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Bruce Neal - One of the best experts on this subject based on the ideXlab platform.
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feasibility and validity of using death surveillance data and smartva for fact and cause of death in clinical trials in rural china a substudy of the china Salt Substitute and stroke study ssass
Journal of Epidemiology and Community Health, 2021Co-Authors: Liping Huang, Xuejun Yin, Zhixin Hao, Lijing L Yan, Bruce Neal, Yishu Liu, Rohina JoshiAbstract:Background In rural China, mortality surveillance data may be an alternative to primary data collection in clinical trials; SmartVA (verbal autopsy) is also a potential alternative for endpoint adjudication. The feasibility and validity of both need to be assessed. Methods We used mortality data from the first 24 months of the China Salt Substitute and Stroke Study (SSaSS) trial and assessed the agreement between (1) mortality surveillance data and face-to-face visits for fact of death; (2) mortality surveillance data and SSaSS adjudication for causes of death; (3) SmartVA and SSaSS adjudication for causes of death; (4) cause-specific mortality fraction of different methods. Face-to-face visits and SSaSS adjudication were taken as reference methods. The agreement was measured by sensitivity, specificity and positive predictive value (PPV) across different 10th Revision of International Statistical Classification of Diseases chapters. Results One thousand three hundred and sixty-five deaths were included. Mortality surveillance data had 82% sensitivity for fact of death and 81% sensitivity for causes of death, with substantial variances across different disease types and reasonable quality for circulatory death (91% sensitivity and 94% PPV). The sensitivity of SmartVA for causes of death was 61%, with reasonable quality for deaths of external causes of morbidity (90% sensitivity). The leading causes of death from different sources were the same with some variances in the fractions. Conclusion Using mortality surveillance data for fact of death in clinical trials need to account for under-reporting. A face-to-face visit to all participants at the completion of trials may be warranted. Neither mortality surveillance data nor SmartVA provided valid data source for endpoint events.
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rationale design and baseline characteristics of the Salt Substitute and stroke study ssass a large scale cluster randomized controlled trial
American Heart Journal, 2017Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Lijing L Yan, Bruce Neal, Paul Elliott, Darwin R Labarthe, Zhixin HaoAbstract:Abstract Lowering sodium intake with a reduced-sodium, added potassium Salt Substitute has been proved to lower blood pressure levels. Whether the same strategy will also reduce the risks of vascular outcomes is uncertain and controversial. The SSaSS has been designed to test whether sodium reduction achieved with a Salt Substitute can reduce the risk of vascular disease. The study is a large-scale, open, cluster-randomized controlled trial done in 600 villages across 5 provinces in China. Participants have either a history of stroke or an elevated risk of stroke based on age and blood pressure level at entry. Villages were randomized in a 1:1 ratio to intervention or continued usual care. Salt Substitute is provided free of charge to participants in villages assigned to the intervention group. Follow-up is scheduled every 6months for 5years, and all potential endpoints are reviewed by a masked adjudication committee. The primary end point is fatal and nonfatal stroke, and the 2 secondary endpoints are total major cardiovascular events and total mortality. The study has been designed to provide 90% statistical power (with 2-sided α = .05) to detect a 13% or greater relative risk reduction for stroke. The power estimate assumes a primary outcome event rate of 3.5% per year and a systolic blood pressure difference of 3.0mm Hg between randomized groups. Recruitment is complete and there are 20,996 participants (about 35 per village) that have been enrolled. Mean age is 65years and 49% are female. There were 73% enrolled on the basis of a history of stroke. The trial is well placed to describe the effects of Salt substitution on the risks of vascular disease and death and will provide important policy-relevant data.
