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Biomedical subjects

Paul S F Yip

Publications and source records attributed to Paul S F Yip.

At least 19 recordsLinked to original sources
PubMed2006

Seasonality of suicides with and without psychiatric illness in Denmark.

This paper studied the seasonality of suicides among persons with and without psychiatric illness in Denmark from 1970 to 1999. A non-homogenous Poisson process was used to examine the data. The seasonality of suicides was shown to be associated with gender and their psychiatric histories with a declining trend of suicide incidence noted over the captured period. A mild seasonal component was reported in the period of the late 70s to early 80s (1975-1984) among females who did not have any psychiatric treatment history, while in the 80s the significant seasonality was mainly contributed by male suicides without a psychiatric history. Another mild possible invoked seasonality in the 90s was in males who suffered from psychiatric illness. The rest could be treated as random events. Apparently, the seasonality among suicides with psychiatric illness exists but its effect could vary in different periods of time and among genders in Denmark.

Analysis of Variance↗
PubMed2006

The effects of a celebrity suicide on suicide rates in Hong Kong.

BACKGROUND: Deaths of celebrities, especially by suicide, can be followed by an increase in population suicide rates, particularly where there is extensive media reporting. We have examined the impact on suicides following the death of a famous Hong Kong pop singer whose death from suicide by jumping from a height, occurred on 1st April 2003, and resulted in extensive and often dramatic media coverage. METHODS: Data on suicides were obtained from the Hong Kong Census and Statistics Department and the Coroner's Court. The numbers of suicides in 2003 before and after the death of celebrity were compared to the same period in 1998-2002. The case files and suicide notes of people who died by suicide in 2003 were also studied qualitatively. RESULTS: There was a significant increase in suicides following the celebrity death, compared with the average over the preceding three months as well as the corresponding monthly average during 1998-2002. It was particularly marked in a subgroup comprising males, aged 25-39 years, many of whom died by jumping. The name of the celebrity was often mentioned in case files and suicide notes. LIMITATIONS: The statistical results in showing the excess of suicides were based on aggregated data only. CONCLUSIONS: This study provides further confirmation of the potential harmful consequences of sensational and excessive reporting of celebrity deaths.

Adult↗
PubMed2006

Quick assessment of hopelessness: a cross-sectional study.

BACKGROUND: Lengthy questionnaires reduce data quality and impose a burden on respondents. Previous researchers proposed that a single item ("My future seems dark to me") and a 4-item component of the Beck's Hopelessness Scale (BHS) can summarise most of the information the BHS provides. There is no clear indication of what BHS cutoff values are useful in identifying people with suicide tendency. METHODS: In a population-based study of Chinese people aged between 15 and 59 in Hong Kong, the Chinese version of the BHS and the Centre for Epidemiologic Studies--Depression scale were administered by trained interviewers and suicidal ideation and suicidal attempts were self-reported. Receiver operating characteristics curve analysis and regression analysis were used to compare the performance of the BHS and its components in identifying people with suicidality and depression. Smoothed level of suicidal tendency was assessed in relation to scores on the BHS and its component to identify thresholds. RESULTS: It is found that the 4-item component and, to a lesser extent, the single item of the BHS perform in ways similar to the BHS. There are non-linear relationship between suicidality and scores on the BHS and the 4-item component; cutoff values identified accordingly have sensitivity and specificity of about 65%. CONCLUSION: The 4-item component is a useful alternative to the BHS. Shortening of psycho-social measurement scales should be considered in order to reduce burden on patients or respondents and to improve response rate.

Adolescent↗
PubMed2006

Suicidal ideation and suicidal attempts in a population-based study of Chinese people: risk attributable to hopelessness, depression, and social factors.

