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The BioMed Central Collection contains articles written by researchers and staff of the The University of the West Indies, Faculty of Medical Sciences (FMS) which have been published in BioMed Central (BMC).

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Evaluation of allogeneic freeze-dried platelet lysate in cartilage exposed to interleukin 1-β in vitro
(2019-11-01) Camargo Garbin, Livia; McIlwraith, C. W; Frisbie, David D
Abstract Background Platelet-rich plasma (PRP) as well as other platelet-derived products have been used as a potential disease-modifying treatment for musculoskeletal diseases, such as osteoarthritis (OA). The restorative properties of such products rely mainly on the high concentrations of growth factors, demonstrating encouraging results experimentally and clinically. Yet, the autologous blood-derived nature of the PRP product lead to limitations that precludes it’s widespread use. The main limitations for PRP use are; product variability, the need for minimum laboratory settings in most cases, and the need for storage at low temperatures to preserve its properties. Based on these limitations, the objective of this study was to investigate an allogeneic off-the-shelf platelet lysate (PL) in cartilage exposed to interleukin 1β (IL-1β). For this purpose, blood and cartilage were harvested from eight skeletally mature and healthy horses. Blood was processed into PL aliquots and divided into three groups (Frozen, Freeze-dried and Filtered freeze-dried), used in autologous and allogeneic conditions and in three different concentrations (1.5, 3 and 6-fold). Different PL preparations were then applied in cartilage culture with interleukin-1 beta and cultured for 10 days. Cartilage and media samples were collected and analyzed for total GAG and 35SO4-labeled GAG content. Results No significant differences between the controls and PL groups in cartilage and media were demonstrated. The effects of PL on cartilage matrix were concentration dependent and intermediate concentrations (3-fold) in PL showed increased 35SO4-labelled GAG in cartilage. Conclusion In conclusion, the allogeneic freeze-dried PL presented equivalent effects compared to frozen autologous PL. Intermediate platelet concentration on average demonstrated improved results, demonstrating less GAG loss compared to other concentrations.
Medical care of acute myocardial infarction patients in a resource limiting country, Trinidad: a cross-sectional retrospective study
(2019-07-18) Bahall, Mandreker; Seemungal, Terrence; Khan, Katija; Legall, George
Abstract Background Cardiovascular disease remains the most common cause of death. However, effective and timely secondary care contributes to improved quality of life, decreased morbidity and mortality. This study analyzed the medical care of patients in a resource limiting country with a first presentation of acute myocardial infarction (AMI). Methods A cross-sectional retrospective study was conducted on first time AMI patients admitted between March 1st 2011 and March 31st 2015 to the only tertiary public hospital in a resource limiting country, Trinidad. Relevant data were obtained from all confirmed AMI patients. Results Data were obtained from 1106 AMI patients who were predominantly male and of Indo Trinidadian descent. Emergency treatment included aspirin (97.2%), clopidogrel (97.2%), heparin (81.3%) and thrombolysis (70.5% of 505 patients with ST elevation MI), but none of the patients had primary angioplasty. Thrombolysis was higher among younger patients and in men. There were no differences in age, sex, and ethnicity in all other treatments. Of the 360 patients with recorded times, 41.1% arrived at the hospital within 4 h. The proportion of patients receiving thrombolysis (door to needle time) within 30 min was 57.5%. In-patient treatment medication included: aspirin (87.1%), clopidogrel (87.2%), beta blockers (76.5%), ACEI (72.9%), heparin (80.6%), and simvastatin (82.5%). Documentation of risk stratification, use of angiogram and surgical intervention, initiation of cardiac rehabilitation (CR), and information on behavioral changes were rare. Electrocardiogram (ECG) and cardiac enzyme tests were universally performed, while echocardiogram was performed in 57.1% of patients and exercise stress test was performed occasionally. Discharge treatment was limited to medication and referrals for investigations. Few patients were given lifestyle and activity advice and referred for CR. The in-hospital death rate was 6.5%. There was a significantly higher relative risk of in-hospital death for non-use of aspirin, clopidogrel, simvastatin, beta blockers, and heparin, but not ACE inhibitors and nitrates. Conclusions Medication usage was high among AMI patients. However, there was very minimal use of non-pharmacological measures. No differences were found in prescribed medication by age, sex, or ethnicity, with the exception of thrombolysis.
Natural Hazard-Induced Disasters and Production Efficiency: Moving Closer to or Further from the Frontier?
