Optical fibre digital pulse-position-modulation assuming a Gaussian received pulse shape

The abundance in bandwidth available in the best monomode fibres may be exchanged for improved receiver sensitivity by employing digital PPM. The paper presents a performance and optimisation analysis for a digital PPM coding scheme operating over a fibre channel employing a PIN-BJT receiver and assuming a Gaussian received pulse shape. The authors present original results for a 50 Mbit/s, 1.3 μm wavelength digital PPM system and conclude that, provided the fibre bandwidth is several times that of the data rate, digital PPM can outperform commercially available PIN-BJT binary PCM system

The Barbados Insulin Matters (BIM) study: Barriers to insulin therapy among a population-based sample of people with type 2 diabetes in the Caribbean island of Barbados.

AIM: The purpose of this study was to document in people with type 2 diabetes (T2DM) in Barbados, attitudes and beliefs that may result in psychological insulin resistance. METHODS: A representative, population-based, sample of 175 eligible people with T2DM 25 years of age and over was surveyed by telephone. The 20-item insulin treatment appraisal scale (ITAS) was administered (score range 20 to 100 for positive to negative perceptions). RESULTS: 117 people participated (67% response rate, 32% male, mean age 66 years, 90% Black, 22% on insulin). Of non-responders, 52 were not contactable and 6 were difficult to communicate with. Negative perceptions about insulin use included - meant a worsening of diabetes (68%), would worry family (63%), feared self-injection (58%), meant a failure in self-management (57%), injections were painful (54%), would be seen as being sicker (46%), increased hypoglycaemia risk (38%), required effort (34%), causes weight gain (27%), causes a deterioration in health (14%), and would have to give up enjoyable activities (10%). Positive perceptions were - helps good glycaemic control (78%), would prevent complications (61%) and improves health (58%). Mean total ITAS score (61.6, SD = 7.7) was lower for those on insulin compared to those not on insulin (53.7 vs. 63.8, p < 0.0001). Sex, age and diabetes diagnosis duration were not significant predictors of ITAS score. CONCLUSIONS: Multiple factors related to patient beliefs and attitudes need to be considered and addressed when initiating insulin in order to minimise psychological insulin resistance and delay. Patients using insulin had less negative perceptions than those not on insulin

Using nutritional survey data to inform the design of sugar-sweetened beverage taxes in low-resource contexts: a cross-sectional analysis based on data from an adult Caribbean population

Funder: Robinson College, University of CambridgeFunder: Medical Research Council; FundRef: http://dx.doi.org/10.13039/501100000265Funder: British Heart Foundation; FundRef: http://dx.doi.org/10.13039/501100000274Funder: UKCRC Public Health Research Centre of ExcellenceFunder: Economic and Social Research Council; FundRef: http://dx.doi.org/10.13039/501100000269Funder: Cancer Research UK; FundRef: http://dx.doi.org/10.13039/501100000289Funder: Wellcome Trust; FundRef: http://dx.doi.org/10.13039/100004440Funder: Yates Unilever FundFunder: The Ministry of Health of the Government of BarbadosFunder: National Institute for Health Research; FundRef: http://dx.doi.org/10.13039/501100000272Funder: Gates Cambridge PhD ScholarshipFunder: Smuts Memorial Fund, University of Cambridge; FundRef: http://dx.doi.org/10.13039/501100000710Funder: Global Food Security FundFunder: Luca D’Agliano ScholarshipObjective: Sugar-sweetened beverage (SSB) taxes have been implemented widely. We aimed to use a pre-existing nutritional survey data to inform SSB tax design by assessing: (1) baseline consumption of SSBs and SSB-derived free sugars, (2) the percentage of SSB-derived free sugars that would be covered by a tax and (3) the extent to which a tax would differentiate between high-sugar SSBs and low-sugar SSBs. We evaluated these three considerations using pre-existing nutritional survey data in a developing economy setting. Methods: We used data from a nationally representative cross-sectional survey in Barbados (2012–2013, prior to SSB tax implementation). Data were available on 334 adults (25–64 years) who completed two non-consecutive 24-hour dietary recalls. We estimated the prevalence of SSB consumption and its contribution to total energy intake, overall and stratified by taxable status. We assessed the percentage of SSB-derived free sugars subject to the tax and identified the consumption-weighted sugar concentration of SSBs, stratified by taxable status. Findings: Accounting for sampling probability, 88.8% of adults (95% CI 85.1 to 92.5) reported SSB consumption, with a geometric mean of 2.4 servings/day (±2 SD, 0.6, 9.2) among SSB consumers. Sixty percent (95% CI 54.6 to 65.4) of SSB-derived free sugars would be subject to the tax. The tax did not clearly differentiate between high-sugar beverages and low-sugar beverages. Conclusion: Given high SSB consumption, targeting SSBs was a sensible strategy in this setting. A substantial percentage of free sugars from SSBs were not covered by the tax, reducing possible health benefits. The considerations proposed here may help policymakers to design more effective SSB taxes

