Quality of and access to green space in relation to psychological distress: results from a population-based cross-sectional study as part of the EURO-URHIS 2 project.

Background: Psychological distress (PD) (mental ill-health) has a frequency between 5 and 25% in urban populations, and there is mounting evidence that access to green space might reduce its occurrence. Evidence suggests that the quality of green space is as important as accessibility in promoting mental well-being. A pilot study for EURO-URHIS 2 allowed investigation of access to green space in relation to PD in a deprived urban population in the UK. Methods: An adult urban health indicator questionnaire, including the GHQ-12 and validated questions on access to and quality of green space, was sent to a stratified random sample of 1680 adults drawn from one general practice list in Sandwell, UK. Multivariable logistic regression was used to determine associations between attributes of green space and PD adjusting for age, sex and levels of deprivation. Results: There were 578 (35%) completed responses. The reported prevalence of PD [n = 131 (22.7%)] was significantly greater than national England and Wales estimates. As well as accessibility (OR = 0.58; 95% CI = 0.35, 0.96) and sufficiency (OR = 0.12; 95% CI = 0.39, 0.89) of green spaces, having the ability to use them for relaxation and recreation were significantly associated with reduced PD [OR = 0.13 (0.42, 0.94) and OR = 0.11 (0.34, 0.80), respectively]. In addition, a dose-response relationship between number of positive green space attributes and PD was identified (P < 0.05). Conclusion: This population-based study in a deprived urban UK population demonstrates an association, and some dose-response relationship, between access to and quality of green spaces with reduced PD. The cross-sectional design and use of subjective measures limit interpretation of causality. More knowledge is needed on how UK planning affects green spaces and the potential mental health consequences.

Health status in Europe: comparison of 24 urban areas to the corresponding 10 countries (EURO-URHIS 2).

Background: : In Europe, over 70% of the population live in urban areas (UAs). Most international comparative health research is done using national level data, as reliable and comparable urban data are often unavailable or difficult to access. This study aims to investigate whether population health is different in UAs compared with their corresponding countries. : Routinely available health-related data were collected by the EURO-URHIS 2 project, for 10 European countries and for 24 UAs within those countries. National and UA level data for 11 health indicators were compared through the calculation of relative difference, and geographical patterns within Europe were investigated using the Mann Whitney U test. Linear regression modelling was used to adjust for population density, gross domestic product and urbanicity. : In general, the urban population in Eastern Europe is less healthy than the Western European urban population. However, people in Eastern Europe have significantly better broad health outcomes in UAs as compared with the corresponding country as a whole, whereas people in Western Europe have generally worse broader health outcomes in UAs. : For most European countries and UAs that were investigated, the national level health status data does not correspond with the health status at UA level. In order to identify health problems in UAs and to provide information for local health policy, health monitoring and international benchmarking should also be conducted at the local level.

Suicidal ideation in ethnic minority and majority adolescents in Utrecht, the Netherlands.

We investigated the prevalence and explored the vulnerability to suicidal ideation across several ethnic minority versus ethnic majority adolescents in the city of Utrecht in The Netherlands. Exploratory analyses were conducted on a dataset obtained from the Municipal Health Services in Utrecht. We examined whether ethnic minority adolescents are at risk for suicidal ideation because of a family background of migration, social-economic position and certain family factors, which influence psychological constellations. We found that levels of suicidal ideation among adolescents of Turkish background were significantly higher than in both majority and other minority adolescents, The Turkish adolescents at risk for suicidal ideation reported that they do not enjoy being at home with their families. Psychological factors, in particular lack of self-pride and the idea of not becoming successful in life, appeared to be important, as well as feelings of loneliness. Suicidal ideation was not found equally across all ethnic minority groups. A history of migration, ethnic minority status, or low socioeconomic status were not sufficient to explain the variation across ethnicities. Our results suggest that specific social-cultural factors, contextualized in the individual and located in the family environment, are relevant in explaining the disproportionate rates for Turkish adolescents in Utrecht.