(2019-05-20) Mohan, Preeya S; Spencer, Nekeisha; Strobl, Eric
Abstract Production efficiency is a key determinant of economic growth and demonstrates how a country uses its resources by relating the quantity of its inputs to its outputs. When a natural hazard-induced disaster strikes, it has a devastating impact on capital and labor, but at the same time provides an opportunity to upgrade capital and increase labor demand and training opportunities, thereby potentially boosting production efficiency. We studied the impact of natural hazard-induced disasters on countries’ production efficiency, using the case study of hurricanes in the Caribbean. To this end we built a country-specific, time-varying data set of hurricane damage and national output and input indicators for 17 Caribbean countries for the period 1940–2014. Our results, using a stochastic frontier approach, show that there is a short-lived production efficiency boost, and that this can be large for very damaging storms.
Characterization of a broad-based mosquito yeast interfering RNA larvicide with a conserved target site in mosquito semaphorin-1a genes
(2019-05-22) Mysore, Keshava; Li, Ping; Wang, Chien-Wei; Hapairai, Limb K; Scheel, Nicholas D; Realey, Jacob S; Sun, Longhua; Severson, David W; Wei, Na; Duman-Scheel, Molly
Abstract Background RNA interference (RNAi), which has facilitated functional characterization of mosquito neural development genes such as the axon guidance regulator semaphorin-1a (sema1a), could one day be applied as a new means of vector control. Saccharomyces cerevisiae (baker’s yeast) may represent an effective interfering RNA expression system that could be used directly for delivery of RNA pesticides to mosquito larvae. Here we describe characterization of a yeast larvicide developed through bioengineering of S. cerevisiae to express a short hairpin RNA (shRNA) targeting a conserved site in mosquito sema1a genes. Results Experiments conducted on Aedes aegypti larvae demonstrated that the yeast larvicide effectively silences sema1a expression, generates severe neural defects, and induces high levels of larval mortality in laboratory, simulated-field, and semi-field experiments. The larvicide was also found to induce high levels of Aedes albopictus, Anopheles gambiae and Culex quinquefasciatus mortality. Conclusions The results of these studies indicate that use of yeast interfering RNA larvicides targeting mosquito sema1a genes may represent a new biorational tool for mosquito control.
Teaching anatomy using an active and engaging learning strategy
(2019-05-16) Singh, Keerti; Bharatha, Ambadasu; Sa, Bidyadhar; Adams, Oswald P; Majumder, Md. A A
Abstract Background Various evidence-based and student-centered strategies such as team-based learning (TBL), case-based learning (CBL), and flipped classroom have been recently applied to anatomy education and have shown to improve student engagement and interaction. These strategies shift the focus of teaching from knowledge transmission to knowledge construction by students and encourage the use of tasks. This study discusses the use of an active and engaging learning strategy to teach the musculoskeletal system to Year 1 MBBS students (Faculty of Medical Sciences, The University of the West Indies, Cave Hill, Barbados) and examines the correlation between assessment modalities and student performance. Methods The “Active and Engaging Learning Strategy” was used to assess student learning in the form of oral presentations. Students had presentations on muscle attachments, muscle actions, blood and nerve supply, and applied anatomy of the limb musculature. Questions on the limbs (Locomotor System) were included in pre and post-presentation spotters, in-course assessments, and final examinations. Percentages, paired t-test, independent sample t-test, and zero-order correlations were performed to confirm the results for the different objectives of the study. Results The main modes of presentation chosen were poems (37.1%), followed by stories (21.2%), songs (11.4%), and skits (10.6%). The majority of students (84%) found the strategies beneficial and recommended such sessions for future cohorts (92%). Students achieved significantly better scores in post-presentation spotters (p < 0.01) and the marks of in-course and final examinations also showed significant improvement (p < 0.01). Conclusion Our study highlighted that the active and engaging learning strategy can be used as an effective learning tool in anatomy. Students were proactive in preparing the muscle presentations by utilizing their own creativity, curiosity, and intelligence. Further studies should be conducted using randomized controlled trials to assess the effectiveness of various learning strategies which could open a new door to medical education.
