Causes of death of patients with substance dependence: a record-linkage study in a psychiatric hospital in Taiwan

Excessive mortality and causes of death among patients with personality disorder with comorbid psychiatric disorders

PURPOSE

Excessive mortality has been seen in patients with personality disorder (PD), but it has not been well-studied when patients also have other psychiatric comorbidities. This study investigated the mortality rates and causes of death in an Asian cohort with PD.

METHOD

We enrolled patients ≥ 18 years of age with PD as defined by DSM-IV criteria (N = 1172), who had been admitted to a psychiatric service center in northern Taiwan between 1985 and 2008. By linking with the national mortality database (1985-2008), cases of mortality (n = 156, 13.3%) were obtained. We calculated the standardized mortality ratios (SMRs) to estimate the mortality gap between patients with PD and the general population. Stratified analyses of mortality rates by Axis I psychiatric comorbidity and sex were performed.

RESULTS

Borderline PD (n = 391, 33.4%) was the dominant disorder among the subjects. The SMRs for all-cause mortality of PD alone, PD comorbid with non-substance use disorder(non-SUD), and PD comorbid with SUD were 4.46 (95% CI 1.94-6.98), 7.42 (5.99-8.85), and 15.96 (11.07-20.85), respectively. Among the causes of death, the SMR for suicide was the highest (46.92, 95% CI 34.29-59.56). The SMR for suicide in PD patients with comorbid SUD was unusually high (74.23, 95% CI 33.88-114.58). Women had a significant increase in suicide with an SMR of 59.00 (95% CI 37.89-80.11). Men had significant increase in SMRs for cardiovascular disease and gastrointestinal disease.

CONCLUSIONS

We found significant synergistic effects of PD and SUD on mortality risk. A personality assessment should be mandatory in all clinical settings to prevent premature death and detect SUD early.

All-cause and cause-specific mortality rates of patients treated for alcohol use disorders: A meta-analysis

BACKGROUND

Although alcohol use disorders (AUDs) are known to increase the relative risk of all-cause and some cause-specific mortality, the absolute mortality rates of the AUD population are unknown. Such knowledge would benefit planners of the provision of services for this population, including in prioritizing the identification and/or treatment of diseases likely to cause their death.

METHODS

We conducted a systematic review of studies in English, reporting the cause-specific mortality rates among people treated for AUDs. Number of deaths by cause and total person-years of follow-up were extracted. All-cause and cause-specific mortality rates per 1000 person-years were meta-analyzed assuming random effects.

RESULTS

Thirty-one studies were included. Participants were mainly middle-aged males. The quality of studies was generally good. A total of 6768 all-cause deaths in 276,990.7 person-years of follow-up (36,375 patients) were recorded, and the pooled all-cause mortality rate was 27.67/1000 person-years (py) (95% confidence interval [CI]: 23.9, 32.04). The most common cause of death in the AUD population was cardiovascular disease (CVD) (6.9/1000 py; 95% CI: 5.61, 8.49), followed by gastrointestinal deaths (5.63/1000 py; 95% CI: 4.1, 7.74), unnatural deaths (4.95/1000 py; 95% CI: 4.01, 6.09)), neoplasms, respiratory diseases, and substance use disorders.

CONCLUSIONS

Patients with AUDs have increased rates of all-cause and cause-specific mortality compared with the general population. Like the general population, they are most likely to die of CVD. In contrast to the general population, gastrointestinal and unnatural deaths are the next most common causes of death. We believe these facts should be considered when planning health care services for patients with AUDs.

Identification and medical utilization of incident cases of alcohol dependence: A population-based case-control study

BACKGROUND

Patients with alcohol dependence (AD) often seek help from medical professionals due to alcohol-related diseases, but the overall distribution of medical specialties identifying new AD cases is unclear. We investigated how such cases were identified and how medical resources were utilized before the identification of AD in a nationwide cohort.

METHODS

We enrolled a population-based cohort (N = 1,000,000) using the National Health Insurance Research Database of Taiwan; 8181 cases with incident AD were retrieved between January 1, 2000, and December 31, 2010. For this nested case-control study, four controls were matched for age and sex with each case based on risk-set sampling. We measured various dimensions of medical utilization before AD was diagnosed, including department visited, physical comorbidity, and medication used. Conditional logistic regression was used for estimating the variables associated with AD.