[Considerable comorbidity in overweight adults: results from the Utrecht Health Project]. / Aanzienlijke comorbiditeit bij volwassenen met overgewicht: resultaten uit het 'Leidsche Rijn Gezondheidsproject'.

OBJECTIVE: To determine the association between overweight, physical and mental health conditions and health-related quality of life in an adult community population upon entering a new primary care practice. DESIGN: Cross-sectional study. METHOD: Baseline data from 4825 participants (mean age: 39 years; 55% women) in the Utrecht Health Project; a dynamic primary care population study with a response rate of over 50%, were used to determine and compare the prevalence of diagnosed medical conditions, complaints and quality of life between individuals of normal weight (BMI 18.5-< 25 kg/m2) and those who were overweight (BMI 25-< 30 kg/m2) or obese (BMI > or = 30 kg/m2). Normal weight was used as the reference category. RESULTS: Overweight individuals were approximately twice as likely to have cardiovascular risk factors and had a 20-60% increased risk of back pain, arthrosis, migraine, dyspepsia and respiratory symptoms than those of normal weight. Obese individuals were almost twice to four times more likely to have these conditions and were additionally at increased risk of obstructive pulmonary disease, cardiovascular disease and arthritis (range of odds ratios (ORs): 1.9-3.3). Somatization and reduced physical well-being were more common among both overweight (ORs: 1.2-1.5) and obese (ORs: 1.7-3.7) individuals, whereas only obese individuals demonstrated a 30-50% increased risk of mental health conditions and reduced mental well-being. CONCLUSION: Overweight was associated with a broad range of physical and mental health conditions and a reduced health-related quality of life. Routine measurement of BMI upon entering a primary care practice is relatively simple and may contribute to the identification of individuals at high risk of comorbidity.

[Smoking, alcohol and drug use in Utrecht, The Netherlands, risk groups and socioeconomic differences in 1999 and 2003]. / Roken, alcohol-en druggebruik in Utrecht, risicogroepen en sociaal-economische verschillen in 1999 en 2003.

OBJECTIVE: To investigate trends in socio-economic inequalities in smoking, alcohol and drug use in the community of Utrecht, the Netherlands. DESIGN: Repeated cross-sectional population surveys. METHOD: Questionnaires were used to collect information about smoking, (problematic) alcohol use and the use of cannabis, ecstasy and other drugs in the general population aged 15-64 years in Utrecht, the Netherlands. Data were collected in 1999 on 2485 responders (response: 56%) and in 2003 on 1840 responders (54%). The male-female ratio was 4:6. RESULTS: The percentage of smokers was 43 in 1999 and 34 in 2003. Excessive use of alcohol was reported by 21% in both 1999 and 2003, cannabis use was reported in 13% and 14%, respectively, and use of hard drugs was reported in 1-3% in both 1999 and 2003. Native Dutch people, men, unmarried people and people with a low education or income level were at increased risk for drinking, smoking and using drugs. People with a low socio-economic status were just as likely to smoke in 1999 as in 2003, while the use of alcohol, cannabis and ecstasy increased. Those with a higher socio-economic status were much less likely to smoke in 2003 than in 1999, while fewer used cannabis and ecstasy use remained the same. CONCLUSION: Socio-economic inequalities in substance abuse were greater in 2003 than in 1999 in the studied population in Utrecht. People with a low socio-economic status showed an increase in unhealthy behaviour concerning the use of alcohol, cannabis and ecstasy.

Maximum impact of HIV prevention measures targeted at injecting drug users.