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effects of Salt Substitute on pulse wave analysis among individuals at high cardiovascular risk in rural china a randomized controlled trial
Hypertension Research, 2009Co-Authors: Xiong Jing Jiang, Liancheng Zhao, Vlado Perkovic, Bai Ling Chen, Bruce NealAbstract:Reduced-sodium, increased-potassium Salt Substitutes lower blood pressure but may also have direct effects on vascular structure and arterial function. This study aimed to test the effects of long-term Salt substitution on indices of these outcomes. The China Salt Substitute Study was a randomized, controlled trial designed to establish the effects of Salt Substitute (65% sodium chloride, 25% potassium chloride, 10% magnesium sulfate) compared with regular Salt (100% sodium chloride) on blood pressure among 600 high-risk individuals living in six rural areas in northern China over a 12-month intervention period. Data on central aortic blood pressure, aortic pressure augmentation (AUG), augmentation index (AIx), the differences of the peak of first and baseline waves (P(1)-P(0)) and pulse wave reflection time (RT) were collected at randomization and at the completion of follow-up in 187 participants using the Sphygmocor pulse wave analysis system. Mean baseline blood pressure was 150.1/91.4 mm Hg, mean age was 58.4 years, 41% were male and three quarters had a history of vascular disease. After 12 months of intervention, there were significant net reductions in peripheral (7.4 mm Hg, P=0.009) and central (6.9 mm Hg, P=0.011) systolic blood pressure levels and central pulse pressure (4.5 mm Hg, P=0.012) and correspondingly there was a significant net reduction in P(1)-P(0) (3.0 mm Hg, P=0.007), borderline significant net reduction in AUG (1.5 mm Hg, P=0.074) and significant net increase in RT (2.59 ms, P=0.001). There were no detectable reductions in peripheral (2.8 mm Hg, P=0.14) or central (2.4 mm Hg, P=0.13) diastolic blood pressure levels or AIx (0.06%, P=0.96). In conclusion, over the 12-month study period the Salt Substitute significantly reduced not only peripheral and central systolic blood pressure but also reduced arterial stiffness.
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the effects of a reduced sodium high potassium Salt Substitute on food taste and acceptability in rural northern china
British Journal of Nutrition, 2008Co-Authors: John F Prescott, Federica Barzi, Liancheng Zhao, Bruce NealAbstract:A potassium chloride-containing Salt Substitute lowers blood pressure levels, but its overall acceptability has been of concern due to its potential adverse effects on food taste. In a large-scale, blinded randomised trial evaluating the comparative effects of a Salt Substitute (65 % sodium chloride, 25 % potassium chloride and 10 % magnesium sulphate) and a normal Salt (100 % sodium chloride) on blood pressure, we collected data on the Saltiness, flavour and overall acceptability of food. We performed this at baseline, 1, 6 and 12 months post-randomisation using 100 mm visual analogue scales for assessments of both home-cooked foods and a standard Salty soup. The mean age of the 608 participants from rural northern China was 60 years and 56 % of them were females. In the primary analyses, the changes in the Saltiness, flavour and overall acceptability of both home-cooked foods and a standard Salty soup were not different between the randomised groups (all P>0.08). In the secondary analyses, weighting each of the data points according to the lengths of the respective follow-up intervals, the flavour of both home-cooked foods (mean difference = - 1.8 mm, P = 0.045) and a standard Salty soup (mean difference = - 1.9 mm, P = 0.03) was slightly weaker in the Salt Substitute group. We conclude that Salt substitution is both an effective and an acceptable means of blood pressure control. Possible small differences in flavour did not importantly deter the use of the Salt Substitute in this study group, although the acceptability of the Salt Substitute by a more general population group would need to be confirmed.
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the effects of a reduced sodium high potassium Salt Substitute on food taste and acceptability in rural northern china
British Journal of Nutrition, 2008Co-Authors: Nicole Li, Federica Barzi, Liancheng Zhao, John Prescott, Yangfeng Wu, Xuequn Yu, Bruce NealAbstract:A potassium chloride-containing Salt Substitute lowers blood pressure levels, but its overall acceptability has been of concern due to its potentialadverse effects on food taste. In a large-scale, blinded randomised trial evaluating the comparative effects of a Salt Substitute (65% sodium chlo-ride, 25% potassium chloride and 10% magnesium sulphate) and a normal Salt (100% sodium chloride) on blood pressure, we collected data onthe Saltiness, flavour and overall acceptability of food. We performed this at baseline, 1, 6 and 12 months post-randomisation using 100mm visualanalogue scales for assessments of both home-cooked foods and a standard Salty soup. The mean age of the 608 participants from rural northernChina was 60 years and 56% of them were females. In the primary analyses, the changes in the Saltiness, flavour and overall acceptability of bothhome-cooked foods and a standard Salty soup were not different between the randomised groups (all P.0·08). In the secondary analyses, weight-ing each of the data points according to the lengths of the respective follow-up intervals, the flavour of both home-cooked foods (meandifference ¼ 21·8mm, P¼0·045) and a standard Salty soup (mean difference ¼ 21·9mm, P¼0·03) was slightly weaker in the Salt Substitutegroup. We conclude that Salt substitution is both an effective and an acceptable means of blood pressure control. Possible small differences inflavour did not importantly deter the use of the Salt Substitute in this study group, although the acceptability of the Salt Substitute by a more generalpopulation group would need to be confirmed.Randomised-controlled trials: Salt: Sodium: Potassium: Taste: China: Blood pressure
Liping Huang - One of the best experts on this subject based on the ideXlab platform.
