Healthcare Big Data in Hong Kong: Development and Implementation of Artificial Intelligence-Enhanced Predictive Models for Risk Stratification.

Routinely collected electronic health records (EHRs) data contain a vast amount of valuable information for conducting epidemiological studies. With the right tools, we can gain insights into disease processes and development, identify the best treatment and develop accurate models for predicting outcomes. Our recent systematic review has found that the number of big data studies from Hong Kong has rapidly increased since 2015, with an increasingly common application of artificial intelligence (AI). The advantages of big data are that i) the models developed are highly generalisable to the population, ii) multiple outcomes can be determined simultaneously, iii) ease of cross-validation by for model training, development and calibration, iv) huge numbers of useful variables can be analyzed, v) static and dynamic variables can be analyzed, vi) non-linear and latent interactions between variables can be captured, vii) artificial intelligence approaches can enhance the performance of prediction models. In this paper, we will provide several examples (cardiovascular disease, diabetes mellitus, Brugada syndrome, long QT syndrome) to illustrate efforts from a multi-disciplinary team to identify data from different modalities to develop models using territory-wide datasets, with the possibility of real-time risk updates by using new data captured from patients. The benefit is that only routinely collected data are required for developing highly accurate and high-performance models. AI-driven models outperform traditional models in terms of sensitivity, specificity, accuracy, area under the receiver operating characteristic and precision-recall curve, and F1 score. Web and/or mobile versions of the risk models allow clinicians to risk stratify patients quickly in clinical settings, thereby enabling clinical decision-making. Efforts are required to identify the best ways of implementing AI algorithms on the web and mobile apps.

Morbimortality and determinants of reperfusion in ischemic stroke

SUMMARY BACKGROUND: Cerebrovascular accident (or stroke) and ischemic heart disease are the the major causes of death in the world. It is estimated that about 85% of strokes are ischemic in origin. Reperfusion therapy in the acute phase of ischemic stroke with a recombinant human tissue plasminogen activator is effective, but some factors influence the success of this treatment. OBJECTIVE: The aim of this study was to evaluate clinical aspects and possible determinants for reperfusion after venous thrombolysis. METHODS: This is a retrospective, cross-sectional, observational study based on a review of hospital records of inpatients diagnosed with ischemic stroke treated with intravenous thrombolysis, the main outcome being reperfusion or not. RESULTS: Data from this study revealed a predominance of females in the group of reperfused patients and males in the non-reperfused group, both maintaining moderate severity on the National Institutes of Health Stroke Scale and admission without statistical significance (p>0.18). In addition, the mean admission severity score was 13.2 for the group of reperfused patients and 14.2 for those not reperfused, and the mean ejection fraction of both groups was within normal functionality, with a mean of 0.50 for reperfused patients and 0.62 for non-reperfused patients. CONCLUSION: We found an association between successful venous chemical thrombolysis reperfusion and lower mortality in patients with acute stroke.

Impact of exergames on bmi and cardiovascular risk factors: a systematic review / Impacto de exergames sobre imc y los factores de riesgo cardiovascular: revisión sistemática / Impacto de exergames no imc e fatores de risco cardiovascular: uma revisão sistemática

