Childhood sexual abuse and pervasive problems across multiple life domains: Findings from a five-decade study.

The aim of this study was to use longitudinal population-based data to examine the associations between childhood sexual abuse (CSA) and risk for adverse outcomes in multiple life domains across adulthood. In 937 individuals followed from birth to age 45y, we assessed associations between CSA (retrospectively reported at age 26y) and the experience of 22 adverse outcomes in seven domains (physical, mental, sexual, interpersonal, economic, antisocial, multi-domain) from young adulthood to midlife (26 to 45y). Analyses controlled for sex, socioeconomic status, prospectively reported child harm and household dysfunction adverse childhood experiences, and adult sexual assault, and considered different definitions of CSA. After adjusting for confounders, CSA survivors were more likely than their peers to experience internalizing, externalizing, and thought disorders, suicide attempts, health risk behaviors, systemic inflammation, poor oral health, sexually transmitted diseases, high-conflict relationships, benefit use, financial difficulties, antisocial behavior, and cumulative problems across multiple domains in adulthood. In sum, CSA was associated with multiple persistent problems across adulthood, even after adjusting for confounding life stressors, and the risk for particular problems incremented with CSA severity. The higher risk for most specific problems was small to moderate, but the cumulative long-term effects across multiple domains reflect considerable individual and societal burden.

Chlamydia Testing in New Zealand: Analysis of the 2014/2015 National Health Survey.

BACKGROUND: Diagnosis rates of Chlamydia trachomatis are high in New Zealand; 1.3% of men and 3.7% of women aged 15 to 29 years were diagnosed in 2016. Because testing rates are also higher in women, we sought to understand chlamydia testing by demographic and behavioral characteristics. METHODS: Chlamydia testing in the past year, sexual behavior, and demographic characteristics were reported in the population-based 2014/2015 New Zealand Health Survey. Those aged 16 to 44 years who had a sexual partner in the past year were included. Testing prevalence was calculated, and associations were modeled. RESULTS: A total of 1677 men and 2323 women participated (89% response rate). Of these, 5.6% (95% confidence interval, 4.3%-7.2%) of men and 16.6% (14.7%-18.7%) of women were tested in the past year. Likelihood of testing in men was associated with having multiple partners and any condomless sex (adjusted relative risk, 11.93; 95% confidence interval, 5.70-24.98) and multiple partners with consistent condom use (3.77, 1.40-10.15) compared with one sexual partner and consistent condom use, and with Maori ethnicity (1.87, 1.05-3.31) compared with European/other. Among women, testing was associated with multiple partners with and without condomless sex (3.61 [2.69-4.85] and 2.81 [1.95-4.05], respectively), pregnancy (1.61, 1.18-2.18), and Asian ethnicity (0.52, 0.30-0.89). CONCLUSIONS: The study confirms that New Zealand men are much less likely to be tested than women, a potential reason for ongoing high chlamydia incidence among both sexes. The high testing rate in women includes many at low risk, and this divergence from recommendations is another issue to address.

Paediatric eosinophilic oesophagitis in New Zealand: A 3-year prospective study.

AIM: Eosinophilic oesophagitis (EoE) is a rare, chronic, relapsing immune/antigen-mediated disease characterised by symptoms of oesophageal dysfunction, with a paucity of data among New Zealand (NZ) children. This 3-year prospective study aimed to characterise EoE diagnosed nationally and to describe initial treatment strategies adopted. METHODS: Information on new diagnoses of paediatric EoE was obtained via the New Zealand Paediatric Surveillance Unit, through monthly questionnaires. RESULTS: From February 2014 to January 2017, 73 new cases (74% male) of EoE were reported, including 74% NZ European, 10% Asian, 7% Maori, 5% Middle-Eastern and 3% Pacific peoples. Median age of symptom onset was 4 years; dysphagia (48%) was the most common, followed by vomiting/regurgitation (40%), food impaction (19%) and epigastric pain (16%). A co-morbid history of other allergic conditions was present in 62% of patients, and 41% had a first degree relative with atopy. Seventy-nine percent of patients had abnormal endoscopic findings, most commonly linear furrows and white plaques; none had strictures. Median eosinophil count per high-powered field was 40 and 50 in the mid and distal oesophagus, respectively. Fifty-four percent of patients were initially managed with dietary manipulation alone (four required elemental feeds, five nasogastric tubes). Fifty-four percent of patients were treated with swallowed corticosteroids and 7% with prednisone. One patient was also treated with a leukotriene receptor antagonist. CONCLUSION: This first prospective study on paediatric patients with EoE in NZ finds similar demographics and disease characteristics as in other populations despite our unique ethnic population. Long-term prospective observational data should significantly improve our knowledge of this rare condition.