RESULTS

Patients living in less urbanized areas who were unemployed were more likely to develop AD. The highest proportions (34.2%) of AD cases were identified in the internal medicine department, followed by the emergency (22.3%) and psychiatry (18.7%) departments. AD patients had a higher risk of comorbid chronic hepatic disease (adjusted RR = 2.72, p < 0.001) before identification of AD than controls. AD patients also had greater numbers of hospital admissions than controls, including non-psychiatric and psychiatric hospitalizations. Outpatient visit numbers were similar for AD patients and controls.

CONCLUSIONS

The findings indicate that clinicians providing care in diverse medical settings should be prepared to screen for unhealthy alcohol use and to mitigate its detrimental effects.

Risk Factors for Sudden Cardiac Death Among Patients with Alcohol Dependence: A Nested Case-Control Study

BACKGROUND

Excessive alcohol consumption causes a broad range of health problems, including premature mortality and sudden cardiac death (SCD). We identified potential clinical characteristics and laboratory indices associated with SCD among patients with alcohol dependence.

METHODS

Patients with alcohol dependence (n = 2,793) admitted to a psychiatric center in northern Taiwan between 1985 and 2008 were linked with a national mortality database for causes of death. Of the 2,793 patients in the cohort, 67 cases died of SCD. The standardized mortality ratio (SMR) of SCD relative to the general population was calculated. Based on a nested case-control design, we selected a set of sex-, age-, and year-of-admission-matched two control subjects for each case derived from the cohort. We collated the clinical information through a standardized review of patients' medical records. Conditional logistic regressions were then conducted to explore potential exposures associated with SCD.

RESULTS

The sample had substantially higher SCD mortality (SMR 12.8) compared to the general population. After adjustments in the multivariate analyses for the clinical profiles at the index (earliest) admission, both abnormal electrocardiography (ECG) (adjusted risk ratio = 16.97, 95% confidence interval (CI) 1.60 to 179.58, p = 0.019) and elevated aspartate aminotransferase levels (adjusted risk ratio = 1.01, 95% CI 1.00 to 1.02, p = 0.046) were significantly associated with SCD.

CONCLUSIONS

This study raises the question of whether intensive follow-up of patients with elevated AST and abnormal ECG findings should be evaluated as a strategy to prevent SCD in patients with alcohol dependence.

Gender differences in mortality and risk factors in a 13-year cohort study of street-recruited injecting drug users

BACKGROUND

Injecting drug users (IDUs) are at risk of premature mortality. This study examined gender differences in mortality, risk factors, and causes of death among IDUs.

METHODS

In a 13-year cohort study including 172 street-recruited IDUs from Oslo, Norway in 1997, interview data was merged with the National Cause of Death Registry. Crude mortality rate (CMR) and indirect standardized mortality ratio (SMR) were estimated with 95% confidence intervals (CI). A log-logistic multivariate survival analysis model was estimated for the full sample. For a smaller data set (1.1.1998-31.12.2004) the influence of substitution treatment and prison were assessed using cox regression survival analysis.

RESULTS

Eight females and 37 males died. Acute intoxications were the most common cause of death. Women were more at risk in the short-term, but more protected in the long-term. CMR was 16.0 [95% CI 8.0, 31.9] for women and 26.0 [95% CI 18.0, 35.8]) for men. SMR was 39.4 [95% CI 0.2, 220.8]) for women and 21.3 [95% CI 5.7, 54.1] for men. More women injected heroin (98% vs. 88% [x2 = 3.5, p = 0.063]), used prescription drugs (73% vs. 52% [x2 = 5.6, p = 0.018]) and combined these to inject (45% vs. 26% [x2 = 5.9, p = 0.015]). Mixing prescription drugs in heroin injections, and sex work (only women) were associated with decreased survival time. There were no gender differences in access to substitution treatment, while significantly more men had been in prison (74% vs. 51% [x2 = 7.5, p = 0.006]). The instance of substitution treatment and prison significantly decreased the mortality risk. Prison release increased the risk, but not statistically significantly.

