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PubMed2003

Strain and age differences in behaviour, fear response and pecking tendency in laying hens.

1. Behaviours associated with a high or low tendency to feather peck could be used as predictors of feather pecking behaviour in selective breeding programmes. This study investigated how strain and age at testing influenced responses in behavioural tests. 2. Four layer-type strains (ISA Brown, Columbian Blacktail, Ixworth and a high feather pecking (HP) and a low feather pecking (LP) line of White Leghorn) were reared in 6 same-strain/line pens of 8 birds from one day old. Birds in half the pens were given an open field test, a novel object test and a test with loose feather bundles between 4 and 12 weeks of age and a tonic immobility (TI) test at 13 weeks of age. All pens were tested with fixed feather bundles at 26 weeks, and undisturbed behaviour in the home pens was videoed at 1 and 27 weeks of age. Daily records of plumage damage were used as an indicator of feather pecking activity in the home pens. 3. Strain did not influence novel object test, open field test or loose feather test behaviour, although age effects in all three tests indicated a reduction in fearfulness and/or an increase in exploratory behaviour with increasing age. 4. White Leghorns showed longer TI durations than the other strains but less pecking at fixed feather bundles than ISA Browns and Columbian Blacktails. 5. There were few associations between behaviour in the 5 different tests, indicating that birds did not have overall behavioural traits that were consistent across different contexts. This suggests hens cannot easily be categorised into different behavioural 'types', based on their test responses and casts doubt on the usefulness of tests as predictors of feather pecking.

Age Factors↗
PubMed1999

Laying hens in large flocks in a perchery system: influence of stocking density on location, use of resources and behaviour.

1. ISA Brown laying hens (3000) were housed in a perchery in 10 pens, each with 300 birds. The pens varied in size to produce 4 different stocking densities: 9.9 birds/m2 (n = 3), 13.5/m2 (n = 2), 16.0/m2 (n = 2) and 19.0/m2 (n = 3). Observations began at 20 weeks of age and continued until 69 weeks to establish the spatial distribution of the birds, usage of the different resources and the expression of behaviour. 2. Overall, birds spent most time on the perch frame (47%), litter area (23%), slatted floor (17%) and nestbox area (9%). 3. There was no effect of density on the proportion of birds observed on the slatted floor or on the elevated perches but as density increased the proportion on the littered area decreased. 4. Space usage was determined vertically, horizontally and longitudinally. Individual birds were seen to use about 80% of the pen volume available to them. This value was similar for all densities and showed that individuals did not have separate home ranges. 5. Fewer vertical movements were made within the main perch frame at the upper than at the lower levels but movements between the perches of the main frame and the nestbox rails were relatively frequent. This may help birds move up and down through the main frame. 6. Behaviours which decreased in incidence with crowding included moving, foraging and dust-bathing. Behaviours which increased with crowding included standing. Behaviours which were unaffected included resting, preening, prelaying behaviour, comfort behaviour and the minor behaviours. 7. The proportion of birds engaged in feeding and drinking was unaffected by density, except each time the chain feeders (which operated intermittently) ran more hens were seen feeding at the lower densities. This suggests that food delivery stimulated feeding behaviour; there may have been some restriction at the higher densities on birds feeding when and where they wanted. 8. Stocking density had no effect on the frequency of agonistic interactions: threats, lunges, comb/head pecks, chases and fights. 9. The incidence of damaging pecking was low and not density dependent. 10. Increasing density within the range investigated inhibited the expression of a number of behaviours and limited the use of specific resources: bird welfare at 19 birds/m2 may have been very slightly impaired.

Aggression↗
PubMed2003

Applying an extended version of the theory of planned behaviour to physical activity.

This prospective study explored whether extending the Theory of Planned Behaviour (TPB) with additional variables (descriptive norm, moral norm, anticipated affective reaction, self-identity and past behaviour) would account for additional variance in physical activity intentions and behaviour. Four interactions with past behaviour were also investigated. UK college employees participated in this study (n = 200, Time 1; n = 146, Time 2). Moral norm, self-identity and past behaviour each explained additional variance in intentions, over and above the TPB variables. Past behaviour moderated the impact of descriptive norm on intentions. Intentions, self-identity and past behaviour were significant predictors of behaviour, as measured by a self-report physical activity questionnaire. To increase physical activity, interventions might target moral norm and self-identity for physical activity. Focusing on positive descriptive norms might benefit sedentary individuals. The significant role of past behaviour is less useful in directing interventions.

