Asthma severity and impact on perinatal outcomes: an updated systematic review and meta-analysis.

BACKGROUND: Large-scale studies exploring the associations of asthma severity, exacerbations and medication use with adverse perinatal outcomes have been published in recent years. OBJECTIVES: To update evidence on the associations of asthma severity, exacerbations and medication use with the adverse perinatal outcomes of preterm delivery (PD), low birthweight (LBW) and small-for-gestational-age (SGA). SEARCH STRATEGY: PubMed, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) from inception to 1 January 2021. SELECTION CRITERIA: Cohort studies comparing the likelihood of adverse perinatal outcomes in groups of asthmatic women stratified by asthma severity, asthma exacerbations or medication use, or comparing the likelihood of adverse perinatal outcomes between non-asthmatic women and asthmatics of various levels of severity and exacerbation. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed risk of bias. Random-effects models were used to meta-analyse the results. MAIN RESULTS: Twenty studies met the inclusion criteria. The odds of delivering SGA babies increased with maternal asthma severity. Pregnant women with an asthma exacerbation had higher odds of delivering LBW babies and SGA babies, compared with pregnant women with asthma but without an exacerbation (pooled adjusted odds ratio [OR] 1.15, 95% CI 1.02-1.29 for LBW; number of studies with adjusted OR 3; I2 = 0%) (pooled adjusted OR 1.13, 95% CI 1.04-1.23 for SGA; number of studies with adjusted OR 4; I2 = 0%) and compared to pregnant women without asthma. Oral corticosteroids use during pregnancy was associated with increased odds of LBW, but not PD. CONCLUSIONS: The available data suggest that maternal asthma severity and exacerbations are associated with increased odds of LBW and SGA babies. TWEETABLE ABSTRACT: A systematic review and meta-analysis found that maternal asthma severity and exacerbations are associated with increased odds of delivering low birthweight and small-for-gestational-age babies.

Age at menarche and risk of vasomotor menopausal symptoms: a pooled analysis of six studies.

OBJECTIVE: To examine the association between age at menarche and risk of vasomotor menopausal symptoms (VMS) and whether midlife body mass index (BMI) modified the association. DESIGN: A pooled analysis of six cohort studies. SETTING: The International collaboration on the Life course Approach to reproductive health and Chronic disease Events (InterLACE). POPULATION: 18 555 women from the UK, USA and Australia. METHODS: VMS frequency data (never, rarely, sometimes and often) were harmonised from two studies (n = 13 602); severity data (never, mild, moderate and severe) from the other four studies (n = 4953). Multinominal logistic regression models were used to estimate relative risk ratios (RRRs) and 95% CIs adjusted for confounders and incorporated study as random effects. MAIN OUTCOME MEASURES: Hot flushes and night sweats. RESULTS: Frequency data showed that early menarche ≤11 years was associated with an increased risk of 'often' hot flushes (RRR 1.48, 95% CI 1.24-1.76) and night sweats (RRR 1.59, 95% CI 1.49-1.70) compared with menarche at ≥14 years. Severity data showed similar results, but appeared less conclusive, with RRRs of 1.16 (95% CI 0.94-1.42) and 1.27 (95% CI 1.01-1.58) for 'severe' hot flushes and night sweats, respectively. BMI significantly modified the association as the risk associated with early menarche and 'often' VMS was stronger among women who were overweight or obese than those of normal weight, while this gradient across BMI categories was not as strong with the risk of 'severe' VMS. CONCLUSIONS: Early age at menarche is a risk factor for VMS, particularly for frequent VMS, but midlife BMI may play an important role in modifying this risk. TWEETABLE ABSTRACT: Overweight and obesity exacerbate the risk of vasomotor symptoms associated with early menarche.

Vasomotor menopausal symptoms and cardiovascular disease risk in midlife: A longitudinal study.

OBJECTIVE: To ascertain the association between vasomotor menopausal symptoms (VSM), hot flushes and night sweats, and cardiovascular disease, coronary heart disease and cerebrovascular disease. STUDY DESIGN: The study sample comprised 8881 women (aged 45-50 years) with available hospital separation data from the 1946-51 cohort (1996-2016) of the ongoing Australian Longitudinal Study on Women's Health, a national prospective cohort study. MAIN OUTCOME MEASURES: First fatal or non-fatal cardiovascular disease, coronary heart disease, and cerebrovascular disease events were obtained through linkage with hospital admission data, the National Death Index, and Medicare Benefits Schedule. Hot flushes and night sweats were assessed via questionnaires at each main survey. Additionally, we calculated the duration of symptoms based on whether or not women reported vasomotor menopausal symptoms in each survey. RESULTS: There were 925 cardiovascular disease, 484 coronary heart disease and 154 cerebrovascular disease events. There was no consistent evidence of any association with vasomotor menopausal symptoms, hot flushes and night sweats. We did find marginally statistically significant associations between presence of night sweats and cardiovascular disease (Hazard Ratio = 1.18, 95 % Confidence Interval: 1.01-1.38), and between the duration of vasomotor menopausal symptoms [years] and coronary heart disease (Hazard Ratioper year = 1.03, 95 % Confidence Interval: 1.00-1.05). However, given the number of associations tested, these findings could very well have arisen by chance. CONCLUSION: In this large longitudinal study with 20 years of follow-up and clinical outcomes we did not find a convincing association between vasomotor menopausal symptoms, hot flushes, night sweats and cardiovascular disease, coronary heart disease and cerebrovascular disease.

