department of Health.
Assuntos
Atitude Frente a Saúde , Inquéritos Epidemiológicos , Estilo de Vida , Saúde Reprodutiva , Comportamento Sexual/estatística & dados numéricos , Adolescente , Adulto , Idoso , Análise por Conglomerados , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Reino UnidoRESUMO
BACKGROUND: Population-based estimates of prevalence, risk distribution, and intervention uptake inform delivery of control programmes for sexually transmitted infections (STIs). We undertook the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) after implementation of national sexual health strategies, and describe the epidemiology of four STIs in Britain (England, Scotland, and Wales) and the uptake of interventions. METHODS: Between Sept 6, 2010 and Aug 31, 2012, we did a probability sample survey of 15,162 women and men aged 16-74 years in Britain. Participants were interviewed with computer-assisted face-to-face and self-completion questionnaires. Urine from a sample of participants aged 16-44 years who reported at least one sexual partner over the lifetime was tested for the presence of Chlamydia trachomatis, type-specific human papillomavirus (HPV), Neisseria gonorrhoeae, and HIV antibody. We describe age-specific and sex-specific prevalences of infection and intervention uptake, in relation to demographic and behavioural factors, and explore changes since Natsal-1 (1990-91) and Natsal-2 (1999-2001). FINDINGS: Of 8047 eligible participants invited to provide a urine sample, 4828 (60%) agreed. We excluded 278 samples, leaving 4550 (94%) participants with STI test results. Chlamydia prevalence was 1·5% (95% CI 1·1-2·0) in women and 1·1% (0·7-1·6) in men. Prevalences in individuals aged 16-24 years were 3·1% (2·2-4·3) in women and 2·3% (1·5-3·4) in men. Area-level deprivation and higher numbers of partners, especially without use of condoms, were risk factors. However, 60·4% (45·5-73·7) of chlamydia in women and 43·3% (25·9-62·5) in men was in individuals who had had one partner in the past year. Among sexually active 16-24-year-olds, 54·2% (51·4-56·9) of women and 34·6% (31·8-37·4) of men reported testing for chlamydia in the past year, with testing higher in those with more partners. High-risk HPV was detected in 15·9% (14·4-17·5) of women, similar to in Natsal-2. Coverage of HPV catch-up vaccination was 61·5% (58·2-64·7). Prevalence of HPV types 16 and 18 in women aged 18-20 years was lower in Natsal-3 than Natsal-2 (5·8% [3·9-8·6] vs 11·3% [6·8-18·2]; age-adjusted odds ratio 0·44 [0·21-0·94]). Gonorrhoea (<0·1% prevalence in women and men) and HIV (0·1% prevalence in women and 0·2% in men) were uncommon and restricted to participants with recognised high-risk factors. Since Natsal-2, substantial increases were noted in attendance at sexual health clinics (from 6·7% to 21·4% in women and from 7·7% to 19·6% in men) and HIV testing (from 8·7% to 27·6% in women and from 9·2% to 16·9% in men) in the past 5 years. INTERPRETATION: STIs were distributed heterogeneously, requiring general and infection-specific interventions. Increases in testing and attendance at sexual health clinics, especially in people at highest risk, are encouraging. However, STIs persist both in individuals accessing and those not accessing services. Our findings provide empirical evidence to inform future sexual health interventions and services. FUNDING: Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and the Department of Health.