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feasibility and validity of using death surveillance data and smartva for fact and cause of death in clinical trials in rural china a substudy of the china Salt Substitute and stroke study ssass
Journal of Epidemiology and Community Health, 2021Co-Authors: Liping Huang, Xuejun Yin, Zhixin Hao, Lijing L Yan, Bruce Neal, Yishu Liu, Rohina JoshiAbstract:Background In rural China, mortality surveillance data may be an alternative to primary data collection in clinical trials; SmartVA (verbal autopsy) is also a potential alternative for endpoint adjudication. The feasibility and validity of both need to be assessed. Methods We used mortality data from the first 24 months of the China Salt Substitute and Stroke Study (SSaSS) trial and assessed the agreement between (1) mortality surveillance data and face-to-face visits for fact of death; (2) mortality surveillance data and SSaSS adjudication for causes of death; (3) SmartVA and SSaSS adjudication for causes of death; (4) cause-specific mortality fraction of different methods. Face-to-face visits and SSaSS adjudication were taken as reference methods. The agreement was measured by sensitivity, specificity and positive predictive value (PPV) across different 10th Revision of International Statistical Classification of Diseases chapters. Results One thousand three hundred and sixty-five deaths were included. Mortality surveillance data had 82% sensitivity for fact of death and 81% sensitivity for causes of death, with substantial variances across different disease types and reasonable quality for circulatory death (91% sensitivity and 94% PPV). The sensitivity of SmartVA for causes of death was 61%, with reasonable quality for deaths of external causes of morbidity (90% sensitivity). The leading causes of death from different sources were the same with some variances in the fractions. Conclusion Using mortality surveillance data for fact of death in clinical trials need to account for under-reporting. A face-to-face visit to all participants at the completion of trials may be warranted. Neither mortality surveillance data nor SmartVA provided valid data source for endpoint events.
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interim effects of Salt substitution on urinary electrolytes and blood pressure in the china Salt Substitute and stroke study ssass
American Heart Journal, 2020Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Zhixin Hao, Matti Marklund, Lijing L Yan, Yishu Liu, Paul Elliott, Darwin R Labarthe, Jingpu ShiAbstract:The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched Salt Substitute compared to usual Salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of Salt Substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of Salt Substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
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benefits and risks of lowering sodium through potassium enriched Salt substitution for patients with chronic kidney disease in china a modelling study or25 05 19
Current Developments in Nutrition, 2019Co-Authors: Matti Marklund, Liping Huang, Gitanjali M Singh, Raquel C Greer, Frederick Cudhea, Kunihiro Matsushita, Renata Micha, Tammy M Brady, Di Zhao, Maoyi TianAbstract:Objectives Population-level replacement of discretionary (i.e, table/cooking) Salt with potassium-enriched Salt Substitutes is a promising strategy to reduce blood pressure (BP) and prevent cardiovascular disease (CVD). This may be particularly impactful in countries like China where sodium intake is high, mainly from discretionary Salt use, and where potassium intake low. However, hyperkalemia resulting from potassium-enriched Substitutes and its adverse CVD consequences are of concern for those with chronic kidney disease (CKD). We aimed to estimate the benefits and risks of nationwide replacement of discretionary Salt with potassium-enriched Salt Substitute on CVD mortality in Chinese CKD patients.
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spot urine samples compared with 24 h urine samples for estimating changes in urinary sodium and potassium excretion in the china Salt Substitute and stroke study
International Journal of Epidemiology, 2018Co-Authors: Liping Huang, Mark Woodward, Sandrine Stepien, Maoyi Tian, Xuejun Yin, Zhixin Hao, Jixin SunAbstract:Background The capacity of spot urine samples for detecting changes in population sodium and potassium excretion is unclear. Methods Changes in urinary sodium and potassium excretion, over a 6-month to 2-year interval, were measured from 24-h urine samples and estimated from spot urine samples using several published methods in 3270 Chinese. Additional estimates were made by multiplying individual spot sodium and potassium concentrations by a single estimated 24-h urine volume derived from external data. Results The measured difference in 24-h urinary excretion between intervention and control groups was -0.35 g (95% CI: -0.68 to -0.02; P = 0.039) for sodium and 0.66 g (95% CI: 0.52 to 0.80; P 0.10). The estimates were -0.65 g for sodium and 1.11 g for potassium using individual spot urine concentrations and an externally derived standard urine volume (both P < 0.01). Conclusions The published equations were unable to detect the differences in sodium excretion measured by 24-h urine samples. A method based upon spot urine electrolyte concentrations and a standard urine volume may offer an alternative approach to measuring differences in sodium and potassium excretion between population groups without requiring 24-h urine, but will need further investigation.
