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Biomedical subjects

M W Ross

Publications and source records attributed to M W Ross.

At least 91 records · Page 5Linked to original sources

Predictors of unsafe injecting drug use.

This paper reports on the incidence of unsafe injecting and the factors which influence this practice in a sample of 1245 Sydney injecting drug users (IDUs). Using a needle and syringe after someone else at some time in the last six months was reported in 41.6% of the sample. Taking into account those who claimed always to clean used needles with virucidal methods, 32.9% had placed themselves at risk of HIV infection from shared needles in the six months prior to interview.Seven factors were predictive of unsafe behaviour. These were (a) the amount spent per week on drugs, (b) the number of times a single needle was used prior to disposal, (c) having shared with a person who is now HIV infected, (d) having a regular sexual partner, (e) the proportion of times high, stoned or drunk when injecting, (f) being part of a group that injects together and (g) having been in prison.

Journal Article↗

Dominant situational determinants of sexual risk behaviour in gay men.

OBJECTIVE: To examine the interplay between situational, social and psychological factors in gay men's decisions about HIV risk behaviour, using multiple hypothetical situations. METHOD: The sample included 79 gay men from Sydney recruited through flyers, press advertisements or personal contact at gay venues. Subjects were presented with 20 hypothetical situations graphically on a computer, which included different levels of attraction to partner, intoxication, attractiveness to partner, condom availability, desire for anal sex by subject, insistence of partner on using a condom and time constraints in each situation. Subjects used a computerized graphic rating scale to indicate the likelihood of unprotected anal sex in each situation, the frequency with which they had experienced the hypothetical situation in real life and satisfaction with their response. The probability of having unsafe anal sex in any given situation was the dependent variable. All other variables were predictors. RESULTS: A vector of predictors accounted for 30% of the variance (r = 0.54). Ratings of the probability of anal sex increased with the frequency that subjects had experienced hypothetical situations in real life, attraction to partner, attractiveness to partner and time elapsed since real life experience similar to the hypothetical one. Ratings of the probability of anal sex decreased with condom availability. CONCLUSIONS: Our results suggest that interventions must address the way that individuals interact with their partner and their environment in order to be successful.

Condoms↗

Explanations for sharing injection equipment in injecting drug users and barriers to safer drug use.

We examined the explanations given by a sample of 1245 injecting drug users in Sydney, Australia for accepting used injection equipment. Factor analysis of these reasons revealed three dimensions of sharing: not caring when withdrawing or intoxicated, unavailability of equipment, and not seeing it as high risk or ease of injecting. The most common reasons given were difficulty in obtaining sterile equipment (73% of cases), the dangers not seeming so important when in withdrawal (40%) and sharing being something done with friends or lovers (31%). Most common reasons for not sharing were related to health issues (91% citing AIDS and 67% hepatitis). These data suggest that interventions target provision of sterile equipment, and education which highlights risk situations such as intoxication and withdrawal.

Adult↗

Mark-recapture estimates of injecting drug users in Sydney.

The number of injecting drug users in the Central and Eastern Sydney Area Health Services (CSAHS and ESAHS) in 1989-1990 was estimated by applying the Petersen mark-recapture method to data obtained from the Australian National AIDS and Injecting Drug Use Surveys conducted in 1989 and in 1990. The population estimates for injecting drug users were 8368 (95 per cent confidence interval (CI) 6099 to 11,829) for ESAHS and 1466 (CI 742 to 2841) for CSHS. An estimate was also obtained for the number of injecting opioid users residing within the ESAHS; our figure of 3597 (CI 2731 to 5737) was consistent with previously reported estimates obtained using mark-recapture but based on different data sets.

Adult↗

Predictors of HIV status among injecting drug users and health promotion.

Two consecutive samples one year apart of injecting drug users (n = 754 and n = 345) were collected in Sydney, Australia and analysed for predictors of Human Immunodeficiency Virus (HIV) prevalence. Data indicated that similar variables were associated with HIV infection in both waves of the study. Risks for HIV infection included number of injections in last typical using month, acceptance of used injecting equipment from other injecting drug users (IDUs) who were known to be infected either before or after the sharing occurred, having sex with people known to be infected with HIV, and sexual orientation. It was not possible to determine whether sexual or equipment sharing with known HIV infected people preceded or followed HIV infection. These data confirm that predictors of HIV prevalence in Sydney are similar to those found in overseas studies and that sexual orientation appears to be the most powerful predictor. These data suggest both that sexual contact is an important route of infection in IDUs, and that sexual risks for HIV infection in IDUs need to be emphasised.

Acquired Immunodeficiency Syndrome↗

Predictors of intoxicated sex in injecting drug users.

