Valerio Baćak

The Increasing Predictive Validity of Self-Rated Health

Using the 1980 to 2002 General Social Survey, a repeated cross-sectional study that has been linked to the National Death Index through 2008, this study examines the changing relationship between self-rated health and mortality. Research has established that self-rated health has exceptional predictive validity with respect to mortality, but this validity may be deteriorating in light of the rapid medicalization of seemingly superficial conditions and increasingly high expectations for good health. Yet the current study shows the validity of self-rated health is increasing over time. Individuals are apparently better at assessing their health in 2002 than they were in 1980 and, for this reason, the relationship between self-rated health and mortality is considerably stronger across all levels of self-rated health. Several potential mechanisms for this increase are explored. More schooling and more cognitive ability increase the predictive validity of self-rated health, but neither of these influences explains the growing association between self-rated health and mortality. The association is also invariant to changing causes of death, including a decline in accidental deaths, which are, by definition, unanticipated by the individual. Using data from the final two waves of data, we find suggestive evidence that exposure to more health information is the driving force, but we also show that the source of information is very important. For example, the relationship between self-rated health and mortality is smaller among those who use the internet to find health information than among those who do not.

Religiosity and Sexual Risk Behavior among Croatian College Students, 1998–2008

A substantial increase in religious identification has been observed in most European post-communist countries. As religiosity has been associated with sexually transmitted infection (STI) and HIV vulnerability among young people, this article examined the impact of religious upbringing and personal religiosity (religiousness) on sexual risks among University of Zagreb first-year undergraduate students, using data collected in 1998, 2003, and 2008. Female participants who reported strict religious upbringing were less knowledgeable about human sexuality than other women. Religiousness was negatively correlated with basic knowledge of human sexuality, but again only among women. Contrary to expectations, no significant associations were found between religious upbringing or religiousness and condom use. Both measures of religiosity, however, were related to decreased odds of sexual debut among young women. In the case of male participants, the impact of religiosity was marginal. Religious upbringing was associated (negatively) with sexual literacy and sexual debut—but only at the beginning of the observed period. Overall, religiosity does not seem to substantially reduce STI- and HIV-related risk-taking, particularly among men. Since the observed increase in the proportion of sexually active students during the 1998 through 2008 period was not matched by an increase in condom use, reducing STI and HIV vulnerability among Croatian youth remains an essential task.

Prevalence of Sexually Transmitted Infections Among Men Who Have Sex with Men in Zagreb, Croatia

We used respondent-driven sampling among men who have sex with men (MSM) in Zagreb, Croatia in 2006 to investigate the prevalence of HIV, other sexually transmitted infections and sexual behaviours. We recruited 360 MSM. HIV infection was diagnosed in 4.5%. The seroprevalence of antibodies to viral pathogens was: herpes simplex virus type-2, 9.4%; hepatitis A, 14.2%; hepatitis C, 3.0%. Eighty percent of participants were susceptible to HBV infection (HBs antigen negative, and no antibodies to HBs and HBc antigen). Syphilis seroprevalence was 10.6%. Prevalence of Chlamydia and gonorrhoea was 9.0%, and 13.2%, respectively. Results indicate the need for interventions to diagnose, treat and prevent sexually transmitted infections among this population.

Changes in human immunodeficiency virus and sexually transmitted infections-related sexual risk taking among young Croatian adults: 2005 and 2010 population-based surveys.