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rationale design and baseline characteristics of the Salt Substitute and stroke study ssass a large scale cluster randomized controlled trial
American Heart Journal, 2017Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Lijing L Yan, Bruce Neal, Paul Elliott, Darwin R Labarthe, Zhixin HaoAbstract:Abstract Lowering sodium intake with a reduced-sodium, added potassium Salt Substitute has been proved to lower blood pressure levels. Whether the same strategy will also reduce the risks of vascular outcomes is uncertain and controversial. The SSaSS has been designed to test whether sodium reduction achieved with a Salt Substitute can reduce the risk of vascular disease. The study is a large-scale, open, cluster-randomized controlled trial done in 600 villages across 5 provinces in China. Participants have either a history of stroke or an elevated risk of stroke based on age and blood pressure level at entry. Villages were randomized in a 1:1 ratio to intervention or continued usual care. Salt Substitute is provided free of charge to participants in villages assigned to the intervention group. Follow-up is scheduled every 6months for 5years, and all potential endpoints are reviewed by a masked adjudication committee. The primary end point is fatal and nonfatal stroke, and the 2 secondary endpoints are total major cardiovascular events and total mortality. The study has been designed to provide 90% statistical power (with 2-sided α = .05) to detect a 13% or greater relative risk reduction for stroke. The power estimate assumes a primary outcome event rate of 3.5% per year and a systolic blood pressure difference of 3.0mm Hg between randomized groups. Recruitment is complete and there are 20,996 participants (about 35 per village) that have been enrolled. Mean age is 65years and 49% are female. There were 73% enrolled on the basis of a history of stroke. The trial is well placed to describe the effects of Salt substitution on the risks of vascular disease and death and will provide important policy-relevant data.
Maoyi Tian - One of the best experts on this subject based on the ideXlab platform.
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effects of a reduced sodium added potassium Salt Substitute on blood pressure in rural indian hypertensive patients a randomized double blind controlled trial
The American Journal of Clinical Nutrition, 2021Co-Authors: Sudhir Raj Thout, Maoyi Tian, Matti Marklund, Clare Arnott, Mark D Huffman, Devarsetty PraveenAbstract:Background High Salt intake is a major modifiable risk factor of hypertension which is prevalent in India. It is not yet clear if Salt Substitutes reduce blood pressure (BP) among Indian hypertensive patients. Objectives Examine the acceptability, usage, and BP effects of a reduced-sodium and added-potassium Salt Substitute among hypertensive patients. Methods We enrolled 502 participants with hypertension (aged 61.6 ± 12.0 y, 58.8% women) from 7 villages in rural India. Participants were randomly assigned to receive either regular Salt (100% sodium chloride) or the Salt Substitute (70% sodium chloride/30% potassium chloride blend), and advised to replace all home Salt use. The primary outcome was the change in systolic BP (SBP) from baseline to 3 mo comparing the Salt Substitute and regular Salt groups. Secondary outcomes included the change in diastolic BP (DBP), 24-h urinary biomarkers, and self-reported use and satisfaction with the study Salt provided. Results A total of 494 (98%) participants completed 1 mo and 476 (95%) participants completed the 3-mo follow-up. At 3 mo, the Salt Substitute intervention significantly decreased the average SBP by 4.6 mmHg (95% CI: 3.0, 6.2, P Conclusion The reduced-sodium added-potassium Salt led to a substantial reduction in SBP in hypertensive patients, supporting Salt substitution as an effective, low-cost intervention for BP lowering in rural India. This trial was registered at clinicaltrials.gov as NCT03909659.
