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Dive into the research topics where Johnny Y. Jiang is active.

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Featured researches published by Johnny Y. Jiang.


Scientific Reports | 2017

International incidence and mortality trends of liver cancer: a global profile

Martin C.S. Wong; Johnny Y. Jiang; William B. Goggins; Miaoyin Liang; Yuan Fang; Franklin D. H. Fung; Colette Leung; Harry H.X. Wang; Grace Lai-Hung Wong; Vincent Wai-Sun Wong; Henry Lik-Yuen Chan

We examined the global incidence and mortality rates of liver cancer, and evaluated the association between incidence/mortality and socioeconomic development (Human Development Index [HDI] and Gross Domestic Product [GDP]) using linear regression analysis. The average annual percent change (AAPC) of the trends was evaluated from join-point regression analysis. The global incidence of liver cancer varied widely by nine-fold, and was negatively correlated with HDI (men: r = −0.232, p = 0.003; women: r = −0.369, p < 0.001) and GDP per capita (men: r = −0.164, p = 0.036; women: r = −0.212, p = 0.007). Its mortality showed a similarly negative correlation with both indices. The greatest incidence rise in men was observed in Poland (AAPC = 17.5, 95% C.I. = 5.6, 30.9) and Brazil (AAPC = 13.2, 95% C.I. = 5.9, 21.0), whereas Germany (AAPC = 6.6, 95% C.I = 2.0, 11.5) and Norway (AAPC = 6.5, 95% C.I. = 3.2, 10.0) had the greatest increase in women. The mortality rates paralleled the incidence rates in most countries. For mortality, Malta (AAPC = 11.5, 95% C.I. = 3.9, 19.8), Australia (AAPC = 6.8, 95% C.I. = 2.2, 11.5) and Norway (APCC = 5.6, 95% C.I. = 2.8, 8.5) reported the biggest increase among men; whilst Australia (AAPC = 13.4, 95% C.I. = 7.8, 19.4) and Singapore (AAPC = 7.7, 95% C.I. = 4.1, 11.5) showed the most prominent rise among women. These epidemiological data identified countries with potentially increasing trends of liver cancer for preventive actions.


Journal of Human Hypertension | 2008

Patterns of antihypertensive prescribing, discontinuation and switching among a Hong Kong Chinese population from over one million prescriptions

Martin C.S. Wong; Johnny Y. Jiang; Augustine Lam; Hong Fung; Sian Griffiths; Stewart W. Mercer

To evaluate the prescription, discontinuation and switching profiles of antihypertensive agents, we studied computerized records for patients prescribed antihypertensive drugs in government primary care clinics of Hong Kong between January 2004 and June 2007, which include 1069836 antihypertensive drug visits (representing 67028 patients). The most commonly prescribed drugs were calcium channel blockers (CCBs, 49%), beta-blockers (BBs, 46%) and angiotensin-converting enzyme inhibitors (ACEIs, 19%). Although thiazide diuretic prescribing was low (13%) and on the decline (from 14% in 2004 to 12% in 2007), prescription of ACEIs was rising (from 16% in 2004 to 23% in 2007); drug discontinuation was highest for BBs (21%) and lowest for CCBs (12%) and the high rates of discontinuation in BBs remained apparent after controlling for confounders. CCBs may be particularly favourable antihypertensive drugs in Chinese and the low use of thiazide diuretics warrants further clinical and cost effectiveness studies among Chinese.


American Journal of Hypertension | 2009

Factors associated with compliance, discontinuation and switching of calcium channel blockers in 20,156 Chinese patients.

