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Biomedical subjects

S Darke

Publications and source records attributed to S Darke.

At least 19 recordsLinked to original sources
PubMed2001

Physical injecting sites among injecting drug users in Sydney, Australia.

A sample of 200 injecting drug users were interviewed about their bodily injection sites. The mean number of injection sites ever used by subjects was 3.1, with a mean of 2.0 sites used in the previous 6 months. Sixteen percent of subjects had injected in five or more sites. Almost all (99%) had injected in the cubital fossa (crook of the arm). The next most popular site was the forearm (71%). Other sites included the hand (53%), foot (19%), leg (18%), neck (10%) and groin (6%). There was a clear progression in sites used, from the cubital fossa at initial injection to the use of sites such as the groin after 10 years of injecting. Females had used significantly more injection sites than males and reported more injection-related problems. The use of more injection sites was independently associated with a greater number of injection-related problems and a greater number of drug classes ever injected.

Adolescent↗
PubMed2001

The relationship between suicide and heroin overdose among methadone maintenance patients in Sydney, Australia.

AIMS: To examine the relationship between attempted suicide and non-fatal heroin overdose among methadone maintenance patients. DESIGN: Cross-sectional survey. SETTING: Sydney, Australia. PARTICIPANTS: Two hundred and twenty-three methadone maintenance patients. FINDINGS: Forty per cent of participants reported a history of at least one suicide attempt. Females were significantly more likely than males to have attempted suicide (50% vs. 31%), and to have done so on more than one occasion (28% vs. 15%). There was a large difference between males and females in the onset of attempted suicide. Females reported an initial attempt, on average, 6 years earlier than males (18.3 vs. 24.7 years), and were significantly more likely than males to have attempted suicide prior to the onset of heroin use (69% vs. 11%). While heroin overdose was common among the sample (66%), the most common methods employed for suicide attempts were overdose of a non-opioid drug (21%) and slitting of wrists (20%). A deliberate heroin overdose as a means of attempted suicide was reported by 10% of participants. Heroin overdoses appeared overwhelmingly to be accidental. Ninety-two per cent of those who had overdosed reported that their most recent overdose was accidental. CONCLUSIONS: Attempted suicide presents a major clinical problem to staff at drug treatment programmes, but one distinct from heroin overdose. While both overdose and suicide present increasing clinical problems, they are separate problems, and require different responses.

Cross-Sectional Studies↗
PubMed2001

Geographical injecting locations among injecting drug users in Sydney, Australia.

AIMS: To document the geographical injection locations of IDU, and the factors and harms associated with injecting in public places. DESIGN: Cross-sectional survey. SETTING: Sydney, Australia. PARTICIPANTS: Two hundred injecting drug users. FINDINGS: Nearly all subjects (96%) had injected in a public place, and 89% had done so in the preceding 6 months. Large proportions had injected in all locations studied, including cars (90%), public toilets (81%), the street (80%) and trains (55%). Injecting in public places also occurred frequently, with 53% of subjects having injected often in at least one public location during the preceding 6 months. Twenty-seven per cent of subjects had injected often in the street over the preceding 6 months, 22% had injected often in cars and 17% had injected often in public toilets. Frequent injectors in public places were more likely to be male, and to have overdosed in the preceding 6 months, injected significantly more drug classes in the preceding 6 months, injected in more bodily injecting sites in the preceding 6 months and had more current injection-related problems than other IDU. CONCLUSIONS: Injecting in public places was practiced by the overwhelming majority of the sample, and a pattern of increased harm was associated with frequent public injecting. In attempting to quantify the harm associated with injecting, and to reduce such harm, the locations injections take place in are of major importance.

Adolescent↗
PubMed2001

Heroin overdose: causes and consequences.

Over the past decade fatal opioid overdose has emerged as a major public health issue internationally. This paper examines the risk factors for overdose from a biomedical perspective. While significant risk factors for opioid overdose fatality are well recognized, the mechanism of fatal overdose remains unclear. Losses of tolerance and concomitant use of alcohol and other CNS depressants clearly play a major role in fatality; however, such risk factors do not account for the strong age and gender patterns observed consistently among victims of overdose. There is evidence that systemic disease may be more prevalent in users at greatest risk of overdose. We hypothesize that pulmonary and hepatic dysfunction resulting from such disease may increase susceptibility to both fatal and non-fatal overdose. Sequelae of non-fatal overdose are recognized in the clinical literature but few epidemiological data exist describing the burden of morbidity arising from such sequelae. The potential for overdose to cause persisting morbidity is reviewed.