Aim To determine changes in sexual behaviors and other relevant characteristics related to human immunodeficiency virus (HIV) and sexually transmitted infection (STI) risks among young Croatian adults. Method We surveyed adults aged 18-24 in 2005 (n = 1092) and 18-25 in 2010 (n = 1005). Both samples were probabilistic and stratified by county, settlement size, age, and gender. The samples were non-matched. Trained interviewers conducted structured face-to-face interviews in participants’ households. The part of the questionnaire assessing sensitive information was self-administered. Results A majority of participants at both survey points (85.2%-86.2%) were sexually active. Median age at sexual debut (17 years) remained unchanged. Lifetime number of sexual partners was also stable. More women than men reported only one lifetime sexual partner. The prevalence of condom use at first intercourse increased (from 62.6 to 70%, P = 0.002), while the prevalence of condom use at most recent sexual intercourse remained stable (54% in 2005 and 54.7% in 2010). Consistent condom use also remained unchanged. About one fifth of participants (19.2% in 2005 and 20% in 2010) reported consistent condom use in the past year. At both survey points for both genders, consistent condom use was associated with age (odds ratio [OR] Women2005 = 0.74, P = 0.004; ORWomen2010 = 0.72, P < 0.001; ORMen2005 = 0.73, P < 0.001; ORMen2010 = 0.80, P = 0.006), negative attitudes toward condom use (ORWomen2005 = 0.84, P = 0.001; ORWomen2010 = 0.90, P = 0.026; ORMen2005 = 0.92, P = 0.032; ORMen2010 = 0.90, P = 0.011)), and condom use at first intercourse (ORWomen2005 = 3.87, P < 0.001; ORWomen2010 = 4.64, P < 0.001; ORMen2005 = 5.85, P < 0.001; ORMen2010 = 4.03, P < 0.001). In the observed period, HIV/AIDS knowledge was stable. Conclusion Risky sexual practices remain common among young Croatian adults. Given the recently reported STI prevalence rates in this age cohort, introduction of school-based sex education that would focus on protective behavioral and communication skills seems to be of crucial epidemiological importance.

Is anal sex a marker for sexual risk-taking? Results from a population-based study of young Croatian adults

BACKGROUND There is evidence that anal sex is becoming increasingly popular among heterosexual women and men. Several studies carried out in especially vulnerable populations (e.g. sex workers and low-income youth) suggested that anal sex may indicate a more general propensity to sexual risk-taking. METHODS To assess whether this epidemiologically important finding holds in the case of young adults from the general population, we analysed data from a cross-sectional probability survey carried out in 2010 on 1005 Croatian women and men aged 18-25. RESULTS Anal intercourse was reported by 36.5% of 861 sexually experienced participants (42.7% of men and 29.8% of women). About one-third of them (34%) used a condom at most recent anal intercourse. The experience of anal sex was significantly associated (P<0.001) with all four indicators of sexual risk-taking (condom use at most recent vaginal intercourse, number of sexual partners in the past year, concurrent sexual relationships and anonymous sex in the past year), as well as with negative attitudes and beliefs about condom use (P<0.01). Sexual sensation-seeking mediated the relationship between anal sex and some of the sexual risk-taking behaviours. CONCLUSION According to the findings, heterosexual anal sex is directly and indirectly associated with increased behavioural risks of acquiring HIV and other sexually transmissible infections (STI). Sex education and STI prevention programs should focus on the importance of using protection when practicing anal sex.

Rising popularity of anal intercourse and sexual risk taking : findings from two national probability studies of young Croatian adults

This study examined the prevalence and correlates of heterosexual anal intercourse in two national probability samples of young Croatian adults aged 18–25 years, which were collected in 2005 and 2010. The lifetime prevalence of anal intercourse increased from 27% to 36%. In multivariate analysis, reporting four or more lifetime sexual partners was the only correlate of the experience of anal intercourse that was significant among both women (odds ratios [ORs] = 1.78–3.27, P < 0.05) and men (ORs = 3.14–4.63, P < 0.01). Information about condom use at most recent anal intercourse was collected in the 2010 study wave only. Age (OR = 0.80, P < 0.05), female gender (OR = 0.29, P < 0.01), holding more negative attitudes towards condoms (OR = 0.28–0.32, P < 0.05) and reporting condom use at most recent vaginal intercourse (OR = 11.45, 95% Confidence interval [CI] = 5.68–23.06) were associated with using a condom at most recent anal intercourse. Given the substantial prevalence of anal intercourse among young heterosexual adults and considerable sexually transmitted infection/HIV risks associated with the practice, sex education programmes should promote the discussion of health risks associated with anal eroticism.

Female sex work and HIV risks in Croatia.