Adult↗
PubMed1999

A non-aversive rehabilitation approach for people with severe behavioural problems resulting from brain injury.

An approach is presented which uses exclusively non-aversive methods in the behavioural rehabilitation of people with severe behaviour problems resulting from acquired brain injury. The approach has five components: (1) behavioural assessment: analysing the way all aspects of a person's functioning may affect their behaviour, (2) positive programming: teaching the skills necessary to allow the person to achieve their desired ends without resorting to inappropriate behaviour, (3) ecological change: altering the environment to achieve a better match with the individual's cognitive deficits, (4) focused treatment: using behavioural contingencies to achieve a rapid reduction in target behaviour, and (5) reactive strategies: specifying action to be taken to gain short-term control over episodes of challenging behaviour. The current literature on behavioural rehabilitation is reviewed in the context of this approach. Two case studies are presented illustrating the use of the approach in practice. The strengths and potential pitfalls of the approach are discussed, along with issues which need to be considered for effective implementation.

Adaptation, Psychological↗
PubMed1999

Gender differences in early adolescence in factors related to outcome of healthy behaviours two years later.

In this study, 390 students comprising 89.7% of the student population answered a questionnaire on health and health behaviours, socioeconomic status (SES), school, family and peer relationships, and intentions regarding behaviours at 13.5 and 15.5 y of age. The aim was to investigate whether there were gender differences in predictors of outcome of behaviours with impact on health at 15.5 y of age. Outcome dealt with three domains: health habits, acquisition of adult lifestyles, and problem behaviours. The material was analysed for correlations. Significant results were entered into multiple regression stepwise procedures. As expected, having already initiated adult lifestyles or exhibiting problem behaviours at 13.5 y were the most important factors associated with such behaviours 2 y later. Further analyses were then limited to those students who had not started such lifestyles to see what factors kept them from doing so in a 2-y period and what gender differences existed, if any. Results differed for the genders, with more boys being more concrete and behaviour-oriented, representing a sample of boys with late to normal puberty. Girls more often expressed intentions regarding behaviour, which predicted positive outcomes. Both genders were prudent in most areas studied: they were well adapted at school, had positive self-esteem and were not moving in circles where smoking and drinking were abundant. The conclusion is that young adolescents who do not start risky behaviours between the ages of 13 and 15 y live in a supportive context, which allows for positive interactions. The next step would be to investigate if alternative strategies may be used to implement similar options for those who lack such support in their natural environment.

Adolescent↗
PubMed2001

Study of perceived norms, beliefs and intended sexual behaviour among higher secondary school students in India.

The objective of this paper is to understand the intended sexual and condom behaviour patterns among teenage higher secondary school students in India. To achieve this, variables including perceived norms, perceived peer group norms, risk behaviour patterns, perceived chances of getting AIDS and relevant sociodemographic variables were regressed on intended sexual behaviour. Regression of actual sexual behaviour was carried out with perceived norms, perceived peer group norms and intended sexual behaviour as the independent variables. In this paper a conceptual model has been framed based on the theory of reasoned action, health belief model and self-efficacy theory. Cumulative scores are computed for perceived norms, perceived peer group norms, risk behaviour patterns, opinion on handling condoms and perceived chances of getting AIDS. Along with these variables, possible confounding variables such as age, gender, type of family, mother's education and father's education were considered for their effect on intended sexual and condom behaviour. The results revealed that perceived norms and perceived peer group norms showed significant association with intended sexual behaviour and actual sexual behaviour and that children of more highly educated parents are less likely to engage in sexual activities in their adolescent years.

Adolescent↗
PubMed2002

Sexual behaviour patterns and condom use in Tanzania: results from the 1996 Demographic and Health Survey.

