Biomedical subjects

Lai-Ming Ho

Publications and source records attributed to Lai-Ming Ho.

At least 19 recordsLinked to original sources

PubMed2007

Non-parametric estimation of the case fatality ratio with competing risks data: an application to Severe Acute Respiratory Syndrome (SARS).

For diseases with some level of associated mortality, the case fatality ratio measures the proportion of diseased individuals who die from the disease. In principle, it is straightforward to estimate this quantity from individual follow-up data that provides times from onset to death or recovery. In particular, in a competing risks context, the case fatality ratio is defined by the limiting value of the sub-distribution function, F(1)(t) = Pr(T infinity, where T denotes the time from onset to death (J = 1) or recovery (J = 2). When censoring is present, however, estimation of F(1)(infinity) is complicated by the possibility of little information regarding the right tail of F(1), requiring use of estimators of F(1)(t(*)) or F(1)(t(*))/(F(1)(t(*))+F(2)(t(*))) where t(*) is large, with F(2)(t) = Pr(T <or=t and J = 2) being the analogous sub-distribution function associated with recovery. With right censored data, the variability of such estimators increases as t(*) increases, suggesting the possibility of using estimators at lower values of t(*) where bias may be increased but overall mean squared error be smaller. These issues are investigated here for non-parametric estimators of F(1) and F(2). The ideas are illustrated on case fatality data for individuals infected with Severe Acute Respiratory Syndrome (SARS) in Hong Kong in 2003.

Computer Simulation↗

PubMed2006

Methods for monitoring influenza surveillance data.

BACKGROUND: A variety of Serfling-type statistical algorithms requiring long series of historical data, exclusively from temperate climate zones, have been proposed for automated monitoring of influenza sentinel surveillance data. We evaluated three alternative statistical approaches where alert thresholds are based on recent data in both temperate and subtropical regions. METHODS: We compared time series, regression, and cumulative sum (CUSUM) models on empirical data from Hong Kong and the US using a composite index (range = 0-1) consisting of the key outcomes of sensitivity, specificity, and time to detection (lag). The index was calculated based on alarms generated within the first 2 or 4 weeks of the peak season. RESULTS: We found that the time series model was optimal in the Hong Kong setting, while both the time series and CUSUM models worked equally well on US data. For alarms generated within the first 2 weeks (4 weeks) of the peak season in Hong Kong, the maximum values of the index were: time series 0.77 (0.86); regression 0.75 (0.82); CUSUM 0.56 (0.75). In the US data the maximum values of the index were: time series 0.81 (0.95); regression 0.81 (0.91); CUSUM 0.90 (0.94). CONCLUSIONS: Automated influenza surveillance methods based on short-term data, including time series and CUSUM models, can generate sensitive, specific, and timely alerts, and can offer a useful alternative to Serfling-like methods that rely on long-term, historically based thresholds.

Algorithms↗

PubMed2006

Clinical prognostic rules for severe acute respiratory syndrome in low- and high-resource settings.

BACKGROUND: An accurate prognostic model for patients with severe acute respiratory syndrome (SARS) could provide a practical clinical decision aid. We developed and validated prognostic rules for both high- and low-resource settings based on data available at the time of admission. METHODS: We analyzed data on all 1755 and 291 patients with SARS in Hong Kong (derivation cohort) and Toronto (validation cohort), respectively, using a multivariable logistic scoring method with internal and external validation. Scores were assigned on the basis of patient history in a basic model, and a full model additionally incorporated radiological and laboratory results. The main outcome measure was death. RESULTS: Predictors for mortality in the basic model included older age, male sex, and the presence of comorbid conditions. Additional predictors in the full model included haziness or infiltrates on chest radiography, less than 95% oxygen saturation on room air, high lactate dehydrogenase level, and high neutrophil and low platelet counts. The basic model had an area under the receiver operating characteristic (ROC) curve of 0.860 in the derivation cohort, which was maintained on external validation with an area under the ROC curve of 0.882. The full model improved discrimination with areas under the ROC curve of 0.877 and 0.892 in the derivation and validation cohorts, respectively. CONCLUSION: The model performs well and could be useful in assessing prognosis for patients who are infected with re-emergent SARS.

Adult↗

PubMed2006

Empirical implications of response acquiescence in discrete-choice contingent valuation.

