Diagnosis delayed: health profile differences between women with undiagnosed polycystic ovary syndrome and those with a clinical diagnosis by age 35 years.

STUDY QUESTION: Are reproductive, metabolic or psychological health profiles of women with clinically diagnosed polycystic ovary syndrome (PCOS) different from those with undiagnosed PCOS? SUMMARY ANSWER: Obtaining a clinical diagnosis of PCOS is strongly linked to the experience of fertility problems, but not clinical depression or poor metabolic health, although these were highly prevalent in women with PCOS irrespective of when they were diagnosed. WHAT IS KNOWN ALREADY: PCOS is an endocrine disorder that is relative common, but heterogeneous in presentation. This may impact on the pathways to diagnosis and timely treatment. STUDY DESIGN, SIZE, DURATION: A cross-sectional analysis of a community-based cohort of 974 women, established retrospectively when women were around 30 years of age. PARTICIPANTS/MATERIALS, SETTING, METHODS: In this cohort of women born in Adelaide, South Australia, half of women who met the Rotterdam criteria for PCOS were previously undiagnosed. We compared women with prior clinical diagnosis of PCOS, those diagnosed through participation in this research, and the remainder in the cohort. Sociodemographic characteristics, reproductive, metabolic and psychological health, including medical conditions and medications were considered. Logistic regression was undertaken to identify independent predictors of prior clinical diagnosis. MAIN RESULTS AND THE ROLE OF CHANCE: There were 56 women with a prior clinical diagnosis of PCOS (5.7%) and a further 64 (6.6%) were undiagnosed until study entry. The great majority of women with a prior diagnosis of PCOS reported having had problems with periods (95%) and excess body hair (63%). Corresponding proportions for women undiagnosed until study participation were slightly lower (81% and 45%, respectively). Although the proportion of women attempting or achieving pregnancy was similar across all groups, those with a prior diagnosis of PCOS were four times more likely to have reported difficulties becoming pregnant than those undiagnosed (odds ratio = 4.05, 95% CI 1.74-9.45) and frequently sought medical assistance. Metabolic problems were higher in both PCOS groups compared to women without PCOS. In both PCOS groups, the prevalence of clinical depression was 50% higher than in those with no PCOS (P = 0.021). LIMITATIONS, REASONS FOR CAUTION: The number of women who were diagnosed with PCOS both prior to and during the study limited statistical power available to detect modest differences between the PCOS groups. Some women in the group classified as not having PCOS may have remained undiagnosed, but any bias from this source would contribute to more conservative findings. WIDER IMPLICATIONS OF THE FINDINGS: Findings reinforce the need for early detection of PCOS symptoms from adolescence, ensuring timely diagnosis and appropriate health care. The high prevalence of depression among clinically diagnosed and undiagnosed women with PCOS suggests this is a feature of the condition and supports recent recommendations in the international PCOS guidelines to screen all women with PCOS for depression and anxiety. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a project grant (2017) from the National Health and Medical Research Council of Australia (NHMRC) Centre for Research Excellence in Polycystic Ovary Syndrome (Grant ID APP1078444). R.C.F. and J.C.A. were supported by Robinson Research Institute Lloyd Cox Career Development Fellowships (2018). Establishment of the cohort was funded by an NHMRC Strategic Award No. 465455, a Career Development Award in Population Health (No. 349548) and the Australian Research Council (Future Fellowship FT100101018) awarded to M.J.D. All authors declared no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Night Shift Among Women: Is It Associated With Difficulty Conceiving a First Birth?