We conducted this study to determine the factors associated with high-risk sexual behaviour and condom use among men and women who participated in the 1996 Tanzania Demographic and Health Survey (TDHS); and to assess changes in sexual behaviour between 1991/92 and 1996 TDHS. Respondents were regarded to have practised high-risk sexual behaviour if they were married or cohabiting and had other regular or non-regular sexual partners; or if they were unmarried and had non-regular partners or multiple regular partners. About 8% of women and 29% of men practised high-risk sexual behaviour. High-risk sexual behaviour was common among younger men and women, and decreased with increasing level of education in women. Respondents who were unmarried, Muslims and those who perceived themselves at increased risk of HIV/AIDS were more likely to practise high-risk sexual behaviour. About 4% of women and 15% of men reported to have used condoms during their last sexual encounter. Condom users were significantly more likely to practise high-risk sexual behaviour. Overall, no major changes in sexual behaviour and condom use were observed during the period between the two surveys. Predictors of high-risk sexual behaviour and condom use identified in this report provide valuable information that can be used to design targeted HIV/AIDS interventions in Tanzania.

Adolescent↗
PubMedDate not supplied

An intervention to reduce disruptive behaviours in children with brain injury.

This study investigated the effectiveness of a behavioural intervention programme in reducing disruptive behaviours in children with brain injury. The behavioural package included programme rules, a token economy with response cost and mystery motivators. Participants were three male patients in an after-school programme at a rehabilitation hospital who were identified as having both a brain injury and disruptive behaviours in the classroom setting. Two control composites were formed, one with children who behaved appropriately and one with children who behaved in a disruptive manner. This study employed a multiple baseline design across individuals. The participants' disruptive behaviour decreased during the intervention phase by an average of 69%; the effect size of each participant's improvement was 'large'. The comparisons' disruptive behaviour was unchanged. This pronounced decrease in disruptive behaviours for the three participants was maintained in the follow-up phase. This short-term, easily implemented package altered important programme and social behaviours positively, were well received by children and staff and resulted in long-term improvements to behavioural deficits secondary to brain injury. These results are discussed in terms of theoretical disagreements, methodological issues and practical community-based interventions in brain-injured children.

Adolescent↗
PubMed1999

Nursing home characteristics and the development of pressure sores and disruptive behaviour.

OBJECTIVE: To determine how nursing home characteristics affect pressure sores and disruptive behaviour. METHOD: Residents (n = 5518, aged > or =60 years) were selected from 70 nursing homes in the National Health Care chain. Homes were classified as high- or low-risk based on incidence tertiles of pressure sores or disruptive behaviour (1989-90). Point-prevalence and cumulative incidence of pressure sores and disruptive behaviour were examined along with other functional and service variables. RESULTS: The overall incidence of pressure sores was 11.4% and the relative risk was 4.3 times greater in high- than low-risk homes; for disruptive behaviour, the incidence was 27% and the relative risk was 7.1 times greater in the high-risk group. At baseline, fewer subjects in homes with a high risk of pressure sores were white or in restraints, but more had received physician visits monthly and had had problems with transfers and eating. High-risk homes also had fewer beds and used less non-licensed nursing staff time. At follow-up (1987-90), 52% of homes in the low-risk group and 35% of those in the high-risk group had maintained their risk status; low-risk homes were more likely to have rehabilitation and maintenance activities. Having multiple clinical risk factors was associated with more pressure sores in high- (but not low-) risk homes, suggesting a care-burden threshold. By logistic regression, the best predictor of pressure sores was a home's prior (1987-88) incidence status. Interestingly, 67% of homes with a high risk of pressure sores were also high-risk for disruptive behaviour, while only 27% of homes with a low risk of pressure sores were high-risk for disruptive behaviour. A threshold effect was also observed between multiple risk factors and behaviour. More homes with a high risk of disruptive behaviour (68%) remained at risk over 4 years, and the best predictor of outcome was a home's previous morbidity level. CONCLUSION: Nursing-home characteristics may have a greater impact than clinical factors on pressure sores and disruptive behaviour in long-stay, institutionalized elders.