The use of discrete-choice contingent valuation (CV) to elicit individuals' preference, expressed as maximum willingness-to-pay (WTP), although primarily developed in environmental economics, has been popular in the economic evaluation of health and healthcare. However, a concern with this method is the potential for 'over-estimating' WTP values due to the presence of response acquiescence, or 'yea-saying' bias. Based on a CV survey conducted to estimate physicians' valuation of clinic computerization, the extent of such bias was estimated from a within-sample open-ended valuation question following the respondents' discrete choice response. Analysis of this data suggests that not only was response acquiescence an issue, but also that the parametric estimation of mean and median WTP, the most common approach to estimating WTP from discrete-choice data, would potentially magnify such bias (to various degrees depending on the distributional assumptions applied). The possible extent of CV design versus analysis in discrete-choice methods therefore warrants further exploration.

Choice Behavior↗

PubMed2006

Promoting smoking cessation among the elderly: what are the predictors of intention to quit and successful quitting?

PURPOSE: To assess the predictors of smoking cessation and intention to quit among the Chinese elderly smokers. DESIGN: A cross-sectional survey of elderly smokers. SETTING: Shamsuipo district, Hong Kong. SUBJECT: A total of 1,318 elderly were interviewed (response rate = 83%). MEASURES: A structured questionnaire was used for data collection. The questionnaire sought information on the subject's sociodemographic background and smoking habits. The predictors for successful quitting and intention to quit were assessed by chi-square tests and multiple logistic regression. RESULTS: Of the respondents, 20.2% were current smokers, 25.4% were ex-smokers, and 54.4% were never smokers. Of the smoker (current and ex-smokers) respondents, 55.7% (335/601) had successfully quit at the time of enumeration. The predictors of quitting were living with others, receiving assistance for mobility, being nondrinkers, smoking for shorter duration, and smoking more cigarettes per day. Having health problems in the past, smoking for shorter duration, and smoking fewer cigarettes per day were predictors of intention to quit smoking. CONCLUSION: The study identified several predictors of successful quitting that could help improve the provision of current smoking cessation services. Population-based smoking cessation programs, especially those targeted to elderly, should take these predictors into consideration in the design of interventions.

Aged↗

PubMed2005

Non-attendance and effective equity of access at four public specialist outpatient centers in Hong Kong.

This study tests whether socio-economic status (SES), at either the individual or ecologic levels, exerts a direct impact on non-attendance or an indirect impact on attendance through longer waiting time for appointments and/or doctor-shopping behavior at four public specialist outpatient centers in Hong Kong. We collected information through three main sources, namely patients' referral letters, telephone interviews with both open- and closed-ended questions (e.g. doctor-shopping data) and hospital administrative databases from a total of 6495 attenders and non-attenders enrolled from July 2000 through October 2001. Individual-level SES was measured by education, occupation and monthly household income. Tertiary planning unit (TPU)-level SES data consisted of proportion unemployed, proportion with tertiary education, median income and Gini coefficient. Direct effects of SES on non-attendance were examined by logistic regression. Indirect contributions mediated through waiting time and doctor-shopping were analyzed by structural equation modeling. We found that SES, at the individual or ecologic level, did not exert a direct effect on non-attendance. Instead, TPU-level SES contributed positively to waiting time (beta=0.06+/-0.03, p=0.048), i.e. worse-off neighborhoods (and those with greater income inequality) had a shorter waiting time. Individual-level SES was also directly associated with the likelihood of doctor-shopping (beta=0.16+/-0.02, p<0.001), i.e. the poor were less likely to doctor-shop. Both waiting time (beta=0.12+/-0.02, p<0.001) and doctor-shopping (beta=0.37+/-0.02, p<0.001) were significantly related to non-attendance. Our findings suggest a highly equitable specialist ambulatory care public system in Hong Kong. Health care resources are appropriately targeted at the socially indigent, and the poor are not discriminated against and pushed to seek alternative sources of care by the system. These results should be confirmed using a prospective design.

Ambulatory Care Facilities↗

PubMed2005

Longitudinal assessment of community psychobehavioral responses during and after the 2003 outbreak of severe acute respiratory syndrome in Hong Kong.

