Impact of incorporating echocardiographic screening into a clinical prediction model to optimise utilisation of echocardiography in primary care.

INTRODUCTION: Access to public subspecialty healthcare is limited in underserved areas of Brazil, including echocardiography (echo). Long waiting lines and lack of a prioritisation system lead to diagnostic lag and may contribute to poor outcomes. We developed a prioritisation tool for use in primary care, aimed at improving resource utilisation, by predicting those at highest risk of having an abnormal echo, and thus in highest need of referral. METHODS: All patients in the existing primary care waiting list for echo were invited for participation and underwent a clinical questionnaire, simplified 7-view echo screening by non-physicians with handheld devices, and standard echo by experts. Two derivation models were developed, one including only clinical variables and a second including clinical variables and findings of major heart disease (HD) on echo screening (cut point for high/low-risk). For validation, patients were risk-classified according to the clinical score. High-risk patients and a sample of low-risk underwent standard echo. Intermediate-risk patients first had screening echo, with a standard echo if HD was suspected. Discrimination and calibration of the two models were assessed to predict HD in standard echo. RESULTS: In derivation (N = 603), clinical variables associated with HD were female gender, body mass index, Chagas disease, prior cardiac surgery, coronary disease, valve disease, hypertension and heart failure, and this model was well calibrated with C-statistic = 0.781. Performance was improved with the addition of echo screening, with C-statistic = 0.871 after cross-validation. For validation (N = 1526), 227 (14.9%) patients were classified as low risk, 1082 (70.9%) as intermediate risk and 217 (14.2%) as high risk by the clinical model. The final model with two categories had high sensitivity (99%) and negative predictive value (97%) for HD in standard echo. Model performance was good with C-statistic = 0.720. CONCLUSION: The addition of screening echo to clinical variables significantly improves the performance of a score to predict major HD.

Health Education about Rheumatic Heart Disease: A Community-Based Cluster Randomized Trial: Rheumatic Heart Disease Educational Strategies.

Introduction: The burden of rheumatic heart disease (RHD) is still high in Brazil. Lack of population awareness about the disease limits the efficacy of prevention programs. We aimed to evaluate the effectiveness of education on RHD in schools, comparing the conventional expository teaching method with tablet-based worked examples. Method: A prospective, cluster randomized trial was conducted over eight months in six randomly selected low-income Brazilian public schools. Each class was considered a cluster (total: 90), being randomized 1:1 to receive one of the educational methods. Pre-test evaluated students' prior knowledge on RHD. Post-tests, 10 days, and three months later, evaluated retention of knowledge. Results: At total 1,301 students (52% female) completed the study, being 63% from high school. Baseline knowledge about RHD was universally low (average score expository classes [G1] 33.9% vs. worked examples [G2] 32.5%, p = 0.23). A significant but similar improvement was observed in both groups in the immediate post-test (pre- vs. post: p < 0.001): G1 57.5% vs. G2 56.7%, p = 0.69. In the late post-test, a significant 20% worsening was observed in both groups and the final scores were again similar: G1 45.0% vs. G2 45.9%, p = 0.87. Highschool students had higher scores (p < 0.001), and girls had better overall performances than boys (p < 0.001). Conclusion: The novel technology of tablet-based worked examples had similar results compared with expository classes for RHD education in schools. Both educational processes resulted in modest gains in knowledge, with low retention. More studies are needed to determine if increased knowledge leads to behavioral changes that could reduce RHD burden. Highlights: In a cluster-randomized trial, two different educational strategies about Rheumatic Heart Disease (RHD) for children - standard expository classes and worked examples based on interactive modules in tablet computers - were compared in public schools of underserved Brazilian neighborhoods.Baseline knowledge was low, and the novel tablet-based technology had similar results compared with traditional teaching for RHD education in schools, with no differences in acquisition and mid-term retention of knowledge.Both educational interventions resulted in similar 71% improvement in the immediate post-test, although with suboptimal retention, with over 20% worsening in three months in both groups.Our data suggests that the optimal strategy for RHD education is yet to be determined, and future studies should be warranted to determine if increased knowledge leads to behavioral changes that could reduce disease burden in endemic areas.

Cost-Effectiveness of Rheumatic Heart Disease Echocardiographic Screening in Brazil: Data from the PROVAR+ Study: Cost-effectiveness of RHD screening in Brazil.