CONCLUSIONS

There were gender differences in mortality and risk factors; sex work and prison were gender specific risk factors. These factors should be investigated further to better design future preventive measures.

Suicide and other-cause mortality among heroin users in Taiwan: a prospective study

AIMS

The present study investigates one-year incidence of mortality from suicide and other causes among heroin users in Taiwan.

DESIGN

A prospective national register-based cohort study.

SETTING

All heroin users who attended the methadone maintenance treatment (MMT) programs in all treatment centers in Taiwan.

PARTICIPANTS

The sample comprised 10,842 heroin users attending MMT. Between Jan 2006 and Dec 2007, cases were identified through the multiple-center register system and followed until Dec 2008 for date and cause of death on the Taiwan national mortality database.

MEASUREMENTS

Standardized mortality ratios within one year of starting MMT were calculated as a ratio of actual versus expected numbers of deaths in the general population in Taiwan. Cox regression models were fitted to estimate the effects of gender, age, education and marital status as well as heroin related behaviors.

FINDINGS

In total, 256 cases died, 67 through suicide. The mortality rate (per 100 person-years) in the first year of all-cause and suicide was 1.71 and 0.45 respectively, representing 7.5- and 18.4-fold age- and gender-standardized mortality ratio (SMR) compared to the general population. Besides, the mortality rate in the first year of overdoses, murder, HIV, somatic was 0.19, 0.02, 0.07, and 0.75 respectively, representing 68.4-, 27.7-, 76.8-, and 4.3-fold SMR increases to the general population. Older age and unemployment were independent risk factors for mortality. Females had higher standardized mortality ratio than males for suicide and all-cause mortality.

CONCLUSIONS

Results showed higher risk of suicide and other-cause mortality among heroin users in MMT than general population. Suicide is an important contributor to overall excess mortality among heroin users in MMT, and especially among women. Suicide prevention and physical health monitoring are important components of MMT programs.

Substance abuse and psychiatric co-morbidity as predictors of premature mortality in Swedish drug abusers: a prospective longitudinal study 1970-2006

BACKGROUND

Few longitudinal cohort studies have focused on the impact of substances abused and psychiatric disorders on premature mortality. The aim of the present study was to identify predictors of increased risk of drug related death and non drug related death in substance abusers of opiates, stimulants, cannabis, sedatives/hypnotics, hallucinogens and alcohol over several decades.

METHODS

Follow-up study of a consecutive cohort of 561 substance abusers, admitted to a detoxification unit January 1970 to February 1978 in southern Sweden, and followed up in 2006. Demographic and clinical data, substance diagnoses and three groups of psychiatric diagnoses were identified at first admission. Causes of death were coded according to ICD-10 and classified as drug related deaths or non drug related deaths. To identify the incidence of some probable risk factors of drug related premature death, the data were subjected to a competing risks Cox regression analysis.

RESULTS

Of 561 patients in the cohort, 11 individuals had either emigrated or could not be located, and 204/561 patients (36.4%) were deceased by 2006. The cumulative risk of drug related death increased more in the first 15 years and leveled out later on when non drug related causes of death had a similar incidence. In the final model, male gender, regular use of opiates or barbiturates at first admission, and neurosis were associated with an increased risk of drug related premature death, while cannabis use and psychosis were associated with a decreased risk. Neurosis, mainly depression and/or anxiety disorders, predicted drug related premature death while chronic psychosis and personality disorders did not. Chronic alcohol addiction was associated with increased risk of non drug related death.

CONCLUSIONS

The cohort of drug abusers had an increased risk of premature death to the age of 69. Drug related premature death was predicted by male gender, the use of opiates or barbiturates and depression and anxiety disorders at first admission. The predicted cumulative incidence of drug related death was significantly higher in opiate and barbiturate abusers over the observed period of 37 years, while stimulant abuse did not have any impact. Alcohol contributed to non drug related death.