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estimating 24 h urinary sodium excretion from casual spot urine specimen among hypertensive patients in northwest china the Salt Substitute and stroke study
Public Health Nutrition, 2021Co-Authors: Yi Zhao, Maoyi Tian, Wanlu Liu, Sha Liu, Ting Yin, Xiuying Liu, Faxuan Wang, Xiaoyu Chang, Tianjing Zhang, Yuhong ZhangAbstract:Objective: To develop an equation that can estimate the 24-h urinary Na excretion by using casual spot urine specimen for older hypertensive participants in rural Ningxia and further to compare with the INTERSalt method, Kawasaki method and Tanaka method. Design: Older hypertensive participants in rural Ningxia provided their casual spot urine samples and 24-h urine samples between January 2015 and February 2017. Sex-specific equation was developed using linear forward stepwise regression analysis. Model fit was assessed using adjusted R2. Approximately half of all participants were randomly selected to validate the equation. Mean differences, intraclass correlation coefficients and Bland–Altman plots were used to evaluate the performance of all methods. Setting: Pingluo County and Qingtongxia County in Ningxia Hui Autonomous Region, China. Participants: Older hypertensive participants in rural Ningxia. Results: Totally, 807 of 1120 invited participants provided qualified 24-h urine samples and spot urine samples. There was no statistical difference comparing the laboratory-based method against the new method and the INTERSalt method, while Kawasaki method had the largest bias with a mean difference of 40·81 g/d (95 % CI 39·27, 42·35 g/d). Bland–Altman plots showed similar pattern of the results. Conclusion: The INTERSalt method and the new equation have the potential to estimate the 24-h urinary Na excretion in this study population. However, the extrapolation of the results to other population needs to be careful. Future research is required to establish a more reliable method to estimate 24-h urinary Na excretion.
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interim effects of Salt substitution on urinary electrolytes and blood pressure in the china Salt Substitute and stroke study ssass
American Heart Journal, 2020Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Zhixin Hao, Matti Marklund, Lijing L Yan, Yishu Liu, Paul Elliott, Darwin R Labarthe, Jingpu ShiAbstract:The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched Salt Substitute compared to usual Salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of Salt Substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of Salt Substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
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benefits and risks of lowering sodium through potassium enriched Salt substitution for patients with chronic kidney disease in china a modelling study or25 05 19
Current Developments in Nutrition, 2019Co-Authors: Matti Marklund, Liping Huang, Gitanjali M Singh, Raquel C Greer, Frederick Cudhea, Kunihiro Matsushita, Renata Micha, Tammy M Brady, Di Zhao, Maoyi TianAbstract:Objectives Population-level replacement of discretionary (i.e, table/cooking) Salt with potassium-enriched Salt Substitutes is a promising strategy to reduce blood pressure (BP) and prevent cardiovascular disease (CVD). This may be particularly impactful in countries like China where sodium intake is high, mainly from discretionary Salt use, and where potassium intake low. However, hyperkalemia resulting from potassium-enriched Substitutes and its adverse CVD consequences are of concern for those with chronic kidney disease (CKD). We aimed to estimate the benefits and risks of nationwide replacement of discretionary Salt with potassium-enriched Salt Substitute on CVD mortality in Chinese CKD patients.
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spot urine samples compared with 24 h urine samples for estimating changes in urinary sodium and potassium excretion in the china Salt Substitute and stroke study
International Journal of Epidemiology, 2018Co-Authors: Liping Huang, Mark Woodward, Sandrine Stepien, Maoyi Tian, Xuejun Yin, Zhixin Hao, Jixin SunAbstract:Background The capacity of spot urine samples for detecting changes in population sodium and potassium excretion is unclear. Methods Changes in urinary sodium and potassium excretion, over a 6-month to 2-year interval, were measured from 24-h urine samples and estimated from spot urine samples using several published methods in 3270 Chinese. Additional estimates were made by multiplying individual spot sodium and potassium concentrations by a single estimated 24-h urine volume derived from external data. Results The measured difference in 24-h urinary excretion between intervention and control groups was -0.35 g (95% CI: -0.68 to -0.02; P = 0.039) for sodium and 0.66 g (95% CI: 0.52 to 0.80; P 0.10). The estimates were -0.65 g for sodium and 1.11 g for potassium using individual spot urine concentrations and an externally derived standard urine volume (both P < 0.01). Conclusions The published equations were unable to detect the differences in sodium excretion measured by 24-h urine samples. A method based upon spot urine electrolyte concentrations and a standard urine volume may offer an alternative approach to measuring differences in sodium and potassium excretion between population groups without requiring 24-h urine, but will need further investigation.
Xuejun Yin - One of the best experts on this subject based on the ideXlab platform.