Transmission of HIV by sexual contact as well as through sharing of contaminated injection equipment is a source of viral spread from injecting drug users (IDUs). We report on an analysis of data from 1,245 IDUs interviewed in Sydney, Australia in which half of the respondents reported being intoxicated during sex for more than half of their sexual encounters. The most common drugs on which people were intoxicated during sex were heroin, cannabis and alcohol. Predictors of having sex when intoxicated were a lower likelihood of having been in treatment, higher number of sexual partners, sharing injection equipment with more people and more recently, being intoxicated when injecting, and not being a sex worker. The data indicate that having sex while intoxicated is common in these IDUs and that sex under the influence of drugs is part of a more general lifestyle of spending a greater time intoxicated. Targeting of those IDUs who spend a significant amount of time intoxicated and their recruitment into treatment may thus reduce both risky sexual behaviour and risky injecting behaviour.

Adult↗

"It'll never happen to me": gay men's beliefs, perceptions and folk constructions of sexual risk.

This article reports on homosexually active men's beliefs about being at sexual risk. Results were generated from paid, in-depth, face-to-face interviews about sexual behavior carried out first with 4 pilot respondents, then with 21 gay respondents aged 18-39, half of whom were HIV seropositive. Findings suggest that there is not a close match between what is epidemiologically accepted as risk behavior and what respondents regarded as risk behavior. The heuristic on which the men based their perceptions of sexual risk comprised a pattern of activities in which there are few absolutes, contrary to the distinctions of "safe", "safer", and "unsafe" categories used by health educators. The men used several categories as signifiers of risk: factors such as age, appearance, diction, and HIV knowledge together with variables reflecting epidemiological data, such as few partners, being the insertive partner in anal intercourse, and past history of infrequent unprotected anal intercourse, and situational determinants such as emotional needs, sexual arousal, and relationship status were constructed into a hierarchy of risk. These hierarchies or pseudo-epidemiological models of risk are similar to what Levine and Siegel (1992) term "folk constructions" of risk of HIV transmission.

Adolescent↗

A comparison of HIV risk between women and men who inject drugs.

Although there is growing evidence of differences between women and men who inject drugs (IDUs) in terms of level of risk for HIV infection, very little research has been conducted specifically addressing the risk practices of women IDUs. This study formed part of a national study of HIV infection risks in IDUs and the purpose of the present analysis was an exploration of gender differences in HIV risk practices, focusing on the HIV risk practices of IDU women. 1,245 IDUs from the inner city area of Sydney took part in this study. Of these, 908 were men and 331 were women. Notable results were that female respondents were more likely to report sharing needles, they injected heroin more times in a typical using month and were more likely to have shared with someone they later found out was HIV seropositive. Female respondents also reported more sexual partners than men, were more likely to engage in prostitution, and were more likely to have sexual partners who were themselves IDUs. The results provide support for the proposition that women who inject drugs may be at greater risk of HIV infection through both their drug taking and their sexual practices. Further research is needed to explore the reasons underlying the risk practices of women who inject drugs and an understanding of these factors needs to be incorporated into HIV risk-reduction and drug harm-reduction policies and programs.

Adolescent↗

Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone in five standardbred racehorses.

Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone (MT3) caused an acute onset of lameness in 5 horses; however, 3 of the horses had historical and radiographic or scintigraphic evidence of chronic tarsal and metatarsal disease before fracture. The pathogenesis of dorsoproximolateral fracture of MT3 remains unclear, but the fracture may occur as a result of the formation of abnormal bone in the proximal aspect of MT3. The prognosis for racing in horses with this fracture appears to be guarded.

Animals↗

Transoral axial division, under endoscopic guidance, for correction of epiglottic entrapment in horses.

Transoral axial division was performed, using endoscopic guidance, in 20 horses with epiglottic entrapment. Mean age of affected horses was 3 years (range, 2 to 5 years), and there were 18 Standardbreds and 2 Thoroughbreds. Standardbreds and female horses were significantly overrepresented when compared with a reference population. Upper respiratory noise prompted endoscopic examination before surgery in 16 horses, but noise was not heard in 4 horses. Ten horses had entrapment by thin tissue without ulceration, 6 horses had entrapment by thin tissue with small, partial-thickness ulceration, 3 horses had entrapment by moderately thick tissue with large, partial-thickness ulceration, and 1 horse had entrapment with thick tissue and severe ulceration. After surgery, horses received anti-inflammatory medication and box stall rest with hand walking for 7 days. All horses returned to race training on day 7 after surgery and returned to their previous level of racing or training. Epiglottic entrapment recurred in 2 horses (10%), and dorsal displacement of the palate developed in 2 horses after surgery. Relationship of epiglottic entrapment and dorsal displacement of the palate to epiglottic hypoplasia was not apparent. Transoral axial division under endoscopic guidance appeared to be a useful, safe, and economic alternative to currently available methods for management of epiglottic entrapment in horses. Horses with entrapment by thick and ulcerated tissue may be best managed by surgical resection of entrapping tissue.

Animals↗

Injecting drug users and HIV/AIDS: risk behaviours and risk perception.