BACKGROUND: In previous literature, the stability and temporal evolution of psychobehavioral responses to an outbreak remained undefined, because of the exclusively cross-sectional nature of such study designs. METHODS: Using random-digit dialing, we sampled 4481 Hong Kong residents in 6 population-based surveys that were conducted at different times during and after the 2003 outbreak of severe acute respiratory syndrome (SARS). RESULTS: Respondents' State-Trait Anxiety Inventory score (range, 10-40) showed a decreasing temporal trend, from a high mean value of 24.8 during the peak of the Amoy Gardens outbreak to a postepidemic mean baseline value of 14.5. Those who perceived a higher likelihood of contracting or dying of SARS had significantly higher anxiety scores. Female respondents, individuals aged 30-49 years, and individuals with only a primary education or less were predisposed to greater anxiety. There was a positive dose-response gradient between anxiety level and uptake of personal protective measures. Males respondents, individuals at the extremes of age, and individuals with lower educational levels were less likely to engage in self-protective behavior. The presence of symptoms was the only consistent predictor for greater use of health services. There was remarkable stability in the magnitude and the direction of associations between predictors and outcomes over time. CONCLUSIONS: Our findings can assist in modifying public service announcements in the future, which should be tailored to psychobehavioral surveillance intelligence to achieve the desired behavioral outcomes. Future research should explore the use of more-sophisticated techniques, including structural equation modeling and game-theoretical frameworks, to analyze population psychology and behavior, and it should integrate such findings with transmission dynamics modeling.

Adult↗

PubMed2005

Health consequences of breast-feeding: doctors' visits and hospitalizations during the first 18 months of life in Hong Kong Chinese infants.

BACKGROUND: The evidence on whether breast-feeding reduces health services use in nonwhite infants is scant. We examined the effects of breast-feeding on health services utilization in Hong Kong Chinese infants. METHODS: We followed a population-based cohort of 8327 infants born in 1997 for 18 months. The main outcome measures were higher (above the sample mean) utilization of outpatient visits and hospitalizations for jaundice, gastrointestinal or respiratory/febrile illnesses, and all illnesses. RESULTS: Breast-fed infants had fewer illness-related doctor visits overall through the first 18 months of life. Results were strongest for infants breast fed exclusively for 2 to 3 months (odds ratio [OR] for higher utilization = 0.78; 95% confidence interval [CI] = 0.62-0.99) and for 4 or more months (0.65; 0.53-0.81). However, breast-fed infants were more likely to receive outpatient care for jaundice, particularly in the first 3 months of life (ORs ranging from 2.5 to 8.4). Any breast-feeding was also associated with more jaundice-related hospital admissions, the effects of which were most acute in the first 3 months of life. Compared with exclusively formula-fed infants, the OR (CI) for mixed breast- and formula-fed was 2.4 (1.7-3.5); for exclusive breast-feeding up to 1 month, 4.5 (2.7-7.6); for exclusive breast-feeding 2 to 3 months, 3.2 (1.8-5.7); and for exclusive breast-feeding 4 or more months, 3.4 (2.0-5.7). CONCLUSIONS: Breast-feeding in Hong Kong Chinese infants reduces doctor visits overall, but increases both outpatient visits and hospitalizations for jaundice.

Adult↗

PubMed2004

The epidemiology of severe acute respiratory syndrome in the 2003 Hong Kong epidemic: an analysis of all 1755 patients.

BACKGROUND: As yet, no one has written a comprehensive epidemiologic account of a severe acute respiratory syndrome (SARS) outbreak from an affected country. OBJECTIVE: To provide a comprehensive epidemiologic account of a SARS outbreak from an affected territory. DESIGN: Epidemiologic analysis. SETTING: The 2003 Hong Kong SARS outbreak. PARTICIPANTS: All 1755 cases and 302 deaths. MEASUREMENTS: Sociodemographic characteristics; infection clusters by time, occupation, setting, and workplace; and geospatial relationships were determined. The mean and variance in the time from infection to onset (incubation period) were estimated in a small group of patients with known exposure. The mean and variance in time from onset to admission, from admission to discharge, or from admission to death were calculated. Logistic regression was used to identify important predictors of case fatality. RESULTS: 49.3% of patients were infected in clinics, hospitals, or elderly or nursing homes, and the Amoy Gardens cluster accounted for 18.8% of cases. The ratio of women to men among infected individuals was 5:4. Health care workers accounted for 23.1% of all reported cases. The estimated mean incubation period was 4.6 days (95% CI, 3.8 to 5.8 days). Mean time from symptom onset to hospitalization varied between 2 and 8 days, decreasing over the course of the epidemic. Mean time from onset to death was 23.7 days (CI, 22.0 to 25.3 days), and mean time from onset to discharge was 26.5 days (CI, 25.8 to 27.2 days). Increasing age, male sex, atypical presenting symptoms, presence of comorbid conditions, and high lactate dehydrogenase level on admission were associated with a greater risk for death. LIMITATIONS: Estimates of the incubation period relied on statistical assumptions because few patients had known exposure times. Temporal changes in case management as the epidemic progressed, unavailable treatment information, and several potentially important factors that could not be thoroughly analyzed because of the limited sample size complicate interpretation of factors related to case fatality. CONCLUSIONS: This analysis of the complete data on the 2003 SARS epidemic in Hong Kong has revealed key epidemiologic features of the epidemic as it evolved.