Martin C.S. Wong; Johnny Y. Jiang; Sian Griffiths

BACKGROUND Noncompliance and nonpersistence to antihypertensive drugs is a recognized worldwide problem. Calcium channel blockers (CCBs) are commonly prescribed among Chinese patients yet few studies have been conducted to study the factors associated with their compliance, discontinuation, and switching profiles. METHODS From clinical databases we studied 20,156 patients prescribed a CCB as their antihypertensive monotherapy from January 2004 to June 2007 in a large Territory of Hong Kong. We evaluated their compliance by medication possession ratios (MPRs), cumulative incidences of discontinuation and switching within 180 days after the prescription; and evaluated their associated factors using multivariable logistic regression analyses. RESULTS The crude compliance level, discontinuation and switching rates at 180 days were 85.0, 3.1, and 5.0%, respectively. Older patients (aged > or =50 years; adjusted odds ratio (aOR) 1.21-1.34, P < 0.001), female gender (aOR 0.89, 95% confidence interval (CI) 0.82-0.96 for males, P = 0.004), fee payers (aOR 1.09, 95% CI 1.00-1.20, P = 0.050), service settings in family medicine specialist clinic (FMSC) (aOR 1.64, 95% CI 1.33-2.01, P < 0.001), and follow-up visits (aOR 3.24, 95% CI 2.93-3.58, P < 0.001) were positively associated with good compliance. Younger age and new visits were significantly associated with drug discontinuation or switching. CONCLUSIONS Younger patients, male subjects, and new visitors were more likely to be noncompliant to CCB among ethnic Chinese. They represent the target subjects where primary care physicians should spend more effort on patient education to improve drug compliance.


American Journal of Hypertension | 2009

Factors Associated With Antihypertensive Drug Discontinuation Among Chinese Patients: A Cohort Study

Martin C.S. Wong; Johnny Y. Jiang; Trevor Gibbs; Sian Griffiths

BACKGROUND Antihypertensive drug discontinuation imposes a substantial health services burden but few studies have addressed the factors associated with their discontinuation in Chinese patients. This study evaluated the association between age, gender, and drug classes with antihypertensive discontinuation. METHODS From clinical databases, we included all adult patients prescribed an antihypertensive medication during January 2004 to June 2007 in one large territory of Hong Kong. We studied the factors associated with drug discontinuation within 180 days after the first prescription date by multivariable regression analysis. RESULTS From 93,286 eligible patients, 13.2% discontinued their antihypertensive prescriptions. Younger (<50 years; adjusted odds ratio (aOR) = 0.63 for patients aged 50-59 years; 0.52 for patients aged 60-69 years; 0.70 for those aged >or=70 years; all P < 0.001) and male patients (aOR = 1.05, P = 0.027) were more likely to have drug discontinuation. When compared with thiazide diuretics, patients prescribed beta-blockers were more likely (aOR = 1.67, P < 0.001) and patients prescribed calcium channel blocker (CCB) (aOR = 0.76, P < 0.001) and combination therapy (aOR = 0.73, P < 0.001) were less likely to have drug discontinuation. Stratified analyses in different age and gender groups reported similar results; except that only elderly male patients (aOR = 1.12, P = 0.002) and younger patients (aOR = 2.43 for patients aged <50 years, P < 0.001) prescribed beta-blocker were more likely to have drug discontinuation. CONCLUSIONS Discontinuation of antihypertensive drug treatment in ethnic Chinese is more likely to occur in younger, male patients, or those prescribed beta-blockers. These data suggest that more meticulous monitoring of patient adherence is required in patients with these characteristics.


Clinical Therapeutics | 2009

Short-Term Adherence to β-Blocker Therapy Among Ethnic Chinese Patients With Hypertension: A Cohort Study

Martin C.S. Wong; Johnny Y. Jiang; Sian Griffiths

BACKGROUND Although poor control of hypertension is a problem worldwide, most published studies of adherence to antihypertensive medications have involved only white subjects. OBJECTIVE This study examined levels of and factors associated with short-term adherence to beta-blocker therapy among a representative sample of ethnic Chinese patients with hypertension from a large territory in Hong Kong. METHODS Data for all hypertensive patients aged > or = 18 years who received a prescription for a beta-blocker at a visit to any public primary care clinic in the New Territory East cluster of Hong Kong and made at least 1 subsequent visit for a refill of this prescription between January 2004 and June 2007 were obtained from a validated clinical database generalizable to the Chinese population. The proportion of patients who were adherent to beta-blocker therapy was measured based on the medication possession ratio (MPR), calculated over 2 consecutive visits. Good adherence was defined as an MPR > or = 80%. Factors potentially associated with adherence to beta-blockers were investigated using multivariable logistic regression analysis, with adjustment for age, sex, payment status, service type, district of residence, visit type, and number of comorbidities. RESULTS Data were obtained for 15,918 eligible patients (62.2% female; mean age, 59.1 years). Of these patients, 81.3% were adherent to beta-blocker therapy. Factors associated with a greater likelihood of good adherence to beta-blocker therapy were age > or = 50 years (adjusted odds ratio [AOR], age 50-59 years = 1.53 [95% CI, 1.38-1.70]; AOR, age 60-69 years = 1.85 [95% CI, 1.64-2.10]; AOR, age > or = 70 years = 1.88 [95% CI, 1.66-2.12]; all, P < 0.001); fee paid versus fee waived (AOR = 1.16 [95% CI, 1.06-1.28]; P = 0.001); attendance at a family medicine specialist clinic (AOR = 1.30 [95% CI, 1.09-1.54]; P = 0.003); and follow-up visit versus new-patient visit (AOR = 2.67 [95% CI, 2.42-2.95]; P < 0.001). CONCLUSION Among these Chinese patients with hypertension, younger patients, those whose fees were waived, and those who were newly prescribed a beta-blocker had a greater likelihood of being nonadherent.