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feasibility and validity of using death surveillance data and smartva for fact and cause of death in clinical trials in rural china a substudy of the china Salt Substitute and stroke study ssass
Journal of Epidemiology and Community Health, 2021Co-Authors: Liping Huang, Xuejun Yin, Zhixin Hao, Lijing L Yan, Bruce Neal, Yishu Liu, Rohina JoshiAbstract:Background In rural China, mortality surveillance data may be an alternative to primary data collection in clinical trials; SmartVA (verbal autopsy) is also a potential alternative for endpoint adjudication. The feasibility and validity of both need to be assessed. Methods We used mortality data from the first 24 months of the China Salt Substitute and Stroke Study (SSaSS) trial and assessed the agreement between (1) mortality surveillance data and face-to-face visits for fact of death; (2) mortality surveillance data and SSaSS adjudication for causes of death; (3) SmartVA and SSaSS adjudication for causes of death; (4) cause-specific mortality fraction of different methods. Face-to-face visits and SSaSS adjudication were taken as reference methods. The agreement was measured by sensitivity, specificity and positive predictive value (PPV) across different 10th Revision of International Statistical Classification of Diseases chapters. Results One thousand three hundred and sixty-five deaths were included. Mortality surveillance data had 82% sensitivity for fact of death and 81% sensitivity for causes of death, with substantial variances across different disease types and reasonable quality for circulatory death (91% sensitivity and 94% PPV). The sensitivity of SmartVA for causes of death was 61%, with reasonable quality for deaths of external causes of morbidity (90% sensitivity). The leading causes of death from different sources were the same with some variances in the fractions. Conclusion Using mortality surveillance data for fact of death in clinical trials need to account for under-reporting. A face-to-face visit to all participants at the completion of trials may be warranted. Neither mortality surveillance data nor SmartVA provided valid data source for endpoint events.
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interim effects of Salt substitution on urinary electrolytes and blood pressure in the china Salt Substitute and stroke study ssass
American Heart Journal, 2020Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Zhixin Hao, Matti Marklund, Lijing L Yan, Yishu Liu, Paul Elliott, Darwin R Labarthe, Jingpu ShiAbstract:The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched Salt Substitute compared to usual Salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of Salt Substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of Salt Substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
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spot urine samples compared with 24 h urine samples for estimating changes in urinary sodium and potassium excretion in the china Salt Substitute and stroke study
International Journal of Epidemiology, 2018Co-Authors: Liping Huang, Mark Woodward, Sandrine Stepien, Maoyi Tian, Xuejun Yin, Zhixin Hao, Jixin SunAbstract:Background The capacity of spot urine samples for detecting changes in population sodium and potassium excretion is unclear. Methods Changes in urinary sodium and potassium excretion, over a 6-month to 2-year interval, were measured from 24-h urine samples and estimated from spot urine samples using several published methods in 3270 Chinese. Additional estimates were made by multiplying individual spot sodium and potassium concentrations by a single estimated 24-h urine volume derived from external data. Results The measured difference in 24-h urinary excretion between intervention and control groups was -0.35 g (95% CI: -0.68 to -0.02; P = 0.039) for sodium and 0.66 g (95% CI: 0.52 to 0.80; P 0.10). The estimates were -0.65 g for sodium and 1.11 g for potassium using individual spot urine concentrations and an externally derived standard urine volume (both P < 0.01). Conclusions The published equations were unable to detect the differences in sodium excretion measured by 24-h urine samples. A method based upon spot urine electrolyte concentrations and a standard urine volume may offer an alternative approach to measuring differences in sodium and potassium excretion between population groups without requiring 24-h urine, but will need further investigation.
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rationale design and baseline characteristics of the Salt Substitute and stroke study ssass a large scale cluster randomized controlled trial
American Heart Journal, 2017Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Lijing L Yan, Bruce Neal, Paul Elliott, Darwin R Labarthe, Zhixin HaoAbstract:Abstract Lowering sodium intake with a reduced-sodium, added potassium Salt Substitute has been proved to lower blood pressure levels. Whether the same strategy will also reduce the risks of vascular outcomes is uncertain and controversial. The SSaSS has been designed to test whether sodium reduction achieved with a Salt Substitute can reduce the risk of vascular disease. The study is a large-scale, open, cluster-randomized controlled trial done in 600 villages across 5 provinces in China. Participants have either a history of stroke or an elevated risk of stroke based on age and blood pressure level at entry. Villages were randomized in a 1:1 ratio to intervention or continued usual care. Salt Substitute is provided free of charge to participants in villages assigned to the intervention group. Follow-up is scheduled every 6months for 5years, and all potential endpoints are reviewed by a masked adjudication committee. The primary end point is fatal and nonfatal stroke, and the 2 secondary endpoints are total major cardiovascular events and total mortality. The study has been designed to provide 90% statistical power (with 2-sided α = .05) to detect a 13% or greater relative risk reduction for stroke. The power estimate assumes a primary outcome event rate of 3.5% per year and a systolic blood pressure difference of 3.0mm Hg between randomized groups. Recruitment is complete and there are 20,996 participants (about 35 per village) that have been enrolled. Mean age is 65years and 49% are female. There were 73% enrolled on the basis of a history of stroke. The trial is well placed to describe the effects of Salt substitution on the risks of vascular disease and death and will provide important policy-relevant data.
