Venous thromboembolic disease in adults admitted to hospital in a setting with a high burden of HIV and TB

BACKGROUND

HIV and tuberculosis (TB) independently cause an increased risk for venous thromboembolic disease (VTE): deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Data from high HIV and TB burden settings describing VTE are scarce. The Wells' DVT and PE scores are widely used but their utility in these settings has not been reported on extensively.

OBJECTIVES

To evaluate new onset VTE, compare clinical characteristics by HIV status, and the presence or absence of TB disease in our setting. We also calculate the Wells' score for all patients.

METHODS

A prospective cohort of adult in-patients with radiologically confirmed VTE were recruited into the study between September 2015 and May 2016. Demographics, presence of TB, HIV status, duration of treatment, CD4 count, viral load, VTE risk factors, and parameters to calculate the Wells' score were collected.

RESULTS

We recruited 100 patients. Most of the patients were HIV-infected (n=59), 39 had TB disease and 32 were HIV/TB co-infected. Most of the patients had DVT only (n=83); 11 had PE, and 6 had both DVT and PE. More than a third of patients on antiretroviral treatment (ART) (43%; n=18/42) were on treatment for <6 months. Half of the patients (51%; n=20/39) were on TB treatment for <1 month. The median (interquartile range (IQR)) DVT and PE Wells' score in all sub-groups was 3.0 (1.0 - 4.0) and 3.0 (2.5 - 4.5), respectively.

CONCLUSION

HIV/TB co-infection appears to confer a risk for VTE, especially early after initiation of ART and/or TB treatment, and therefore requires careful monitoring for VTE and early initiation of thrombo-prophylaxis.

Systematic review of statistical methods for safety data in malaria chemoprevention in pregnancy trials

Background

Drug safety assessments in clinical trials present unique analytical challenges. Some of these include adjusting for individual follow-up time, repeated measurements of multiple outcomes and missing data among others. Furthermore, pre-specifying appropriate analysis becomes difficult as some safety endpoints are unexpected. Although existing guidelines such as CONSORT encourage thorough reporting of adverse events (AEs) in clinical trials, they provide limited details for safety data analysis. The limited guidelines may influence suboptimal analysis by failing to account for some analysis challenges above. A typical example where such challenges exist are trials of anti-malarial drugs for malaria prevention during pregnancy. Lack of proper standardized evaluation of the safety of antimalarial drugs has limited the ability to draw conclusions about safety. Therefore, a systematic review was conducted to establish the current practice in statistical analysis for preventive antimalarial drug safety in pregnancy.

Methods

The search included five databases (PubMed, Embase, Scopus, Malaria in Pregnancy Library and Cochrane Central Register of Controlled Trials) to identify original English articles reporting Phase III randomized controlled trials (RCTs) on anti-malarial drugs for malaria prevention in pregnancy published from January 2010 to July 2019.

Results

Eighteen trials were included in this review that collected multiple longitudinal safety outcomes including AEs. Statistical analysis and reporting of the safety outcomes in all the trials used descriptive statistics; proportions/counts (n = 18, 100%) and mean/median (n = 2, 11.1%). Results presentation included tabular (n = 16, 88.9%) and text description (n = 2, 11.1%). Univariate inferential methods were reported in most trials (n = 16, 88.9%); including Chi square/Fisher’s exact test (n = 12, 66.7%), t test (n = 2, 11.1%) and Mann–Whitney/Wilcoxon test (n = 1, 5.6%). Multivariable methods, including Poisson and negative binomial were reported in few trials (n = 3, 16.7%). Assessment of a potential link between missing efficacy data and safety outcomes was not reported in any of the trials that reported efficacy missing data (n = 7, 38.9%).

Conclusion

The review demonstrated that statistical analysis of safety data in anti-malarial drugs for malarial chemoprevention in pregnancy RCTs is inadequate. The analyses insufficiently account for multiple safety outcomes potential dependence, follow-up time and informative missing data which can compromise anti-malarial drug safety evidence development, based on the available data.