Aged↗
PubMed2001

Behavioural management of aggression in dementia: a randomized controlled trial.

OBJECTIVE: To evaluate the efficacy of a brief behaviour management training programme for family carers of patients with dementia and aggressive behaviour. DESIGN: A randomized controlled trial of a four-session, community-based behaviour management programme. The primary outcome measure was the Rating Scale for Aggressive Behaviour in the Elderly. PARTICIPANTS: 62 patients with dementia, and their co-resident carers. RESULTS: There were no significant differences in aggression scores between behaviour management and control groups at follow-up. After adjusting for baseline differences in Rating Scale for Aggressive Behaviour in the Elderly scores, there was a trend towards a reduction in aggressive behaviour in the patients in the behaviour management group compared with those in the control group (F = 3.37, P = 0.071). CONCLUSIONS: This study adds to the small evidence base for the effectiveness of behavioural management strategies in dementia.

Aged↗
PubMed1998

Brain-behaviour relationships. Some models and related statistical procedures for the study of brain-damaged patients.

The study of brain-damaged patients provides the opportunity to examine the anatomy of brain functions, and has been renewed by the development of structural neuroimaging. Despite the development of neuroimaging and neuropsychological assessment, major uncertainties persist on the exact delimitation of the brain areas involved in specific processes, and these contribute to the enduring controversies over the effective lesions associated with neuropsychological disorders. These uncertainties are mainly due to the methods used in the study of brain-behaviour relationships, which frequently rely on a group comparison design. The aim of this study was to provide models for the study of brain-behaviour relationships and to assess the reliability of related statistical procedures. In the present work, four theoretical modes of brain-behaviour relationship consistent with neuropsychological data are put forward: unicity, equivalence, association and summation. The first experimental study was based on a simulated population of patients. Lesions associated with the occurrence of a deficit were predetermined according to modes of brain-behaviour relationship and were compared with lesions selected by statistical analysis. The study showed that (i) the group comparison design did not allow determination of the effective lesion, (ii) stepwise regression analysis was sensitive to the relative frequency of lesions, especially when the occurrence of a deficit depended on two lesions, but did not allow determination of the mode of brain-behaviour relationship, and (iii) the classification tree test described the data very satisfactorily and permitted the determination of the mode of brain-behaviour relationships. In order to assess the validity of statistical analyses, a second study was performed in which lesion locations associated with motor weakness in stroke patients were examined. Selected lesions were compared with the anatomy of the human motor system. The study mainly showed that (i) the stepwise regression analysis of selected lesions was not related to the presence of a motor deficit, and (ii) the classification tree test provided perfect agreement with motor weakness predicted by lesion locations and suggested an equivalence mode of brain-behaviour relationship consistent with current neurological knowledge. These studies provide models of brain-behaviour relationships and related statistical procedures that may allow more precise documentation of the anatomy of brain functions and its pathology, and further investigation of the modalities of brain-behaviour relationships.

Behavior↗
PubMed2004

Behavioural disorders induced by external globus pallidus dysfunction in primates II. Anatomical study.