ABSTRACT Introduction: Exergames or active video games are digital platforms with functionality associated with body movement, which dialogue with improving physical activity levels, stimulating pleasure in practice and adherence to change habits, physically active behavior, and better quality of life. Objective: This study aimed to synthesize the available evidence on the contribution of exergame to Body Mass Index, physical activity level, glycemic control, blood pressure, and cardiorespiratory fitness in adolescents. Methods: This is a systematic review, reported following the PRISMA writing recommendations, without language restrictions, for articles indexed in the following databases: MEDLINE / PubMed, Embase, Cochrane Library, and Lilacs. Data extraction was performed analogously in a spreadsheet previously tested and standardized. The assessment of the risk of bias in the included studies was carried out by the RoB 1.0 tool in all of its domains in duplicate of reviewers. Initially, 3.039 studies were found. Results: The studies cover a total of 526 adolescents aged ten to 19. The most used platform in the studies was the Nintendo Wii, followed by the PlayStation, Xbox 360, and Dance Dance Revolution. The results indicated that interventions using exergames were effective for changing BMI, but there was no evidence on cardiovascular outcomes, with no effective changes in glycemic control and blood pressure and a significant response (p <0.05) in cardiorespiratory fitness. Conclusion: The exergame points to satisfactory results in improving health and can be incorporated as a relevant public policy in the adolescent health promotion. (PROSPERO Registration CRD42020181772). Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMEN Introducción: Los Exergames o videojuegos activos son plataformas digitales con funcionalidad asociada al movimiento corporal, que dialogan con la mejora de los niveles de actividad física, estimulando el placer en la práctica y la adherencia a cambios de hábitos, conducta físicamente activa y mejor calidad de vida. Objetivo: Este estudio tuvo como objetivo sintetizar la evidencia disponible sobre la contribución del exergame al índice de masa corporal, nivel de actividad física, control glucémico, presión arterial y aptitud cardiorrespiratoria en adolescentes. Métodos: Se trata de una revisión sistemática, reportada siguiendo las recomendaciones de redacción de PRISMA, sin restricción de idioma, para artículos indexados en las siguientes bases de datos: MEDLINE / PubMed, Embase, Cochrane Library y Lilacs. La extracción de datos se realizó de manera similar en una hoja de cálculo estandarizada y probada previamente. La evaluación del riesgo de sesgo en los estudios incluidos se realizó mediante la herramienta RoB 1.0 en todos sus dominios por duplicado de revisores. Inicialmente, se encontraron 3.039 estudios. Resultados: Los estudios abarcaron un total de 526 adolescentes de 10 a 19 años. La plataforma más utilizada en estudios fue la Nintendo Wii, seguida de la PlayStation, Xbox 360 y Dance Dance Revolution. Los resultados indicaron que las intervenciones con exergames fueron efectivas para cambiar el IMC, pero no hubo evidencia sobre los resultados cardiovasculares, no hubo cambios efectivos en el control glucémico y la presión arterial, y una respuesta explicativa (p <0.05) en la aptitud cardiorrespiratoria. Conclusión: El exergame muestra resultados satisfactorios en la mejora de la salud y puede ser incorporado como una política pública relevante en la promoción de la salud de los adolescentes. (Registro PROSPERO CRD42020181772). Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

RESUMO Introdução: Exergames ou vídeo games ativos são plataformas digitais com funcionalidade associada ao movimento corporal, que dialogam com a melhora dos níveis de atividade física, estimulando o prazer na prática e a adesão à mudança de hábitos, comportamento ativo e melhor qualidade de vida. Objetivo: Este estudo teve como objetivo sintetizar as evidências disponíveis sobre a contribuição do exergame para o Índice de Massa Corporal, nível de atividade física, controle glicêmico, pressão arterial e aptidão cardiorrespiratória em adolescentes. Métodos: Trata-se de uma revisão sistemática, relatada seguindo as recomendações de redação do PRISMA, sem restrição de idioma, para artigos indexados nas seguintes bases de dados: MEDLINE / PubMed, Embase, Cochrane Library e Lilacs. A extração dos dados foi realizada de forma análoga em planilha previamente testada e padronizada. A avaliação do risco de viés nos estudos incluídos foi realizada pela ferramenta RoB 1.0 em todos os seus domínios em duplicata de revisores. Inicialmente, foram encontrados 3.039 estudos. Resultados: Os estudos abrangeram um total de 526 adolescentes de dez a 19 anos. A plataforma mais utilizada nos estudos foi o Nintendo Wii, seguido do PlayStation, Xbox 360 e Dance Dance Revolution. Os resultados indicaram que as intervenções com exergames foram eficazes para alterar o IMC, mas não houve evidências sobre os desfechos cardiovasculares, sem alterações eficazes no controle glicêmico e na pressão arterial e uma resposta significativa (p <0,05) na aptidão cardiorrespiratória. Conclusão: O exergame aponta resultados satisfatórios na melhoria da saúde e pode ser incorporado como uma política pública relevante na promoção da saúde do adolescente. (Registro PROSPERO CRD42020181772). Nível de evidência II; Estudos terapêuticos: investigação dos resultados do tratamento.

Effect of Mobilization with Movement on Pain, Disability, and Range of Motion in Patients with Shoulder Pain and Movement Impairment: A Systematic Review and Meta-Analysis.