Causes of premature mortality in Swedish drug abusers: a prospective longitudinal study 1970-2006

AIMS

To evaluate premature mortality and causes of death from young adulthood to middle age in a cohort of drug users followed during almost four decades.

DESIGN

Follow-up study of a consecutive cohort of patients with drug abuse/dependence.

METHODS

A cohort of 561 drug abusers, admitted to a detoxification and short-term rehabilitation unit 1970-1978 was followed to December 31st, 2006. Standardized interviews and hospital records with toxicological analyses were used for demographic data, substance use and psychiatric diagnoses at admission. For Follow-up analyses, autopsy protocols including toxicology tests and death certificates were obtained for assessment of causes of death which were coded according to ICD-10. Age-group standardized mortality ratios were calculated independently for both sexes.

RESULTS

204 persons (36.4%) were deceased by 2006. SMR was 5.94 for the cohort. Compared to an age- and gender-matched population, the risk of premature death was about eighteen times higher between the ages of 20-44 and about five times higher from 45 up to the age of 69. Of 120 (59%) drug-related deaths, 43 were opiate overdoses, and 3 were overdose from amphetamine. A total of 53 (26%) persons died violent deaths: 39 suicides, of which 25 were drug-related, 3 homicides and 12 accidents. The Swedish national causes of death register underestimated drug-related death by 37% and suicide by 85% compared to the results from this study.

CONCLUSIONS

The cohort of drug abusers had an increased risk of premature often drug-related and violent death well into middle age, and to a great extent the drug addicts died from the same drug they had abused when they were first admitted for treatment. The underestimation of drug-related death and suicide in some national death cause registers could be reduced if the doctor routinely records ICD codes when issuing death certificates and autopsy protocols.

Causes of death of patients with methamphetamine dependence: a record-linkage study

INTRODUCTION AND AIMS

Methamphetamine use leads to increased likelihood of premature death. The authors investigated the causes of death and risk of mortality in a large cohort of patients with methamphetamine dependence.

DESIGN AND METHODS

A cohort of 1254 subjects with methamphetamine dependence, admitted to a psychiatric centre in Taiwan from January 1990 to December 2007, was retrospectively studied. Diagnostic and sociodemographic data for each subject were extracted from the medical records based on a chart review process. Mortality data were obtained by linking to the National Death Certification System and standardised mortality ratios (SMRs) were estimated. The risk and protective factors for all-cause deaths were explored by means of survival analyses.

RESULTS

During the study period, 130 patients died. Of them, 63.1% died unnatural deaths, while the remaining 36.9% died natural deaths. The 1 year cumulative rates for unnatural and natural deaths were 0.018 and 0.006, respectively, and the 5 year rates were 0.046 and 0.023, respectively. The cohort had excessive mortality (SMR = 6.02), and women had a higher SMR for unnatural deaths than men (26.19 vs. 9.82, P = 0.001). For all-cause deaths, comorbidity with other substance use disorders was associated with increased risk of death, despite that being married was associated with a reduced risk.

DISCUSSION AND CONCLUSIONS

A substantial proportion of the deceased died natural deaths, but most died unnatural deaths. The findings show significant evidence to provide valuable insight into premature deaths among methamphetamine-dependent users. This information is valuable for development of prevention and intervention programs.

Mortality and cause of death among 1705 illicit drug users: a 37 year follow up

INTRODUCTION AND AIMS

To examine the overall mortality and causes of deaths of a large cohort of users of illicit drugs in Stockholm over 37 years.

DESIGN AND METHODS

People with substance abuse were identified through records collected by different institutions in Stockholm in 1967. Subjects were followed in registers recording mortality and cause of death and in-patient care stays until 2003.

RESULTS

More than half (n = 860) of the 1705 identified substance abusers died at an average age of 47 years, 25-30 years younger than the general population. The standardised rate ratio (SRR) for mortality was 3.3 among men and 3.5 among women. Incidence of mortality per 1000 person-years was also increased, but somewhat lower for women. The difference between these two measures is mainly explained by a lower mortality among women in general. In-patient care stays with both alcohol and drug-related diagnoses were associated with higher risk of dying among women than men: SRR = 14.5 and SRR = 4.0, respectively. Accidents and suicide were the most common cause of death among the youngest subjects (15-24 years) and cardiovascular diseases and tumours among the oldest (> or =55 years).