The anatomical organization of the basal ganglia supports their involvement in movement and behavioural disorders. Thus dyskinesia, attention deficit with or without hyperactivity, and stereotyped behaviour can be induced by microinjections of bicuculline, a GABAergic antagonist, into different parts of the external globus pallidus (GPe) in monkeys. The aim of the present study was to determine the anatomo-functional circuits inside the basal ganglia which are specifically related to each of these behavioural changes. For that, axonal tracers were injected in the same pallidal sites where abnormal behaviours have previously been obtained by bicuculline microinjections. The labelling was mapped in the different basal ganglia and matched with the topography of the cortico-striato-pallidal projections already reported in the literature and with the distribution of calbindin immunoreactivity. Our results first show that the pallidal sites related to dyskinesia, attention deficit with or without hyperactivity, and stereotyped behaviour, were respectively in motor, associative and limbic territories, defined as weak, moderate and intensive calbindin immunoreactivity. The same relationship was observed between the distribution of the labelling in the different basal ganglia after tracer injections performed in these different pallidal sites and the anatomo-functional territories. Thus regarding the origin of the circuits within the striatum, tracer injections performed in the dyskinesia site labelled neurons located in the posterior sensorimotor putamen, those performed in the hyperactivity and/or attention deficit labelled neurons in the laterodorsal putamen and caudate nucleus, regions corresponding to associative and anterior motor territories, while those performed in the stereotyped behaviour site labelled neurons in the ventral limbic striatum. Regarding the GPe output on the basal ganglia, the different circuits also appeared underlined by different anatomo-functional territories, even if a partial overlap exists. Each of these anatomical circuits systematically involves both the internal globus pallidus (GPi) and the substantia nigra pars reticulata (SNr) but, whereas movement circuit is mainly related to the GPi, stereotyped behaviour is mainly related to the SNr. Additionally, subregions of the subthalamic nucleus were also systematically involved, depending on the movement or behavioural disorder produced. These results demonstrate that distinct circuits involving different anatomo-functional territories of the basal ganglia, with partial overlap, participate in different behavioural disorders in monkeys. It seems likely that these neuronal circuits are involved in pathologies like Tourette's syndrome, attention deficit/hyperactivity disorders and obsessional compulsive troubles. This study provides the basis for further researches with a therapeutical viewpoint.

Animals↗
PubMed2004

Sport involvement, sport violence and health behaviours of Greek adolescents.

BACKGROUND: Within the context of problem-behaviour theory, this study investigated the intra-relationship between attitudes and behaviours towards exercise, sport involvement, violence in sport-related events, eating fruits, smoking and hashish or ecstasy use in a sample of Greek adolescents. Age and gender patterns are considered. METHODS: Participants were 5991 Greek school pupils who responded to questionnaires assessing behaviour and attitudes towards health-related behaviours. RESULTS: Positive associations were found between pupils' reports of violence in sport-related events, smoking and hashish or ecstasy use on the one hand, and eating fruits and participation in sport and exercise on the other. In contrast, small positive association was observed between sport involvement and violence in sport-related events. Attitudes towards health risk behaviours were inversely related to attitudes towards health-promoting behaviours, and attitudes were positively related to corresponding behaviours. Sport involvement and regular exercise decreased but smoking and use of hashish or ecstasy increased with age. More males than females participated in organized sport and violent acts in sport-related events. Males' involvement in sport violence increased with age. CONCLUSION: Sport is a suitable context for the promotion of several health-related behaviours apart from exercise. Nevertheless, the present sport structure excludes most young people and is positively linked with sport violence. A less demanding sport context should be provided for the majority of young people, particularly for females. Sport programmes designed to promote health behaviours should be encouraged. More concentrated actions to combat sport violence are required.

Adolescent↗
PubMed1995

Evidence for the validity and utility of the Stages of Exercise Behaviour Change scale in young adults.

This study examined the validity and utility of the Stages of Exercise Behaviour Change (SEBC) scale in 244 young British adults. One-way ANOVA revealed significant differences (F > 7.34, P < 0.01) between the Exercise Behaviour Change Categories of Precontemplation/Contemplation (n = 49), Preparation (n = 87) and Action/Maintenance (n = 108) in self-report levels of exercise behaviour. Significant differences (F > 3.14, P < 0.05) were also revealed in exercise self-efficacy, physical self-perception sub-domains and global self-esteem scores. Subsequent step-wise discriminant analyses revealed that discrimination between the Categories of Exercise Behaviour Change was possible on the basis of selected behavioural and psychological parameters (Canonical r = 0.76-0.82, Wilks' lambda = 0.30-0.33, chi 2 = 60.3-94.6, d.f. = 14, P < 0.0001). In both males and females, the most dominant discriminatory variables in the first Function were revealed to be perceived physical conditioning and 'strenuous' exercise behaviour. For males, the second Function comprised exercise self-efficacy and perceived bodily attractiveness, whilst for females it comprised perceived bodily attractiveness, perceived sports competence and perceived physical strength. Subsequent cross-validation analysis, using a randomly selected 40% sub-sample, revealed that 67.8-70.7% of subjects were assigned to the correct Category. These results appear to confirm the concurrent validity of the SEBC scale in terms of self-report of exercise behaviour. Furthermore, the utility of the SEBC scale was demonstrated via the ability to predict membership of specific Categories of Exercise Behaviour Change using a selection of behavioural and psychological parameters.