The burden of infertility in New Zealand: A baseline survey of prevalence and service use.

BACKGROUND: Studies in southern New Zealand indicate that up to a quarter of women experienced infertility, likely due to delay in childbearing. However, these findings may not be generalisable to the whole population. AIMS: To assess the lifetime prevalence of infertility and evidence for disparities for New Zealand men and women in a nationally representative sample. MATERIALS AND METHODS: In 2014/15 a general health survey with a module on sexual and reproductive health was conducted among New Zealand residents aged 16-74 years; 3792 men and 5222 women provided information on infertility. RESULT(S): There were 8.2% (95% CI 7.1-9.4%) of men and 12.5% (11.3-13.8%) of women who had experienced infertility; among fertility-tested women this was 15.4% (14.0-16.9%). Prevalence peaked in the 35-44 year age group (14.3% for men, 19.1% for women and 20.8% for fertility-tested women). Estimates for European, Maori and Asian ethnicities were similar. Pacific men and women had higher relative risks: 2.37 (95% CI 1.51-3.71) and 1.76 (1.27-2.44), respectively, compared with Europeans. Medical help was sought by 69.3% (95% CI 62.4-75.5%) of infertile men and 68.2% (63.1-72.9%) of women; this was significantly lower for Maori and Pacific. CONCLUSIONS: Infertility levels for those of European ethnicity were similar to studies in southern New Zealand, and in other high-income countries. However, infertility levels were just as high for Maori, and higher for Pacific people, despite experiencing fertility at younger ages. Focusing on reducing causes of infertility other than delayed childbearing would likely contribute to addressing this health disparity.

Ethnicity classification systems for public health surveys: experiences from HIV behavioural surveillance among men who have sex with men.

BACKGROUND: Race and ethnicity classification systems have considerable implications for public health, including the potential to reveal or mask inequities. Given increasing "super-diversity" and multiple racial/ethnic identities in many global settings, especially among younger generations, different ethnicity classification systems can underrepresent population heterogeneity and can misallocate and render invisible Indigenous people and ethnic minorities. We investigated three ethnicity classification methods and their relationship to sample size, socio-demographics and sexual health indicators. METHODS: We examined data from New Zealand's HIV behavioural surveillance programme for men who have sex with men (MSM) in 2006, 2008, 2011, and 2014. Participation was voluntary, anonymous and self-completed; recruitment was via community venues and online. Ethnicity allowed for multiple responses; we investigated three methods of dealing with these: Prioritisation, Single/Combination, and Total Response. Major ethnic groups included Asian, European, indigenous Maori, and Pacific. For each classification method, statistically significant associations with ethnicity for demographic and eight sexual health indicators were assessed using multivariable logistic regression. RESULTS: Overall, 10,525 MSM provided ethnicity data. Classification methods produced different sample sizes, and there were ethnic disparities for every sexual health indicator. In multivariable analysis, when compared with European MSM, ethnic differences were inconsistent across classification systems for two of the eight sexual health outcomes: Maori MSM were less likely to report regular partner condomless anal intercourse using Prioritisation or Total Response but not Single/Combination, and Pacific MSM were more likely to report an STI diagnosis when using Total Response but not Prioritisation or Single/Combination. CONCLUSIONS: Different classification approaches alter sample sizes and identification of health inequities. Future research should strive for equal explanatory power of Indigenous and ethnic minority groups and examine additional measures such as socially-assigned ethnicity and experiences of discrimination and racism. These findings have broad implications for surveillance and research that is used to inform public health responses.