BACKGROUND: The population attributable fraction of hopelessness, depression and other risk factors for suicidal ideation and suicidal attempts in Asian population is unknown. Social support is often said to be a buffer against the effect of hopelessness and depression. METHODS: Suicidal ideation, suicidal attempts as well as demographic and psychometric data were delineated in a random and representative population sample of 2,219 Chinese people in Hong Kong. The population attributable fraction was used to determine the contribution of hopelessness, depression and other risk factors to suicidal ideation and attempts. RESULTS: Multivariate modelling shows that about 40% of suicidal ideation and attempts was attributable to depression and about 20% was attributable to hopelessness. Drug abuse and marital dissolution were also significant contributors to suicidality. The impact of hopelessness and depression was not affected by social support. LIMITATIONS: Suicidality was self-reported. CONCLUSIONS: Suicidal ideation and suicidal attempts were to a large extent attributable to depression and hopelessness, and, to a lesser extent, drug abuse and marital dissolution. Social support appeared to play little role as a buffer.

Adolescent↗
PubMed2006

Suicide in Hong Kong: a case-control psychological autopsy study.

BACKGROUND: The relative contribution of psychosocial and clinical risk factors to suicide among Chinese populations is an important issue. In Hong Kong, this issue requires vigorous examination in light of a 50% increase in suicide rate between 1997 and 2003. METHOD: Using a case-control psychological autopsy method, 150 suicide deceased were compared with 150 living controls matched by age and gender. Semi-structured interviews were conducted with the next-of-kin of the subjects. Data were collected on a wide range of potential risk and protective factors, including demographic, life event, clinical and psychological variables. The relative contribution of these factors towards suicide was examined in a multiple logistic regression model. RESULTS: Six factors were found to significantly and independently contribute to suicide: unemployment, indebtedness, being single, social support, psychiatric illness, and history of past attempts. CONCLUSIONS: Both psychosocial and clinical factors are important in suicides in Hong Kong. They seem to have mediated suicide risk independently. In addition, socio-economic adversities seem to have played a relatively important role in the increasing suicide rate in Hong Kong.

Adolescent↗
PubMed2006

Socio-economic and psychological correlates of suicidality among Hong Kong working-age adults: results from a population-based survey.

BACKGROUND: The global toll of suicide is estimated to be one million lives per year, which exceeded the number of deaths by homicide and war combined. A key step to suicide prevention is to prevent less serious suicidal behaviour to preclude more lethal outcomes. Although 61% of the world's suicides take place in Asia and the suicide rates among middle age groups have been increasing since the economic crisis in many Asian countries, population-based studies of suicidal behaviour among working-age adults in non-western communities are scarce. METHOD: Data from a population-based survey with 2015 participants were used to estimate the prevalence of suicidal ideation and behaviour among the working-age population in Hong Kong, and to study the associated socio-economic and psychological correlates. We focused particularly on potential modulating factors between life-event-related factors and suicidal ideation. RESULTS: Six per cent of the Hong Kong population aged 20-59 years considered suicide in the past year, while 1.4% attempted suicide. Hopelessness, reasons for living, and reluctance to seek help from family and friends had direct association with past-year suicidal ideation. Reasons for living were found to moderate the effect of perceived stress on suicidal ideation. CONCLUSIONS: Suicidality is a multi-faceted problem that calls for a multi-sectored, multi-layered approach to prevention. Prevention programmes can work on modulating factors such as reasons for living to reduce suicidal risk in working-age adults.

Adult↗
PubMed2006

The ecological fallacy and the gender ratio of suicide in China.

China is the only country in which the suicide rate is higher among women than men. We provide a demographic perspective on the gender differential in suicide in China. This shows that the male/female ratio of suicide increased between 1991 and 2001 and there is reason to believe this trend will continue. Among the population subgroups, only young women living in rural areas had much higher suicide rates than their male counterparts. It is argued that consideration of the gender ratio of suicide in China must take age-, gender- and region-specific suicide patterns and the population structure into account. The increasing urbanisation of China is likely to be associated with more male suicides and we predict that before long the male suicide rate will overtake that of females.

Adult↗
PubMed2005

Suicide rates in China during a decade of rapid social changes.