Background: Asynchrony in circadian processes alters many physiological systems, including female reproduction. Thus, there are possible reproductive consequences of night shift work for women including menstrual irregularity, endometriosis, and prolonged time to conception. This study examined whether women who worked night shift were more likely than those who did not to require fertility treatment to conceive a first birth, whether they had specific infertility diagnoses, and if such relationships were age-specific. Methods: In a retrospective data linkage study of 128,852 primiparous women, fertility treatment data were linked to the state perinatal registry for South Australia (1986-2002). Potential exposure to night shift work was assessed using a job-exposure matrix. First, the association between night shift work and fertility treatment was assessed among (1) all women, then (2) women in paid employment, using logistic regression. Interactions between age and shift work status were also examined. Secondly, among women who conceived with fertility treatment, we assessed associations between night shift work and type of infertility diagnosis. Potential confounders were considered in all analyses. Results: Among women ≤35 years, night shift workers were more likely to require fertility treatment (all: OR = 1.40, 95% CI 1.19-1.64; in paid employment: OR = 1.27, 95% CI 1.08-1.50). There were no associations among women >35 years. Ethnicity, socioeconomic status and smoking did not affect these results. Among women who underwent fertility treatment, night shift workers were more likely than day workers to have menstrual irregularity (OR = 1.42, 95% CI 1.05-1.91) or endometriosis (OR = 1.34, 95% CI 1.00-1.80). Conclusions: Night shift work may contribute to increased need for fertility treatment in younger women. This increased risk may reflect young women's vulnerability in terms of poor tolerance of night shift work, and/or lack of control and choice about shift schedule.

Postnatal depression in a community-based study of women with polycystic ovary syndrome.

INTRODUCTION: Women with polycystic ovary syndrome are susceptible to depression and anxiety and so may also be at risk for postnatal depression. This study investigates whether women with polycystic ovary syndrome have an elevated risk of postnatal depression. MATERIAL AND METHODS: Cross-sectional data for parous women (n = 566) were available from a birth cohort. Polycystic ovary syndrome was diagnosed using the Rotterdam criteria. Details of reproductive history, pregnancy, birth, and postnatal depression were obtained through structured interview. Comparisons were made between women with and without polycystic ovary syndrome using logistic regression analysis, including the investigation of interactions. RESULTS: A positive but statistically non-significant association was found between polycystic ovary syndrome and postnatal depression (odds ratio 1.6, 95% confidence interval 0.9-2.9). Compared with their counterparts, women with polycystic ovary syndrome were substantially more likely: to have difficulty conceiving (odds ratio 5.2, 95% confidence interval 2.9-9.4), to have conceived with medical assistance (odds ratio 11.6, 95% confidence interval 5.5-24.4), and to have pregnancy complications (gestational diabetes, pregnancy-induced hypertension, or preeclampsia; odds ratio 2.0, 95% confidence interval 1.1-3.5). Where women with polycystic ovary syndrome had a history of miscarriage or conceived with medical assistance, the combination interacted (p = 0.06 and p < 0.05, respectively), with over half of such women having postnatal depression. CONCLUSIONS: Although women with polycystic ovary syndrome may not have an excess risk of postnatal depression overall, those who had suffered a miscarriage or required medical assistance to conceive were at substantially elevated risk. Findings point to vulnerability inherent in polycystic ovary syndrome being amplified, either by stressful experiences on the pathway to pregnancy/childbirth or by specific fertility treatment regimens.

The impact of specific fertility treatments on cognitive development in childhood and adolescence: a systematic review.