Barbados Insulin Matters (BIM) study:perceptions on insulin initiation by primary care doctors in the Caribbean island of Barbados

Aims: With regards to insulin initiation in Barbados we explored primary care doctor (PCD) perception, healthcare system factors and predictors of PCD reluctance to initiate insulin. Methods: PCDs completed a questionnaire based on the theory of planned behaviour (TPB) and a reluctance to initiate insulin scale. Using linear regression, we explored the association between TPB domains and the reluctance to initiate insulin scale. Results: Of 161 PCDs, 70% responded (75 private and 37 public sector). The majority felt initiating insulin was uncomplicated (68%) and there was benefit if used before complications developed (68%), but would not use it until absolutely necessary (58%). More private than public sector PCDs (p . </p

Prevalence and phenotype of diabetes and prediabetes using fasting glucose vs HbA1c in a Caribbean population.

BACKGROUND: Both fasting plasma glucose (FPG) and HbA1c are recommended for the diagnosis of diabetes and prediabetes by the American Diabetes Association (ADA), and for diabetes by the World Health Organization. The ADA guidance is influential on clinical practice in many developing countries, including in the Caribbean and Latin America. We aimed to compare the prevalence and characteristics of individuals identified as having diabetes and prediabetes by FPG and HbA1c in a predominantly African ancestry Caribbean population. METHODS: A representative population-based sample of 1234 adults (≥25 years of age) resident in Barbados was recruited. Standard methods with appropriate quality control were used to collect data on height, weight, blood pressure, fasting lipids and history of diagnosed diabetes, and to measure fasting glucose and HbA1c. Those with previously diagnosed diabetes (n = 192) were excluded from the analyses. Diabetes was defined as: FPG ≥7.0 mmol/L or HbA1c ≥6.5%; prediabetes as: FPG ≥5.6 to <7mmol/L or HbA1c ≥5.7 to <6.5%. RESULTS: Complete data were available on 939 participants without previously diagnosed diabetes. The prevalence of undiagnosed diabetes was higher, but not significantly so, by HbA1c (4.9%, 95% CI 3.5, 6.8) vs FPG (3.5%, 2.4, 5.1). Overall 79 individuals had diabetes by either measure, but only 21 on both. The prevalence of prediabetes was higher by HbA1c compared to FPG: 41.7% (37.9, 45.6) vs 15.0% (12.8, 17.5). Overall 558 individuals had prediabetes by either measure, but only 107 on both. HbA1c, but not FPG, was significantly higher in women than men; and FPG, but not HbA1c, was significantly associated with raised triglycerides and low HDL cholesterol. CONCLUSION: The agreement between FPG and HbA1c defined hyperglycaemia is poor. In addition, there are some differences in the phenotype of those identified, and HbA1c gives a much higher prevalence of prediabetes. The routine use of HbA1c for screening and diagnosis in this population would have major implications for clinical and public health policies and resources. Given the lack of robust evidence, particularly for prediabetes, on whether intervention in the individuals identified would improve outcomes, this approach to screening and diagnosis cannot be currently recommended for this population

A cross-sectional study of physical activity and sedentary behaviours in a Caribbean population: combining objective and questionnaire data to guide future interventions