Complications following frenotomy for ankyloglossia: A 24-month prospective New Zealand Paediatric Surveillance Unit study.

AIM: To investigate the incidence and characteristics of complications arising from frenotomy for ankyloglossia (tongue-tie) in New Zealand. METHODS: Prospective surveillance among hospital-based paediatricians of complications arising from frenotomy for ankyloglossia to children <1 year old was conducted by the New Zealand Paediatric Surveillance Unit for 24 months, from August 2016 to July 2018, inclusive. RESULTS: A total of 16 cases of complications arising from frenotomy were reported. The overall average annual incidence rate was 13.9/100 000. Geographic variation was noted with a peak of 85.6/100 000 in one region. Complications reported: poor feeding (44%), respiratory events (25%), pain (19%), bleeding (19%) and weight loss (19%). Three children (19%) also had delayed diagnosis of an underlying medical condition initially overlooked in favour of treating their ankyloglossia, this has not previously been reported. The majority (75%) of cases required admission to hospital. Treatments given included supplementary feeds (44%), surgical intervention (25%), breastfeeding support (19%), analgesia (13%) and blood products (13%). A total of 25% of children had one or more frenotomies; 50% were treated for two or more of: 'anterior' ankyloglossia, 'posterior' ankyloglossia or 'lip tie'; 50% had their frenotomies performed out of the hospital. Dentists were the most common performing practitioner (31%). CONCLUSIONS: Frenotomy rates in New Zealand are unknown. Poor feeding, pain, bleeding, weight loss and delayed diagnosis of an alternative underlying medical condition are important complications that require hospital assessment and admission. Practitioners and parents/families need to be aware of these possibilities. Centralised guidelines with access to specialist second opinions should be developed.

Consistent condom use and its predictors among female sexual Partners of People who Inject Drugs in Klang Valley, Malaysia.

BACKGROUND: Men who inject drugs (MWIDs) comprise the highest percentage of diagnosed HIV cases in Malaysia. Their female partners risk being infected through unprotected sexual contact. This paper reports the prevalence of consistent condom use and its predictors among the wives and regular sexual partners of MWIDs in Klang Valley, Malaysia. METHODS: A cross-sectional study using a self-administered questionnaire was conducted among the wives and regular sexual partners of MWIDs in the study location; 221 women were recruited through respondent-driven sampling. Data were analysed descriptively for the prevalence of consistent condom use, HIV status and HIV risk-related behaviour. Subsequently, simple and multiple logistic regressions were undertaken to identify the predictors of consistent condom use. RESULTS: The prevalence of consistent condom use among respondents was 19.5%. Slightly more than half (52.5%) of respondents had never used condoms with their partner. Fourteen women (6.3%) reported being HIV positive. While 7.7% had HIV-positive partners, 45.7% were unaware of their partner's HIV status. Consistent condom use was significantly higher among single women (AOR = 4.95; 95% CI: 2.45, 9.99), women who lived in urban areas (AOR = 2.97; 95% CI: 1.30, 6.78), HIV-positive women (AOR = 3.45; 95% CI: 1.13, 10.5) and women involved in sex work (AOR = 3.55, 95% CI: 1.45, 8.67). CONCLUSIONS: Inconsistent condom use among the majority of female sexual partners of MWIDs underscores the heightened risk faced by these women and calls for alternative prevention methods that women are able to control.

Chlamydia trachomatis Incidence Using Self-Reports and Serology by Gender, Age Period, and Sexual Behavior in a Birth Cohort.