STUDY QUESTION: Does fertility treatment influence cognitive ability in school aged children, and does the impact vary with the type of treatment? SUMMARY ANSWER: The available high-quality evidence indicates that specific treatments may give rise to different effects on cognitive development, with certain treatments, including ICSI, associated with cognitive impairment. WHAT IS KNOWN ALREADY: Previous reviews of the literature concerning cognitive outcomes among children conceived with medical assistance have concluded that study findings are generally 'reassuring', but limited attention has been paid to the quality of this research. In addition, no review has separately assessed the range of treatment modalities available, which vary in invasiveness, and thus, potentially, in their effects on developmental outcomes. STUDY DESIGN, SIZE, DURATION: A systematic review was undertaken. We searched PubMed, PsycINFO and the Educational Resources Information Centre database to identify English-language studies published up until 21 November 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Two authors independently reviewed identified articles, extracted data and assessed study quality. Studies were eligible if they assessed cognitive development from age 4 years or more, among children conceived with fertility treatment compared with either children conceived naturally or children born from a different type of fertility treatment. Where available, data were extracted and reported separately according to the various components of treatment (e.g. mode of fertilization, embryo freezing, etc.). Risk of bias was assessed using the Newcastle-Ottawa Scale, with a score ≥7/9 indicative of high quality. MAIN RESULTS AND THE ROLE OF CHANCE: The search identified 861 articles, of which 35 were included. Of these, seven were rated high quality. Most studies (n = 22) were subject to selection bias, due to the exclusion of children at increased risk of cognitive impairment. Among high-quality studies, there was no difference in cognitive outcomes among children conceived with conventional IVF and those conceived naturally. Findings among high-quality studies of children conceived with ICSI were inconsistent: when compared with children conceived naturally, one study reported lower intelligence quotient (IQ; 5-7 points, on average) among ICSI children whereas the remaining two high-quality studies reported no difference between groups. Furthermore, among the three high-quality studies comparing children conceived with ICSI compared with conventional IVF, one reported a significant increase in the risk of mental retardation, one reported a small difference in IQ (3 points lower, on average) and one no difference at all. There were scant studies examining exposure to embryo freezing, or less invasive treatments such as ovulation induction without IVF/ICSI. LIMITATION, REASONS FOR CAUTION: Most existing studies had methodological limitations including selection bias and/or failure to address confounding by family background. In addition, a meta-analysis could not be performed due to heterogeneity in the assessment of cognitive outcomes. These factors impeded our ability to synthesize the evidence and draw reliable conclusions. WIDER IMPLICATIONS OF THE FINDINGS: The conflicting findings among studies of children conceived with ICSI require clarification, in light of the increasing use of this technique for reasons other than male-factor infertility. Further population-based studies are needed that utilize contemporary data to examine specific aspects of treatment and combinations of techniques (e.g. ICSI with frozen embryo cycles). Importantly, studies should include the complete group of children exposed to treatment. STUDY FUNDING/COMPETING INTEREST(S): A.R.R. is supported by a Career Development Fellowship from the National Health and Medical Research Council of Australia. L.J.M. is funded by a fellowship from the Heart Foundation of Australia. The authors declare there are no competing interests. TRIAL REGISTRATION NUMBER: Not applicable.

Fixed or Rotating Night Shift Work Undertaken by Women: Implications for Fertility and Miscarriage.

This review summarizes the evidence concerning effects of night shift work on women's reproductive health, specifically difficulty in conceiving and miscarriage. We distinguish between fixed night shift and rotating night shift, as the population subgroups exposed, the social and biological mechanisms, and the magnitude of effects are likely to differ; of note, women working fixed night shift are known to have high tolerance for this schedule. We identified two relevant systematic reviews with meta-analyses and five additional studies. Night shift work may give rise to menstrual cycle disturbances, but effect sizes are imprecise. Endometriosis may be elevated in night shift workers, but evidence is only preliminary. Adequate data are lacking to assess associations between night shift work and infertility or time to pregnancy. The weight of evidence begins to point to working at night, whether in fixed or rotating shifts, as a risk factor for miscarriage. There are many methodological problems with this literature, with substantial variation in the definitions of night shift and schedule types making comparisons between studies difficult and pooling across studies questionable. Nevertheless, there appears to be grounds for caution and counselling where women have concerns about night shift work and their reproductive health.

Perinatal outcomes by mode of assisted conception and sub-fertility in an Australian data linkage cohort.