OBJECTIVE: To examine whether the decrease in HIV incidence and injecting risk behaviours is ongoing in Amsterdam, and to study the determinants of injecting risk behaviours. DESIGN: Prospective open cohort study (1986-1997) amongst injecting drug users (IDU). METHODS: HIV incidence was studied using Poisson regression analysis. Trends in injecting risk behaviours were determined using 6645 visits of 879 participants, stratified by HIV serostatus and number of the follow-up visit. Generalized estimating equations were used to account for repeated measurements, and additive model structures were used. RESULTS: A large initial risk reduction (1986-1991) occurred concerning borrowing and lending of used needles, multiple needle use and frequent injecting. However, except for frequent injecting, the rate of behaviour change significantly decreased, and from 1991-1993 onwards there was no substantial further risk reduction. HIV incidence followed a similar pattern. Injecting risk was much lower at follow-up visits. The following determinants of borrowing and lending among both HIV-positive and negative IDU were largely comparable: young age, non-injecting heroin and cocaine use, frequent tranquillizer use, multiple needle use, injecting with others, and irregular use of needle-exchange programmes. CONCLUSIONS: The observed residual risk, given the extensive HIV prevention measures in Amsterdam, indicates that further prevention is difficult. Because this risk was associated with an HIV incidence of 3-4% per year, HIV prevalence is likely to be high for many years. Therefore, prevention measures should be maintained because of the possibility of behavioural relapse associated with recent availability of potent HIV treatments. To prevent an HIV epidemic amongst a new generation of drug users, prevention of injecting itself is warranted.

Increasing morbidity without rise in non-AIDS mortality among HIV-infected intravenous drug users in Amsterdam.

OBJECTIVE: We determined pneumonia, endocarditis, hospitalizations and death rates in a group of HIV-infected and non-infected IVDU recruited at low-threshold methadone programmes in Amsterdam, The Netherlands to examine the influence of HIV infection on morbidity and non-AIDS mortality in intravenous drug users (IVDU) without AIDS. DESIGN: A prospective epidemiologic study among HIV-infected and non-infected IVDU in Amsterdam. SETTING: We analysed patients attending the Municipal Health Service of Amsterdam. PATIENTS: The patient group consisted of 197 HIV-seropositive IVDU and 193 HIV-seronegative IVDU as controls. MAIN OUTCOME MEASURES: We analysed incidence rates per person-year of bacterial pneumonia; hospitalizations and non-AIDS mortality; and relative risks for HIV-infected IVDU compared to non-infected IVDU. RESULTS: The incidence of bacterial pneumonia rose from 0.1 in 1986 to 0.29 in 1989 in HIV-infected IVDU. The overall relative risk for this group was 4.0 (95% confidence interval, 1.7-9.7) compared with non-infected controls. HIV-infected IVDU were more frequently hospitalized for bacterial pneumonia than non-infected IVDU (50 versus 13%). In contrast, non-AIDS mortality rates remained stable for both HIV-infected and non-infected IVDU. HIV seropositivity was not found to be an independent risk factor for non-AIDS mortality. CONCLUSION: We found a high and rising incidence of bacterial pneumonia among HIV-infected IVDU in Amsterdam without any consequential rise in non-AIDS mortality. This contrasts with reports from studies conducted in New York City, New York, USA, where bacterial pneumonia-related mortality has been found to increase markedly, coincident with the AIDS epidemic. Early detection of bacterial pneumonia and easy access to both inpatient and outpatient medical care may be important factors in preventing early death due to common bacterial pathogens in IVDU without AIDS.

Trends in sexual behaviour and the incidence of sexually transmitted diseases and HIV among drug-using prostitutes, Amsterdam 1986-1992.

