Principles-based medical informatics for success--how Hong Kong built one of the world's largest integrated longitudinal electronic patient records.

Since 1994, the Hospital Authority has been developing and deploying clinical applications at its constituent 41 hospitals and 121 clinics. The Clinical Management System (CMS) is now used by over 4000 doctors and 20000 other clinicians on a daily basis to order, document and review care. The territory-wide Electronic Patient Record (ePR) has given clinicians an integrated, longitudinal, lifelong view of a patient's record. Today the CMS and ePR form an essential clinical and management tool to the Hospital Authority. The CMS handles two million clinical transactions per day, and the ePR has over 6TB of data covering 57 million episodes for 7.9 million patients. This paper describes how the HA has taken a principles-based approach to Medical Informatics to achieve its success in the enterprise-wide deployment and deep utilization of a comprehensive clinical information system.

A territory-wide electronic health record--from concept to practicality: the Hong Kong experience.

In Hong Kong, a pilot project is being undertaken to implement a web-based electronic patient record system to allow integrated, real time patient based information to be shared in clinics, private and public hospitals. Such sharing aims to ensure that complete and accurate healthcare information is available to citizens' multiple points of care through a stable IT system. A challenge is to share this electronic information whilst ensuring privacy and security. Hong Kong has achieved its initial goals and pioneered in building a territory-wide electronic health record (EHR). This paper will outline the tasks involved, approach, method used and initial review of the pilot project. Barriers to implementation are discussed and critical success factors are identified.

Building a womb-to-tomb health record in Hong Kong--an application of information architecture.

The Hospital Authority developed the Information Architecture (IA) model in 2002 to support a fast, robust, flexible and accurate electronic patient record (ePR) to meet the high-tempo health care environment in Hong Kong. With several successful applications in sharing data that were created for the same patients in various systems, the IA model was further developed to extend the longitudinal ePR to include one's fetal data as entered in the mother's record. This paper describes how various IA elements: Section, View, Form, Group, Entity, Content, Document supports the building of a true womb-to-tomb ePR for the HA patients. The future focus of Information Architecture in the HA will include building a Information Architecture Management System and linking the ePR with other patient records in the community.

Early clinical predictors of severe acute respiratory syndrome in the emergency department.

OBJECTIVES: To assess the association of diagnostic predictors available in the emergency department (ED) with the outcome diagnosis of severe acute respiratory syndrome (SARS). METHODS: This retrospective cohort study describes all patients from the Amoy Garden complex who presented to an ED SARS screening clinic during a 2-month outbreak. Clinical and diagnostic predictors were recorded, along with ED diagnoses. Final diagnoses were established independently based on diagnostic tests performed after the ED visit. Associations of key predictors with the final diagnosis of SARS were described. RESULTS: Of 821 patients, 205 had confirmed SARS, 35 undetermined SARS and 581 non-SARS. Multivariable logistic regression showed that the strongest predictors of SARS were abnormal chest x-ray (odds ratio [OR] = 17.4), subjective fever (OR = 9.7), temperature degrees >38 degrees C (OR = 6.4), myalgias (OR = 5.5), chills and rigors (OR = 4.0) and contact exposure (OR = 2.6). In a subset of 176 patients who had a complete blood cell count performed, the strongest predictors were temperature >or=38 degrees C (OR = 15.5), lymphocyte count <1000 (OR = 9.3) and abnormal chest x-ray (OR = 5.7). Diarrhea was a powerful negative predictor (OR = 0.03) of SARS. CONCLUSIONS: Two components of the World Health Organization case definition - fever and contact exposure - are helpful for ED decision-making, but respiratory symptoms do not discriminate well between SARS and non-SARS. Emergency physicians should consider the presence of diarrhea, chest x-ray findings, the absolute lymphocyte count and the platelet count as significant modifiers of disease likelihood. Prospective validation of these findings in other clinical settings is desirable.

Accuracy of clinical diagnosis versus the World Health Organization case definition in the Amoy Garden SARS cohort.