Adolescent↗
PubMed2001

A prospective audit of complex wound and graft infections in Great Britain and Ireland: the emergence of MRSA.

BACKGROUND: a number of studies have examined the outcome of complex wound and graft infections, but most include small numbers of patients collected over a prolonged period of time. To date, there is little information on the clinical outcome of infections involving methicillin-resistant Staphylococcus aureus (MRSA). METHODS: between February 1998 and January 1999, two prospective multi-centre audits were performed in order to examine the current outcomes following (1) complex vascular wound infections and (2) graft infections in Britain and Ireland with particular reference to outcome associated with MRSA infection. RESULTS: seventy-five complex wound infections (Szylagyi II and III) were reported, with the commonest single organism being MRSA. Type II infections were associated with a 5% risk of death and/or amputation as opposed to 75% in those with a type III infection. Fifty-five graft infections were reported, with the commonest single organism being MRSA. Overall, 30 (55%) died or underwent amputation. MRSA wound and graft infections were associated with a significantly higher risk of amputation and prolonged hospital stay (but not of death) as compared with MRSA negative patients. CONCLUSIONS: in this audit, MRSA was the commonest single organism cultured in patients with complex wound and graft infections after vascular surgery. This represents a major change in the spectrum of causative organisms relative to other, older published series. MRSA infections contribute towards an increased risk of adverse outcome and prolonged hospital stay.

Cross Infection↗
PubMed2000

Heroin-related deaths in New South Wales, Australia, 1992-1996.

The coronial files of all heroin-related fatalities that occurred in New South Wales (NSW) over the period 1992-1996 were inspected. There were 953 heroin-related fatalities in NSW over the study period. There was a substantial, statistically significant increase in heroin-related fatalities over the study period, from 152 deaths in 1992 to 226 during 1996. The mean age of cases was 31.0 years, 85% were male, and 85% were classified as dependent on heroin at the time of death. There was a significant increase in the age of cases over the study period and the proportion of cases that were employed. Fatalities predominantly occurred in home settings (61%). No intervention occurred in 79% of cases. Fifty deaths (5%) occurred in the month following release from prison, 16 of which occurred the first 24 hours after release. Morphine concentrations rose from 0.24 mg/l in 1992 to 0.38 mg/l in 1996. Seventy six percent of cases involved heroin in combination with other drugs: alcohol (46%), benzodiazepines (27%), antidepressants (7%) and cocaine (7%). In only 24% of cases was morphine the sole drug detected. Males were significantly more likely to have alcohol detected at autopsy (49 vs. 24%), while females were more likely to have benzodiazepines detected (41 vs. 17%). The median blood morphine concentration among cases in which alcohol was detected was significantly lower than other cases (0.27 vs. 0.39 mg/l). It is concluded that heroin-related deaths continued to rise throughout the study period, and that deaths were predominantly among older, untreated males. Despite the rise in blood morphine concentrations, polydrug use remained the predominant toxicological pattern.

Adolescent↗
PubMed2000

A comparison of the harms associated with the injection of heroin and amphetamines.

An investigation into whether or not the level of harm associated with injecting drug use varies depending on the drug that is injected was conducted among 151 primary heroin injectors and 145 primary amphetamine injectors. Compared to primary amphetamine injectors, primary heroin injectors were more dependent on their primary drug, had poorer social functioning, and had recently exhibited a higher degree of criminal behaviour. There were no differences between the two groups in terms of the prevalence of needle sharing, their health, or their psychological functioning, despite the amphetamine users being significantly younger and having used less frequently. It is concluded that while there are some harms that are attributable to injecting per se, the type of drug that is injected does play a mediating role in the relationship between injecting drug use and its associated harm.

Adolescent↗
PubMed2000

The nature of benzodiazepine dependence among heroin users in Sydney, Australia.