Abstract The aim of this paper was to analyze and compare the prevalence of HIV-related sexual risk taking among Croatian female sex workers (FSW) in two major urban areas. Two groups of FSWs were interviewed in Zagreb (n=65) and Split (n=89). Participants’ mean age was 33.3 (SD=8.32). Interviews were conducted by outreach organizations that provide health services to sex workers in the two cities. The study used a brief questionnaire with standardized behavioral and HIV knowledge indicators. The two groups of FSWs differed significantly in most socio-demographic and socio-sexual indicators. Women from the Split sample were somewhat younger (χ2=6.87, p<0.05), less educated (χ2=7.71, p<0.05), less likely to be single (χ2=19.81, p<0.001), and less likely to be unemployed (χ2=5.22, p<0.05). In addition, they injected drugs in higher proportion (χ2=35.03, p<0.001), but had less clients in the preceding month (χ2=12.54, p<0.001) and were less likely to be abused by them (χ2=7.18, p<0.01). HIV testing was significantly more prevalent among participants in the Split sample (χ2=4.95, p<0.05). In multivariate analysis, selling sex in Zagreb (OR = 14.48, p<0.01), having secondary or higher education (OR = 4.76, p<0.05), ever tested for HIV (OR = 8.34, p<0.05), and having assessed the risk of getting infected with HIV as high (OR = 0.23, p<0.05) were significantly associated with consistent condom use with clients in the last month. The findings of this first systematic study on HIV-related risks among FSWs in Croatia point to the need to update targeted intervention programs by improving the prevention of HIV risks associated with injecting drug use (Split) and by a more efficient HIV educational approach.

Orange Is Still Pink Mental Illness, Gender Roles, and Physical Victimization in Prisons

Although research has established a very strong relationship between the presence of a psychiatric disorder and victimization in prisons, some gaps remain in our understanding. This study considers the importance of gender differences in this relationship. Estimates based on the 2004 Survey of Inmates in State and Federal Correctional Facilities show that psychiatric disorders have a stronger relationship with victimization among male inmates than among female inmates. Yet the size of the gender difference varies greatly depending on the specific disorder. Depressive disorders have a much stronger relationship with victimization among men than among women, but other disorders, such as psychosis, show no gender difference. Symptom-specific analyses further confirm the nature of the difference. Victimization appears to be based in part on how well symptoms do or do not overlap with traditional gender roles. Male-atypical symptoms (e.g., sadness) have a stronger relationship with victimization among men, whereas female-atypical symptoms (e.g., anger) have a stronger relationship with victimization among women. Gender-neutral symptoms (e.g., hallucinations and delusions) have an equivalent relationship between genders. Further analyses suggest that these gender differences are not explained (with some exceptions) by verbal or physical provocation. These findings are interpreted in light of the literature on the nature of social control in men’s and women’s prisons as well as the literature on stigma.

Principled Machine Learning Using the Super Learner: An Application to Predicting Prison Violence

A rapidly growing number of algorithms are available to researchers who apply statistical or machine learning methods to answer social science research questions. The unique advantages and limitations of each algorithm are relatively well known, but it is not possible to know in advance which algorithm is best suited for the particular research question and the data set at hand. Typically, researchers end up choosing, in a largely arbitrary fashion, one or a handful of algorithms. In this article, we present the Super Learner—a powerful new approach to statistical learning that leverages a variety of data-adaptive methods, such as random forests and spline regression, and systematically chooses the one, or a weighted combination of many, that produces the best forecasts. We illustrate the use of the Super Learner by predicting violence among inmates from the 2005 Census of State and Federal Adult Correctional Facilities. Over the past 40 years, mass incarceration has drastically weakened prisons’ capacities to ensure inmate safety, yet we know little about the characteristics of prisons related to inmate victimization. We discuss the value of the Super Learner in social science research and the implications of our findings for understanding prison violence.

Availability of Health-Related Programs in Private and Public Prisons

Little is known about the resources available to protect inmates’ health in private prisons compared to their public counterparts. This is the first national-level study that exclusively examined the availability of health-related programs in private and public prisons in the United States. We applied propensity score weighting and doubly robust estimation to compare private prisons to comparable public prisons. Data were self-reported by prison administrators as part of the 2005 Census of State and Federal Adult Correctional Facilities. We found that private prisons offered fewer substance dependency, psychological/psychiatric, and HIV/AIDS-related programs. But the differences were progressively reduced when the comparison was limited to public prisons most similar on a variety of facility-level characteristics. The extent to which the two types of prisons differ is closely tied to the characteristics of the facilities that are compared.