Adolescent↗
PubMed1999

Knowledge, risk perception of AIDS and reported sexual behaviour among students in secondary schools and colleges in Tanzania.

A questionnaire survey was carried out among 1041 students in secondary schools and colleges in Dar-es-Salaam, Tanzania to evaluate the relationship between HIV-risky sexual behaviour and anti-condom bias, as well as with AIDS-related information, knowledge, perceptions and attitudes. Self-reportedly, 54% of students (75% of the boys and 40% of the girls) were sexually active, 39% had a regular sexual partner and 13% had multiple partners in the previous year. The condom use rate was higher than previous reports. However, 30% of sexually active respondents did not always use condoms (Risk-1 behaviour) and 35% of those with multiple partners in the previous year did not always use condoms (Risk-2 behaviour). Multiple logistic regression analyses indicated that 'sex partner hates condom' had association with both Risk-1 behaviour (OR 2.47; 95% CI 1.58-3.85) and Risk-2 behaviour (OR 2.47; 95% CI 1.10-5.48). 'Use of condom prevents HIV infection' also had association with both Risk-1 behaviour (OR 2.09; 95% CI 1.19-3.67) and Risk-2 behaviour (OR 3.73; 95% CI 1.28-11.03). Students engaging in risky behaviour were aware of the risk, even though they failed to change their behaviour. Reasons for the AIDS epidemic among Tanzanian students and the importance of more effective AIDS education are also discussed.

Adolescent↗
PubMed1993

Evaluation of a cognitive-behavioural intervention for HIV prevention among injecting drug users.

OBJECTIVE: To evaluate the effectiveness of relapse prevention (RP) and brief intervention (BI) in reducing HIV risk-taking behaviours among injecting drug users (IDU) enrolled in methadone programmes. The hypotheses tested were: (1) that a six-session RP programme would be more effective in reducing HIV risk-taking behaviours than a one-session BI and a non-intervention control condition (C); and (2) that BI would be more effective in reducing HIV risk-taking behaviours than C. DESIGN: Clients of methadone programmes were randomly assigned to either RP, BI, or C. Follow-up occurred 6 months after pre-intervention assessment and was conducted by independent research assistants who were not aware of subjects' group allocations. SETTING: Confidential assessment interviews and interventions generally took place at the methadone unit treating the subject. PARTICIPANTS: Ninety-five IDU enrolled in methadone programmes. Study entry criteria were: injection of any drug in the 6 months before the day of pre-intervention assessment; literacy in English; agreement to HIV-antibody testing for research purposes; and no known diagnosis of a serious mental illness. Eighty subjects were contacted successfully for a 6-month follow-up. INTERVENTIONS: The RP intervention was a six-session programme. Each 60-90 min session was conducted individually. The BI was a one-session motivational interview lasting 60-90 min, accompanied by a self-help booklet. MAIN OUTCOME MEASURES: All subjects were administered the Drug Use Scale and HIV Risk-Taking Behaviour Scale of the Opiate Treatment Index and consented to the collection of a capillary blood sample for HIV-antibody testing at pre-intervention assessment and follow-up. At follow-up, the Highest HIV Risk-Taking Behaviour Scale, collateral reports from subjects' sexual partners pertaining to the previous month and urinalysis results for the month before follow-up were collected. RESULTS: Compliance with interventions was good. Correspondence of self-reports with urinalysis and collateral reports was satisfactory. There were no significant differences between groups in risk-taking behaviours during the month before follow-up. However, there was evidence of a lower rate of needle-risk behaviour (sharing and cleaning) during the heaviest risk-taking month since pre-intervention assessment in the group given RP. There were no indications that BI was of greater benefit than the usual methadone treatment and neither intervention appeared to reduce sexual risk behaviour. CONCLUSIONS: The results are cautiously interpreted as showing that individual RP programmes decrease the level of needle-risk behaviour during relapse episodes, but further research is required to replicate this finding.