OBJECTIVES: To compare the diagnostic accuracy of emergency department (ED) physicians with the World Health Organization (WHO) case definition in a large community-based SARS (severe acute respiratory syndrome) cohort. METHODS: This was a cohort study of all patients from Hong Kong's Amoy Garden complex who presented to an ED SARS screening clinic during a 2-month outbreak. Clinical findings and WHO case definition criteria were recorded, along with ED diagnoses. Final diagnoses were established independently based on relevant diagnostic tests performed after the ED visit. Emergency physician diagnostic accuracy was compared with that of the WHO SARS case definition. Sensitivity, specificity, predictive values and likelihood ratios were calculated using standard formulae. RESULTS: During the study period, 818 patients presented with SARS-like symptoms, including 205 confirmed SARS, 35 undetermined SARS and 578 non-SARS. Sensitivity, specificity and accuracy were 91%, 96% and 94% for ED clinical diagnosis, versus 42%, 86% and 75% for the WHO case definition. Positive likelihood ratios (LR+) were 21.1 for physician judgement and 3.1 for the WHO criteria. Negative likelihood ratios (LR-) were 0.10 for physician judgement and 0.67 for the WHO criteria, indicating that clinician judgement was a much more powerful predictor than the WHO criteria. CONCLUSIONS: Physician clinical judgement was more accurate than the WHO case definition. Reliance on the WHO case definition as a SARS screening tool may lead to an unacceptable rate of misdiagnosis. The SARS case definition must be revised if it is to be used as a screening tool in emergency departments and primary care settings.

Private primary care physicians' perspectives on factors affecting the adoption of electronic medical records: a qualitative pre-implementation study.

BACKGROUND: Use of electronic medical records (EMR) has the potential to offer quality and safety benefits, but without the adoption of the technology, the benefits will not be realized. OBJECTIVE: This study aimed to identify the factors perceived as relevant by private physicians when considering EMR adoption. METHODS: A qualitative pre-implementation study was conducted using semi-structured, face to face interviews to explore the perspectives of physicians (n=16) operating in private clinics on the factors affecting their adoption of EMR. A multilevel, work system approach and the immersion/crystallization data analysis technique guided the researchers in examining the data, identifying patterns and key themes, and extracting representative quotes to illustrate these themes. RESULTS: The major factors associated with EMR adoption, which relate to the five categories of a work system, were system usefulness; user interface design; technical support; cost; system reliability; the privacy, confidentiality, and security of patient information; physical space in the clinic; data migration process; adverse work-related factors; and the computer and systems skills of physicians. CONCLUSIONS: Pre-implementation identification of factors important to adoption can allow system developers to focus proactively on these factors when developing the system and its implementation strategies, to maximize the likelihood of successful introduction.

Factors associated with multimorbidity and its link with poor blood pressure control among 223,286 hypertensive patients.

Multimorbidity has become the norm worldwide as populations age. It remains, however, infrequently researched. This study evaluated factors associated with multimorbidity in a predominantly Chinese hypertensive population. We included all adult patients prescribed their first antihypertensive agents in the entire public sector in Hong Kong from a validated database. Multimorbidity was defined as having one or more medical conditions (cardiovascular diseases; respiratory diseases; diabetes or impaired fasting glucose; renal disease) in addition to hypertension. We studied the prevalence of multimorbidity and performed multinomial regression analyses to evaluate factors independently associated with multimorbidity. 223,286 hypertensive patients (average age of 59.9 years, SD 17.6) were included. The prevalence of having 0, 1 and ≥ 2 additional conditions was 59.6%, 32.8% and 7.5%, respectively. The most common conditions were cardiovascular disease (24.2%) and diabetes (23.0%), followed by respiratory disorders (14.6%) and renal disease (10.9%). Older age (>50 years), male sex, lower household income, receipt of social security allowance and suboptimal blood pressure control (>140 mmHg or >90 mmHg; >130 mmHg or >80 mmHg for diabetes patients; AOR = 3.38-4.49) were significantly associated with multimorbidity. There exists a synergistic effect among these variables as older (≥ 70 years), male patients receiving security allowance had substantially higher prevalence of multimorbidity (19.9% vs 7.5% among all patients). Multimorbidity is very common in hypertensive patients and its prevalence increased markedly with the presence of risk factors identified in this study. Hypertensive patients with multimorbidities should receive more meticulous clinical care as their blood pressure control tends to be poorer.

Medication adherence to first-line antihypertensive drug class in a large Chinese population.