OBJECTIVE: To determine trends in commercial sexual risk behaviour among drug-using prostitutes in Amsterdam after local and national prevention campaigns began in 1987. DESIGN: A subgroup of 281 drug-using prostitutes was selected from a comprehensive, open cohort study of drug users in Amsterdam. METHODS: Cross-sectional (at intake) and within-person trends in sexual behaviour were evaluated. Person-time analysis was used to determine trends in incidence of sexually transmitted disease (STD). RESULTS: From 1986 to 1992, 'always' use of condoms in the 6 months preceding intake increased from 21 to 58% (P < 0.001) and the number of commercial contacts declined from 84 to 64 per month (P = 0.06). Consequently, the mean number of unprotected commercial contacts declined from 26 to nine per month (P < 0.001). Temporal trends within individual prostitutes from visits 1 to 8 (mean interval between visits, 4 months) showed a somewhat larger risk reduction than the cross-sectional trends. From 1989 to 1992, the STD incidence declined from 61 to 40 episodes per 100 person-years (P = 0.06). Prostitutes residing in Amsterdam for shorter time periods reported more STD and a relatively small core group reported the majority of STD episodes. At intake, when < 10% of all participants knew their HIV serostatus, HIV-positive prostitutes reported significantly lower levels of condom use and more STD than HIV-negatives, while, after learning their serostatus, levels of condom use and the STD-incidence were comparable. Prevalent and incident HIV infections were not observed among non-injecting prostitutes. CONCLUSIONS: Drug-using prostitutes have reduced sexual risk behaviour. There is evidence for the effectiveness of HIV testing and counseling. At present, new infections among clients of drug-using prostitutes are expected to occur, although not on a large scale. Since the incidence of STD continues to be high, it is important to monitor the spread of HIV among heterosexuals, including prostitutes and their clients, closely.

HIV, sexually transmitted diseases and gynaecologic disorders in women: increased risk for genital herpes and warts among HIV-infected prostitutes in Amsterdam.

OBJECTIVES: To determine the incidence of sexually transmitted diseases (STD; gonorrhoea, early syphilis, Chlamydia trachomatis infection, trichomoniasis and primary genital herpes) and gynaecologic disorders (vaginal candidiasis, anaerobic vaginosis, genital ulcerations of unknown cause, pelvic inflammatory disease, recurrent genital herpes, recurrent genital warts) in a cohort of HIV-infected and non-infected drug-using prostitutes in Amsterdam between 1986 and 1992. DESIGN: A subgroup of 212 female drug users with a history of prostitution, who made at least one visit to a special STD clinic for drug-using prostitutes was selected from an ongoing cohort study of drug users in Amsterdam. METHODS: Using Poisson regression, the relative risk (RR) for each outcome was calculated for HIV-positive women compared with HIV-negative women. To determine potential causal relations with immune suppression, associations between disease incidence and immunologic markers (CD4 cell count and anti-CD3 response) were assessed in HIV-positive women. RESULTS: Adjusted for number of clients and frequency of condom use, HIV-positive women were at strong and significantly increased risk for primary genital herpes (RR, 7.64), recurrent herpes (RR, 8.33) and recurrent genital warts (RR, 15.93); moderately (significantly) increased risks were found for gonorrhoea (RR, 1.43), trichomoniasis (RR, 1.39), vaginal candidiasis (RR, 2.11) and genital ulcers of unknown aetiology (RR, 2.60). Of these HIV-related outcomes, the risk for recurrent genital herpes and genital warts were strongly associated with decreased CD4 cell counts. CONCLUSIONS: HIV-infected women experience an excess morbidity of STD and gynaecologic disorders. The strongly increased risk for genital herpes and warts in HIV-seropositive women indicates a causal relation with HIV. This study emphasizes the need for accessible medical care for drug-using prostitutes.

Methadone maintenance treatment modalities in relation to incidence of HIV: results of the Amsterdam cohort study.

STUDY OBJECTIVE: To evaluate methadone maintenance treatment modalities, prescribed within the concept of harm reduction, in relation to incidence of HIV infection among drug users with a history of methadone treatment in Amsterdam, The Netherlands. DESIGN: Prospective observational cohort study among 582 HIV-negative drug users. To ensure valid and detailed assessment of methadone treatment, data from the Central Methadone Register in Amsterdam were linked to the Amsterdam cohort study among drug users. METHODS: Poisson regression analysis was used to identify independent and significant predictors of incidence of HIV. MAIN RESULTS: During 1906 person years, 58 drug users seroconverted, the overall incidence of HIV being 3.0 per 100 person years with a declining trend for current injectors. An increase in frequency of methadone programme attendance [relative risk (RR), 2.4; 95% confidence interval (CI), 1.2-4.6, compared with no change] and increase in methadone dosage (RR, 0.8; 95% CI, 0.6-1.0, per category of change of 10 mg/day) were significantly associated with incidence of HIV in multivariate analysis. Methadone dosage and frequency of programme attendance in itself were not significant predictors. Other multivariate significant risk factors were homelessness, current injecting and in-patient hospital care. CONCLUSIONS: Among drug users who receive methadone maintenance treatment in a harm-reduction setting, which includes ancillary services such as needle-exchange programmes and HIV testing and counselling, prescription of high methadone dosages is not sufficient to stop the spread of HIV. However, an individual increase of the methadone dosage and measures to achieve high treatment retention could contribute to the prevention of HIV among drug users.