Reduced forced vital capacity is independently associated with ethnicity, metabolic factors and respiratory symptoms in a Caribbean population: a cross-sectional study
(2019-03-14) Sakhamuri, Sateesh; Lutchmansingh, Fallon; Simeon, Donald; Conyette, Liane; Burney, Peter; Seemungal, Terence
Abstract Background Relationships between low forced vital capacity (FVC), and morbidity have previously been studied but there are no data available for the Caribbean population. This study assessed the association of low FVC with risk factors, health variables and socioeconomic status in a community-based study of the Trinidad and Tobago population. Methods A cross-sectional survey was conducted using the Burden of Obstructive Lung Disease (BOLD) study protocol. Participants aged 40 years and above were selected using a two-stage stratified cluster sampling. Generalized linear models were used to examine associations between FVC and risk factors. Results Among the 1104 participants studied a lower post-bronchodilator FVC was independently associated with a large waist circumference (− 172 ml; 95% CI, − 66 to − 278), Indo-Caribbean ethnicity (− 180 ml; 95% CI, − 90 to − 269) and being underweight (− 185 ml; 95% CI, − 40 to − 330). A higher FVC was associated with smoking cannabis (+ 155 ml; 95% CI, + 27 to + 282). Separate analyses to examine associations with health variables indicated that participants with diabetes (p = 0∙041), history of breathlessness (p = 0∙007), and wheeze in the past 12 months (p = 0∙040) also exhibited lower post-bronchodilator FVC. Conclusion These findings suggest that low FVC in this Caribbean population is associated with ethnicity, low body mass index (BMI), large waist circumference, chronic respiratory symptoms, and diabetes.
Tutor assessment of PBL process: does tutor variability affect objectivity and reliability?
(2019-03-08) Sa, Bidyadhar; Ezenwaka, Chidum; Singh, Keerti; Vuma, Sehlule; Majumder, Md. Anwarul A
Abstract Background Ensuring objectivity and maintaining reliability are necessary in order to consider any form of assessment valid. Evaluation of students in Problem-Based Learning (PBL) tutorials by the tutors has drawn the attention of critiques citing many challenges and limitations. The aim of this study was to determine the extent of tutor variability in assessing the PBL process in the Faculty of Medical Sciences, The University of the West Indies, St Augustine Campus, Trinidad and Tobago. Method All 181 students of year 3 MBBS were assigned randomly to 14 PBL groups. Out of 18 tutors, 12 had an opportunity to assess three groups: one assessed 2 groups and 4 tutors assessed one group each; at the end each group had been assessed three times by different tutors. The tutors used a PBL assessment rating scale of 12 different criteria on a six-point scale to assess each PBL Group. To test the stated hypotheses, independent t-test, one-way ANOVA followed by post-hoc Bonferroni test, Intra Class Correlation, and Pearson product moment correlations were performed. Result The analysis revealed significant differences between the highest- and lowest-rated groups (t-ratio = 12.64; p < 0.05) and between the most lenient and most stringent raters (t-ratio = 27.96; p < 0.05). ANOVA and post-hoc analysis for highest and lowest rated groups revealed that lenient- and stringent-raters significantly contribute (p < 0.01) in diluting the score in their respective category. The intra class correlations (ICC) among rating of different tutors for different groups showed low agreement among various ratings except three groups (Groups 6, 8 and 13) (r = 0.40). The correlation between tutors’ PBL experiences and their mean ratings was found to be moderately significant (r = 0.52; p > 0.05). Conclusion Leniency and stringency factors amongst raters affect objectivity and reliability to a great extent as is evident from the present study. Thus, more rigorous training in the areas of principles of assessment for the tutors are recommended. Moreover, putting that knowledge into practice to overcome the leniency and stringency factors is essential.
Experiences of gender-based violence among female sex workers, men who have sex with men, and transgender women in Latin America and the Caribbean: a qualitative study to inform HIV programming
(2019-03-05) Evens, Emily; Lanham, Michele; Santi, Karin; Cooke, Juana; Ridgeway, Kathleen; Morales, Giuliana; Parker, Caleb; Brennan, Claire; de Bruin, Marjan; Desrosiers, Pavel C; Diaz, Xenia; Drago, Marta; McLean, Roger; Mendizabal, Modesto; Davis, Dirk; Hershow, Rebecca B; Dayton, Robyn
Abstract Background Female sex workers, MSM, and transgender women—collectively referred to as key populations (KPs)—are disproportionately affected by gender-based violence (GBV) and HIV, yet little is known about the violence they face, its gender-based origins, and responses to GBV. The purpose of this study was to understand the nature and consequences of GBV experienced, to inform HIV policies and programming and to help protect KPs’ human rights. Methods Using a participatory approach, FSWs, MSM, and transgender women in Barbados, El Salvador, Trinidad and Tobago, and Haiti conducted 278 structured interviews with peers to understand their experiences of and responses to GBV. Responses to open-ended questions were coded in NVivo and analyzed using an applied thematic analysis. Results Nearly all participants experienced some form of GBV. Emotional and economic GBV were the most commonly reported but approximately three-quarters of participants reported sexual and physical GBV and other human rights violations. The most common settings for GBV were at home, locations where sex work took place such as brothels, bars and on the street; public spaces such as parks, streets and public transport, health care centers, police stations and—for transgender women and MSM—religious settings and schools. The most common perpetrators of violence included: family, friends, peers and neighbors, strangers, intimate partners, sex work clients and other sex workers, health care workers, police, religious leaders and teachers. Consequences included emotional, physical, and sexual trauma; lack of access to legal, health, and other social services; and loss of income, employment, housing, and educational opportunities. Though many participants disclosed experiences of GBV to friends, colleagues and family, they rarely sought services following violence. Furthermore, less than a quarter of participants believed that GBV put them at risk of HIV. Conclusions Our study found that across the four study countries, FSWs, MSM, and transgender women experienced GBV from state and non-state actors throughout their lives, and much of this violence was directly connected to rigid and harmful gender norms. Through coordinated interventions that address both HIV and GBV, this region has the opportunity to reduce the national burden of HIV while also promoting key populations’ human rights.