Adult↗

PubMed2004

Secondhand smoke exposure, smoking hygiene, and hospitalization in the first 18 months of life.

BACKGROUND: Recognizing the suboptimal public health effects of a complete cessation strategy for parents and child caregivers who smoke, some researchers have called for a harm reduction approach; however, the evidence remains scanty and controversial. OBJECTIVE: To examine the effects of secondhand smoke and smoking hygiene on infant health and related health care costs during the first 18 months of life. METHODS: We conducted prospective follow-up on 8327 newborns during April and May of 1997 for 18 months in a population-based birth cohort of infants from Hong Kong, China. MAIN OUTCOME MEASURES: Number of hospital admissions, adjusted odds ratios for ever hospitalization for each secondhand smoke exposure variable, and corresponding population attributable risks. RESULTS: Most secondhand smoke exposure came from fathers and other household contacts, whereas only 2.8% of mothers smoked postpartum. The odds ratio of ever hospitalization due to all illnesses combined for infants living in a household with any (maternal, paternal, or other) smoker who was smoking at least 3 m away from the infant, as reported by a parent, was 1.00 (95% confidence interval, 0.88-1.13) compared with those in a smoke-free household. The corresponding odds ratio for infants living with any smoker at home with poor smoking hygiene (<3 m away) was 1.28 (95% confidence interval, 1.07-1.52), which translated into 2.8% of all inpatient episodes in the first year of life, representing an additional 616 admissions. CONCLUSIONS: Hospital admission was significantly more likely among infants exposed to secondhand smoke if it was accompanied by poor smoking hygiene. Harm reduction strategies should be rigorously adhered to when complete cessation is not possible.

Adult↗

PubMed2004

Prepayment was superior to postpayment cash incentives in a randomized postal survey among physicians.

OBJECTIVE: Improving response rates, particularly among physicians, is important to minimize nonresponder bias and increase the effective sample size in epidemiologic research. We conducted a randomized trial to examine the impact of prepayment vs. postpayment incentives on response rates. STUDY DESIGN AND SETTING: Self-completion postal questionnaires were mailed to 949 physicians who were respondents to an earlier survey and representative of the general physician population in Hong Kong. These physicians were randomly allocated to receive a HK dollar 20 cash prepayment incentive that accompanied the survey (n=474) or a postpayment reward of the same amount on receipt of the completed questionnaire (n=475). RESULTS: The final prepayment response rate was 82.9%, compared with 72.5% in the postpayment arm (P < .001). Of the eight alternative incentive and follow-up strategies evaluated, three lie on the efficiency frontier (i.e., not dominated), including postpayment with three mailings at HK dollar 42.7, prepayment with three mailings at HK dollar 66.5 and prepayment with three mailings and telephone follow-up at HK dollar 112.1 per responder recruited (US dollar 1=HK dollar 7.8). CONCLUSION: The findings demonstrate that prepayment cash incentives are superior to postpayment of the equivalent amount in improving response rates among a representative sample of Hong Kong physicians. Further research should concentrate on confirming the generalizability of these findings in other health care occupation groups and settings.

Attitude of Health Personnel↗

PubMed2004

A tale of two cities: community psychobehavioral surveillance and related impact on outbreak control in Hong Kong and Singapore during the severe acute respiratory syndrome epidemic.