Progression of HIV infection among injecting drug users: indications for a lower rate of progression among those who have frequently borrowed injecting equipment.

OBJECTIVE: To study markers of progression in a cohort of HIV-infected intravenous drug users (IDU). DESIGN: A prospective epidemiologic study. SETTING AND PATIENTS: We studied progression of HIV infection among 126 IDU attending the Municipal Health Service in Amsterdam. MAIN OUTCOME MEASURES: Progression was defined as a decline of the CD4 cell count to < 200 x 10(6)/l on two consecutive follow-up visits or AIDS. RESULTS: Using Cox modelling, the following baseline variables were predictive of progression. Enhanced progression was associated with: age > 30 years [relative hazard (RH), 7.7 [95% confidence intervals (CI), 1.7-36.0]], core antibody negativity [RH, 5.3 (95% CI, 1.6-17.6)], CD4 cell count [for CD4 cells 350-500 x 10(6)/l, RH, 1.38 (95% CI, 0.37-5.16); for CD4 cells 200-350 x 10(6)/l, RH, 9.20 (95% CI, 2.73-31.05) compared with a CD4 count > 500 x 10(6)/l]. A lower rate of progression was associated with borrowing used injecting equipment. IDU who reported borrowing injecting equipment between 1980 and baseline 10-99 times or > 99 times had a RH of 0.44 (95% CI, 0.22-0.88) and 0.19 (95% CI, 0.03-0.37), respectively, compared with IDU who had borrowed < 10 times. p24 antigen positivity was more predictive than core antibody negativity in a model with time-dependent variables, the relative risk for p24 antigen-positive participants was 3.5 (95% CI, 1.3-9.3). Additional analysis of progression to AIDS in a larger group of IDU showed comparable results with regard to the effect of borrowing on progression. CONCLUSIONS: Our observation that those IDU who reported borrowing injecting equipment most frequently appeared to have the lowest rate of progression, corrected for some sources of potential confounding, requires further epidemiologic confirmation and extended laboratory studies since other sources of bias might have been present. Baseline CD4 count, age and core antibody or p24 antigen were predictive of progression in IDU. We wish to emphasize that our results do not imply that borrowing should be encouraged, but may have implications for our understanding of HIV pathogenesis.

HIV surveillance among sexually transmitted disease clinic attenders in Amsterdam, 1991-1996.

OBJECTIVE: To determine trends in HIV prevalence among attenders of a clinic for sexually transmitted diseases (STD), with emphasis on heterosexuals who did not have a history of injecting drug use. METHODS: Anonymous unlinked HIV surveys with individual consent, conducted each half year from 1991 to 1996 (except 1993) among STD clinic attenders who came for evaluation of a possible new STD episode. RESULTS: Of 10,940 eligible attenders 10,046 (92%) accepted HIV testing. Of all tested attenders, 312 (3.1%) were HIV-infected. Overall HIV prevalence decreased significantly from 4.6% in 1991 to 2.8% in 1996. HIV prevalence among heterosexual men and women who were not injecting drug users was less than 1% in all but one survey period. Except for one woman, none of the 48 HIV-infected heterosexuals was aware of their current serostatus. Among HIV-infected heterosexuals, 21 out of 28 males (75%) and 18 out of 20 females (90%) were of non-Dutch origin. HIV prevalence was 16% among all homosexual men, and 12% among young homosexual men aged < 30 years. HIV prevalence among young homosexual men decreased significantly over time. Among HIV-infected homosexual men, 58% of older men and 59% of younger men were not aware of their current HIV infection. Rates of current STD were generally significantly higher among HIV-infected participants compared with non-HIV-infected participants. CONCLUSIONS: Although HIV prevalence among heterosexual clinic attenders is low, there is a clear potential for ongoing sexual HIV transmission. Most heterosexually acquired HIV infections are found in non-Dutch persons. This observation suggests migration of HIV-infected heterosexuals or the separation of Dutch and non-Dutch heterosexual networks. Awareness of serostatus is almost non-existent among HIV-infected heterosexuals, and is low among male homosexual clinic attenders. To increase awareness of current HIV serostatus and possibly decrease risk behaviour, HIV counselling and testing should be offered actively to all clinic attenders.