BACKGROUND: China accounts for more than 30% of the world's suicides and displays a unique pattern of suicide rates. Prior research had established the link between macrosocial changes and suicide. Comprehensive surveillance system of suicide in this rapidly developing country is much needed. This paper examined the trends of national-, region-, gender-, and age-specific suicide rates, and male to female ratios in suicide in China for the period of 1991-2000, which was a time that rapid economic and social changes took place. METHODS: A regression model was used to detect any variations in national-, region-, gender-, and age-specific suicide rates and gender ratios reported by the most recent mortality statistics from China's Ministry of Health. RESULTS: National, urban, and rural suicide rates for both men and women decreased significantly for the period of 1991-2000; age-specific suicide rates, however, showed that there were different patterns of changes in suicide rates in rural and urban areas. Although elderly suicide rates showed the most significant decrease in urban areas, younger women showed the largest decrease in rural areas; male to female gender ratio in suicide increased significantly in the urban areas, but no significant change was found in rural areas. CONCLUSIONS: Possible explanations that may account for the downward trends in suicide rates and increase in male to female gender ratio in urban area were provided. Longer historical studies are needed to reveal the relationship between macrosocial changes and the pattern of suicide.

Adult↗
PubMed2005

A chain multinomial model for estimating the real-time fatality rate of a disease, with an application to severe acute respiratory syndrome.

It is well known that statistics using cumulative data are insensitive to changes. World Health Organization (WHO) estimates of fatality rates are of the above type, which may not be able to reflect the latest changes in fatality due to treatment or government policy in a timely fashion. Here, the authors propose an estimate of a real-time fatality rate based on a chain multinomial model with a kernel function. It is more accurate than the WHO estimate in describing fatality, especially earlier in the course of an epidemic. The estimator provides useful information for public health policy makers for understanding the severity of the disease or evaluating the effects of treatments or policies within a shorter time period, which is critical in disease control during an outbreak. Simulation results showed that the performance of the proposed estimator is superior to that of the WHO estimator in terms of its sensitivity to changes and its timeliness in reflecting the severity of the disease.

Epidemiologic Methods↗
PubMed2005

A semiparametric method for estimating population size for capture-recapture experiments with random covariates in continuous time.

A semiparametric estimation procedure is proposed to model capture-recapture data with the aim of estimating the population size for a closed population. Individuals' covariates are possibly time dependent and missing at noncaptured times and may be measured with error. A set of estimating equations (EEs) based on covariate process and capture-recapture data is constructed to estimate the relevant parameters and the population size. These EEs can be solved by an algorithm similar to an EM algorithm. Simulation results show that the proposed procedures work better than the naive estimate. In some cases they are even better than "ideal" estimates, for which the true values of covariates are available for all captured subjects over the entire experimental period. We apply the method to a capture-recapture experiment on the bird species Prinia flaviventris in Hong Kong.

Algorithms↗
PubMed2005

Prevalence of depression and its correlates in Hong Kong's Chinese older adults.

OBJECTIVE: Because of the rapid aging of the population and inconsistent findings of previous epidemiological studies in Hong Kong, a prevalence study of depression among older adults was timely. The authors assessed the prevalence of depression among older adults and identified factors associated with it. METHODS: The authors interviewed a random representative sample of 917 community-dwelling Chinese adults age 60 and over. The 15-item Chinese Geriatric Depression Scale with a cutoff of > or = 8 was used to identify clinically significant depression in the older adults. RESULTS: The authors found that 11.0% and 14.5% of older Chinese men and women, respectively, scored above the cutoff, a prevalence rate similar to those found in other countries, including the United States, England, and Finland. Factors that were associated with an increased likelihood of depression among older adults included poor self-rated health, long-term pain, vision problems, higher level of impairment in activities of daily living, residing in Hong Kong less than 20 years, financial strain, and having less social support. CONCLUSIONS: The prevalence rate of depression among older Chinese adults in Hong Kong is more or less similar to rates found in Western countries. The data suggest that older adults who receive less social support are more likely to be depressed.

Aged↗
PubMed2005

Attempted suicide in elderly Chinese persons: a multi-group, controlled study.