BACKGROUND: Shoulder pain is a disabling musculoskeletal disorder worldwide. Thus, it is important to identify interventions able to improve pain and disability. OBJECTIVE: To investigate the effects of mobilization with movement (MWM) on pain, disability, and range of motion in patients with shoulder pain and movement impairment. METHODS: A systematic search of different databases was performed. The systematic review protocol has been registered in PROSPERO (CRD42023404128). A random-effects model for meta-analysis was used to determine the mean difference (MD), standardized mean differences (SMD), and 95% confidence interval for the outcome of interest. RESULTS: Twenty-six studies were included. Of these, eighteen were included in the meta-analysis. MWM improved pain during movement with a moderate effect SMD of (-0.6; 95% confidence interval, -1.1 to -0.1, I2 = 0%; N = 66;) and shoulder abduction MD of (12.7°; 1.3 to 24.0; I2 = 73%; N = 90) compared to sham MWM in the short term (0-6 weeks). Combined MWM and conventional rehabilitation improved pain at rest, with a MD of (-1.2; -2.2 to -0.2; I2 = 61%; N = 100), and disability SMD of (-1.3; confidence interval -2.2 to -0.4; I2 = 87%; N = 185) compared to conventional rehabilitation alone in the short term. Combined MWM and conventional rehabilitation also resulted in improvement in shoulder abduction and external rotation. Compared to Maitland, MWM resulted in improvement in the shoulder abduction MD (20.4°; confidence interval 4.3 to 36.5; I2 = 89%; N = 130) in the short term. There is no information regarding long-term effects. CONCLUSION: Evidence suggests that MWM may reduce shoulder pain and restore shoulder range of motion and function. Our findings are promising, but the evidence is not strong enough to recommend it pragmatically.

University indigenous students' perspectives on climate change and survival of indigenous peoples in Brazil: a concept mapping study.

Introduction: This study aimed to identify what indigenous university students in Brazil perceived to be important and feasible actions to protect the survival of indigenous peoples from climate change-related impacts. Methods: Concept mapping, which is a participatory mixed methodology, was conducted virtually with 20 indigenous students at two universities in Brazil. A focus prompt was developed from consultations with indigenous stakeholders and read "To protect the survival of the Indigenous Peoples from climate change, it is necessary to…". Students brainstormed 46 statements, which they then sorted into clusters based on conceptual similarity. They rated each statement for importance and feasibility. Quantitative multivariate analyses of clusters and ratings were conducted to produce multiple visual maps of perceived actionable priorities. These analyses used the Group Wisdom TM software. Results: Students agreed on 8 clusters that reflect the factors that influence the survival of indigenous peoples-preservation of lands 0.16 (SD 0.13), protection of demarcated lands 0.31 (SD 0.10), indigenous health and wellbeing 0.35 (SD 0.14), ancestral customs 0.46 (SD 0.04), global and national actions 0.61 (SD 0.13), indigenous rights 0.64 (SD 0.23), collective living 0.71 (SD 0.21), and respect 0.75 (SD 0.14). Discussion: The most actionable priorities are related to the respect for their lands and customs, educational initiatives in schools about the importance of indigenous peoples to society, guarantees for basic health rights, and culturally appropriate provision of care, with specific mention of mental healthcare. The findings aligned closely with the concept of indigenous self-determination, which is rooted in autonomy and respect for cultural diversity, and the right to make decisions that impact their lives, land, and resources.

Morbimortality and determinants of reperfusion in ischemic stroke.

BACKGROUND: Cerebrovascular accident (or stroke) and ischemic heart disease are the the major causes of death in the world. It is estimated that about 85% of strokes are ischemic in origin. Reperfusion therapy in the acute phase of ischemic stroke with a recombinant human tissue plasminogen activator is effective, but some factors influence the success of this treatment. OBJECTIVE: The aim of this study was to evaluate clinical aspects and possible determinants for reperfusion after venous thrombolysis. METHODS: This is a retrospective, cross-sectional, observational study based on a review of hospital records of inpatients diagnosed with ischemic stroke treated with intravenous thrombolysis, the main outcome being reperfusion or not. RESULTS: Data from this study revealed a predominance of females in the group of reperfused patients and males in the non-reperfused group, both maintaining moderate severity on the National Institutes of Health Stroke Scale and admission without statistical significance (p>0.18). In addition, the mean admission severity score was 13.2 for the group of reperfused patients and 14.2 for those not reperfused, and the mean ejection fraction of both groups was within normal functionality, with a mean of 0.50 for reperfused patients and 0.62 for non-reperfused patients. CONCLUSION: We found an association between successful venous chemical thrombolysis reperfusion and lower mortality in patients with acute stroke.