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using a low sodium high potassium Salt Substitute to reduce blood pressure among tibetans with high blood pressure a patient blinded randomized controlled trial
PLOS ONE, 2014Co-Authors: Xingshan Zhao, Xuejun Yin, Lijing L Yan, Christopher T Lam, Wuxiang Xie, Ba Sang, Gesang LuobuAbstract:Objectives To evaluate the effects of a low-sodium and high-potassium Salt-Substitute on lowering blood pressure (BP) among Tibetans living at high altitude (4300 meters). Method The study was a patient-blinded randomized controlled trial conducted between February and May 2009 in Dangxiong County, Tibetan Autonomous Region, China. A total of 282 Tibetans aged 40 or older with known hypertension (systolic BP≥140 mmHg) were recruited and randomized to intervention (Salt-Substitute, 65% sodium chloride, 25% potassium chloride and 10% magnesium sulfate) or control (100% sodium chloride) in a 1: 1 allocation ratio with three months’ supply. Primary outcome was defined as the change in BP levels measured from baseline to followed-up with an automated sphygmomanometer. Per protocol (PP) and intention to treat (ITT) analyses were conducted. Results After the three months’ intervention period, the net reduction in SBP/DBP in the intervention group in comparison to the control group was −8.2/−3.4 mmHg (all p<0.05) in PP analysis, after adjusting for baseline BP and other variables. ITT analysis showed the net reduction in SBP/DBP at −7.6/−3.5 mmHg with multiple imputations (all p<0.05). Furthermore, the whole distribution of blood pressure showed an overall decline in SBP/DBP and the proportion of patients with BP under control (SBP/DBP<140 mmHg) was significantly higher in Salt-Substitute group in comparison to the regular Salt group (19.2% vs. 8.8%, p = 0.027). Conclusion Low sodium high potassium Salt-Substitute is effective in lowering both systolic and diastolic blood pressure and offers a simple, low-cost approach for hypertension control among Tibetans in China. Trial Registration ClinicalTrials.gov NCT01429246
Lijing L Yan - One of the best experts on this subject based on the ideXlab platform.
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feasibility and validity of using death surveillance data and smartva for fact and cause of death in clinical trials in rural china a substudy of the china Salt Substitute and stroke study ssass
Journal of Epidemiology and Community Health, 2021Co-Authors: Liping Huang, Xuejun Yin, Zhixin Hao, Lijing L Yan, Bruce Neal, Yishu Liu, Rohina JoshiAbstract:Background In rural China, mortality surveillance data may be an alternative to primary data collection in clinical trials; SmartVA (verbal autopsy) is also a potential alternative for endpoint adjudication. The feasibility and validity of both need to be assessed. Methods We used mortality data from the first 24 months of the China Salt Substitute and Stroke Study (SSaSS) trial and assessed the agreement between (1) mortality surveillance data and face-to-face visits for fact of death; (2) mortality surveillance data and SSaSS adjudication for causes of death; (3) SmartVA and SSaSS adjudication for causes of death; (4) cause-specific mortality fraction of different methods. Face-to-face visits and SSaSS adjudication were taken as reference methods. The agreement was measured by sensitivity, specificity and positive predictive value (PPV) across different 10th Revision of International Statistical Classification of Diseases chapters. Results One thousand three hundred and sixty-five deaths were included. Mortality surveillance data had 82% sensitivity for fact of death and 81% sensitivity for causes of death, with substantial variances across different disease types and reasonable quality for circulatory death (91% sensitivity and 94% PPV). The sensitivity of SmartVA for causes of death was 61%, with reasonable quality for deaths of external causes of morbidity (90% sensitivity). The leading causes of death from different sources were the same with some variances in the fractions. Conclusion Using mortality surveillance data for fact of death in clinical trials need to account for under-reporting. A face-to-face visit to all participants at the completion of trials may be warranted. Neither mortality surveillance data nor SmartVA provided valid data source for endpoint events.