Systematic review of analytical methods applied to longitudinal studies of malaria

BACKGROUND

Modelling risk of malaria in longitudinal studies is common, because individuals are at risk for repeated infections over time. Malaria infections result in acquired immunity to clinical malaria disease. Prospective cohorts are an ideal design to relate the historical exposure to infection and development of clinical malaria over time, and analysis methods should consider the longitudinal nature of the data. Models must take into account the acquisition of immunity to disease that increases with each infection and the heterogeneous exposure to bites from infected Anopheles mosquitoes. Methods that fail to capture these important factors in malaria risk will not accurately model risk of malaria infection or disease.

METHODS

Statistical methods applied to prospective cohort studies of clinical malaria or Plasmodium falciparum infection and disease were reviewed to assess trends in usage of the appropriate statistical methods. The study was designed to test the hypothesis that studies often fail to use appropriate statistical methods but that this would improve with the recent increase in accessibility to and expertise in longitudinal data analysis.

RESULTS

Of 197 articles reviewed, the most commonly reported methods included contingency tables which comprised Pearson Chi-square, Fisher exact and McNemar's tests (n = 102, 51.8%), Student's t-tests (n = 82, 41.6%), followed by Cox models (n = 62, 31.5%) and Kaplan-Meier estimators (n = 59, 30.0%). The longitudinal analysis methods generalized estimating equations and mixed-effects models were reported in 41 (20.8%) and 24 (12.2%) articles, respectively, and increased in use over time. A positive trend in choice of more appropriate analytical methods was identified over time.

CONCLUSIONS

Despite similar study designs across the reports, the statistical methods varied substantially and often represented overly simplistic models of risk. The results underscore the need for more effort to be channelled towards adopting standardized longitudinal methods to analyse prospective cohort studies of malaria infection and disease.

Psychosocial correlates of alcohol and other substance use among low-income adolescents in peri-urban Johannesburg, South Africa: A focus on gender differences

Alcohol and other drug use is prevalent among peri-urban, South African adolescents. We identified correlates of alcohol and other drug use by gender among adolescents (age = 16-18 years; N = 822) in peri-urban Johannesburg. Interviewer-administered surveys assessed sexual activity, alcohol and other drug use, and relevant psychosocial factors. In separate logistic regression models of alcohol and other drug use stratified by gender, violence exposure and sexual activity were associated with alcohol use for both males and females. For females only, depressive symptoms were associated with drug use. For males only, being older and sexually active were associated with drug use. Substance use interventions for South African adolescents should consider psychological health, sexual health, and tailoring by gender.

Psychosocial correlates of alcohol and other substance use among low-income adolescents in peri-urban Johannesburg, South Africa: A focus on gender differences

Alcohol and other drug use is prevalent among peri-urban, South African adolescents. We identified correlates of alcohol and other drug use by gender among adolescents (age = 16-18 years; N = 822) in peri-urban Johannesburg. Interviewer-administered surveys assessed sexual activity, alcohol and other drug use, and relevant psychosocial factors. In separate logistic regression models of alcohol and other drug use stratified by gender, violence exposure and sexual activity were associated with alcohol use for both males and females. For females only, depressive symptoms were associated with drug use. For males only, being older and sexually active were associated with drug use. Substance use interventions for South African adolescents should consider psychological health, sexual health, and tailoring by gender.

Exposure to and experiences of violence among adolescents in lower socio-economic groups in Johannesburg, South Africa

Background

We explored exposure to and experiences of violence and their risk factors amongst ethnically diverse adolescents from lower socio economic groups in Johannesburg.

Methods

This cross-sectional study recruited a stratified sample of 16–18 year old adolescents from four low socio-economic suburbs in Johannesburg to reflect ethnic group clustering. We collected socio-demographic, sexual behaviour, alcohol and drug use and trauma events data. Proportions and risk factors were assessed by chi-square and logistic regression.