Climate change and mental health of Indigenous peoples living in their territory: a concept mapping study.

Background: The alarming increase in annual deforestation rates has had devastating consequences in climate change, and it is affecting Indigenous people, who depend entirely on the land for survival and has also weakened the rainforest's crucial role in stabilizing the global climate. Recognizing and respecting Indigenous people's needs and social, economic, and historical conditions influence health and healthcare. This study aimed to conduct online concept mapping workshops with university students to identify perceived important and feasible actions for improving the mental health of Indigenous people living in their territory in association with climate change. Methods: Concept mapping, a participatory mixed methodology, was conducted virtually with 20 Indigenous students at two universities in Brazil. A focus prompt was developed from consultations with Indigenous stakeholders and read-"To improve the mental health of Indigenous peoples in their territory during climate change crises, it is necessary to…." Results: University students organized 42 unique statements in 6 clusters that cover a wide range of topics: family support, 0.68 (SD 0.19); respect and understanding, 0.37 (SD 0.08); improvement actions, 0.52 (SD 0.07); public policies in favor of Indigenous people's mental health, 0.24 (0.09); health actions, 0.15 (SD 0.08); Indigenous training in health and its importance in improving mental health 0.32 (SD 0.07). Conclusion: These clusters range from community initiatives, public policies, health actions, and strengthening professional services in Indigenous communities. These all provide numerous concrete ideas for developing interventions designed to address mental health challenges associated with climate change.

Dysglycemia and arrhythmias.

Disorders in glucose metabolism can be divided into three separate but interrelated domains, namely hyperglycemia, hypoglycemia, and glycemic variability. Intensive glycemic control in patients with diabetes might increase the risk of hypoglycemic incidents and glucose fluctuations. These three dysglycemic states occur not only amongst patients with diabetes, but are frequently present in other clinical settings, such as during critically ill. A growing body of evidence has focused on the relationships between these dysglycemic domains with cardiac arrhythmias, including supraventricular arrhythmias (primarily atrial fibrillation), ventricular arrhythmias (malignant ventricular arrhythmias and QT interval prolongation), and bradyarrhythmias (bradycardia and heart block). Different mechanisms by which these dysglycemic states might provoke cardiac arr-hythmias have been identified in experimental studies. A customized glycemic control strategy to minimize the risk of hyperglycemia, hypoglycemia and glucose variability is of the utmost importance in order to mitigate the risk of cardiac arrhythmias.

Secular trends of health care resource utilization and costs between Brugada syndrome and congenital long QT syndrome: A territory-wide study.

BACKGROUND: Health care resource utilization (HCRU) and costs are important metrics of health care burden, but they have rarely been explored in the setting of cardiac ion channelopathies. HYPOTHESIS: This study tested the hypothesis that attendance-related HCRUs and costs differed between patients with Brugada syndrome (BrS) and congenital long QT syndrome (LQTS). METHODS: This was a retrospective cohort study of consecutive BrS and LQTS patients at public hospitals or clinics in Hong Kong, China. HCRUs and costs (in USD) for Accident and Emergency (A&E), inpatient, general outpatient and specialist outpatient attendances were analyzed between 2001 and 2019 at the cohort level. Comparisons were made using incidence rate ratios (IRRs [95% confidence intervals]). RESULTS: Over the 19-year period, 516 BrS (median age of initial presentation: 51 [interquartile range: 38-61] years, 92% male) and 134 LQTS (median age of initial presentation: 21 [9-44] years, 32% male) patients were included. Compared to LQTS patients, BrS patients had lower total costs (2 008 126 [2 007 622-2 008 629] vs. 2 343 864 [2 342 828-2 344 900]; IRR: 0.857 [0.855-0.858]), higher costs for A&E attendances (83 113 [83 048-83 177] vs. 70 604 [70 487-70 721]; IRR: 1.177 [1.165-1.189]) and general outpatient services (2,176 [2,166-2,187] vs. 921 [908-935]; IRR: 2.363 [2.187-2.552]), but lower costs for inpatient stay (1 391 624 [1 391 359-1 391 889] vs. 1 713 742 [1 713 166-1 714 319]; IRR: 0.812 [0.810-0.814]) and lower costs for specialist outpatient services (531 213 [531 049-531 376] vs. 558 597 [558268-558926]; IRR: 0.951 [0.947-0.9550]). CONCLUSIONS: Overall, BrS patients consume 14% less health care resources compared to LQTS patients in terms of attendance costs. BrS patients require more A&E and general outpatient services, but less inpatient and specialist outpatient services than LQTS patients.