BACKGROUND: Fertility treatment is associated with increased risk of major birth defects, which varies between in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), and is significantly reduced by embryo freezing. We therefore examined a range of additional perinatal outcomes for these exposures. METHODS: All patients in South Australia receiving assisted conception between Jan 1986-Dec 2002 were linked to the state-wide perinatal collection (all births/stillbirths ≥20 weeks gestation or 400 g birth weight, n = 306 995). We examined stillbirth, mean birth weight, low birth weight (<2500 g, <1500 g), small size for gestational age (<10th percentile, <3rd percentile), large size for gestational age (>90th percentile), preterm birth (32-<37 weeks, <32 weeks gestation), postterm birth (≥41 weeks gestation), Apgar <7 at 5 minutes and neonatal death. RESULTS: Relative to spontaneous conceptions, singletons from assisted conception were more likely to be stillborn (OR = 1.82, 95% Confidence Interval (CI) 1.34-2.48), while survivors as a group were comprehensively disadvantaged at birth, including lower birth weight (-109 g, CI -129--89), very low birth weight (OR = 2.74, CI 2.19-3.43), very preterm birth (OR = 2.30, CI 1.82-2.90) and neonatal death (OR = 2.04, CI 1.27-3.26). Outcomes varied by type of assisted conception. Very low and low birth weight, very preterm and preterm birth, and neonatal death were markedly more common in singleton births from IVF and to a lesser degree, in births from ICSI. Using frozen-embryos eliminated all significant adverse outcomes associated with ICSI but not with IVF. However, frozen-embryo cycles were also associated with increased risk of macrosomia for IVF and ICSI singletons (OR = 1.36, CI 1.02-1.82; OR = 1.55, CI 1.05-2.28). Infertility status without treatment was also associated with adverse outcomes. CONCLUSIONS: Births after assisted conception show an extensive range of compromised outcomes that vary by treatment modality, that are substantially reduced after embryo freezing, but which co-occur with an increased risk of macrosomia.

Effect of air pollution and racism on ethnic differences in respiratory health among adolescents living in an urban environment.

Recent studies suggest that stress can amplify the harm of air pollution. We examined whether experience of racism and exposure to particulate matter with an aerodynamic diameter of less than 2.5 µm and 10 µm (PM2.5 and PM10) had a synergistic influence on ethnic differences in asthma and lung function across adolescence. Analyses using multilevel models showed lower forced expiratory volume (FEV1), forced vital capacity (FVC) and lower rates of asthma among some ethnic minorities compared to Whites, but higher exposure to PM2.5, PM10 and racism. Racism appeared to amplify the relationship between asthma and air pollution for all ethnic groups, but did not explain ethnic differences in respiratory health.

Effects of birth size, post-natal growth and current size on insulin resistance in 9-year-old children: a prospective cohort study.

The influence of pre-natal conditions on later type 2 diabetes risk factors such as insulin resistance (IR) may be mediated by post-natal growth trajectory. We aimed to investigate the association of body size at birth and 9 years with IR at 9 years. Using data from a prospective Australian cohort study, we examined the influence of body size from birth to 9 years [z-score for weight or body mass index (BMI)] on IR at 9 years (estimated by homeostasis model assessment). At age 9 years, 151 children provided a fasting blood sample. z-BMI at age 9 was positively associated with IR. Birth z-BMI was inversely associated with IR only after adjustment for z-BMI at age 9 years. This may be interpreted as an effect of accelerated growth between birth and 9 years on IR. There was a statistically significant interaction between birth and 9-year z-BMI. Results from regression models including z-BMI at all available time points (birth, 6 and 12 months, and 2, 3.5 and 9 years) indicate a possible inverse association between body size at 3.5 years and HOMA-IR at 9 years. Results were similar when the analyses were repeated with z-weight substituted for z-BMI. These results add to the body of evidence concerning the importance of growth in early life for later IR, and highlight a possible interaction between pre- and post-natal growth. The potential influence of growth at around 3.5 years for HOMA-IR at 9 years warrants further investigation.

The effects of house moves during early childhood on child mental health at age 9 years.