BACKGROUND: Although understanding chlamydia incidence assists prevention and control, analyses based on diagnosed infections may distort the findings. Therefore, we determined incidence and examined risks in a birth cohort based on self-reports and serology. METHODS: Self-reported chlamydia and behavior data were collected from a cohort born in New Zealand in 1972/3 on several occasions to age 38 years. Sera drawn at ages 26, 32, and 38 years were tested for antibodies to Chlamydia trachomatis Pgp3 antigen using a recently developed assay, more sensitive in women (82.9%) than men (54.4%). Chlamydia incidence by age period (first coitus to age 26, 26-32, and 32-38 years) was calculated combining self-reports and serostatus and risk factors investigated by Poisson regression. RESULTS: By age 38 years, 32.7% of women and 20.9% of men had seroconverted or self-reported a diagnosis. The highest incidence rate was to age 26, 32.7 and 18.4 years per 1000 person-years for women and men, respectively. Incidence rates increased substantially with increasing number of sexual partners. After adjusting age period incidence rates for partner numbers, a relationship with age was not detected until 32 to 38 years, and then only for women. CONCLUSIONS: Chlamydia was common in this cohort by age 38, despite the moderate incidence rates by age period. The strongest risk factor for incident infection was the number of sexual partners. Age, up to 32 years, was not an independent factor after accounting for partner numbers, and then only for women. Behavior is more important than age when considering prevention strategies.

Ovulation monitoring and fertility knowledge: Their relationship to fertility experience in a cross-sectional study.

BACKGROUND: Various aspects of fertility knowledge, including the timing of the fertile window, have consistently been found to be poor. Limited evidence also suggests ovulation monitoring to time intercourse could be common. However, there have been no studies that compare these two aspects of fertility and women's fertility/infertility experiences. AIM: To examine the frequency of ovulation monitoring and its relationship with fertility knowledge and experience. METHOD: A cross-sectional study of women aged 25-50 years resident in southern New Zealand was undertaken in 2011. Randomly selected women were asked to complete a fertility questionnaire. Outcome prevalence measures were calculated with 95% confidence intervals (CI) and associations investigated using χ2 tests and Poisson regression. RESULTS: Ovulation monitoring was common, having ever been undertaken by 31.4% (95% CI: 28.5-34.3%) of the 1034 participants. However, knowledge was poor, particularly regarding the fertile window. More women who had ever monitored ovulation correctly identified the fertile window, although the proportion was still very low (18.4 vs 13.1% in those who had not, P = 0.027). Regression modelling showed ovulation monitoring was independently associated with seeking medical help to conceive, education and fertility experience, but not with knowledge. CONCLUSION: This study confirms ovulation monitoring was commonly undertaken. However, many women, including those who had monitored their ovulation, had poor fertility knowledge and failed to identify the fertile window. Poor fertility knowledge needs to be addressed, especially among women intending to conceive.

Self-reported STIs and sexual health checks in a cross-sectional study of gay and bisexual men in New Zealand.

OBJECTIVES: To determine the incidence of self-reported sexually transmitted infections (STIs) and sexual health checks in community and internet samples of New Zealand gay, bisexual and other men who have sex with men (MSM) and factors associated with these. METHODS: We analysed anonymous self-completed data from 3138 MSM who participated in the location-based Gay Auckland Periodic Sex Survey (GAPSS) and the internet-based Gay Online Sex Survey (GOSS) undertaken in February 2011. RESULTS: Overall 8.2% of the participants reported at least one STI in the previous 12 months, which did not differ significantly by demographic factors or HIV status. While having anal sex and more partners were associated with more STI, after adjustment for the number of partners, the type of partner (regular or casual) was not. Medium and low condom users reported STIs more than high condom users, regardless of partner type. Overall 40% had a sexual health check-up without an STI diagnosed in the past year, with similar numbers attending general practice and sexual health clinics. Having a check-up was lower among Pacific and Asian men, those identifying as bisexual and recruited online. While those with more partners, having anal intercourse and diagnosed with HIV were more likely to go for a check-up, those using condoms less often were not. CONCLUSIONS: STIs are commonly reported in this community sample of MSM but will underestimate the true incidence due to asymptomatic infection. Screening for STIs outside sexual health clinics should be normalised for MSM and made accessible, safe and relevant.

Trends in web-based HIV behavioural surveillance among gay and bisexual men in New Zealand: complementing location-based surveillance.