Abstract Background Current understanding of population physical activity (PA) levels and sedentary behaviour in developing countries is limited, and based primarily on self-report. We described PA levels using objective and self-report methods in a developing country population. Methods PA was assessed in a cross-sectional, representative sample of the population of Barbados (25–54 years), using a validated questionnaire (RPAQ) and individually calibrated combined heart rate and movement sensing monitors. The RPAQ collects information on recalled activity in 4 domains: home, work, transport, and leisure. Physical inactivity was defined according to World Health Organization (WHO) guidelines; sedentary lifestyle was defined as being sedentary for 8 h or more daily; PA overestimation was defined as perceiving activity to be sufficient, when classified as ‘inactive’ by objective measurement. Results According to objective estimates, 90.5 % (95 % CI: 83.3,94.7) of women and 58.9 % (48.4,68.7) of men did not accumulate sufficient activity to meet WHO minimum recommendations. Overall, 50.7 % (43.3,58.1) of the population was sedentary for 8 h or more each day, and 60.1 % (52.8,66.9) overestimated their activity levels. The prevalence of inactivity was underestimated by self-report in both genders by 28 percentage points (95 % CI: 18,38), but the accuracy of reporting differed by age group, education level, occupational grade, and overweight/obesity status. Low PA was greater in more socially privileged groups: higher educational level and higher occupational grade were both associated with less objectively measured PA and more sedentary time. Variation in domain-specific self-reported physical activity energy expenditure (PAEE) by educational attainment was observed: higher education level was associated with more leisure activity and less occupational activity. Occupational PA was the main driver of PAEE for women and men according to self-report, contributing 57 % (95 % CI: 52,61). The most popular leisure activities for both genders were walking and gardening. Conclusions The use of both objective and self-report methods to assess PA and sedentary behaviour provides important complementary information to guide public health programmes. Our results emphasize the urgent need to increase PA and reduce sedentary time in this developing country population. Women and those with higher social economic position are particularly at risk from low levels of physical activity

Are there gender differences in acute management and secondary prevention of acute coronary syndromes in Barbados? A cohort study.

OBJECTIVES: In Barbados, high case fatality rates have been reported after myocardial infarction (MI) with higher rates in women than men. To explore this inequality, we examined documented pharmacological interventions for ST-segment elevated myocardial infarction (STEMI), non-STEMI (NSTEMI) and unstable and chronic angina in women and men. DESIGN: Prospective cohort registry data for STEMI and NSTEMI and retrospective chart review for unstable and chronic angina. SETTING: Tertiary care (acute coronary syndromes) and primary care (chronic angina) centres in Barbados. PARTICIPANTS: For the years 2009-2016, a total of 1018 patients with STEMI or NSTEMI were identified via the prospective study. For unstable and chronic angina, 136 and 272 notes were reviewed respectively for the years 2010-2014. OUTCOME MEASURES: The proportions of patients prescribed recommended medication during the first 24 hours after an acute event, at discharge and for chronic care were calculated. Prescribed proportions were analysed by gender after adjustment for age. RESULTS: Between 2009 and 2016, for the acute management of patients with NSTEMI and STEMI, only two (aspirin and clopidogrel) of six drugs had documented prescription rates of 80% or more. Patients with STEMI (n=552) had higher prescription rates than NSTEMI (n=466), with gender differences being more pronounced in the former. Among patients with STEMI, after adjustment for age, diabetes, hypertension and smoking, men were more likely to receive fibrinolytics acutely, OR 2.28 (95% CI 1.24 to 4.21). Compared with men, a higher proportion of women were discharged on all recommended treatments; this was only statistically significant for beta-blockers: age-adjusted OR 1.87 (95% CI 1.16 to 3.00). There were no statistically significant differences in documented prescription of drugs for chronic angina. CONCLUSION: Following acute MI in Barbados, the proportion of patients with documented recommended treatment is relatively low. Although women were less likely to receive appropriate acute care than men, by discharge gender differences were reversed

Ethnic and Gender Disparities in Premature Adult Mortality in Belize 2008-2010.