BACKGROUND: Residential mobility is common in families with young children; however, its impact on the social development of children is unclear. We examined associations between the number, timing and type of house moves in childhood and child behaviour problems using data from an ongoing longitudinal study. METHODS: Complete data on residential mobility and child behaviour was available for 403 families. Three aspects of mobility were considered: (a) number of house moves from birth to <2 years, 2 to <5 years and 5 to 9 years; (b) lifetime number of house moves; and (c) moves associated with different housing trajectories characterized by changes in housing tenure. The primary outcomes were internalizing and externalizing behaviour problems at 9 years derived from Achenbach's Child Behaviour Checklist. Linear regression analyses were used to investigate the effect of the housing variables on internalizing and externalizing behaviour problem scores with adjustment for a range of sociodemographic and household covariates. RESULTS: Moving house ≥2 times before 2 years of age was associated with an increased internalizing behaviour score at age 9 years. This association remained after adjustment for sociodemographic and household factors. There was no association between increased residential mobility in other time periods and internalizing behaviour, or mobility in any period and externalizing behaviour. There was no effect of lifetime number of moves, or of an upwardly or downwardly mobile housing trajectory. However, a housing trajectory characterized by continuous rental occupancy was associated with an increased externalizing behaviour score. CONCLUSIONS: These findings may suggest that there is a sensitive period, in the first few years of life, in which exposure to increased residential mobility has a detrimental effect on mental health in later childhood.

Waist-to-height ratio is not a predictor of systolic blood pressure in 3-year-old children.

Waist:height has been proposed as an indicator of cardiovascular risk. We investigated the association of waist:height with systolic BP (sBP) in 3 year old children. Body mass index was a significant predictor of sBP, whereas waist:height was not: suggesting waist:height is not a useful indicator of sBP in this age group.

Maternal depressive symptoms and child care during toddlerhood relate to child behavior at age 5 years.

BACKGROUND: Disentangling the effects of maternal depression in toddlerhood from concurrent maternal depression on child behavior is difficult from previous research. Child care may modify any effects of maternal depression on subsequent child behavior, but this has not been widely investigated. METHODS: We examined the influence of maternal depressive symptoms during toddlerhood on children's behavior at the age of 5 years and investigated if formal or informal child care during toddlerhood modified any relationship observed. RESULTS: Data were available from 438 mothers and their children (227 girls and 211 boys); the mothers who completed questionnaires during the children's infancy, in toddlerhood, and at the age of 5 years. Recurrent maternal depressive symptoms in toddlerhood (when study children were aged 2 and 3½ years) was a significant risk factor for internalizing, externalizing, and total behavior problems when children were aged 5 years. Intermittent maternal depressive symptoms (study child age 2 or 3½ years) did not significantly affect child behavior problems. Formal child care at the age of 2 years modified the effect of recurrent maternal depressive symptoms on total behavior problems at age 5 years. Informal child care in toddlerhood did not significantly affect child behavior problems. CONCLUSIONS: Recurrent, but not intermittent, maternal depressive symptoms when children were toddlers were associated with child behavior problems at age 5 years. As little as half a day in formal child care at the age of 2 years significantly modified the effect of recurrent maternal depressive symptoms on total behavior problems. Formal child care for toddlers of depressed mothers may have positive benefits for the child's subsequent behavior.

The influence of parental smoking and family type on saliva cotinine in UK ethnic minority children: a cross sectional study.