Most HIV behavioural surveillance programmes for gay, bisexual and other men who have sex with men (MSM) sample from location-based (offline) or web-based (online) populations, but few combine these two streams. MSM sampled online have been found to differ demographically and behaviourally from those sampled offline, meaning trends identified in one system may not hold for the other. The aim was to examine trends among MSM responding to supplementary repeat online behavioural surveillance surveys who had not participated in offline surveillance earlier that year in the same city, to see whether trends were parallel, converged or diverged. We recruited a total of 1613 MSM from an Internet dating site in Auckland, New Zealand in 2006, 2008 and 2011 using identical questionnaires and eligibility criteria to offline surveillance. Condom use was stable over time, HIV testing rates rose, the proportion reporting over 20 recent male partners declined, and anal intercourse rates increased, consistent with trends in offline surveillance conducted concomitantly and reported elsewhere. Variant trends included greater stability in condom use with casual partners among online-recruited MSM, and a rise in regular fuckbuddy partnering not identified among offline-recruited MSM. Among MSM recruited online, the frequency of checking Internet dating profiles increased between 2008 and 2011. In conclusion, supplementary web-based behavioural surveillance among MSM generally corroborates trends identified in offline surveillance. There are however some divergent trends, that would have been overlooked if only one form of surveillance had been conducted. As MSM populations increasingly shift their socialising patterns online and diversify, multiple forms of HIV behavioural monitoring may be required.

Prospective surveillance of hospitalisations associated with varicella in New Zealand children.

AIM: Varicella is a vaccine-preventable disease not notifiable in New Zealand (NZ), and varicella vaccine is not funded in the National Immunisation Schedule (NIS). Hospitalisations can occur because of bacterial secondary infection and other complications, which can result in long-term sequelae. Varicella may not be acknowledged in discharge coding when complications occur weeks after infection. Using the New Zealand Paediatric Surveillance Unit (NZPSU), the aim of this study was to document the hospitalisation burden of this disease. METHODS: Cases (0-14 years) of varicella and post-varicella complications requiring hospitalisation, including stroke syndromes where varicella occurred in the preceding 6 months, were notified to NZPSU between 1 November 2011 and 31 October 2013. Herpes zoster cases were excluded. Questionnaires were used to capture demographics, clinical features, management and short-term outcomes. RESULTS: One hundred seventy-eight notifications were received and 144 were confirmed cases. Overall incidence was 8.3/100,000 children per year. Fifty-two percent were women with a median age of 2.4 years. Maori and Pacific Island (PI) children accounted for 74% of hospitalisations, with incidence rate ratios compared with European children of 2.8 and 3.9, respectively (P < 0.01). Complications included: infection (75%), respiratory (11%), neurological (11%), electrolyte disturbance (6%) and haemorrhagic varicella (4%). Nine percent were immunocompromised. Median duration of hospital admission was 4 days with 9% requiring intensive care admission. There were no reported deaths; however, 19% had ongoing problems at discharge. CONCLUSION: Varicella has more associated morbidity than commonly perceived in immunocompetent children. Maori and PI children are more likely to have complications. This surveillance gives support for inclusion of universal varicella vaccine in the NZ NIS.

Performance of acute flaccid paralysis surveillance compared with World Health Organization standards.

AIM: To compare acute flaccid paralysis (AFP) surveillance systems used by members of the International Network of Paediatric Surveillance Units (INoPSU) across the five AFP surveillance performance indicators recommended by the World Health Organization (WHO) for the maintenance of polio-free certification. METHODS: A survey was administered to AFP surveillance co-ordinators in five INoPSU member countries (Australia, Belgium, Canada, New Zealand and Switzerland). Data collected included information on surveillance system processes, WHO-recommended performance indicators, investigative practices and final diagnoses of cases from 2006 to 2010. RESULTS: All countries contacted completed the survey. Each country used similar case definitions and processes for collecting AFP data. All countries used at least one of the WHO indicators for surveillance. No country consistently met the performance indicator for incidence or stool sampling. In all countries, at least one form of neurological testing was used to diagnose cases of AFP. Guillain-Barré syndrome was the most common final diagnosis in all countries for all years examined. CONCLUSIONS: Industrialised countries surveyed do not consistently meet the WHO-recommended AFP surveillance performance indicators. An opportunity exists for INoPSU to suggest a standard way for member countries to collect AFP data in order to examine the potential for strengthening the current systems or introducing additional enterovirus surveillance or alternative/complementary neurological performance measures suitable for countries that have eliminated polio. INoPSU member countries are evaluating these possibilities.