AIMS: To determine the extent to which heroin users meet criteria for benzodiazepine dependence, to examine the appropriateness of these criteria for assessing benzodiazepine dependence among this population, and to assess what other substance use, depressive and anxiety disorders are associated with benzodiazepine dependence. DESIGN: Cross-sectional survey. SETTING: Sydney, Australia. PARTICIPANTS: Two hundred and twenty-two heroin injectors recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth. FINDINGS: Twenty-six per cent (52/202) of those who had used benzodiazepines received a life-time diagnosis of benzodiazepine dependence, with 22% of current benzodiazepine users being dependent. A principal components analysis revealed that a unidimensional construct underlies the benzodiazepine dependence syndrome. Those respondents with life-time benzodiazepine dependence were more likely than others to meet criteria for anxiety or depressive disorders. CONCLUSIONS: The inclusion of the benzodiazepine dependence syndrome in DSM-III-R (and DSM-IV) is justified. A disturbingly high proportion of heroin users meet the criteria for benzodiazepine dependence, a condition that should be regarded as a significant marker for co-morbidity among this group.

Adolescent↗
PubMed2000

The use of antidepressants among injecting drug users in Sydney, Australia.

AIMS: To ascertain the prevalence and patterns of antidepressant use among IDU in Sydney and to determine any harm associated with antidepressant use. DESIGN: Cross-sectional survey. SETTING: Sydney, Australia. PARTICIPANTS: Two hundred and one Sydney injecting drug users (IDU) recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth. FINDINGS: Forty per cent of subjects had used antidepressants, 21% in the preceding 6 months. Similar proportions of subjects had used tricyclics (26%) and selective serotonin reuptake inhibitors (SSRIs) (24%), with 8% reporting use of a monoamine oxidase inhibitor. Recent use favoured the SSRIs; however, there was still widespread use of tricyclics. The injection of antidepressants was rare, with only three subjects reporting ever having injected the drugs. Antidepressant use was associated with higher levels of polydrug use, poorer health, higher levels of psychiatric distress and a greater risk of heroin overdose. The excess risk of overdose was specifically associated with tricyclics, rather than SSRIs. CONCLUSIONS: The study confirmed that, like other pharmaceutical products, the use of antidepressants was common among IDU in Sydney. The prescription of tricyclics to heroin users would appear to increase their risk of overdose. If it is considered appropriate to prescribe antidepressants to IDU, it would appear safer to prescribe SSRIs.

Adolescent↗
PubMed2000

Fatal heroin overdoses resulting from non-injecting routes of administration, NSW, Australia, 1992-1996.

AIMS: To document cases of fatal heroin overdose in New South Wales by non-injecting routes of administration, and to compare the characteristics and toxicology of these cases with injecting fatalities. DESIGN: Examination of coronial files. SETTING: New South Wales, Australia. PARTICIPANTS: All fatal heroin overdose cases in NSW between 1992 and 1996. FINDINGS: There were 10 cases of death resulting from non-injecting routes of heroin administration between 1992 and 1996, representing 1% of cases. In three cases the route of administration was by inhalation, in five cases by nasal administration and in two cases by swallowing. The mean age of cases was 29.6 years, and nine of the cases were male. The median blood morphine concentration of non-injectors was 0.31 mg/l (range 0.06-0.99 mg/l). Drugs other than morphine were also detected in seven cases. CONCLUSIONS: Heroin overdose deaths are not restricted to the injection of heroin. While injection may constitute a greater overdose risk-factor, there is no safe, overdose-free way to use heroin.

Administration, Inhalation↗
PubMed2000

Cognitive impairment among methadone maintenance patients.