BACKGROUND: In the United Kingdom, there has been an increase in cigarette smoking in ethnic minority adults since the 1970s; in some groups levels are now similar to that of White British people. We aimed to examine the determinants of exposure to secondhand smoke in ethnic minority children. We hypothesised that exposure to secondhand smoke in children will vary across ethnic groups, but that the correlates of exposure would be similar to that of Whites. METHODS: The Determinants of Adolescent Social well-being and Health sample comprises 3468 White United Kingdom and ethnic minority (Black Caribbean, Black African, Indian, Pakistani, Bangladeshi) pupils aged 11-13 yrs. Outcome was saliva cotinine concentration. Explanatory variables collected by self-complete questionnaire included ethnicity, child reported household smoking and socio-economic circumstances. Data were analysed using linear regression models with a random intercept function. RESULTS: Ethnic minority children had lower saliva cotinine than Whites, partly explained by less smoking among parents. White and Black Caribbean children had higher cotinine levels if they lived in a household with a maternal smoker only, than with a paternal smoker only. Living in a lone compared to a dual parent household was associated with increased cotinine concentration of 45% (95%CI 5, 99%) in Whites, 27% (95%CI 5,53%) in Black Caribbeans and 21% (95%CI 1, 45%) in Black Africans after adjusting for household smoking status. Material disadvantage was a significant correlate only for White children (40% (95%CI 1, 94%) increase in cotinine in least compared to most advantaged group). CONCLUSIONS: Ethnic minority children were less exposed to secondhand smoke than Whites, but the variations within groups were similarly patterned. These findings suggest that it is important not to be complacent about low smoking prevalence in some minority groups.

Asthma in Black African, Black Caribbean and South Asian adolescents in the MRC DASH study: a cross sectional analysis.

BACKGROUND: Ethnic differences in the prevalence of asthma among children in the UK are under-researched. We aimed to determine the ethnic differences in the prevalence of asthma and atopic asthma in children from the main UK ethnic groups, and whether differences are associated with differential distributions in social and psychosocial risk factors. METHODS: 6,643 pupils aged 11-13 years, 80% ethnic minorities. Outcomes were asthma/wheeze with (atopic) and without hay fever/eczema. Risk factors examined were family history of asthma, length of residence in the UK, socioeconomic disadvantage, tobacco exposure, psychological well-being, and body mass index (BMI). RESULTS: There was a pattern of lower prevalence of asthma in Black African boys and girls, and Indian and Bangladeshi girls compared to White UK. The overall prevalence was higher in Mixed Black Caribbean/White boys, with more atopic asthma in Black Caribbean boys and Mixed Black Caribbean/White boys due to more hayfever. Poor psychological well-being and family history of asthma were associated with an increased risk of asthma within each ethnic group. UK residence for

Effect of supplemental folic acid in pregnancy on childhood asthma: a prospective birth cohort study.

This study aimed to investigate the effect of the timing, dose, and source of folate during pregnancy on childhood asthma by using data from an Australian prospective birth cohort study (n = 557) from 1998 to 2005. At 3.5 years and 5.5 years, 490 and 423 mothers and children participated in the study, respectively. Maternal folate intake from diet and supplements was assessed by food frequency questionnaire in early (<16 weeks) and late (30-34 weeks) pregnancy. The primary outcome was physician-diagnosed asthma, obtained by maternal-completed questionnaire. Asthma was reported in 11.6% of children at 3.5 years (n = 57) and in 11.8% of children at 5.5 years (n = 50). Folic acid taken in supplement form in late pregnancy was associated with an increased risk of childhood asthma at 3.5 years (relative risk (RR) = 1.26, 95% confidence interval (CI): 1.08, 1.43) and with persistent asthma (RR = 1.32, 95% CI: 1.03, 1.69). The effect sizes did not change with adjustment for potential confounders. The association was similar at 5.5 years but did not reach statistical significance (RR = 1.17, 95% CI: 0.96, 1.42) in univariable models. These findings on childhood asthma support previous observations that supplementation with folate in pregnancy leads to an allergic asthma phenotype in mice via epigenetic mechanisms and is associated with poorer respiratory outcomes in young children.

Ethnic differences in adolescent lung function: anthropometric, socioeconomic, and psychosocial factors.