OBJECTIVES: To compare the public's knowledge and perception of SARS and the extent to which various precautionary measures were adopted in Hong Kong and Singapore. DESIGN: Cross-sectional telephone survey of 705 Hong Kong and 1,201 Singapore adults selected by random-digit dialing. RESULTS: Hong Kong respondents had significantly higher anxiety than Singapore respondents (State Trait Anxiety Inventory [STAI] score, 2.06 vs 1.77; P < .001). The former group also reported more frequent headaches, difficulty breathing, dizziness, rhinorrhea, and sore throat. More than 90% in both cities were willing to be quarantined if they had close contact with a SARS case, and 70% or more would be compliant for social contacts. Most respondents (86.7% in Hong Kong vs 71.4% in Singapore; P < .001) knew that SARS could be transmitted via respiratory droplets, although fewer (75.8% in Hong Kong vs 62.1% in Singapore; P < .001) knew that fomites were also a possible transmission source. Twenty-three percent of Hong Kong and 11.9% of Singapore respondents believed that they were "very likely" or "somewhat likely" to contract SARS during the current outbreak (P < .001). There were large differences between Hong Kong and Singapore in the adoption of personal precautionary measures. Respondents with higher levels of anxiety, better knowledge about SARS, and greater risk perceptions were more likely to take comprehensive precautionary measures against the infection, as were older, female, and more educated individuals. CONCLUSION: Comparative psychobehavioral surveillance and analysis could yield important insights into generic versus population-specific issues that could be used to inform, design, and evaluate public health infection control policy measures.

Adolescent↗

PubMed2004

Evaluation of a handheld clinical decision support tool for evidence-based learning and practice in medical undergraduates.

INTRODUCTION: Handheld computers (PDAs) uploaded with clinical decision support software (CDSS) have the potential to facilitate the adoption of evidence-based medicine (EBM) at the point-of-care among undergraduate medical students. Further evaluation of the usefulness and acceptability of these tools is required. METHODS: All 169 Year 4 undergraduate medical students at the University of Hong Kong completed a post-randomised controlled trial survey. Primary outcome measures were CDSS/PDA usefulness, satisfaction, functionality and utilisation. Focus groups were also conducted to derive complementary qualitative data on the students' attitudes towards using such new technology. RESULTS: Overall, the students found the CDSS/PDA useful (mean score = 3.90 out of 6, 95% confidence interval (CI) = 3.78, 4.03). They were less satisfied with the functional features of the CDSS (mean score = 3.45, 95% CI = 3.32, 3.59) and the PDA (mean score = 3.51 95% CI = 3.40, 3.62). Utilisation was low, with the average frequency of use less than once per week. Although students reported a need for information in patient care at least once daily, they infrequently used the CDSS in a clinical setting (20.4 +/- 10.4% of the time), with an average information retrieval success rate of 37.6 +/- 22.1% requiring 63.7 +/- 86.1 seconds. Multivariable regression shows that higher perceived CDSS/PDA usefulness was associated with more supportive faculty attitudes, greater knowledge of EBM, better computer literacy skills and increased use in a clinical setting. Greater satisfaction with the CDSS/PDA was associated with increased use in a clinical setting and higher successful search rates. Qualitative results were consistent with these quantitative findings and yielded additional information on students' underlying feelings that may explain the observations. CONCLUSIONS: While PDAs uploaded with the CDSS are able to provide students with better access to high quality information, improvements in faculty attitudes, students' knowledge of EBM and computer literacy skills, and having the CDSS specially designed for undergraduate use are essential to increasing student adoption of such point-of-care tools.

Attitude of Health Personnel↗

PubMed2003

Randomised controlled trial of clinical decision support tools to improve learning of evidence based medicine in medical students.

OBJECTIVE: To assess the educational effectiveness on learning evidence based medicine of a handheld computer clinical decision support tool compared with a pocket card containing guidelines and a control. DESIGN: Randomised controlled trial. SETTING: University of Hong Kong, 2001. PARTICIPANTS: 169 fourth year medical students. MAIN OUTCOME MEASURES: Factor and individual item scores from a validated questionnaire on five key self reported measures: personal application and current use of evidence based medicine; future use of evidence based medicine; use of evidence during and after clerking patients; frequency of discussing the role of evidence during teaching rounds; and self perceived confidence in clinical decision making. RESULTS: The handheld computer improved participants' educational experience with evidence based medicine the most, with significant improvements in all outcome scores. More modest improvements were found with the pocket card, whereas the control group showed no appreciable changes in any of the key outcomes. No significant deterioration was observed in the improvements even after withdrawal of the handheld computer during an eight week washout period, suggesting at least short term sustainability of effects. CONCLUSIONS: Rapid and convenient access to valid and relevant evidence on a portable computing device can improve learning in evidence based medicine, increase current and future use of evidence, and boost students' confidence in clinical decision making.

Adult↗

PubMed2003

Epidemiological determinants of spread of causal agent of severe acute respiratory syndrome in Hong Kong.