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interim effects of Salt substitution on urinary electrolytes and blood pressure in the china Salt Substitute and stroke study ssass
American Heart Journal, 2020Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Zhixin Hao, Matti Marklund, Lijing L Yan, Yishu Liu, Paul Elliott, Darwin R Labarthe, Jingpu ShiAbstract:The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched Salt Substitute compared to usual Salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of Salt Substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of Salt Substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
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rationale design and baseline characteristics of the Salt Substitute and stroke study ssass a large scale cluster randomized controlled trial
American Heart Journal, 2017Co-Authors: Liping Huang, Maoyi Tian, Xuejun Yin, Lijing L Yan, Bruce Neal, Paul Elliott, Darwin R Labarthe, Zhixin HaoAbstract:Abstract Lowering sodium intake with a reduced-sodium, added potassium Salt Substitute has been proved to lower blood pressure levels. Whether the same strategy will also reduce the risks of vascular outcomes is uncertain and controversial. The SSaSS has been designed to test whether sodium reduction achieved with a Salt Substitute can reduce the risk of vascular disease. The study is a large-scale, open, cluster-randomized controlled trial done in 600 villages across 5 provinces in China. Participants have either a history of stroke or an elevated risk of stroke based on age and blood pressure level at entry. Villages were randomized in a 1:1 ratio to intervention or continued usual care. Salt Substitute is provided free of charge to participants in villages assigned to the intervention group. Follow-up is scheduled every 6months for 5years, and all potential endpoints are reviewed by a masked adjudication committee. The primary end point is fatal and nonfatal stroke, and the 2 secondary endpoints are total major cardiovascular events and total mortality. The study has been designed to provide 90% statistical power (with 2-sided α = .05) to detect a 13% or greater relative risk reduction for stroke. The power estimate assumes a primary outcome event rate of 3.5% per year and a systolic blood pressure difference of 3.0mm Hg between randomized groups. Recruitment is complete and there are 20,996 participants (about 35 per village) that have been enrolled. Mean age is 65years and 49% are female. There were 73% enrolled on the basis of a history of stroke. The trial is well placed to describe the effects of Salt substitution on the risks of vascular disease and death and will provide important policy-relevant data.
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using a low sodium high potassium Salt Substitute to reduce blood pressure among tibetans with high blood pressure a patient blinded randomized controlled trial
PLOS ONE, 2014Co-Authors: Xingshan Zhao, Xuejun Yin, Lijing L Yan, Christopher T Lam, Wuxiang Xie, Ba Sang, Gesang LuobuAbstract:Objectives To evaluate the effects of a low-sodium and high-potassium Salt-Substitute on lowering blood pressure (BP) among Tibetans living at high altitude (4300 meters). Method The study was a patient-blinded randomized controlled trial conducted between February and May 2009 in Dangxiong County, Tibetan Autonomous Region, China. A total of 282 Tibetans aged 40 or older with known hypertension (systolic BP≥140 mmHg) were recruited and randomized to intervention (Salt-Substitute, 65% sodium chloride, 25% potassium chloride and 10% magnesium sulfate) or control (100% sodium chloride) in a 1: 1 allocation ratio with three months’ supply. Primary outcome was defined as the change in BP levels measured from baseline to followed-up with an automated sphygmomanometer. Per protocol (PP) and intention to treat (ITT) analyses were conducted. Results After the three months’ intervention period, the net reduction in SBP/DBP in the intervention group in comparison to the control group was −8.2/−3.4 mmHg (all p<0.05) in PP analysis, after adjusting for baseline BP and other variables. ITT analysis showed the net reduction in SBP/DBP at −7.6/−3.5 mmHg with multiple imputations (all p<0.05). Furthermore, the whole distribution of blood pressure showed an overall decline in SBP/DBP and the proportion of patients with BP under control (SBP/DBP<140 mmHg) was significantly higher in Salt-Substitute group in comparison to the regular Salt group (19.2% vs. 8.8%, p = 0.027). Conclusion Low sodium high potassium Salt-Substitute is effective in lowering both systolic and diastolic blood pressure and offers a simple, low-cost approach for hypertension control among Tibetans in China. Trial Registration ClinicalTrials.gov NCT01429246