Location-based HIV behavioural surveillance among MSM in Auckland, New Zealand 2002-2011: condom use stable and more HIV testing.

OBJECTIVES: Over the last decade, annual HIV diagnoses among men who have sex with men (MSM) in New Zealand increased, then stabilised in 2006 and have not increased further. The aim was to examine trends in behaviours in order to better understand this pattern and inform community-based prevention. METHODS: From 2002 to 2011, we conducted five repeat cross-sectional behavioural surveillance surveys among MSM at community locations in Auckland (fair day, gay bars, sex-on-site venues; n=6091). Participation was anonymous and self-completed. Recruitment methods were consistent at each round. RESULTS: Overall, the samples became more ethnically diverse and less gay community attached over time. Condom use during anal intercourse was stable across three partnering contexts (casual, current regular fuckbuddy, current regular boyfriend), with a drop among casual contacts in 2011 only. In the 6 months prior to surveys, there was a gradual decline over time in the proportion reporting >20 male partners, an increase in acquiring partners from the internet and increases in engagement in anal intercourse in some partnering contexts. HIV testing in the 12 months prior to surveys rose from 35.1% in 2002 to 50.4% in 2011, mostly from 2008. CONCLUSIONS: This first indepth examination of trends in HIV-related behaviours among five consecutive large and diverse samples of MSM in New Zealand does not suggest condom use is declining. However, subtle changes in sexual networks and partnering may be altering the epidemic determinants in this population and increasing exposure.

HSV-2 incidence by sex over four age periods to age 38 in a birth cohort.

OBJECTIVES: To examine herpes simplex virus type 2 (HSV-2) incidence over four periods to age 38 in a birth cohort, and to compare risks for men and women, taking into account sexual behaviour. METHODS: At ages 21, 26, 32 and 38, participants in the Dunedin Multidisciplinary Health and Development Study were invited to provide serum for HSV-2 serology, and information on sexual behaviour. HSV-2 incidence rates were calculated for four age periods, and comparisons made by sex and period, taking into account number of sexual partners. RESULTS: By age 38, 17.3% of men and 26.8% of women had ever been seropositive for HSV-2. Incidence peaked for women from age 21 to 26 (19.1 per 1000 person-years) and men from age 26 to 32 (14.1 per 1000 person-years); it fell markedly for both from age 32 to 38 (5.1 and 6.8 per 1000 person-years for men and women, respectively). Overall risk was significantly higher for women: adjusted incidence rate ratio 1.9 (95% CI 1.4 to 2.7); the sex difference was most marked from age 21 to 26 (3.4, 95% CI 1.9 to 6.3). CONCLUSIONS: Our findings are consistent with a greater biological susceptibility to HSV-2 among women, and with the increasing risk to the early/mid-20s for women and late 20s/early 30s for men, being driven by an increasing pool of prevalent infection. The reduced risk in the mid-30s is consistent with declining infectivity of long-term prevalent infections.

Factors associated with recent HIV testing among younger gay and bisexual men in New Zealand, 2006-2011.