DISCUSSION AND CONCLUSIONS

Accidents and suicide, especially at a young age, are two common causes of death that might be prevented by increased awareness in medical personnel, along with better treatment and supportive measures.

Alterations in oxidative stress status during early alcohol withdrawal in alcoholic patients

BACKGROUND/PURPOSE

Alcohol-induced oxidative stress is the result of the combined production of reactive oxygen species [ROS; e.g. malondialdehyde (MDA), an index of lipid peroxidation] and impairment of antioxidant defenses [e.g. superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), which are involved in the elimination of ROS]. Little is known about the oxidative stress markers among patients with alcohol dependence in Taiwan. This study aimed to investigate serial alterations of various oxidative stress markers during early detoxification in alcoholic patients.

METHODS

We enrolled 121 inpatients who fulfilled the DSM-IV-TR criteria for alcohol dependence, and 19 healthy controls. Fasting serum MDA level and antioxidant activity, including SOD, CAT and GPX, were measured at baseline in both groups, and after 1 and 2 weeks of detoxification in alcoholic patients.

RESULTS

MDA level in alcoholics was higher at baseline than in healthy controls. It decreased after 1 week of detoxification, and normalized at week 2. SOD and GPX activities remained significantly lower throughout the 2-week period. CAT activity in alcoholics was comparable to that in the controls at baseline, but decreased at week 1 of detoxification, and was significantly lower than that in the controls after 2 weeks. Moreover, baseline MDA level was correlated with baseline CAT activity in alcoholics; the magnitude of the decrease in MDA level was correlated with the decrease in CAT activity following the 1-week detoxification.

CONCLUSION

The findings suggest severe oxidative stress and weakened antioxidant activity in alcoholic patients, and limited changes in oxidative stress in the early stages of alcohol withdrawal.

Alcohol abuse and related factors in Asia

Alcohol problems are a global issue, and the nature of alcohol abuse is very complicated. The susceptibility to alcohol abuse varies greatly from one individual to another and also from one nation to another, depending on the availability of alcohol, a country's regulation related to alcohol, a country's cultural background, religious tradition and its economics. Alcohol dependence is also a complicated disease process. The prevalence of alcohol dependence also varies greatly from one ethnic group to another. Asia is the world's largest and most populous continent. The natural disasters, religious conflicts as well as political disputes cause people lack of opportunity in many countries. People in this region do not consume more alcohol than the people in the rest of the world. The prevalence of alcohol dependence is not as high as is seen in other regions. In Asia, not only socio-economic factors, but also biological factors influence drinking behaviour. Findings of functional genetic polymorphism of the major alcohol metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) have led to the suggestion that this enzyme system may possibly play a diverse but critical role in alcohol dependence and in the alcohol-related disease process in the different ethnic groups. This paper reviews alcohol problems and related factors. Their management and prevention strategy are discussed.

Premature mortality among males with substance use disorders

OBJECTIVE

Previous studies have demonstrated that substance use disorders (SUD) are associated with premature mortality in clinical populations, though findings regarding the effect of antisocial personality disorder (ASP) on mortality among persons with SUD are less clear. However, it is unclear to what extent that finding generalizes to persons with SUD in the community, because very little work has been done involving mortality in longitudinal studies of mortality associated with SUD. The objective of this study was to assess whether the presence of SUD or ASP is associated with early mortality among males (fathers) in a predominantly community sample, using a 15-year prospective longitudinal study design.

METHOD

We conducted a prospective longitudinal study of adolescents and their fathers. The adolescent subjects were recruited at age 10-12 years, with follow-up evaluations at ages 14, 16, 19, 22, and 25. Questions were asked about paternal mortality during each of those visits. The study sample for this study was the 769 fathers of the adolescent subjects, who included N=341 fathers with a DSM-III-R diagnosis of SUD and N=428 control fathers without a SUD. 89% of these fathers were recruited from the community, and 11% were recruited from clinical sources. Comorbidity patterns were described. A multivariate Cox regression analysis was performed with the father's age at death or last assessment as the dependent variable, and education, SUD, and ASP as the independent variables.