Frequent injecting impairs lymphocyte reactivity in HIV-positive and HIV-negative drug users.

To investigate whether drug use affected immunological parameters, we conducted a cross-sectional study of 321 drug users. Absolute numbers of CD4+ lymphocytes and the T-cell reactivity were lower in HIV-positive than in HIV-negative people. The functional capacity of the T-cell system as measured after stimulation with a monoclonal antibody directed against CD3 was found to be strongly associated with the frequency of injecting, while no relationship was found between the frequency of injecting and the total number of lymphocytes or T-cell subsets. HIV-negative and HIV-positive drug users who had injected a mean of three times a day in the preceding 4-6 months had a T-cell reactivity which was 40-50% lower compared with seronegative and with seropositive drug users who had not injected in the preceding months. We conclude that lymphocyte reactivity is depressed by frequent injecting in HIV-negative and HIV-positive drug users.

The incubation period to AIDS in injecting drug users estimated from prevalent cohort data, accounting for death prior to an AIDS diagnosis.

OBJECTIVE: To estimate the incubation-period distribution (time from seroconversion to AIDS) accounting for death before an AIDS diagnosis (DBAD) in a cohort of injecting drug users (IDU) in Amsterdam, The Netherlands and to compare these estimates with those previously obtained from a contemporaneous study of homosexual and bisexual men in Amsterdam carried out using the same facilities. DESIGN: Participants in a cohort study begun in Amsterdam at the end of 1985 have scheduled follow-up visits every 4 months. All participants of Dutch nationality and who had two or more follow-up visits before January 1996 from which CD4 measurements were available were included in this study. Data concerning AIDS diagnosis and death were verified through review of national and municipal registries. METHODS: Because time of seroconversion was unknown for study participants and because IDU are at substantial risk for DBAD, we used a Markov model with CD4-based stages that allows for DBAD. The parameters in this model were estimated using the method of maximum likelihood and confidence intervals were calculated using bootstrap methods. RESULTS: A total of 173 IDU (134 seroprevalent, 39 seroincident) made 1829 visits. Nearly 10% of the visits were non-consecutive. Forty-five IDU developed AIDS and 25 died without an AIDS diagnosis. We estimated that 24% [95% confidence interval (CI), 17-25%] of IDU die before an AIDS diagnosis. As a result, the median time from seroconversion to AIDS (10.5 years; 95% CI, 9.1-10.7 years) is considerably longer than the median time from seroconversion to death (8.3 years; 95% CI, 7.9-8.5 years). Conditional on survival to an AIDS diagnosis, the median time to AIDS is 8.2 years (95% CI, 7.7-8.7 years). The median survival time after a diagnosis of AIDS is estimated to be 1.0 years. CONCLUSION: The high occurrence of DBAD in IDU has a considerable influence on estimates of the incubation-period distribution. Progression from seroconversion to death was faster in the IDU cohort than in a cohort of homosexual men in Amsterdam (median, 8.3 years and 9.6 years, respectively). However, progression to AIDS conditional on survival to an AIDS diagnosis seems to be similar in both the IDU cohort and in the cohort of homosexual men (median, 8.2 years and 8.3 years, respectively).