Introduction: In recent years, new technologies - noticeably ultra-portable echocardiographic machines - have emerged, allowing for Rheumatic Heart Disease (RHD) early diagnosis. We aimed to perform a cost-utility analysis to assess the cost-effectiveness of RHD screening with handheld devices in the Brazilian context. Methods: A Markov model was created to assess the cost-effectiveness of one-time screening for RHD in a hypothetical cohort of 11-year-old socioeconomically disadvantaged children, comparing the intervention to standard care using a public perspective and a 30-year time horizon. The model consisted of 13 states: No RHD, Undiagnosed Asymptomatic Borderline RHD, Diagnosed Asymptomatic Borderline RHD, Untreated Asymptomatic Definite RHD, Treated Asymptomatic Definite RHD, Untreated Mild Clinical RHD, Treated Mild Clinical RHD, Untreated Severe Clinical RHD, Treated Severe Clinical RHD, Surgery, Post-Surgery and Death. The initial distribution of the population over the different states was derived from primary echo screening data. Costs of the different states were derived from the Brazilian public health system database. Transition probabilities and utilities were derived from published studies. A discount rate of 3%/year was used. A cost-effectiveness threshold of $25,949.85 per Disability Adjusted Life Year (DALY) averted is used in concordance with the 3x GDP per capita threshold in 2015. Results: RHD echo screening is cost-effective with an Incremental Cost-Effectiveness Ratio of $10,148.38 per DALY averted. Probabilistic modelling shows that the intervention could be considered cost-effective in 70% of the iterations. Conclusion: Screening for RHD with hand held echocardiographic machines in 11-year-old children in the target population is cost-effective in the Brazilian context. Highlights: A cost-effectiveness analysis showed that Rheumatic Heart Disease (RHD) echocardiographic screening utilizing handheld devices, performed by non-physicians with remote interpretation by telemedicine is cost-effective in a 30-year time horizon in Brazil.The model included primary data from the first large-scale RHD screening program in Brazilian underserved populations and costs from the Unified Health System (SUS), and suggests that the Incremental Cost-Effectiveness Ratio of the intervention is considerably below the acceptable threshold for Brazil, even after a detailed sensitivity analysis.Considering the high prevalence of subclinical RHD in Brazil, and the significant economic burden posed by advanced disease, these data are important for the formulation of public policies and surveillance approaches.Cost-saving strategies first implemented in Brazil by the PROVAR study, such as task-shifting to non-physicians, computer-based training, routine use of affordable devices and telemedicine for remote diagnosis may help planning RHD control programs in endemic areas worldwide.

Atrial fibrillation detection with a portable device during cardiovascular screening in primary care.

INTRODUCTION: A novel handheld dual-electrode stick is a portable atrial fibrillation (AF) screening device (AFSD). We evaluated AFSD performance in primary care patients referred for echocardiogram (echo). METHODS: The AFSD has a light indication of irregular rhythm and single-lead ECG recording. Patients were instructed to hold the device for 1 min, and AF indication was recorded. A 12-lead ECG was performed for all AFSD-positive patients and 250 patients with negative AFSD screen. Echos were performed based on a clinical risk score: all high-risk patients and a sampling of low-risk patients underwent complete echo. Intermediate risk patients first had a screening echocardiogram, with a follow-up complete study if abnormality was suspected. RESULTS: In 5 days, 1518 patients underwent clinical evaluation and cardiovascular risk stratification: mean age 58±16 years, 66% women. The AFSD was positive in 6.4%: 12.6% high risk, 6.1% intermediate risk and 2.2% low risk. Older age was a risk factor (9.3% vs 4.8% in those more than and less than 65 years, p=0.001). AFSD positive was independently associated with heart disease in echo (OR=3.9, 95% CI 2.1 to 7.2, p<0.001). Compared with 12-lead ECG, the AFSD had sensitivity of 90.2% (95% CI 77.0% to 97.3%) and specificity of 84.0% (95% CI 79.3% to 88.0%) for AF detection. CONCLUSION: AFSD demonstrated high sensitivity for AF detection in primary care patients referred for echo. AF prevalence was substantial and independently associated with structural or functional heart disease, suggesting that AFSD screening could be a useful primary care tool to stratify risk and prioritise echo.