Stigma in health facilities: why it matters and how we can change it
(2019-02-15) Nyblade, Laura; Stockton, Melissa A; Giger, Kayla; Bond, Virginia; Ekstrand, Maria L; Lean, Roger M; Mitchell, Ellen M H; Nelson, La R E; Sapag, Jaime C; Siraprapasiri, Taweesap; Turan, Janet; Wouters, Edwin
Abstract Stigma in health facilities undermines diagnosis, treatment, and successful health outcomes. Addressing stigma is fundamental to delivering quality healthcare and achieving optimal health. This correspondence article seeks to assess how developments over the past 5 years have contributed to the state of programmatic knowledge—both approaches and methods—regarding interventions to reduce stigma in health facilities, and explores the potential to concurrently address multiple health condition stigmas. It is supported by findings from a systematic review of published articles indexed in PubMed, Psychinfo and Web of Science, and in the United States Agency for International Development’s Development Experience Clearinghouse, which was conducted in February 2018 and restricted to the past 5 years. Forty-two studies met inclusion criteria and provided insight on interventions to reduce HIV, mental illness, or substance abuse stigma. Multiple common approaches to address stigma in health facilities emerged, which were implemented in a variety of ways. The literature search identified key gaps including a dearth of stigma reduction interventions in health facilities that focus on tuberculosis, diabetes, leprosy, or cancer; target multiple cadres of staff or multiple ecological levels; leverage interactive technology; or address stigma experienced by health workers. Preliminary results from ongoing innovative responses to these gaps are also described. The current evidence base of stigma reduction in health facilities provides a solid foundation to develop and implement interventions. However, gaps exist and merit further work. Future investment in health facility stigma reduction should prioritize the involvement of clients living with the stigmatized condition or behavior and health workers living with stigmatized conditions and should address both individual and structural level stigma.
What is the financial incentive to immigrate? An analysis of salary disparities between health workers working in the Caribbean and popular destination countries
(2019-02-08) George, Gavin; Rhodes, Bruce; Laptiste, Christine
Abstract Background The continuous migration of Human Resources for Health (HRH) compromises the quality of health services in the developing supplying countries. The ability to increase earnings potentially serves as a strong motivator for HRH to migrate abroad. This study adds to limited available literature on HRH salaries within the Caribbean region and establishes the wage gap between selected Caribbean and popular destination countries. Methods Salaries are reported for registered nurses, medical doctors and specialists. Within these cadres, experience is incorporated at three different levels. Earnings are compared using purchasing power parity (PPP) exchange rates allowing for cost of living adjusted salary differentials, awarded to different levels of work experience for the chosen health cadres in the selected Caribbean countries (Jamaica, Dominica, St Lucia and Grenada) and the three destination countries (United States, United Kingdom and Canada). Results Registered nurses in the destination countries, across all experience levels, have greater spending power compared to their Caribbean counterparts. Recently qualified registered nurses earn substantially more in the UK (86.4%), US (214.2%) and Canada (182.5% more). The highest PPP salary ($) gap amongst more experienced nurses (5-10 years) is found within the US, with a gap of 163.9%. PPP salary gaps amongst medical doctors were pronounced, with experienced cadres (10–20 years of experience) in the US earning 316.3% more than their Caribbean counterparts, whilst UK doctors (183.5%) and Canadian doctors (251.3%) also earning significantly more. Large salary differentials remained for medical specialists and consultants. US specialist salaries were 540.4% higher than their Caribbean based counterparts, whilst UK and Canadian specialists earned 95.2 and 181.6% more respectively. Conclusion The PPP adjusted HRH salaries in the three destination countries are superior to those of comparable HRH working in the Caribbean countries selected. The extent of the salary gaps vary according to country and the health cadre under examination, but remain considerable even for newly qualified HRH. The financial incentive to migrate for HRH trained and working in the Caribbean region remains strong, with governments having to consider earning potential abroad when formulating policies and strategies aimed at retaining health professionals.