Large diurnal variation in CD4 cell count and T-cell function among drug users: implications for clinical practice and epidemiological studies.

OBJECTIVE: To measure diurnal variation in the CD4 cell count and T-cell reactivity of drug users. DESIGN: A prospective epidemiological study among HIV-infected and non-infected drug users attending the Municipal Health Service of Amsterdam, The Netherlands. PATIENTS: Eleven HIV-infected and seven non-infected drug users. MAIN OUTCOME MEASURES: CD4 cell counts and T-cell reactivity three times a day. T-cell subsets and T-cell reactivity were determined from blinded samples within 2 hours. RESULTS: The number of CD4 cells increased by 130 x 10(6)/l (P < 0.05) in HIV-infected intravenous drug users over 8 hours. Following stimulation with anti-CD3 monoclonal antibodies, the T-cell reactivity of HIV-infected drug users rose from 118 to 221 c.p.m. (P < 0.01) over 8 hours. CD4 cell counts of the total study population increased by 37% and T-cell reactivity by 93%. The increase in the number of CD4 cells was more marked among active drug users than among drug users who had not used drugs recently. CONCLUSION: Variation in the CD4 cell count and in T-cell reactivity is large among drug users.

Human immunodeficiency virus infection and other risk factors for skin abscesses and endocarditis among injection drug users.

OBJECTIVE: To study incidence rates of and risk factors for skin abscesses at the site of injection and episodes of endocarditis among injection drug users (IDU). DESIGN: A comprehensive, open cohort study of drug users on the natural history of human immunodeficiency virus (HIV) infection. METHODS: From 1986 to 1994, injection drug users in Amsterdam were included in the study. Incidence rates of self-reported skin abscesses and verified episodes of endocarditis were calculated. In uni- and multivariate Poisson regression analysis, risk factors for skin abscesses and endocarditis were determined. RESULTS: 521 HIV-seronegative and 237 HIV-seropositive IDU were followed for 1640 person-years. A total of 545 skin abscesses were reported by 269 IDU (incidence 33/100 person-years). HIV infection, female gender, prostitution among females, foreign nationality, injection of heroin and cocaine, a high frequency of injecting, and obtaining syringes through the needle exchange program were independently and positively associated with skin abscesses. During follow-up, 17 verified episodes of endocarditis were observed (incidence 1.3/100 person-years). Endocarditis was independently associated with HIV infection and a previous history of endocarditis. Furthermore, women and IDU with a skin abscess appeared to be at an increased risk for endocarditis. CONCLUSIONS: HIV infection is an independent risk factor for skin abscesses and endocarditis. Also, women are at an increased risk for these injection-related infections. Prevention activities, like promotion of skin cleaning, should be directed at those IDU in whom one or more risk factors have been identified.

The validity of drug users' self-reports in a non-treatment setting: prevalence and predictors of incorrect reporting methadone treatment modalities.

BACKGROUND: Epidemiological studies among drug users are often based on retrospective self-reports. However, among others, memory failure, being under the influence of drugs, psychopathology, misunderstanding of questions and socially desirable answering may generate inaccurate reporting. METHODS: This study validated self-reported current (methadone dosage) and medium-term (main location of methadone dispensing and frequency of methadone programme attendance over the previous 4-6 months) aspects of methadone treatment in the Amsterdam AIDS cohort study among drug users, using data of the Central Methadone Register. In addition to descriptive measures, logistic regression analysis was used (adjusted for intra-individual correlation) to identify subgroups with incorrect reporting. Data collected at 4406 visits of 505 cohort participants were analysed. RESULTS: Current methadone dosage was accurately reported (unweighted kappa [kappa]: 0.94, weighted kappa [kappa W]: 0.97). A low methadone dosage, short duration of school education and depressive or euphoric mood during the interview were significant and independent predictors of incorrect reporting of methadone dosage. For main location of dispensing kappa was 0.82, for frequency of programme attendance kappa was 0.53 and kappa W 0.87. There was a tendency to reporting the extreme answering categories. Infrequent programme attendance was the only significant predictor of incorrectly reporting frequency of programme attendance. CONCLUSIONS: Drug users are able to give valid self-reports in a setting where social desirability does not play an important role. The main reasons of incorrect reporting were impaired cognitive functioning, memory failure and misunderstanding of questions.