BACKGROUND: Health authorities worldwide, especially in the Asia Pacific region, are seeking effective public-health interventions in the continuing epidemic of severe acute respiratory syndrome (SARS). We assessed the epidemiology of SARS in Hong Kong. METHODS: We included 1425 cases reported up to April 28, 2003. An integrated database was constructed from several sources containing information on epidemiological, demographic, and clinical variables. We estimated the key epidemiological distributions: infection to onset, onset to admission, admission to death, and admission to discharge. We measured associations between the estimated case fatality rate and patients' age and the time from onset to admission. FINDINGS: After the initial phase of exponential growth, the rate of confirmed cases fell to less than 20 per day by April 28. Public-health interventions included encouragement to report to hospital rapidly after the onset of clinical symptoms, contact tracing for confirmed and suspected cases, and quarantining, monitoring, and restricting the travel of contacts. The mean incubation period of the disease is estimated to be 6.4 days (95% CI 5.2-7.7). The mean time from onset of clinical symptoms to admission to hospital varied between 3 and 5 days, with longer times earlier in the epidemic. The estimated case fatality rate was 13.2% (9.8-16.8) for patients younger than 60 years and 43.3% (35.2-52.4) for patients aged 60 years or older assuming a parametric gamma distribution. A non-parametric method yielded estimates of 6.8% (4.0-9.6) and 55.0% (45.3-64.7), respectively. Case clusters have played an important part in the course of the epidemic. INTERPRETATION: Patients' age was strongly associated with outcome. The time between onset of symptoms and admission to hospital did not alter outcome, but shorter intervals will be important to the wider population by restricting the infectious period before patients are placed in quarantine.

Adolescent↗

PubMed2003

Transmission dynamics of the etiological agent of SARS in Hong Kong: impact of public health interventions.

We present an analysis of the first 10 weeks of the severe acute respiratory syndrome (SARS) epidemic in Hong Kong. The epidemic to date has been characterized by two large clusters-initiated by two separate "super-spread" events (SSEs)-and by ongoing community transmission. By fitting a stochastic model to data on 1512 cases, including these clusters, we show that the etiological agent of SARS is moderately transmissible. Excluding SSEs, we estimate that 2.7 secondary infections were generated per case on average at the start of the epidemic, with a substantial contribution from hospital transmission. Transmission rates fell during the epidemic, primarily as a result of reductions in population contact rates and improved hospital infection control, but also because of more rapid hospital attendance by symptomatic individuals. As a result, the epidemic is now in decline, although continued vigilance is necessary for this to be maintained. Restrictions on longer range population movement are shown to be a potentially useful additional control measure in some contexts. We estimate that most currently infected persons are now hospitalized, which highlights the importance of control of nosocomial transmission.

Cluster Analysis↗

PubMed2003

The development and validation of a knowledge, attitude and behaviour questionnaire to assess undergraduate evidence-based practice teaching and learning.

OBJECTIVES: Most evidence-based practice (EBP) educational assessment tools evaluated to date have focused on specific knowledge components or technical skills. Other important potential barriers to the adoption of EBP, such as attitudinal, perceptual and behavioural factors, have yet to be studied, especially in the undergraduate setting. Therefore, we developed and validated a knowledge, attitude and behaviour questionnaire designed to evaluate EBP teaching and learning in an undergraduate medical curriculum. METHODS: We derived the questionnaire from a comprehensive literature review, informed by international and local experts and a Year 5 student focus group. We determined its factor structure and refined and validated the questionnaire according to the responses of a cohort of Year 5 and a combined group of Years 2 and 3 students using principal components factor analysis with varimax rotation. Factor reliability was computed using Cronbach's alpha coefficient. We assessed construct validity by correlating the factors with other measures of EBP activity and examined responsiveness through paired t-test of the pre/post factor mean scores. RESULTS: A 43-item questionnaire was developed. Four factors were identified from both student groups. The overall questionnaire as well as each factor had high construct validity (Cronbach's alpha > 0.7 for each scale). No significant correlations were found between the 4 factors, confirming their orthogonality. Positive correlations, however, resulted between factor mean scores and other EBP activities. The responsiveness of the questionnaire was satisfactory. CONCLUSION: A reliable knowledge, attitude and behaviour measure of EBP teaching and learning appropriate for undergraduate medical education has been developed and validated.

Adult↗

PubMed2002

Cesarean trends.

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Cesarean Section↗