Results

Of 822 adolescents, 57% (n = 469) were female. Approximately 62% (n = 506) were Black, 13% (n = 107) Coloured, 13% (n = 106) Indian and 13% (n = 103) White. Approximately 67% (n = 552) witnessed violence to a non-family member, 28% (n = 228) experienced violence by a non-family member, and 10% (n = 83) reported sexual abuse. Multivariate analysis determined that witnessing violence in the community was associated with being Black (OR: 4.6, 95%CI: 2.7-7.9), Coloured (OR: 3.9, 95%CI: 2.0-7.4) or White (OR: 8.0, 95%CI:4.0-16.2), repeating a grade (OR: 1.5, 95%CI: 1.01-2.1), having more than one sexual partner (OR: 1.7, 95%CI: 1.1-2.5) and ever taking alcohol (OR: 2.1, 95%CI: 1.5-2.9). Witnessing violence in the family was associated with being female (OR: 1.8, 95%CI: 1.3-2.6), being Black (OR: 2.2, 95%CI: 1.1-4.1), or White (OR: 3.0, 95%CI: 1.4-6.4), repeating a grade (OR: 1.6, 95%CI: 1.1-2.2) and ever taking alcohol (OR: 2.9, 95%CI: 2.0-4.3).

Conclusions

In low socio-economic areas in Johannesburg, Black, White and Coloured adolescents experience a high burden of violence. Interventions to mitigate the effects of violence are urgently required.

Factors associated with mortality in HIV-infected people in rural and urban South Africa

Background

Factors associated with mortality in HIV-infected people in sub-Saharan Africa are widely reported. However rural–urban disparities and their association with all-cause mortality remain unclear. Furthermore, commonly used classical Cox regression ignores unmeasured variables and frailty.

Objective

To incorporate frailty in assessing factors associated with mortality in HIV-infected people in rural and urban South Africa.

Design

Using data from a prospective cohort following 6,690 HIV-infected participants from Soweto (urban) and Mpumalanga (rural) enrolled from 2003 to 2010; covariates of mortality were assessed by the integrated nested Laplace approximation method.

Results

We enrolled 2,221 (33%) rural and 4,469 (67%) urban participants of whom 1,555 (70%) and 3,480 (78%) were females respectively. Median age (IQR) was 36.4 (31.0–44.1) in rural and 32.7 (28.2–38.1) in the urban participants. The mortality rate per 100 person-years was 11 (9.7–12.5) and 4 (3.6–4.5) in the rural and urban participants, respectively. Compared to those not on HAART, rural participants had a reduced risk of mortality if on HAART for 6–12 (HR: 0.20, 95% CI: 0.10–0.39) and >12 months (HR: 0.10, 95% CI: 0.05–0.18). Relative to those not on HAART, urban participants had a lower risk if on HAART >12 months (HR: 0.35, 95% CI: 0.27–0.46).

The frailty variance was significant and >1 in rural participants indicating more heterogeneity. Similarly it was significant but <1 in the urban participants indicating less heterogeneity.

Conclusion

The frailty model findings suggest an elevated risk of mortality in rural participants relative to the urban participants potentially due to unmeasured variables that could be biological, socio–economic, or healthcare related. Use of robust methods that optimise data and account for unmeasured variables could be helpful in assessing the effect of unknown risk factors thus improving patient management and care in South Africa and elsewhere.

Correlates of sexual risk among sexual minority and heterosexual South African youths

We explored psychosocial correlates of sexual risk among heterosexual and sexual minority youths (SMYs) in Johannesburg, South Africa. Young people 16 to 18 years old (n = 822) were administered surveys assessing demographic characteristics, sexual behaviors, mental health, and parent-child communication. Adjusted multivariate regressions examining correlates of sexual risk revealed that SMYs had more sexual partners than heterosexual youths (B = 3.90; SE = 0.95; P < .001) and were more likely to engage in sex trading (OR = 3.11; CI = 1.12-8.62; P < .05). South African SMYs are at increased risk relative to their heterosexual peers.