RESULTS

Lower education level, the presence of a substance use disorder, and the presence of antisocial personality disorder were significantly associated with earlier mortality (Wald=5.1, df=1, p=0.024; Wald=5.1, df=1, p=0.024, and Wald=5.5, df=1, p=0.019, respectively). Most subjects died from medical illnesses, as opposed to drug overdoses or accidents, which is different from the pattern often noted in clinical samples.

CONCLUSIONS

The results of this study demonstrate that the presence of SUD, the presence of ASP, and a lower education level were associated with early mortality in our primarily community-based sample, which extends previous reports of similar findings in clinical samples. The magnitude of the prematurity of the deaths was less that that generally noted in previous studies involving clinical samples, and the causes of death were also somewhat different from those noted in clinical samples. The majority of cases of mortality in our SUD sample resulted from medical illnesses rather than from accidents or overdoses.

Mortality in opioid-maintained patients after release from an addiction clinic

AIM

To investigate the mortality rate in a cohort of 269 opioid-dependent patients and the outcome of survivors meeting DSM-IV criteria for opioid dependence.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients enrolled in synthetic opioid maintenance therapy during a time frame from 1998 to 1999 originally at the Addiction Clinic and then discharged to general practitioners.

METHODS

Structured interviews (Europ-ASI), urinalysis at time of interview as well as autopsy findings from deceased patients.

RESULTS

After six mailings, information from 147 (54.6%) patients was gained. 85 patients (31.6%) were interviewed. From these 76.5% (n = 65) were still enrolled in maintenance therapy, 18.8% (n = 16) were drug-free and 4.7% (n = 4) relapsed. From 29 fatalities, 37.9% died of intoxication with illicit substances, 34.5% related to AIDS and 27.6% of somatic complications. The Standardized Mortality Ratio (SMR) was 29.13 (95% CI = 19.27-44.04). A higher lifetime frequency of hospitalization, less working days and a lack of social relationships were factors associated with high mortality.

CONCLUSIONS

The study confirms the high mortality rate in this patient group and supports the importance of maintenance therapy. Although great efforts were undertaken in locating patients, about 45% of the target group could not be located.

Causes of death among crack cocaine users

OBJECTIVE: The study accompanied 131 crack-cocaine users over a 5-year period, and examined mortality patterns, as well as the causes of death among them. METHOD: All patients admitted to a detoxification unit in Sao Paulo between 1992 and 1994 were interviewed during two follow-up periods: 1995-1996 and 1998-1999. RESULTS: After 5 years, 124 patients were localized (95%). By the study endpoint (1999), 23 patients (17.6%) had died. Homicide was the most prevalent cause of death (n = 13). Almost one third of the deaths were due to the HIV infection, especially among those with a history of intravenous drug use. Less than 10% died from overdose. CONCLUSIONS: The study suggests that the mortality risk among crack cocaine users is greater than that seen in the general population, being homicide and AIDS the most common causes of death among such individuals.

Psychiatric severity and mortality in substance abusers: a 15-year follow-up of drug users

Previous research has shown that most transitions into abstinence happens in the stages of the drug career quickly after the first treatment episode. Mortality is somewhat reduced for patients who become abstinent, but remains high for patients who remain addicted. However, even among substance abusers who become abstinent, mortality is often higher than in the general population. A consecutive sample of drug users admitted for detoxification was followed for 15 years. Face-to-face interviews were conducted at 5-year follow-up. At 15-year follow-up, 24% were dead. Cox proportional hazard regression was conducted to predict mortality for continuous variables, and Gehan's Wilcoxon test was used to predict mortality for dichotomous variables. Psychiatric status at 5-year follow-up was predictive of 15-year mortality, whereas abstinence was not. Subjects who later died had higher scores on the Symptom Checklist 90 [SCL-90] Global Severity Index, lower meaningfulness on the Sense of Coherence scale, and lower Global Assessment of Functioning [GAF] scores at 5-year follow-up. By contrast, there were no associations between baseline drug use and antisocial personality disorder diagnoses and mortality. Psychiatric treatment, including psychotherapy, may be more life-saving for substance abusers than drug-abuse services.