OBJECTIVE: Attempted suicide in later life is under-researched despite its public health significance. In this study, the authors delineated the characteristics of elderly suicide attempters in a representative Chinese sample by comparing them with suicide completers and comparison subjects age 65 years or over who were randomly selected from the community. METHODS: There were 224 subjects in this study: 66 suicide attempters, 67 suicide completers, and 91 comparison subjects from the community. Using a case-control design and standardized measuring instruments, authors examined the risk and protective factors associated with attempted suicide, making direct comparisons with the community-comparison subjects and suicide completers. RESULTS: A current diagnosis of major depression was associated with a nearly 60-fold increased risk for attempted suicide, and a population attributable risk (PAR) of 67%. Other risk factors included past suicide attempts, poorer function of self-care, arthritis, and specific personality dispositions, particularly low Conscientiousness. Co-residence with children decreased risk. Although the profiles of suicide attempters and completers were similar, they could be distinguished by suicide intent, recent life events (particularly hospitalization), functional competence, religious denomination, and personality characteristics. CONCLUSIONS: A high degree of clinical vigilance and multidisciplinary collaboration are required in the management of elderly suicide attempters. The treatment of depression should form a crucial part of the prevention program. Features that distinguish suicide completers from suicide attempters may also carry implications for the secondary prevention of suicide in elderly persons.

Aged↗
PubMed2005

Charcoal-burning suicide in post-transition Hong Kong.

BACKGROUND: Charcoal-burning, a new suicide method, emerged in Hong Kong during the latest economic recession. Within 2 months charcoal-burning had become the third most common suicide method. AIMS: To examine the characteristics of suicides by charcoal-burning, and to delineate the pathways linking macro-level economic and social changes with the subjective experiences of those surviving a charcoal-burning suicide attempt. METHOD: Both quantitative and qualitative methods were used. In the coroner's records study, the first 160 cases of suicide by charcoal-burning were compared with a control group. In the ethnographic enquiry, we interviewed 25 consecutive informants who had survived serious suicide attempt using charcoal-burning. RESULTS: People who completed suicide by the charcoal-burning method were more likely to have been economically active and physically healthy, and were less likely to have had pre-existing mental illness. Charcoal-burning suicide was associated with overindebtedness. Media reports were pivotal in linking overindebtedness and financial troubles with charcoal-burning. CONCLUSIONS: The political economy of suicide by charcoal-burning illustrated how historical, socio-economic and cultural forces shaped the lived experience that preceded suicide.

Air Pollution, Indoor↗
PubMed2005

Characteristics of suicide attempters and nonattempters with schizophrenia in a rural community.

In this study, demographic and clinical characteristics of individuals with schizophrenia in a Chinese rural community who had attempted suicide at some time in their lives and those who had not made a suicide attempt were compared. Among individuals with schizophrenia, subjects with (n = 38) and without (n = 472) a lifetime history of suicide attempt were assessed with the Present State Examination. The results indicate that attempters had a significantly younger age, higher level of education, higher rate of lifetime depressed mood and hopelessness, and a larger number of positive symptoms than patients without suicide attempts. The logistic regression models also indicated that hopelessness, the number of positive symptoms and age were the most important predictors. Early interventions focusing on reducing hopelessness and controlling positive symptoms may help reduce the risk of suicide attempts among patients with schizophrenia.

Adolescent↗
PubMed2005

Seasonal changes in suicide in the United States, 1971 to 2000.

The seasonality of suicides in the USA increased from the 1970s to the 1990s. A significant proportion of suicide variation due to the seasonal component has been reported. Noted increments in seasonal rhythms in the latter part of the 1980s and 1990s seem to support those of Warren, et al. but contradict the conclusions of diminishing drawn by Hakko, et al., Rhimer, et al., and Yip, et al.

Analysis of Variance↗
PubMed2004

Estimation of reporting delay and suicide incidence in Hong Kong.

This paper uses a semi-parametric method to examine the reporting delay distribution in suicides in Hong Kong reporting system. The data arise from a rightly truncated situation in which only suicide cases registered before a specific time are known to have occurred; otherwise they are not recorded in the known death files even if they have occurred. It is shown that the poisoning-related suicide deaths have a longer reporting delay than other suicide methods. By modelling the reporting delay function, a Horvitz-Thompson-type estimator is suggested to adjust for reporting delay and to provide a more timely estimate of the suicide incidences for monitoring the suicide problem in Hong Kong. Based on these analyses, we recommended a suitable cut-off date to collect suicide cases occurring in the previous year and reported before this date in Hong Kong.

Adult↗