Virtual medical research mentoring.

BACKGROUND: Medical research is important for professional advancement, and mentoring is a key means by which students and early-career doctors can engage in research. Contrasting international research collaborations, research mentoring programmes are often geographically limited. As the COVID-19 pandemic has led to increased use of online technology for classes and conferences, a virtual, international approach to medical research mentoring may be valuable. APPROACH: We hereby describe our experience at the Cardiovascular Analytics Group, a virtual international medical research mentoring group established in 2015. We make use of virtual platforms in multi-level mentoring with peer mentoring and emphasise active participation, early leadership, an open culture, accessible research support and a distributed research workflow. EVALUATION: With 63 active members from 14 different countries, the Group has been successful in training medical students and early-career medical graduates in academic medicine. Our members have led over 100 peer-reviewed publications of original research and reviews since 2015, winning 13 research prizes during this time. IMPLICATIONS: Our accessible-distributed model of virtual international medical research collaboration and multi-level mentoring is viable and efficient and caters to the needs of contemporary healthcare. Others should consider building similar models to improve medical research mentoring globally.

Ophthalmic artery Doppler in the complementary diagnosis of preeclampsia: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the accuracy of different parameters of the ophthalmic artery Doppler (OAD) in the complementary diagnosis of preeclampsia (PE). METHODS: This meta-analysis adhered to the PRISMA guidelines. To investigate the mean difference in OAD values, peak systolic velocity (PSV), end-diastolic velocity (EDV), second systolic velocity peak (P2), resistance index (RI), pulsatility index (PI), and peak ratio (PR), between PE cases (overall and according to severity) and controls, random-effects meta-analyses were conducted for each Doppler parameter, with overall PE and mild and severe PE subgroups. Diagnostic performance and heterogeneity were evaluated with summary receiver operating characteristic (sROC) curves and 95% confidence intervals obtained with bivariate models. RESULTS: Eight studies stratified the results into mild and severe or late and early PE, involving 1,425 pregnant women. PR and P2 had better diagnostic performance than the other indexes, with the PR of AUsROC at 0.885, the sensitivity of 84%, and specificity of 92%, with a low false-positive rate of 0.08 and the P2 with AUsROC of 0.926, the sensitivity of 85% and specificity of 88%. RI, PI, and EDV showed good performance and consistency across studies but lower AUsROC values of 0.833, 0.794, and 0.772, respectively. CONCLUSION: Ophthalmic artery Doppler is a complementary tool with good performance for the diagnosis of overall and severe preeclampsia, with high and best sensitivity and specificity when using PR and P2 parameters.

Long-term consequences of COVID-19 on mental health and the impact of a physically active lifestyle: a narrative review.

BACKGROUND: Coronavirus-19 disease (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Respiratory viruses damage not only the upper respiratory tract in humans, but also several different organs such as the brain. Some of the neurological consequences of COVID-19 reported are anosmia, headache, stroke, declined cognitive function, and impaired mental health, among others. People who had COVID-19 have a higher risk of sequelae in the central nervous system (CNS). However, it is not known which are all possible sequelae and how long will last the long-term effects of the COVID-19 pandemic on behavioral patterns and quality of life. AIM: We intend to address the long-term impacts of COVID-19 on mental health and the relevance of physical exercise during the pandemic. METHODS: We conducted a literature search using PubMed to find the articles that were related to these themes. RESULTS: We found 23,489 papers initially, and then we applied the inclusion/exclusion criteria to narrow down our search to 3617 articles and selected 1380 eligible articles after a thorough reading of titles and abstracts. The findings indicated that COVID-19 impacted general mental health and led many not only hospitalized patients to develop cognitive decline, memory impairment, anxiety, sleep alterations, and depressive-like behavior. Furthermore, the fear of vaccines and their effects had negatively affected mental health and directly impacted mortality rates in unvaccinated COVID-19 patients. CONCLUSIONS: Preventive measures must be undertaken, such as the vaccination of the entire population, vaccination hesitancy discouragement by creating awareness among individuals, and people's engagement in a physically active lifestyle, since being physically active is a low-cost and effective measure to restore or inhibit the negative outcomes from COVID-19 on mental health.

Burden of disease due to amphetamines, cannabis, cocaine, and opioid use disorders in South America, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019.