Validity of self-reported sexually transmitted diseases in a cohort of drug-using prostitutes in Amsterdam: trends from 1986 to 1992.

BACKGROUND: Rates of self-reported sexually transmitted diseases (STD) among drug-using prostitutes in Amsterdam have been shown to be declining. However, self reports may provide biased estimates. METHODS: We determined the prevalence of risk indicators for and time trends in incorrect self-reported STD in a cohort of drug-using prostitutes. Rates of self-reported STD were validated with diagnosed STD from a special STD clinic for drug-using prostitutes. RESULTS: Between 1986 and 1992, 314 STD were diagnosed in 85 (65%) of 131 studied prostitutes. Overall, 34% of diagnosed STD was not reported in the cohort, referred to as underreporting. For 40% of reported STD, no diagnosis was obtained ('overreporting'). In spite of these misclassifications, absolute numbers of reported and diagnosed STD practically balanced. Underreporting was independently associated with longer residence in Amsterdam (OR = 2.34 per 5 years), more than six clinic visits between two cohort visits (OR = 0.31), daily use of non-parenteral drug (OR = 8.45) and mainly injecting heroin (OR = 6.93); overreporting was independently associated only with a lower frequency of clinic visits. Multivariate analyses showed that trends in underreporting and overreporting were in part explained by a higher number of visits in the cohort and by lower numbers of clinic visits between two cohort visits. CONCLUSIONS: Self-reporting of STD in our cohort is unreliable and misclassification prevalent; risk factors for and associates of self-reported STD are biased. Inferences drawn from self reports are potentially misleading and therefore such data need to be validated. Trends in misclassification can be interpreted as recall errors and as a study participation effect. For monitoring of STD prevalences in relation to trends in sexual risk behaviours, diagnosed STD should be used in preference to self reports.

Young and recent-onset injecting drug users are at higher risk for HIV.

AIMS: To determine whether young or recent-onset injecting drug users (IDUs) are at increased risk of HIV infection, and to compare trends in risk behaviours and HIV incidence among subgroups of IDUs. DESIGN: Associations of age and onset of injecting with HIV prevalence and injecting risk behaviours were determined among current IDUs who entered an Amsterdam cohort between 1989 and 1995, and compared with current IDUs recruited in two street surveys in 1990 and 1993. In the cohort, trends from 1986 through 1995 in injecting risk behaviour (as reported at entry) and in HIV seroconversion (among current IDUs during follow-up) were determined using logistic and Poisson regression. FINDINGS: Sizable portions of IDUs were young (< or = 25 years: 14-30%) or had recently started injecting (within the last 3 years: 17-21%). Between 37% and 50% of young IDUs recently started injecting. HIV prevalence was 12-24% among young IDUs, and 5-12% among recent-onset IDUs. Young IDUs more often reported current borrowing than older IDUs. Borrowing declined significantly in all subgroups, except young IDUs. The crude HIV incidence declined from 18/100 person-years (PY) in 1986 to 5/100 PY in 1995. Trends in HIV incidence were not significantly different for subgroups of age or onset of injecting. In a multivariate analysis, recent onset of injecting was an independent predictor (p = 0.04) for HIV seroconversion, but age was not (p = 0.68). CONCLUSIONS: Important proportions of drug users are young or have recently started injecting. HIV prevalence is relatively high among young and recent-onset IDUs. Recent onset of injection is an independent predictor for HIV seroconversion. Our observations may be explained by non-random patterns of borrowing used needles/syringes. Recent-onset IDUs should be approached more actively for HIV counselling and testing.