RATIONALE: The relative contribution of body proportion and social exposures to ethnic differences in lung function has not previously been reported in the United Kingdom. OBJECTIVES: To examine ethnic differences in lung function in relation to anthropometry and social and psychosocial factors in early adolescence. METHODS: The subjects of this study were 3,924 pupils aged 11 to 13 years, of whom 80% were ethnic minorities with satisfactory lung function measures. Data were collected on economic disadvantage, psychological well-being, tobacco exposure, height, FEV(1), and FVC. MEASUREMENTS AND MAIN RESULTS: The lowest FEV(1) was observed for Black Caribbean/African children after adjusting for standing height (SH) (white boys: 2.475 L; 95% confidence interval [CI], 2.442-2.509; white girls: 2.449 L; 95% CI, 2.464-2.535]; Black Caribbean boys: -14% [95% CI, -16 to -12]; Black Caribbean girls: -13% [95% CI, -16 to -11]; Black African boys: -15% [95% CI, -17 to -13]; Black African girls: -17% [95% CI, -19 to -14]; Indian boys: -13% [95% CI, -16 to -11]; Indian girls: -11% [95% CI, -14 to -8]; Pakistani/Bangladeshi boys: -7% [95% CI, -9 to -5]; Pakistani/Bangladeshi girls: -9% [95% CI, -11 to -6]). Adjustment for upper body segment instead of SH achieved a further reduction in ethnic differences of 41 to 51% for children of Black African origin and 26 to 39% for the other groups. Overcrowding (boys) and poor psychological well-being (boys and girls) were independent correlates of FEV(1), explaining up to a further 10% of ethnic differences. Similar patterns were observed for FVC. Social exposures were also related to height components. CONCLUSIONS: Differences in upper body segment explained more of the ethnic differences in lung function than SH, particularly among Black Caribbeans/African subjects. Social correlates had a smaller but significant impact. Future research needs to consider how differential development of lung capacity is compromised by the social patterning of growth trajectories.

A database to record, track and report health student rural placements.

The Spencer Gulf Rural Health School (SGRHS), South Australia, is funded by the Australian Commonwealth Government to deliver health education in the rural setting. The SGRHS required a database to record, track and report on student rural placements to satisfy Commonwealth reporting requirements, and for internal academic and administration staff use. Staff in widely separate rural locations needed to be able to access the database. A web-based relational database was created using Microsoft Access. The student rural placement database has been successfully utilised as the primary tool to record and track student placements in the SGRHS for 2 years, and has generated data for eight Commonwealth reports in this time. Future database developments include student accessible sections. With few alterations the database could be utilised by other Australian Rural Clinical Schools and University Departments of Rural Health.

Environmental exposure to carcinogens causing lung cancer: epidemiological evidence from the medical literature.

OBJECTIVE: In 2000 there were 1.1 million lung or bronchial cancer deaths worldwide, with relatively limited evidence of causation other than for smoking. We aimed to search and appraise the literature regarding evidence for a causal relationship between air pollution and lung cancer according to the 10 Bradford Hill criteria for causality. METHODOLOGY: A MEDLINE search was performed using the following key words: 'lung neoplasm', 'epidemiology', 'human', 'air pollution'and 'not molec*'. The criteria for inclusion was: cited original research that described the study population, measured environmental factors, was of case control or cohort design, and was undertaken after 1982. RESULTS: Fourteen papers (10 case control, four cohort studies) fulfilled the search criteria, with a sample size ranging from 101 cases and 89 controls, to a cohort of 552 cases and 138 controls. Of the 14 papers that fulfilled the search criteria the number of papers addressing each of the Bradford Hill criteria were as follows: Strength of association: eight studies demonstrated significant positive associations between environmental exposure and lung cancer with a relative risk range of 1.14-5.2. One study found a negative association with relative risk 0.28. Consistency: eight of 14 studies found significant positive associations and one of 14 a significant negative association. Specificity: tobacco smoking and occupational exposure were addressed in all studies (often crudely with misclassification). Temporality: exposure prior to diagnosis was demonstrated in nine studies. Dose-response relationship: evident in three studies. Coherence, analogy: not addressed in any study. CONCLUSION: Evidence for causality is modest, with intermediate consistency of findings, limited dose-response evidence and crude adjustment for important potential confounders. Large studies with comprehensive risk factor quantification are required to clarify the potentially small effect of air pollution given the relatively large effects of tobacco smoking and occupational carcinogen exposure.