PURPOSE: Suboptimal adherence to antihypertensive agents leads to adverse clinical outcomes. This study aims to evaluate the association between first-line antihypertensive drug class and medication adherence in a large Chinese population. METHODS: All patients prescribed ≥ one antihypertensive drug in 2001-2003 and 2005 who have paid at least two consecutive clinic visits in the public healthcare system of Hong Kong were included. We excluded patients who have followed-up in the clinics for ≤ 30 days. Interval-based Proportion of Days Covered (PDC) was used to assess medication adherence. All patients were followed-up for up to 5 years. Binary logistic regression analysis was used to evaluate the factors associated with optimal adherence, defined as PDC ≥ 80%. RESULTS: From 147,914 eligible patients, 69.2% were adherent to the antihypertensive prescriptions. When compared with angiotensin converting enzyme inhibitors (ACEIs), patients initially prescribed α-blockers (adjusted odds ratio [AOR]=0.234, 95% C.I. 0.215-0.256), ß-blockers (AOR=0.447, 95% C.I. 0.420, 0.477), thiazide diuretics (AOR=0.431 95% C.I. 0.399, 0.466) and calcium channel blockers (AOR=0.451, 95% C.I. 0.423, 0.481) were significantly less likely to be drug adherers. Angiotensin receptor blockers (ARBs) and fixed-dose combination therapies were similarly likely to be medication adherent. Older age, male gender, visits in general out-patient clinics, residence in urbanized regions, and the presence of comorbidity were positively associated with optimal drug adherence. CONCLUSION: Patients receiving initial prescriptions of ACEIs, ARB and combination therapy had more favorable adherence profiles than the other major antihypertensive classes in real-life clinical practice.

Initial antihypertensive prescription and switching: a 5 year cohort study from 250,851 patients.

PURPOSE: Adverse effects of antihypertensive therapy incur substantial cost. We evaluated whether any major classes of antihypertensive drugs were significantly associated with switching as a proxy measure of medication side effects in a large Chinese population in Hong Kong. METHODS: From a clinical database, all adult patients newly prescribed an antihypertensive mono-therapy in Hong Kong between the years 2001-2003 and 2005 were included. Those who paid only one visit, died or stayed in the cohort for <180 days after the prescription, or prescribed more than one antihypertensive agent were excluded. The factors associated with switching at 180 days were evaluated by multivariate regression analyses. Age, gender, payment status, service type, district of residence, drug class, systolic and diastolic blood pressure levels were predictor variables. RESULTS: From 250,851 subjects, 159,813 patients were eligible. A total of 6,163 (3.9%) switched their medications within 180 days. Patients prescribed thiazide diuretics had the highest switching rate (5.6%), followed by ACEIs (4.5%), CCBs (4.4%) and beta-blockers (3.2%). When compared with ACEIs, patients on thiazide diuretics were significantly more likely to be switchers (adjusted odds ratio [AOR] 1.49, 95% C.I. 1.31-1.69, p<0.001), whilst patients prescribed CCBs and beta-blockers were similarly likely to have switching. Following these patients up for 5 years showed that thiazide had the most marked increase in switching rate. CONCLUSIONS: The higher rates of switching among thiazide diuretics in this study might raise a probably greater incidence of their adverse effects in this Chinese population, yet other factors might also influence switching rates. Patients prescribed thiazide diuretics for longer term should be observed for their intolerability.

Drug adherence and the incidence of coronary heart disease- and stroke-specific mortality among 218,047 patients newly prescribed an antihypertensive medication: a five-year cohort study.