Predictors of delay in the diagnosis and treatment of suspected tuberculosis in HIV co-infected patients in South Africa

SETTING

In South Africa, the majority of tuberculosis (TB) patients are co-infected with the human immunodeficiency virus (HIV), and delays in diagnosis and treatment likely exacerbate morbidity and mortality.

OBJECTIVE

To determine predictors of delays in the diagnosis and treatment of hospitalised suspected pulmonary TB patients co-infected with HIV.

DESIGN

Post-analysis of data collected in a three-centre prospective cohort of in-patients clinically diagnosed with active TB in three hospitals in South Africa between 2006 and 2009 during the first 24 h of admission. Delay was assessed by asking time of first symptoms and any prior health-seeking behaviour for this episode of illness.

RESULTS

Data from a total of 891 participants with a median age of 36 years and a CD4 count of 67 cells/mm(3) were analysed. Median patient, system and total delays were respectively 28, 1 and 28 days. Unemployment, treatment at Tshepong Hospital, alcohol consumption, crowding index, seeking prior treatment, cotrimoxazole treatment and WHO Stage 4 disease predicted prolonged total delay.

CONCLUSION

Patient delay in seeking care for TB in this high HIV prevalence setting is substantial. Factors identified with delay could be used to develop interventions to improve care seeking and earlier diagnosis of TB.

A review of the study designs and statistical methods used in the determination of predictors of all-cause mortality in HIV-infected cohorts: 2002-2011

BACKGROUND

Research in the predictors of all-cause mortality in HIV-infected people has widely been reported in literature. Making an informed decision requires understanding the methods used.

OBJECTIVES

We present a review on study designs, statistical methods and their appropriateness in original articles reporting on predictors of all-cause mortality in HIV-infected people between January 2002 and December 2011. Statistical methods were compared between 2002-2006 and 2007-2011. Time-to-event analysis techniques were considered appropriate.

DATA SOURCES

Pubmed/Medline.

STUDY ELIGIBILITY CRITERIA

Original English-language articles were abstracted. Letters to the editor, editorials, reviews, systematic reviews, meta-analysis, case reports and any other ineligible articles were excluded.

RESULTS

A total of 189 studies were identified (n = 91 in 2002-2006 and n = 98 in 2007-2011) out of which 130 (69%) were prospective and 56 (30%) were retrospective. One hundred and eighty-two (96%) studies described their sample using descriptive statistics while 32 (17%) made comparisons using t-tests. Kaplan-Meier methods for time-to-event analysis were commonly used in the earlier period (n = 69, 76% vs. n = 53, 54%, p = 0.002). Predictors of mortality in the two periods were commonly determined using Cox regression analysis (n = 67, 75% vs. n = 63, 64%, p = 0.12). Only 7 (4%) used advanced survival analysis methods of Cox regression analysis with frailty in which 6 (3%) were used in the later period. Thirty-two (17%) used logistic regression while 8 (4%) used other methods. There were significantly more articles from the first period using appropriate methods compared to the second (n = 80, 88% vs. n = 69, 70%, p-value = 0.003).

CONCLUSION

Descriptive statistics and survival analysis techniques remain the most common methods of analysis in publications on predictors of all-cause mortality in HIV-infected cohorts while prospective research designs are favoured. Sophisticated techniques of time-dependent Cox regression and Cox regression with frailty are scarce. This motivates for more training in the use of advanced time-to-event methods.

Factors associated with not testing for HIV and consistent condom use among men in Soweto, South Africa

Background

Besides access to medical male circumcision, HIV testing, access to condoms and consistent condom use are additional strategies men can use to prevent HIV acquisition. We examine male behavior toward testing and condom use.

Objective

To determine factors associated with never testing for HIV and consistent condom use among men who never test in Soweto.

Methods

A cross-sectional survey in Soweto was conducted in 1539 men aged 18–32 years in 2007. Data were collected on socio-demographic and behavioral characteristics to determine factors associated with not testing and consistent condom use.