Prevalence and associations of depression among patients with cardiac diseases in a public health institute in Trinidad and Tobago
(2019-01-07) Bahall, Mandreker
Abstract Background Psychosocial issues are major determinants as well as consequences of cardiovascular disease (CVD). This study sought to assess the prevalence and identify factors associated with depression among patients with cardiac disease in a public health institute in Trinidad and Tobago. Methods A cross-sectional study was conducted with a convenience sample of 388 hospitalised, stable, adult patients with cardiac disease admitted in the only tertiary public health institute in South Trinidad. Patients were identified and interviewed 3 to 5 days after admission using a questionnaire comprising questions on demographic, medical, and lifestyle issues and the 9-item Patient Health Questionnaire (PHQ-9). Results The prevalence of clinically significant depression (PHQ-9 > 9) among hospitalised patients with cardiac disease was 40.0%. However, the prevalence of non-minimal depression (PHQ-9 ≥ 5) in this study was 78.4%. It was greater among women (83.1%) than among men (72.9%). Non-minimal depression was associated with sex (p = 0.015), employment status (p = 0.007), hypertension (p = 0.017), stressful life (p ≤ 0.001), feelings of depression (p ≤ 0.001), regular exercise (p ≤ 0.001), and living alone (p = 0.006). Age, ethnicity, education level, income, or religious affiliations were not associated (p > 0.05) with depression. Participants diagnosed with depression commonly reported feeling tired (81.2%), having trouble sleeping (74.7%), and moving/speaking slowly (73.5%). Patients with self-claimed depression (past or current) were four times more likely to have depression and those with self-reported stress and loneliness were twice as likely to have depression. Employed patients and those who exercised regularly were approximately 50% less likely to have depression. Conclusions Clinical depression prevalence among hospitalised patients with cardiac disease was 40.0%. Approximately twice as many (78.4%) had non-minimal depression, with higher prevalence among women. Employment, sex, hypertension, stressful life, feelings of depression, regular exercise, and living alone were associated with non-minimal depression. Patients with self-claimed depression, stress, and those living alone had a much higher likelihood of having depression, while those who were employed and exercised regularly were approximately half as likely to have depression.
The National Alcohol Survey of Households in Trinidad and Tobago (NASHTT): willingness to support changes in policy, laws and regulations
(2018-10-25) Maharaj, Rohan G; Babwah, Terence; Motilal, M. S; Nunes, Paula; Brathwaite, Rachel; Legall, George; Reid, Sandra D
Abstract Background Over 60% of households (HHs) in Trinidad and Tobago (T&T) consume alcohol. These HHs were more likely to report illnesses, relationship problems, and behavioral problems with children. This study set out to determine what proportion of HHs were willing to support changes in specific policies, laws and regulations in a national alcohol campaign. Methods A cross-sectional convenience sample of HHs were surveyed from a random sample of enumeration districts (ED) in T&T. An interviewer-applied, field pre-tested de novo questionnaire had 5 domains and was developed over 1 1/2 years after an extensive literature review and consultation. Many of the WHO ‘best buys’ recommendations were included. Results One thousand six hundred ninety-five HHs (from 53 ED) responded from a total of 1837 HHs approached (response rate 92%). In a national campaign the following proportions of HHs would support: setting the legal age for drinking at 21 years (82.4%); restricting or banning alcohol advertising on TV and other media (73.1% and 54.4% respectively); banning all alcohol advertising at sports and cultural events (64.8%); banning radio stations playing songs with reference to alcohol use (71.3%); holding sellers of alcohol responsible for the amount of alcohol sold (79.5%); advocating that proof of age to be shown by persons buying alcohol (87.4%); placing more prominent warning labels on products displaying alcohol content (87.2%); placing more prominent warning labels on products showing harmful effects (88.5%); increasing taxes on alcohol sales (87.7%). Less than 50% of HH supported restrictions in density of outlets and reduction in opening times for alcohol outlets. Conclusions Many HHs in T&T are willing to support changes in policies around alcohol, including many of the policies shown by the WHO to be effective in reducing the harmful consumption of alcohol.