BACKGROUND: Data on disparities in mortality within low and middle income countries are limited, with little published data from the Caribbean or Central America. Our aim was to investigate disparities in overall and cause specific premature adult mortality in the multi-ethnic middle income country of Belize. METHODS: Mortality data from Belize 2008-2010 classified using the International Classification of Diseases 10 and the 2010 census stratified by age and ethnicity were used to calculate age, sex, and ethnic specific mortality rates for those 15-59 years, and life table analysis was used to estimate the probability of death between the ages of 15 and 59 (45q15). RESULTS: The probability of death among those aged 15 to 59 years was 18.1% (women 13.5%, men 22.7%). Creole and Garifuna ethnic groups have three times the 45q15 probability of death compared to Mayan and Mestizo groups (Creole 31.2%, Garifuna 31.1%, Mayan 10.2%, Mestizo 12.0%). This pattern of ethnic disparity existed in both sexes but was greater in men. The probability of death from injuries was 14.8% among Creole men, more than twice the rate of other ethnicities and peaks among young Creole men. These deaths are dominated by homicides and unspecified deaths involving firearms. CONCLUSIONS: Marked disparities in mortality between ethnic groups exist in this Central American/Caribbean country, from rates that are typical of high-income countries to those of low-income countries. The pattern of these extreme differences likely suggests that they reflect underlying social determinants rooted in the country's colonial past

Trends in beverage prices following the introduction of a tax on sugar-sweetened beverages in Barbados.

A 10% excise tax on sugar sweetened beverages (SSBs) was implemented in Barbados in September 2015. A national evaluation has been established to assess the impact of the tax. We present a descriptive analysis of initial price changes following implementation of the SSB tax using price data provided by a major supermarket chain in Barbados over the period 2014-2016. We summarize trends in price changes for SSBs and non-SSBs before and after the tax using year-on-year mean price per liter. We find that prior to the tax, the year-on-year growth of SSB and non-SSB prices was very similar (approximately 1%). During the quarter in which the tax was implemented, the trends diverged, with SSB price growth increasing to 3% and that of non-SSBs decreasing slightly. The growth of SSB prices outpaced non-SSBs prices in each quarter thereafter, reaching 5.9% compared to <1% for non-SSBs. Future analyses will assess the trends in prices of SSBs and non-SSBs over a longer period and will integrate price data from additional sources to assess heterogeneity of post-tax price changes. A continued examination of the impact of the SSB tax in Barbados will expand the evidence base available to policymakers worldwide in considering SSB taxes as a lever for reducing the consumption of added sugar at the population level.Financial support for the analyses presented in this paper was from the US Center for Disease Control and Prevention (TEPHINET). The full evaluation is receiving support from the Canadian International Development Research Centre (grant no. 107604-001), the Pan American Health Organization. MA is funded through a Gates Cambridge PhD Scholarship. JA is funded by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged

Anthropometric cut-offs to identify hyperglycemia in an Afro-Caribbean population: a cross-sectional population-based study from Barbados.

INTRODUCTION: Body mass index (BMI) and waist circumference (WC) cut-offs associated with hyperglycemia may differ by ethnicity. We investigated the optimal BMI and WC cut-offs for identifying hyperglycemia in the predominantly Afro-Caribbean population of Barbados. RESEARCH DESIGN AND METHODS: A cross-sectional study of 865 individuals aged ≥25 years without known diabetes or cardiovascular disease was conducted. Hyperglycemia was defined as fasting plasma glucose ≥5.6 mmol/L or hemoglobin A1c ≥5.7% (39 mmol/mol). The Youden index was used to identify the optimal cut-offs from the receiver operating characteristic (ROC) curves. Further ROC analysis and multivariable log binomial regression were used to compare standard and data-derived cut-offs. RESULTS: The prevalence of hyperglycemia was 58.9% (95% CI 54.7% to 63.0%). In women, optimal BMI and WC cut-offs (27 kg/m2 and 87 cm, respectively) performed similarly to standard cut-offs. In men, sensitivities of the optimal cut-offs of BMI ≥24 kg/m2 (72.0%) and WC ≥86 cm (74.0%) were higher than those for standard BMI and WC obesity cut-offs (30.0% and 25%-46%, respectively), although with lower specificity. Hyperglycemia was 70% higher in men above the data-derived WC cut-off (prevalence ratio 95% CI 1.2 to 2.3). CONCLUSIONS: While BMI and WC cut-offs in Afro-Caribbean women approximate international standards, our findings, consistent with other studies, suggest lowering cut-offs in men may be warranted to improve detection of hyperglycemia. Our findings do, however, require replication in a new data set.The project was supported by the Ministry of Health of the Government of Barbados. ANW is supported by the Fogarty International Center of the National Institutes of Health under Award Number K43TW010698. This paper describes the views of the authors and does not necessarily represent the official views of the National Institutes of Health (USA)