Results

Over two thirds (71%) of men had not had an HIV test and the majority (55%, n = 602) were young (18–23). Of those not testing, condom use was poor (44%, n = 304). Men who were 18–23 years (aOR: 2.261, CI: 1.534–3.331), with primary (aOR: 2.096, CI: 1.058–4.153) or high school (aOR: 1.622, CI: 1.078–2.439) education, had sex in the last 6 months (aOR: 1.703, CI: 1.055–2.751), and had ≥1 sexual partner (aOR: 1.749, CI: 1.196–2.557) were more likely not to test. Of those reporting condom use (n = 1036, 67%), consistent condom use was 43% (n = 451). HIV testing did not correlate with condom use.

Conclusion

Low rates of both condom use and HIV testing among men in a high HIV prevalence setting are worrisome and indicate an urgent need to develop innovative behavioral strategies to address this shortfall. Condom use is poor in this population whether tested or not tested for HIV, indicating no association between condom use and HIV testing.

Using VCT statistics from Kenya in understanding the association between gender and HIV

This paper demonstrates the importance of utilising official statistics from the voluntary counselling and testing centres (VCT) to determine the association between gender and HIV infection rates in Kenya.The study design adopted was a record based survey of data collected from VCT sites in Kenya between the second quarter of 2001 and the second quarter of 2004. Of those who were tested, significantly more females tested positive (P<0.0001) and had twice as high a chance of being infected by HIV (Odds ratio 2.27 with CI 2.23 to 2.31) than males.We conclude that VCT statistics may lead to better planning of services and gender sensitive interventions if utilised well.

Improving national data collection systems from voluntary counselling and testing centres in Kenya

PROBLEM

Voluntary counselling and testing (VCT) data from the registered sites in Kenya have been fraught with challenges, leading to insufficient statistics in the national office for planning purposes. An exercise was carried out to determine the barriers to the flow of data in VCT sites in Kenya.

APPROACH

A record-based survey was conducted at 332 VCT sites in Kenya. Data from on-site records were compared with those in the national office. The exercise was conducted in 2004 between 5 September and 15 October.

LOCAL SETTING

All registered VCT sites in Kenya.

RELEVANT CHANGES

After the exercise, various measures to enhance VCT data collection and reporting were implemented. They include the provision of a uniform data collection and reporting tool to all the districts in the country, the strengthening of a feedback mechanism to update provinces and districts on their reporting status and increased support to the data component of the national quality assurance for VCT.

LESSONS LEARNED

Periodical field visits by the national officials to offer on-the-job training about data management to data collectors and to address data quality issues can dramatically improve the quality and completeness of VCT reports. The perceived relevance of the data and the data collection process to those working at the sites is the critical factor for data quality and timeliness of reporting.

Intention-to-treat analysis in the chronic suppurative otitis media trials

OBJECTIVE

To determine the extent of application of the intention to treat principle in the chronic suppurative otitis media (CSOM) randomised controlled trials.

DESIGN

Data were extracted from 28 CSOM randomised controlled trials.

MAIN OUTCOME MEASURES

Conceptual and methodological approaches of dealing with protocol deviations with respect to withdrawal, missing response and non-compliance.

RESULTS

Of the 28 CSOM trials included in this study, only one (4%) trial mentioned intention-to-treat (ITT) analysis. However, 10(36%) other trials which did not mention ITT, had no protocol deviations and thus carried out an ITT analysis by default. It is highly likely that a biased treatment effect existed in the trial that mentioned ITT since the authors undertook a complete case analysis disregarding the 22% protocol deviators. There were no attempts in any of the trials to impute for missing responses and carrying out a sensitivity analysis. For trials with a big percentage of protocol deviations, the validity of their results are brought to question.

CONCLUSIONS

In practice, not all those entered into a randomised-controlled trial will complete the trial. Thus intention-to-treat analysis is an important aspect of randomised controlled trials of health care interventions which tries to bridge this gap. It is important for authors to explicitly state the protocol deviations, the methods used to handle them and the potential effect with reference to bias and study outcome.