Psychometric properties of the severity of the dependence scale for Khat (SDS-Khat) in polysubstance users
(2018-10-19) Manzar, Md. D; Alamri, Majed; Mohammed, Salahuddin; Khan, Mohammed A Y; Chattu, Vijay K; Pandi-Perumal, Seithikurippu R; Bahammam, Ahmed S
Abstract Background Current evidence suggests that the addiction on one substance may underpin or affect addiction on another in polysubstance users. However, there is no tool that has been shown to have psychometric validation for assessment of the severity of khat addiction in polysubstance users. Methods Polysubstance users with khat chewing habit (n = 178, age = 25.8 ± 3.6, BMI = 23.3 ± 2.8 kg/m2) were recruited from randomly selected houses for a cross-sectional study in Mizan, Ethiopia. The survey including severity of dependence scale for khat (SDS-khat), a brief metacognition questionnaire, and a semi-structured socio-demographics tool were administered by trained interviewers. Results There was no ceiling effect or floor effect in the SDS-Khat scores. Internal consistency was moderate (Cronbach’s alpha = 0.58). Internal homogeneity was adequate (Item-total correlations of the SDS-Khat; r ≥ 0.55). Significant negative correlations between the SDS-Khat and the metacognition (r = −.19 to −.34, p < 0.05 or p < 0.01) indicated convergent validity. The findings of exploratory factor analysis were non-unanimous with a suggestion of two models, i.e., a 2-factor and a 1-factor model, while the confirmatory factor analysis favored 1-Factor model. Conclusion The SDS-Khat has adequate psychometric validity for the assessment of psychological severity of khat addiction in the polysubstance users.
Gene expression programming and artificial neural network to estimate atmospheric temperature in Tabuk, Saudi Arabia
(2018-09-27) Azamathulla, H. M; Rathnayake, Upaka; Shatnawi, Ahmad
Abstract Climate change is not a myth. There is enough evidence to showcase the impact of climate change. Town planners and authorities are looking for potential models to predict the climatic factors in advance. Being an agricultural area in Saudi Arabia, Tabuk region gets greater interest in developing such a model to predict the atmospheric temperature.Therefore, this paper presents two different studies based on artificial neural networks (ANNs) and gene expression programming (GEP) to predict the atmospheric temperature in Tabuk. Atmospheric pressure, rainfall, relative humidity and wind speed are used as the input variables in the developed models. Multilayer perceptron neural network model (ANN model), which is high in precession in producing results, is selected for this study. The GEP model that is based on evolutionary algorithms also produces highly accurate results in nonlinear models. However, the results show that the GEP model outperforms the ANN model in predicting atmospheric temperature in Tabuk region. The developed GEP-based model can be used by the town and country planers and agricultural personals. Graphical abstract
The viability of slim-hole drilling onshore Trinidad
(2018-09-10) Hosein, Raffie; Serrattan, Sheva; Jupiter, Andrew
Abstract Slim-hole drilling refers to the drilling of a well with a wellbore typically less than 7 in. in diameter. Slim-hole drilling is beneficial to the low-budget operator as there are considerable savings on rig time and costs and the rig size is ideal for drilling in remote areas. During slim-hole drilling, drilling fluid hydraulics is of great concern since significant pressure losses can occur in the drill pipe and annulus due to the reduced annular clearances. In addition, the flow regime generated in a slim-hole and the compatibility of the drilling fluid with the formation can have an impact on the stability of the wellbore. Slim-hole drilling has been successfully conducted onshore Trinidad in the Morne Diablo/Quinam Block for a number of years. The most commonly used drilling fluid is saltwater-based mud since it is cheaper and easier to dispose of than oil-based mud. However, the open literature did not show any studies conducted to determine the impact of drilling fluid hydraulics and drilling fluid compatibility on well-bore stability. In this study, 25 water-based drilling mud formulations were prepared using different concentrations of sodium chloride, potassium chloride and calcium chloride. The rheological properties of each formulation were determined and the Bingham plastic and power law models were applied. The frictional pressure losses for three commonly drilled slim-hole configurations were then computed and compared. Outcrop shale samples from the area were then treated with each formulation and the percentage loss in mass due to hydration and disintegration was measured for each sample. The results from these two tests showed that of the mud formulations tested, overall, those with KCl (2.9%) and CaCl2 (0.7%), KCl (3.6%), KCl (0.7%) and NaCl (2.9%), NaCl (0.7%), and CaCl2 (2.9%) were determined as best suitable for slim-hole drilling for the well configurations used. For these mud formulations, frictional pressure losses using both rheological models were the lowest and provide adequate rheological properties. The outcrop samples also showed the lowest percentage loss by mass when treated with these formulations indicating that they possess the desired well-bore inhibition properties. However, formulations containing NaCl only are the least expensive with straight KCl formulations being the most expensive.