BACKGROUND: South America's substance use profile, poverty, income inequality, and cocaine-supplier role make it a unique place for substance use research. This study investigated the burden of disease attributable to amphetamine use disorder, cannabis use disorder (CAD), cocaine use disorder, and opioid use disorder (OUD) in South America from 1990 to 2019, on the basis of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. METHODS: GBD 2019 estimated the incidence, prevalence, mortality, years of life lost (YLL), years of life lived with disability (YLD), and disability-adjusted life-years (DALYs) due to substance use disorders in each of the 12 South American countries (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela). Data were modelled using standardised tools (ie, the Cause of Death Ensemble model, spatio-temporal Gaussian process regression, and disease modelling meta-regression) to generate estimates of each quantity of interest by sex, location, and year. The analysis included comparisons by sex and country, and against regional and global estimates. FINDINGS: In 2019, the highest amphetamine use disorder burden per 100 000 population in South America was in Peru (66 DALYs). CAD DALY rates per 100 000 in South America were stable between 1990 and 2019, except in Chile and Colombia, which had the highest rates in 2019 (19 DALYs for Chile and 18 DALYs for Colombia). OUD DALYs per 100 000 increased during the period in Brazil and Peru, which in 2019 had the highest rates in South America (82 DALYs for Brazil and 70 DALYs for Peru). In 2019, Brazil had the highest cocaine use disorder DALYs per 100 000 (45 DALYs), nearly double its rate in 1990. DALY rates were higher in males than females for each substance use disorder, except in Paraguay. The overall burden of substance use disorders was higher in males than in females, mainly because of cocaine use disorder and CAD, whereas for amphetamine use disorder, the difference between sexes was minimal, and for OUD there was no difference. For males and females, the highest rate of substance use disorders DALYs per 100 000 was for OUD except in Argentina (in males, 58 DALYs for cocaine use disorder vs 52 DALYs for OUD) and in Paraguay (in females, 77 for amphetamine use disorder vs 50 for OUD). CAD DALY rates were generally the lowest among the substance use disorders for males and females. Amphetamine use disorder YLD rates were reasonably stable throughout the period and were highest in Peru, Paraguay, and Uruguay (>40 YLD per 100 000). For CAD, YLD rates were stable in all countries except Chile and Colombia. Cocaine use disorder YLD rates per 100 000 for the top four countries (Argentina, Uruguay, Chile, and Brazil) increased from 1990 to 2010 (eg, from 19 to 33 in Brazil), but decreased between 2010 and 2019 (eg, from 36 to 31 in Chile). For OUD, YLD rates showed a slight increase in most countries apart from Brazil, which increased from 52 in 1990 to 80 in 2019 and was top among the countries. Amphetamine use disorder YLL rates per 100 000 were highest in Suriname and Peru during the period, although in Suriname it increased from 2·7 in 2010 to 3·2 in 2019, whereas in Peru it decreased from 2·1 to 1·7. The highest YLL rate for cocaine use disorder was in Brazil, which increased from 3·7 in 1990 to 18·1 in 2019. Between 2000 and 2019, Chile and Uruguay showed the highest OUD YLL rates (11·6 for Chile and 10·9 for Uruguay). A high incidence of CAD was found in Chile, Colombia, Guyana, and Suriname. There were high incidences of amphetamine use disorder in Paraguay, cocaine use disorder in Argentina, and OUD in Ecuador. A decrease in annual prevalence for substance use disorders during the period was observed in Venezuela (amphetamine use disorder, CAD, and OUD), Brazil (CAD and amphetamine use disorder), Colombia (amphetamine use disorder and cocaine use disorder), Peru (amphetamine use disorder and cocaine use disorder), Chile and Suriname (amphetamine use disorder), Uruguay (CAD), and Bolivia (OUD). Overall, the cocaine use disorder burden stabilised then decreased. OUD was less prevalent than other substance use disorders but its burden was the highest. INTERPRETATION: The decrease in the burden of cocaine use disorder probably reflects the success of national standardised treatment programmes. Programmes for amphetamine use disorder, CAD, and OUD management should be improved. We did not find an increase in CAD burden in Uruguay, the country with the highest degree of cannabis decriminalisation in the region. Countries in South America should improve monitoring of substance use disorders, including regular surveys to provide more accurate data on which to base policy decisions. FUNDING: The Bill & Melinda Gates Foundation.