Oxidative status in patients with alcohol dependence: a clinical study in Taiwan

The aim of this study is to examine the relationship between alcohol dependence and oxidative status. The biochemical parameters and antioxidants status were measured among 28 patients with alcohol dependence. Nineteen healthy persons without drinking problem were recruited as the control subjects. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (gamma-GT), and levels of cholesterol, triglyceride (TG), and uric acid were significantly increased in the specimen of patients compared with control. Serum malondialdehyde (MDA) levels of the patients were found to be significantly increased compared with controls and decreased after abstinence. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were, respectively, 86% and 37% lower in alcoholic patients. After 14 d of abstinence, SOD activity was significantly reduced by 85%, CAT by 52%, and GPX by 54%, whereas no change was found in activity of glutathione reductase (GR). The duration of alcohol dependence is significantly correlated with the levels of MDA. In addition, the activity of CAT was significantly correlated with MDA levels. The results of this study suggest that oxidative stress occurred during alcohol dependence and subsequently affected the antioxidants mechanisms.

Mortality in a cohort of opiate and amphetamine users in Perth, Western Australia

AIMS

This study compares the hazard of death among opiate and amphetamine using clients who accessed drug treatment with individuals who had no specialist treatment contact between 1985 and 1998.

DESIGN, SETTING, PARTICIPANTS

This was a retrospective cohort study of 4280 drug-using individuals (2887 opiate users, 1393 amphetamine users) admitted to Perth metropolitan hospitals or Perth psychiatric institutions between 1985 and 1998. Of these, 1469 attended Next Step Specialist Drug and Alcohol Services (928 received methadone and 541 attended counselling or support groups) and 2811 had no contact with this service.

METHODS

Data from two drug treatment programmes were linked with hospital morbidity, psychiatric services and the mortality database using record linkage.

FINDINGS

The results show that people who were currently in drug treatment had a lower hazard of death compared with non-clients and those who had ceased treatment. Those who had ceased treatment more than 6 months ago had 7.0 times the hazard of all-cause death and 8.4 times the hazard of drug-cause death. Opiate users were at 1.4 times the hazard of all-cause death and 2.4 times the hazard of drug-cause death compared with amphetamine users. Males were at 1.79 times the hazard of all-cause death and, unexpectedly, were found to be at 2.69 times the hazard of drug-cause death compared with females.

CONCLUSIONS

Treatment protected clients from premature death compared with people who did not receive treatment and also those who ceased treatment. While amphetamine users had a lower risk of mortality compared with opiate users, the full extent of the relationship between amphetamine use and mortality needs to be examined further.

A practical method of linking data from Medicare claims and a comprehensive electronic medical records system

BACKGROUND

Linking administrative and clinical databases provides opportunities for richer studies to improve healthcare, but linkage may require sophisticated algorithms. Linking US Medicare data with large databases used for everyday clinical practice is seldom described in detail in medical literature.

OBJECTIVES

Test a deterministic method of linking data from a local electronic medical records system to Medicare data, and report specific details of the algorithm used as well as lessons learned from the linkage process.

SUBJECTS

Medicare beneficiaries with medical encounters in selected Indiana counties in the 5-year period ending in 1999.

RESULTS

For 6,388 beneficiaries with Medicare data indicating inpatient encounters in the system, 98% had links to the clinical database. Of 7,231 patients hospitalized and registered in the local clinical system, 86% contained a link to Medicare data, and 69% contained a link even without using Social security number (SSN) as an identifier. Medicare data that conflicted with local hospital records by indicating no local hospitalization occurred in 1.8%. More than 2,000 claims contained hospital identifiers that did not exist in the hospital codebook.

CONCLUSIONS

Details of a practical, deterministic method of linking Medicare claims to a large electronic records system have been applied and described. Most records were linked without SSN. A variety of inconsistencies were found and these, along with missing or incomplete data, can influence linking. Integrity of specific variables must be assessed carefully.