AIMS: To compare the cognitive performance of methadone maintenance patients (MMPs) and a matched sample of non-heroin-using control subjects, and to ascertain risk factors for poorer cognitive performance. DESIGN: Matched control study. SETTING: Sydney, Australia. PARTICIPANTS: Thirty MMPs and 30 non-heroin using controls, matched for age, gender and education. FINDINGS: The MMP group had significantly higher rates than controls of alcohol dependence, heroin overdose and head injury. There was no difference between the groups on pre-morbid functioning. The MMP group performed significantly poorer than controls on all of the neuropsychological domains measured: information processing, attention, short-term visual memory, delayed visual memory, short-term verbal memory, long-term verbal memory and problem solving. A life-time diagnosis of alcohol dependence and the number of non-fatal heroin overdoses were independent significant predictors of poorer cognitive performance. CONCLUSIONS: In addition to high rates of psychiatric morbidity, MMPs also show cognitive deficits compared to matched controls. A history of alcohol dependence and repeated exposure to overdose increase the likelihood of cognitive impairment. The current study does not rule out the possibility of other factors, that were not measured, that may contribute to cognitive impairment among this MMPs.

Adult↗
PubMed2000

A strategy for vascular services--testing the 600,000 population model.

BACKGROUND: Vascular services' delivery has been criticised, and re-organisation based on a 600,000 population model suggested. We assessed the feasibility of this model in three geographically disparate English regions. METHODS: Surgical arterial activity by Trust was analyzed using 1994/95 data from Hospital Episode Statistics. A postal survey of acute Trusts was used to assess vascular facilities and personnel. Distances between hospitals and enumeration districts were mapped using a Geographical Information System. MAIN OUTCOME MEASURES: Number (proportion) of Trusts performing over 100 arterial procedures a year. Number (proportion) of Trusts with a vascular on-call rota. Proportion of population likely to live more than 40 km away (equivalent to 1 h blue-light ambulance travel time) from a vascular unit under the proposed model. RESULTS: Twelve of the 32 Trusts (38%) performed over 100 arterial procedures annually; 23 Trusts completed the survey. Of these, five (22%) had a vascular on-call rota. Under the 600,000 model, in East Anglia a further 16.5% of the population would live > 40 km from a vascular unit. In Wessex, a further 0.4% of the population would live > 40 km from a vascular unit. Impact on access in North West Thames was negligible. CONCLUSIONS: A 600,000 population model could be feasible in urbanized regions, but not in geographically remote ones.

Delivery of Health Care↗
PubMed1999

Fluctuations in heroin purity and the incidence of fatal heroin overdose.

In order to determine the role played by heroin purity in fatal heroin overdoses, time series analyses were conducted on the purity of street heroin seizures in south western Sydney and overdose fatalities in that region. A total of 322 heroin samples were analysed in fortnightly periods between February 1993 to January 1995. A total of 61 overdose deaths occurred in the region in the study period. Cross correlation plots revealed a significant correlation of 0.57 at time lag zero between mean purity of heroin samples per fortnight and number of overdose fatalities. Similarly, there was a significant correlation of 0.50 at time lag zero between the highest heroin purity per fortnight and number of overdose fatalities. The correlation between range of heroin purity and number of deaths per fortnight was 0.40. A simultaneous multiple regression on scores adjusted for first order correlation indicated both the mean level of heroin purity and the range of heroin purity were independent predictors of the number of deaths per fortnight. The results indicate that the occurrence of overdose fatalities was moderately associated with both the average heroin purity and the range of heroin purity over the study period.

Adolescent↗
PubMed1999

Value of routine computed tomography in the preoperative assessment of abdominal aneurysm replacement.

This study compares the findings of conventional computed tomography (CT) and ultrasound (US) imaging in the preoperative evaluation of patients with abdominal aortic aneurysm (AAA). It also assesses the impact of preoperative CT-derived information on operative strategy. A prospective study was conducted of 96 patients who were considered for aortic aneurysm surgery, and the operative notes and US and CT reports were analyzed to assess correlation of findings and influence of CT on operative tactics. Agreement between CT and US in sizing the aneurysm was generally good. CT was more accurate than US for defining the upper and lower extent of the aneurysm (75% and 83%, respectively, with CT, compared to 47% and 41% with US), although it had a high false positive rate (48%) for juxtarenal disease. Its advantage over US in regard to showing other intraabdominal pathology was only marginal, and it predicted an inflammatory reaction in only two of the five cases. Its influence on operative strategy was minimal: Of the 25 cases where a juxtarenal aneurysm was predicted by CT, only 2 patients did not have surgery as a result. CT is a relatively expensive and time-consuming procedure, and its ionizing radiation, however small, and potential side effects from contrast material hypersensitivity cannot be ignored. In light of the above findings, we suggest that CT scanning need not be routinely employed in the preoperative workup of elective aortic aneurysm repair but should be used only in selected cases.