BACKGROUND: Randomized trials have shown that optimal adherence to antihypertensive agents could protect against cardiovascular diseases, but whether adherence reduces cardiovascular deaths in community settings has not been explored so fully. This study evaluates the association between antihypertensive adherence and cardiovascular (coronary heart disease and stroke) mortality in the primary care settings. METHODS: From a territory-wide database in Hong Kong, we included all patients who were prescribed their first-ever antihypertensive agents in the years between 2001 and 2005 from the public healthcare sector. All patients were followed up for five years, and assigned as having poor (Proportion of Days Covered [PDC]<40%), intermediate (40-79%), and high (≥ 80%) adherence to antihypertensive agents. The association between antihypertensive adherence and cardiovascular mortality was evaluated by using the Cox proportional hazard models. RESULTS: From a total of 218,047 eligible patients, 3825 patients (1.75%) died of cardiovascular disease within five years after having received their first-ever antihypertensive agents. The proportions of patients having poor, intermediate, and high medication adherence were 32.9%, 12.1%, and 55.0%, respectively. Higher adherence levels at PDC 40%-79% (HR=0.46, 95% C.I. 0.41-0.52, p<0.001) and ≥ 80% (HR=0.91, 95% C.I. 0.85-0.98, p=0.012) were significantly less likely to be associated with mortality than the poor adherence (PDC0.040) group. CONCLUSIONS: Better antihypertensive adherence was associated with lower cardiovascular mortality. This highlights the need to promote adherence through strategies which have been proved to be effective in clinical settings.

Antihypertensive prescriptions over a 10-year period in a large Chinese population.

BACKGROUND: International guidelines recommending antihypertensive prescriptions for the management of hypertension have been published in the past decade. Beta-blocker use was discouraged by a significant body of evidence and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) were found more effective among younger patients. This study aims to evaluate the trends in prescription profiles in a large Chinese population because patterns of antihypertensive agent dispensation represent important information for physicians and policymakers. METHODS: From clinical databases consisting of all patient records in the public health-care system of Hong Kong, we examined all antihypertensive prescriptions according to the drug classes (thiazide diuretics, alpha-blockers, beta-blockers, calcium channel blockers (CCBs), ACEIs, ARBs, fixed-dose combinations, and polytherapy (2, ≥3)) between 2001 and 2010. We retrieved >6.3 million prescription episodes for 223,287 patients. RESULTS: The average age of the patients was 59.9 years (SD = 17.6), and 54.8% were women. According to prescription episodes, the most commonly prescribed medications were beta-blockers (31.7%) and CCBs (29.2%), followed by ACEIs (13.9%), thiazide diuretics (5.0%), and alpha-blockers (4.5%). Between 2001 and 2010, the prescription proportions of beta-blockers decreased from 41.5% to 21.5%, whereas that of ARBs increased from 0.5% to 1.0% (P < 0.001, χ(2) test for trend). It was found that the decline of beta-blockers (71.0% to 35.4%) and increase in ARB prescriptions (0.4% to 1.0%) were particularly marked among younger subjects aged <55 years. CONCLUSIONS: These findings provided information on the prescription patterns of antihypertensive agents in a large Chinese population. It sets a future research direction to study the various reasons influencing these drug class-specific trends.

Predictors of the incidence of all-cause mortality and deaths due to diabetes and renal diseases among patients newly prescribed antihypertensive agents: a cohort study.

BACKGROUND: Randomized trials have shown that the major antihypertensive drug classes are similarly effective to reduce mortality, but whether these drug class difference exists in clinical practice has been scarcely explored. This study evaluated the association between antihypertensive drug class, all-cause mortality and deaths due to diabetes or renal disease in real-life clinical settings. METHODS: A clinical database in Hong Kong included all patients who were prescribed their first-ever antihypertensive agents between 2001 and 2005 from the public healthcare sector. All patients were followed up for five years, and grouped according to the initial antihypertensive prescription. The associations between antihypertensive drug class, all-cause mortality or combined diabetes and renal mortality, respectively, were evaluated by Cox proportional hazard models. RESULTS: From 218,047 eligible patients, 33,288 (15.3%) died within five years after their first-ever antihypertensive prescription and among which 1055 patients (0.48%) died of diabetes or renal disease. After adjusted for age, gender, socioeconomic status, service settings, district of residence, medication adherence, and the number of comorbidities, each drug class was similarly likely to be associated with mortality due to diabetes or renal disease [Adjusted Hazard Ratios (AHR) ranged from 0.92 to 1.73, p=0.287-0.939] and all-cause mortality (AHR ranged from 0.83 to 1.02) except for beta-blockers (AHR=0.815, 95% C.I. 0.68-0.87, p=0.024) when ACEI was used as a reference group in propensity score-adjusted analysis. CONCLUSIONS: These findings provide real-life evidence reinforcing that any major antihypertensive drug class is suitable as a first-line agent for management of hypertension as recommended by international guidelines.