Cancer incidence and mortality rates and trends in Trinidad and Tobago
(2018-07-04) Warner, Wayne A; Lee, Tammy Y; Badal, Kimberly; Williams, Tanisha M; Bajracharya, Smriti; Sundaram, Vasavi; Bascombe, Nigel A; Maharaj, Ravi; Lamont-Greene, Marjorie; Roach, Allana; Bondy, Melissa; Ellis, Matthew J; Rebbeck, Timothy R; Slovacek, Simeon; Luo, Jingqin; Toriola, Adetunji T; Llanos, Adana A M
Abstract Background Cancer is the second leading cause of death in the Caribbean, including the islands of Trinidad and Tobago (TT). The population of TT consists of over 1.3 million people with diverse ancestral and sociocultural backgrounds, both of which may influence cancer incidence and mortality. The objective of this study was to examine incidence and mortality patterns and trends in TT. Methods Cancer surveillance data on 29,512 incident cancer cases reported to the Dr. Elizabeth Quamina Cancer Registry (population-based cancer registry of TT) between 1995 and 2009 were analyzed. Age-standardized rates, overall and by sex, ancestry, and geography, were reported. Results The highest incidence and mortality rates were observed for cancers related to reproductive organs in women, namely, breast, cervical, and uterine cancers, and prostate, lung and colorectal cancers among men. Average incidence rates were highest in areas covered by the Tobago Regional Health Authority (TRHA) (188 per 100,000), while average mortality rates were highest in areas covered by the North West Regional Health Authority (108 per 100,000). Nationals of African ancestry exhibited the highest rates of cancer incidence (243 per 100,000) and mortality (156 per 100,000) compared to their counterparts who were of East Indian (incidence, 125 per 100,000; mortality, 66 per 100,000) or mixed ancestry (incidence, 119 per 100,000; mortality, 66 per 100,000). Conclusions Our findings highlight the need for national investment to improve the understanding of the epidemiology of cancer in Trinidad and Tobago, and to ultimately guide much needed cancer prevention and control initiatives in the near future.
Evaluating wind speed probability distribution models with a novel goodness of fit metric: a Trinidad and Tobago case study
(2018-05-17) Dookie, Isa; Rocke, Sean; Singh, Arvind; Ramlal, Craig J
Abstract Wind energy has been explored as a viable alternative to fossil fuels in many small island developing states such as those in the Caribbean for a long time. Central to evaluating the feasibility of any wind energy project is choosing the most appropriate wind speed model. This is a function of the metric used to assess the goodness of fit of the statistical models tested. This paper compares a number of common metrics then proposes an alternative to the application-blind statistical tools commonly used.Wind speeds at two locations are considered: Crown Point, Tobago; and Piarco, Trinidad. Hourly wind speeds over a 15-year period have been analyzed for both sites. The available data is modelled using the Birnbaum–Saunders, Exponential, Gamma, Generalized Extreme Value, Generalized Pareto, Nakagami, Normal, Rayleigh and Weibull probability distributions. The distributions were compared graphically and their parameters were estimated using maximum likelihood estimation. Goodness of fit was assessed using the normalised mean square error testing, Chi-squared testing, Kolmogorov–Smirnov, R-squared, Akaike information criteria and Bayesian information criteria tests and the distributions ranked. The distribution ranking varied widely depending on the test used highlighting the need for a more contextualized goodness of fit metric. With this in mind, the concept of application-specific information criteria (ASIC) for testing goodness of fit is introduced. This allows distributions to be ranked by secondary features which are a function of both the primary data and the application space.
Health services in Trinidad: throughput, throughput challenges, and the impact of a throughput intervention on overcrowding in a public health institution
(2018-02-20) Bahall, Mandreker
Abstract Background Throughput might be partially responsible for sub-optimum organisational and medical outcomes. The present study examined throughput and the challenges to ensuring optimum throughput in hospitals, and determined the effectiveness of a throughput intervention in reducing overcrowding in a public healthcare institution in Trinidad and Tobago. Methods First, a literature review of throughput and its processes in relation to improving hospital care was conducted. Second, the challenges to throughput in healthcare were reviewed. Data were also collected from print media, hospital records, and the central statistical office in Trinidad and Tobago to discuss throughput and describe the throughput status in hospitals. Finally, the effect of a throughput intervention on overcrowding was determined. The intervention was implemented over six months, from October 2010 to March 2011, and comprised three stages of a five-stage throughput process: transferring patients to a specific medical ward, bedside electrocardiograms (ECG), and promptly obtaining patient investigative reports and patient files. Results Problems with the throughput process led to prolonged delays or failures in obtaining lab reports, radiology services, ECGs, and pharmaceutical supplies, as well as inadequate social work services and other specialised services. During the throughput intervention, there was a reduction in overcrowding/overflow to 5–10 patients per day with a daily admission rate of 58. However, at post-intervention, there was increased overcrowding/overflow to 20–30 per day but fewer admissions (52 per day) i.e. similar to pre-intervention period. Additionally, there was an increase in bed complement in the department of medicine from 209 (2011) to 227 (2012). Overcrowding continued into 2016 and beyond: medical admissions in 2016 were 46.4 per day and the medical bed capacity was 327 (indicating a 44% increase in capacity from 2012). Conclusion Hospital throughput processes are currently suboptimum. Improving specific throughput processes or targeting the greatest primary constraints might help decrease overcrowding.