Aged↗
PubMed1999

Transitions between the injection of heroin and amphetamines.

AIMS: To assess in current injecting heroin and amphetamine users to what extent their history of injecting represents a transition from amphetamine to heroin. DESIGN: Cross-sectional survey. SETTING: Sydney, Australia. PARTICIPANTS: One hundred and fifty-one primary heroin injectors and 145 primary amphetamine injectors recruited through advertisements, needle exchanges, methadone maintenance clinics and by word of mouth. FINDINGS: Six major transition patterns were detected: heroin-heroin (n = 61), amphetamines-heroin (n = 60), heroin-amphetamines-heroin (n = 30), amphetamines-amphetamines (n = 80), amphetamines-heroin-amphetamines (n = 41) and heroin-amphetamines (n = 24). A logistic regression analysis predicting presence or absence of a transition from the original primary drug indicated that length of injecting career, years of education and original drug injected were independent predictors. Thus, the longer the injecting career, the greater the likelihood of a transition. If the original drug injected was amphetamine, the greater the likelihood of transition; and the more prior years of education, the lower the chances of a transition. CONCLUSIONS: While there was a small preponderance of movement from primary amphetamine injecting to primary heroin injecting, there was also movement in the other direction. Heroin use is not necessarily a stable endpoint for injecting careers.

Adolescent↗
PubMed1998

The onset of heroin use and criminal behaviour: does order make a difference?

The extent to which the onset of criminality with respect to heroin use accounts for heterogeneity within a heroin-using population was investigated among 400 community and incarcerated methadone maintenance patients. Those for whom crime preceded heroin use (primary antisocials) were younger and more likely to be male than those for whom heroin use preceded crime (secondary antisocials). Primary antisocials were also more likely to have committed violent crime and to qualify for a diagnosis of antisocial personality disorder (ASPD). It is concluded that taking the order of onset of heroin use and criminality into account may reduce the risk of overdiagnosing ASPD among this population and help clarify the relationship between drug use and crime.

Adult↗
PubMed1998

Trends in opiate overdose deaths in Australia 1979-1995.

AIMS: To determine if there had been an increase in the rate of opioid overdose deaths between 1979 and 1995, and to describe the characteristics of persons who died of an opioid overdose. METHOD: Opioid overdose deaths were defined according to ICD-9 as deaths due to drug dependence (codes 304.0 and 304.7) and accidental opiate poisoning (code E850.0). Data were obtained from a national register of deaths compiled by the Australian Bureau of Statistics on: age at death, sex and jurisdiction of all such deaths between 1979 and 1995 inclusive. Mortality rates were calculated for each sex for the 15-24, 25-34 and 35-44 age groups. RESULTS: The number of opioid overdose deaths rose from 70 in 1979 to 550 in 1995. The rate (per million of the population aged 15-44) increased from 10.7 to 67.0. The increase was more marked among males than females, increasing 6.8 times among males (from 15.3 in 1979 to 104.6 in 1995) and 4.7 times among females (from 5.9 in 1979 to 27.9 in 1995). New South Wales consistently accounted for around a half of all male overdose fatalities and its overdose mortality rate was almost twice that in Victoria, and three times that in the remaining states. The average age at death for males increased from 24.5 years in 1979 to 30.6 years in 1995. The increase in overdose mortality was greatest among men and women aged 35 to 44 years, and 25 and 34 years. An analysis by birth cohort showed that 46% of male overdose deaths and 50% of female overdose deaths in the period occurred among those born between 1960 and 1969. Deaths among persons born between 1950 and 1959 accounted for 38% of male and 33% of female deaths. CONCLUSIONS: There has been a statistically significant increase in opioid overdose mortality between 1979 and 1995, most of it occurring among persons who initiated heroin use in the late 1970s and early 1980s. Recent initiations of heroin use among those born between 1970 and 1979 have begun to be reflected in an increased rate of opioid overdose deaths. If their mortality experience replicates that of earlier birth cohorts then opioid overdose mortality will continue to increase.

Adolescent↗