Hypertension Research | 2010

Adherence to combination therapy among ethnic Chinese patients: a cohort study

Martin C.S. Wong; Johnny Y. Jiang; Sian Griffiths

Discontinuation of antihypertensive combination therapy imposes a substantial public health burden, but few studies have addressed the factors associated with their discontinuation in Chinese patients. This study evaluated the association between patient age, gender, and number of comorbidities with discontinuation of combination therapies. From clinical databases, we included all adult patients prescribed an antihypertensive fixed-dose combination therapy during January 2004 to June 2007 in any government primary care clinics in one large Territory of Hong Kong. We studied the factors associated with drug discontinuation within 180 days after the first prescription date by multivariable regression analysis, controlling for age, gender, socioeconomic status, service setting, district of residence, visit types (new vs. follow-up), and the number of comorbidities. From 29 253 eligible patients, 7.1% discontinued their antihypertensive prescriptions. Younger (<50 years; adjusted odds ratios [aOR]: 0.78, 95% confidence interval [CI]: 0.66–0.92 for patients aged 50–59 years, P=0.003; aOR: 0.71, 95% CI: 0.60–0.84 for patients aged 60–69 years, P<0.001) and male patients (aOR: 1.19, 95% CI: 1.08–1.31, P<0.001) were more likely to have drug discontinuation. Patients with one (aOR: 0.64, 95% CI: 0.57–0.73, P<0.001) and at least two (aOR: 0.68, 95% CI: 0.54–0.87, P=0.002) comorbidities were less likely to have their medications discontinued. Combination therapies in Chinese patients had a low discontinuation rate when compared with Caucasian patients. Discontinuation was more likely among younger, male patients and those without concomitant comorbidities, in which more meticulous monitoring of their adherence patterns was needed.


Journal of Human Hypertension | 2010

Switching of antihypertensive drugs among 93 286 Chinese patients: a cohort study

Martin C.S. Wong; Johnny Y. Jiang; Sian Griffiths

Antihypertensive drug switching induces substantial public health costs. This cohort study evaluated factors associated with switching of antihypertensive agents 180 days after the first date of prescription among ethnic Chinese patients. We included all adult patients aged ⩾18 years, who had paid at least two consecutive visits to all public primary care clinics in one large territory of Hong Kong during the study period from January 2004 to June 2007. Binary logistic regression analyses were carried out with antihypertensive drug switching as an outcome variable, while controlling for age, gender, payment status, service types, district of residence, visit types and the number of comorbidities. Among 93 286 eligible patients, 5281 (5.7%) switched their antihypertensive prescriptions to another drug class within 180 days. Patients aged ⩾70 years (adjusted odds ratio (aOR) 0.88, P=0.005), male subjects (aOR 0.87, P<0.001) and follow-up visitors (aOR 0.67, P<0.001) were less likely to have their drugs switched. When compared with thaizide diuretics, all other antihypertensive drug classes were associated with a lower likelihood of drug switching (aOR 0.27–0.69, all P<0.001). Closer observations of drug utilization profiles among these patient groups are recommended, and future studies should evaluate the reasons for drug switching.


American Journal of Surgery | 2010

Peri-operative hyperglycemia: a consideration for general surgery?