Quality of life of patients with first-time AMI: a descriptive study
(2018-02-13) Bahall, Mandreker; Khan, Katija
Abstract Background Outcomes following acute myocardial infarction (AMI) may result in death, increased morbidity, and change in quality of life (QOL). This study explores health-related QOL of first-time patients following AMI. Methods This cross-sectional study used a sample of patients with first-time AMI experienced between April 2011 and March 2015 at a tertiary health institution. Recruited patients belonged to different post-AMI periods: 2–10 weeks, 5–22 months, and > 22 months to 4 years post AMI. Inclusion criteria were not confused and communicating freely. Exclusion criteria were non-contactable, refusing to participate, and deceased. One-on-one interviews were conducted using the validated and pre-tested Quality of Life after Myocardial Infarction (QLMI) questionnaire. QOL of patients after AMI was evaluated at each period. Descriptive, Mann–Whitney U, Kruskal–Wallis, and regression analyses were conducted using SPSS version 24. Results A total of 534 participant interviews (overall response rate 65.4%) were conducted. Interviewees were predominantly male (67%), aged 51–65 years (45%), Indo-Trinidadian (81.2%), NSTEMI (64.4%), and hypertensive (72.4%). Overall QOL improved over time and in all domains: Emotional, Physical, and Social. Lower QOL was found among women, patients with NSTEMI, and diabetics in all domains; in patients with hypertension and renal disease in the Physical and Social domains only; and in patients with ischaemic heart disease (IHD) in the Physical domain only. Self-reported stress and lack of exercise were associated with lower QOL while drinking alcohol and eating out were related to better QOL. Hypercholesterolemia, smoking, and ethnicity showed no association with QOL. Declining QOL in the Physical domain with age was also found. The leading components of QOL were self-confidence and social exclusion (early post AMI), lack of self-confidence (intermediate post AMI), and tearfulness (late post AMI). Conclusions QOL in AMI survivors improves over time. Female gender, NSTEMI, diabetes, hypertension, renal disease, stress, and lack of exercise were associated with lower QOL while hypercholesterolemia, smoking, and ethnicity showed no association with QOL. Cardiac rehabilitation and psychological support may enhance earlier increased QOL among survivors, particularly among vulnerable groups.
Rapid increase of overweight and obesity among primary school-aged children in the Caribbean; high initial BMI is the most significant predictor
(2018-01-30) Mumena, Walaa A; Francis-Granderson, Isabella; Phillip, Leroy E; Gray-Donald, Katherine
Abstract Background To examine predictors of increasing overweight among children in two developing countries. Methods Primary school children (6–10 y at baseline, n = 336) and their caregivers. Longitudinal data were collected in 2012, with follow-up 18 months later. Data on children’s height, weight and dietary intake were collected within 8 primary public schools in Trinidad and 7 schools in St. Kitts. Caregivers’ demographic and anthropometric data were also collected. Results At baseline, children’s age and sex and caregivers’ BMI, age, and marital status and reported dietary intake were similar across all weight groups. The incidence of overweight and obesity among children was 8.8% and 8.1%, respectively. Dietary intake at baseline was not related to becoming overweight or obese. Similarly there were no differences in reported intake among children who became overweight or obese except that they consumed fewer fruits (0.54±0.92 vs. 0.98±1.66, p = 0.017). Misreporting of energy intake was higher among overweight/obese children as compared to those who were not overweight/obese (27% vs. 17%, p = 0.047). The baseline predictors of increasing BMI (adjusted) of the children were older age, higher baseline BMI z-score and higher height-for-age (HFA) z-score; caregiver BMI, children’s energy intake (with adjustment for misreporting) did not predict changes in children’s BMI. Conclusions The increasing prevalence of overweight/obesity among children is a serious problem in the Caribbean. Heavier children are at elevated risk of continued rapid increase in their weight status, pointing to the need for early intervention.

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