BACKGROUND: Understanding HIV testing behaviour is vital to developing evidence-based policy and programming that supports optimal HIV care, support, and prevention. This has not been investigated among younger gay, bisexual, and other men who have sex with men (YMSM, aged 16-29) in New Zealand. METHODS: National HIV sociobehavioural surveillance data from 2006, 2008, and 2011 was pooled to determine the prevalence of recent HIV testing (in the last 12 months) among YMSM. Factors associated with recent testing were determined using manual backward stepwise multivariate logistic regression. RESULTS: Of 3,352 eligible YMSM, 1,338 (39.9%) reported a recent HIV test. In the final adjusted model, the odds of having a recent HIV test were higher for YMSM who were older, spent more time with other gay men, reported multiple sex partners, had a regular partner for 6-12 months, reported high condom use with casual partners, and disagreed that HIV is a less serious threat nowadays and that an HIV-positive man would disclose before sex. The odds of having a recent HIV test were lower for YMSM who were bisexual, recruited online, reported Pacific Islander or Asian ethnicities, reported no regular partner or one for >3 years, were insertive-only during anal intercourse with a regular partner, and who had less HIV-related knowledge. CONCLUSION: A priority for HIV management should be connecting YMSM at risk of infection, but unlikely to test with appropriate testing services. New generations of YMSM require targeted, culturally relevant health promotion that provides accurate understandings about HIV transmission and prevention.

A gradient of childhood self-control predicts health, wealth, and public safety.

Policy-makers are considering large-scale programs aimed at self-control to improve citizens' health and wealth and reduce crime. Experimental and economic studies suggest such programs could reap benefits. Yet, is self-control important for the health, wealth, and public safety of the population? Following a cohort of 1,000 children from birth to the age of 32 y, we show that childhood self-control predicts physical health, substance dependence, personal finances, and criminal offending outcomes, following a gradient of self-control. Effects of children's self-control could be disentangled from their intelligence and social class as well as from mistakes they made as adolescents. In another cohort of 500 sibling-pairs, the sibling with lower self-control had poorer outcomes, despite shared family background. Interventions addressing self-control might reduce a panoply of societal costs, save taxpayers money, and promote prosperity.

Who is omitted from repeated offline HIV behavioural surveillance among MSM? Implications for interpreting trends.

Repeated behavioural surveillance should sample all epidemiologically relevant subgroups to provide a complete picture of trends in HIV risk behaviours. Web-based recruitment has been mooted but little empirical data exist on country experiences. We describe who is omitted from three rounds of a conventional offline-only surveillance programme among men who have sex with men (MSM) 2006-2011, but recruited subsequently on Internet dating sites, and the implications of this for understanding trends. The latter were younger, less gay identified and less gay community attached. Importantly, they reported different partnering patterns, lower condom use with casual and fuckbuddy-type male partners, and lower rates of HIV testing, compared to MSM routinely captured in offline surveillance. The replacement of offline socio-sexual activity by the Internet among many MSM means that current venue-based surveillance systems may underestimate risk behaviours, overlook trends among unsampled online MSM, and misinterpret trends observed in sampled MSM due to "sample drift" of most-at-risk MSM.

Stability and change in same-sex attraction, experience, and identity by sex and age in a New Zealand birth cohort.

Gaps remain in knowledge of changes in sexual orientation past adolescence and early adulthood. A longitudinal study of a New Zealand birth cohort was used to examine differences by age and sex in change in sexual attraction between 21 (1993/1994) and 38 years (2010/2011), sexual experiences between 26 and 38 years, and sexual identity between 32 and 38 years. Any same-sex attraction was significantly more common among women than men at all ages. Among women, any same-sex attraction increased up to age 26 (from 8.8 to 16.6 %), then decreased slightly by age 38 (12.0 %); among men, prevalence was significantly higher at age 38 (6.5 %) than 21 (4.2 %), but not in the intermediate assessments. It is likely that the social environment becoming more tolerant was responsible for some of the changes. Same-sex attraction was much more common than same-sex experiences or a same-sex identity, especially among women, with no major sex differences in these latter dimensions. Women exhibited much greater change in sexual attraction between assessments than men; for change in experiences and identity, sex differences were less marked and not statistically confirmed. Changes in the respective dimensions appeared more likely among those initially with mixed attraction and experiences, and among those initially identifying as bisexual, but this did not account for the sex difference in likelihood of change. These results provide contemporary information about the extent and variation of reported sexual attraction, experiences, and identity that we show continues across early and mid-adulthood.