This paper reports on the incidence of risk taking behaviours, and the relationship between risk perception and risk behaviours in a sample of 1245 Sydney injecting drug users (IDUs). Almost all respondents reported engaging in behaviours that placed them at risk of HIV infection: 32.9% through unsafe injecting, 84.4% because of unsafe sexual behaviour and 89.2% because of either injecting or sexual behaviour. Injecting and sexual behaviour were poorly correlated. This study also found that risk perception is unrelated to injecting or sexual behaviours, previous history of sexually transmitted diseases, a range of demographic characteristics including age and gender, and the number of times tested for HIV. Social policy and prevention programs should aim to change unsafe injecting and sexual behaviours directly, rather than attempting to achieve change indirectly by changing risk perception.

AIDS Serodiagnosis↗

Future time perspective in current and previous injecting drug users.

Future time perspective (FTP) is a measure of an individual's ability to conceptualise the future which has been shown to be foreshortened in drug addicts. We studied 100 opiate injecting drug users (IDUs) in New South Wales, Australia, of which half were currently injecting and half were not. There was a significant difference between the two groups on FTP, with those currently injecting having a truncated FTP extension. Factor analysis of the FTP scale suggested that the dimensions of future time may differ between groups, with current injectors having a perspective of loss and isolation compared to the dimension of self-evaluation and self-acceptance in those not currently injecting. These data support previous studies which demonstrated truncated FTP, also demonstrating a difference in currently (as opposed to previously) IDUs and suggest that both extension of FTP and an alteration of the dimensions of FTP are associated with cessation of injecting and entry into treatment.

Adult↗

Significant relationships and social supports of injecting drug users and their implications for HIV/AIDS services.

Strong social support networks have been associated with positive outcomes for health and well-being throughout the life-cycle. This paper investigates the structural and functional nature of social support networks of 100 injecting drug users (IDUs) in Sydney and the implications for HIV/AIDS services. Using a modified ISEL respondents saw support in terms of its tangibility of people and support, in terms of an appraisal of having friends, and as a self-esteem measure. We found the majority of respondents 'hung around' with other IDUs, lived with other IDUs, and were satisfied with the support they received from their friends. Friends appeared to be a more important source of social support than biological families and if respondents were to become HIV infected they would be more open about their status with friends than family. Where family was involved in support it was likely to be provided by mothers and siblings who were also the family members who knew about the respondent's drug use. There was no relationship between numbers of supports and satisfaction of support, suggesting quality and quantity of support were independent. Non-social supports were conceptualized primarily in terms of medical services.

Acquired Immunodeficiency Syndrome↗

Changes in equipment sharing in injecting drug users in Sydney 1989-1990.

We investigated levels of equipment sharing in injecting drug users in Sydney, Australia, in two consecutive samples recruited in a non-treatment setting using similar methodology in 1989 (n = 1,245) and 1990 (n = 550). Comparison between the two waves of the study indicated that there were consistent and major reductions in percentage of time used equipment was re-used, and number of people from whom used equipment had been accepted. There was a corresponding significant and major increase in use of sterile injection equipment, obtained more frequently in the second sample from needle and syringe exchanges. The proportion of respondents reporting they had never shared equipment rose significantly. These data suggest that there is a continuing increase in the adoption of safer injecting practices and utilisation of needle and syringe exchanges over time in response to the threat of HIV transmission in injecting drug users.

Journal Article↗

Racing performance of standardbreds after conservative and surgical treatment for tarsocrural osteochondrosis.

A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC-affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presenting sign in the group that received surgical treatment. There was no association between presence of lameness and the type of treatment used. Data from the race records of treated and control horses (including the number of starts, lifetime earnings and record racing times) were compared. Overall, horses treated for OC had significantly fewer starts than, but earnings similar to, those in the control group. However, when stratification by sex was performed, females with OC made fewer starts and had lower earnings than did their control group. There was no significant difference in record time between OC-affected horses and controls. These results indicate that horses treated for osteochondrosis of the cranial intermediate ridge of the distal tibia performed as well as matched controls.

Age Factors↗

A comparison of drug use and HIV infection risk behavior between injecting drug users currently in treatment, previously in treatment, and never in treatment.

We compared three groups of injecting drug users in a large cross-sectional study on HIV/AIDS and risk behaviors in Sydney, Australia, to determine what differences existed between those who had never been in treatment (n = 458), had previously been in treatment (n = 387), and were currently in treatment (n = 367). Drug use for those currently in treatment was assessed during the last typical using month before treatment. Those previously and currently in treatment were similar in terms of drug use patterns and HIV risk-related injecting behaviors. Those never in treatment were younger, had a lower level of HIV risk-related injecting behaviors, and reported lower drug use and less involvement in the drug subculture. There was little difference between the three groups on HIV risk-related sexual behaviors. These data suggest that those never in treatment are less dysfunctional and possibly less involved in drug-using careers, whereas there appears to be a close relationship between being previously and currently in treatment.

Adult↗