Wendy Bower; Ping Yin Lee; Alice P.S. Kong; Johnny Y. Jiang; Malcolm J. Underwood; Juliana C.N. Chan; C. Andrew van Hasselt

BACKGROUND Intraoperative hyperglycemia in cardiac and neurosurgical patients is significantly associated with morbidity. Little is known about the perioperative glycemic profile or its impact in other surgical populations or in nondiabetic patients. METHODS A systematic review of blood glucose values during major general surgical procedures reported since 1980 was conducted. Data extracted included blood glucose measures, study sample size, gender distribution, age grouping, study purpose, surgical procedure, anesthetic details, and infusion regime. Excluded studies were those with subjects with diabetes insipidus, insulin-treated diabetes, renal or hepatic failure, adrenal gland tumors or dysfunction, pregnancy, and emergency or trauma surgery. RESULTS Blood glucose levels rose significantly with the induction of anesthesia (P < .001) in nondiabetic patients. At incision, 2 hours, 4 hours, and 6 hours, 30%, 40%, 38%, and 40% of studies, respectively, reported hyperglycemia. CONCLUSIONS Factors that confound or protect against significant rises in perioperative glycemic levels in nondiabetic patients were identified. The findings facilitate investigating the impact of hyperglycemia on general surgical outcomes.


Journal of Human Hypertension | 2008

Antihypertensive drug class and dyslipidemia: risk association among Chinese patients with uncomplicated hypertension

Martin C.S. Wong; Johnny Y. Jiang; M K Ali; Hong Fung; Sian Griffiths; Stewart W. Mercer

Antihypertensive drug class and dyslipidemia: risk association among Chinese patients with uncomplicated hypertension


American Journal of Hypertension | 2009

Association of Antihypertensive Monotherapy With Serum Sodium and Potassium Levels in Chinese Patients

Johnny Y. Jiang; Martin C.S. Wong; Mohammed K. Ali; Sian Griffiths; Stewart W. Mercer

BACKGROUND International guidelines on management of hypertension recommend any major classes of antihypertensive drugs. However, the low prescribing rate of thiazides has been attributed to concerns about electrolyte disturbances and studies between antihypertensive drug classes and hyponatremia/hypokalemia among Chinese patients were scarce. METHODS From clinical databases we included 2,759 patients who received their first-ever antihypertensive monotherapy from January 2004 to June 2007 in a large territory of Hong Kong. We studied the plasma sodium and potassium levels 8 weeks after prescriptions and factors associated with hyponatremia and hypokalemia by multivariable regression analyses. RESULTS Among major antihypertensive drug classes, thiazide users had the lowest sodium level (139.6 mEq/l, 95% confidence interval (CI) 139.3, 140.0, P < 0.001) and patients-prescribed calcium channel blockers (CCBs; 3.92 mEq/l, 95% CI 3.89, 3.95) or thiazide diuretics (3.99 mEq/l, 95% CI 3.93, 4.04) had the lowest potassium levels (P < 0.001). Multivariate analysis reported that advanced age (> or =70 years, odds ratio (OR) 7.49, 95% CI 2.84, 19.8, P < 0.001), male gender (OR 2.38, 95% CI 1.45, 3.91, P < 0.001), and thiazide users (OR 2.42, 95% CI 1.29, 4.56, P = 0.006) were significantly associated with hyponatremia, while renin-angiotensin system (RAS) (OR 0.31, 95% CI 0.13, 0.73, P = 0.008) and beta-blockers (BBs) (OR 0.35, 95% CI 0.23, 0.54, P < 0.001) users were less likely to present with hypokalemia. However, the proportions having normonatremic (95.1%) and normokalemic (89.4%) levels were high. CONCLUSIONS In view of the low prevalence of hyponatremia and hypokalemia associated with thiazides, physicians should not be deterred from prescribing thiazide diuretics as first-line antihypertensive agents as recommended by most international guidelines.

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Martin C.S. Wong

The Chinese University of Hong Kong

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Sian Griffiths

The Chinese University of Hong Kong

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Chun Pong Yu

The Chinese University of Hong Kong

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Jason Liwen Huang

The Chinese University of Hong Kong

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C.M. Yu

The Chinese University of Hong Kong

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Hong Fung

The Chinese University of Hong Kong

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Miaoyin Liang

The Chinese University of Hong Kong

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Bernard Yan

Royal Melbourne Hospital

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