Adolescent↗
PubMed2000

Risk behaviour change and HIV infection among injection drug users in Montreal.

OBJECTIVE: To investigate the independent association between changes in risk behaviour and HIV seroconversion risk among Montreal injection drug users (IDU). DESIGN: A longitudinal study of risk behaviour change and the maintenance of low-risk practices. At baseline and semi-annually, subjects were tested for HIV, and questionnaires on risk behaviour were completed. RESULTS: A total of 833 IDU were recruited from January 1992 to June 1998, and completed a minimum of three visits. Large fluctuations in risk behaviour were observed, and the risk of HIV infection appeared to be dependent upon the consistency of risk behaviour practised. IDU who consistently engaged in risky behaviour were at high risk of HIV infection. IDU who attempted to practise low-risk behaviour but experienced relapses to risky behaviour were also at considerable risk of infection. IDU who managed to maintain low-risk practices were at minimal risk. Using Cox regression analysis, the hazard ratio (HR) of HIV seroconversion among IDU who consistently and inconsistently shared needles with an HIV-positive partner was 8.17 (95% CI 3.59-18.59) and 2.63 (95% CI 1.33-5.17), respectively, relative to non-needle sharers. Corresponding HIV incidence rates were 30.42 per 100 person-years (py) among consistent sharers, 13.78 per 100 py among inconsistent sharers and 2.51 per 100 py among non-sharers. CONCLUSION: Although some HIV risk reduction was evident, behaviour change seems to be effective only in IDU who adopt and maintain low-risk practices. Additional strategies may be needed to assist IDU in the maintenance of low-risk practices.

Adolescent↗
PubMed2001

Interpreting sexual behaviour data: validity issues in the multicentre study on factors determining the differential spread of HIV in four African cities.

BACKGROUND: The main conclusion of the multicentre study on factors determining the differential spread of HIV in four African cities was that differences in sexual behaviour could not, by themselves, explain the differences in HIV prevalence between the four cities. The present paper examines three potential sources of bias that could invalidate this conclusion: (1) changes in sexual behaviour since the start of the HIV epidemics; (2) bias due to the low response rates of men; and (3) bias in reported sexual behaviour. METHODS: To assess whether there have been any changes in sexual behaviour over time, selected parameters of sexual behaviour were compared between different age groups in the four cities. The maximum likely extent of bias due to non-participation of men in Yaoundé, Kisumu and Ndola was assessed with a simulation exercise, in which records of non-participants were replaced with records of 'low activity men' in Yaoundé and 'high activity men' in Kisumu and Ndola. To assess the validity of the sexual behaviour data, internal validity checks were carried out: comparing biological data on sexually transmitted infections with reports; comparing reports of spouses; and comparing numbers of sex partners reported by men and women. A fourth method consisted of comparing the findings of the multicentre study with an external source, Demographic and Health Surveys (DHS). RESULTS: There were differences in sexual behaviour between the younger and the older age groups in all four cities but there was no evidence of a shift towards safer sexual behaviour in the high HIV prevalence cities. After simulating results for male non-participants in Yaoundé, Kisumu and Ndola, the median lifetime number of sex partners was similar in Yaoundé, Kisumu and Ndola. By testing for various sexually transmitted infections among men and women aged 15-24 years who reported that they had never had sexual intercourse, we could establish that, in all four cities, at least 1-9% of men and 6-18% of women had misreported their sexual activity. The number of non-spousal partners in the past 12 months reported by men was two to three times higher than the number reported by women, as has been found in other studies. The most consistent differences between our survey and the DHS were found in the numbers of non-spousal partners in the past 12 months reported by never-married men and women. In all four cities, participants reported more non-spousal partners in the DHS than in our survey. CONCLUSIONS: In all four cities, we found evidence that men as well as women misreported their sexual behaviour, but overall it seems that under-reporting of sexual activity was not more common or more serious in the two high HIV prevalence cities than in the two low HIV prevalence cities. We believe that the main conclusions of the multicentre study still hold.

Adolescent↗