Protective effect of hormone therapy among women with hysterectomy/oophorectomy.

Study question: Does exposure to menopausal hormone therapy (MHT) in mid-aged women alter their risk of cardiovascular disease (CVD) mortality and all-cause mortality? Summary answer: MHT soon after menopause is unlikely to increase the risk of CVD mortality or all-cause mortality and may have a protective effect for women with hysterectomy/oophorectomy. What is known already: The balance of benefits and risks of MHT are currently unclear and may differ according to when treatment starts and whether women have an intact uterus. Study design size, duration: A total of 13 715 participants from the mid-aged population-based cohort (born 1946-1951) of the Australian Longitudinal Study on Women's Health (ALSWH) were followed from 1998 to 2013. Participants/materials setting methods: The measures included cardiovascular and all-cause mortality, exposure to MHT and menopausal status (based on 3-yearly self-reports). Electronic prescriptions data on MHT were also available from mid-2002 onwards. At each follow-up survey wave, participants were classified as: an existing user of MHT, an initiator of MHT or a non-initiator of MHT. Main results and the role of chance: After adjusting for confounding variables, existing users of MHT had a reduced risk (hazard ratio 0.63; 95% CI, 0.43-0.92) of CVD mortality compared with non-initiators. Insufficient evidence of an association was identified for initiators of MHT (0.66; 0.35-1.24). For all-cause mortality, risks were reduced for both initiators (0.69; 0.55-0.87) and existing users (0.80; 0.70-0.91). In a subgroup analysis, women with hysterectomy/oophorectomy had lower risks of CVD mortality for both initiators (0.14; 0.02-0.98) and existing users (0.55; 0.34-0.90), but no evidence of an association was found for women whose MHT commenced during or after menopause. Similarly for all-cause mortality, only the women with hysterectomy/oophorectomy had lower risks for both initiators (0.47; 0.31-0.70) and existing users (0.69; 0.58-0.82). Limitations, reasons for caution: Limitations include the observational nature of the study, the small number of deaths, MHT use being self-reported and the classification of menopausal status also being based on self-reported information. Wider implications of the findings: Women considering MHT soon after menopause can be reassured that the treatment is unlikely to increase their risk of CVD mortality or all-cause mortality. Study funding/competing interest(s): The Australian Longitudinal Study on Women's Health is funded by the Australian Department of Health. G.D.M. is funded by the Australian Research Council Future Fellowship. L.C. was funded by a China scholarship council (CSC) graduate scholarship. All authors report no conflict of interest. Trial registration number: N/A.

Young women's psychological distress after a diagnosis of polycystic ovary syndrome or endometriosis.

STUDY QUESTION: Do young women with polycystic ovary syndrome (PCOS) or endometriosis report more psychological distress than their peers without a history of these conditions? SUMMARY ANSWER: Young women (aged 18-23 years) with PCOS or endometriosis had a greater risk of moderate to severe psychological distress than women without a history of these conditions. WHAT IS KNOWN ALREADY: Psychological distress appears common among women with PCOS and endometriosis. However, population-based studies that examine the psychological outcomes for adolescents and young women are generally absent from the literature. STUDY DESIGN, SIZE, DURATION: This is a secondary analysis of data collected from 17 015 young, Australian women participating in a national, longitudinal cohort study. Women were first surveyed in 2012-2013 when they were aged 18-23 years. In 2014, women completed the second survey when they were aged 19-24 years and 11324 (67%) women responded. PARTICIPANTS/MATERIALS, SETTING, METHODS: We analysed data from 11 238 women who participated in both Surveys 1 and 2 and who responded to questions about PCOS and endometriosis. Using logistic regression, we compared the odds of moderate to severe psychological distress at Surveys 1 and 2 for women reporting a recent diagnosis (within the last 12 months) of PCOS or endometriosis and women with a pre-existing diagnosis, with that for women without a history of these conditions. MAIN RESULTS AND THE ROLE OF CHANCE: At Survey 2, around 60% of women reporting a diagnosis of PCOS or endometriosis had moderate to severe levels of psychological distress. Compared to women without a history of these conditions, the odds of moderate to severe psychological distress at Survey 2 were significantly higher for women recently diagnosed with PCOS [Adjusted Odds Ratio (AOR) = 1.62, 95% CI = 1.21-2.18] or endometriosis (AOR= 1.77; 95% CI = 1.20-2.63) and for women with a pre-existing diagnosis of PCOS (AOR = 1.57, 95% CI = 1.30-1.89) or endometriosis (AOR = 1.61; 95% CI = 1.26-2.06). Women recently diagnosed with PCOS or endometriosis also had a greater likelihood of moderate to severe distress in the year prior to their diagnosis. The association between PCOS and psychological distress was attenuated when adjusting for BMI, but hormonal contraceptive use did not attenuate the risk of distress among the women with PCOS or endometriosis. LIMITATIONS, REASONS FOR CAUTION: All data were self-reported and, therefore, the diagnoses of PCOS or endometriosis were not confirmed by a medical practitioner. WIDER IMPLICATIONS OF THE FINDINGS: Health professionals should be aware of the potential psychosocial and healthcare needs among young women with these conditions, particularly women with PCOS who are obese. While hormonal contraceptives may help to regulate the hormonal aspects of these conditions, they do not appear to reduce women's psychological distress. Because psychological distress among the young women in this study remained elevated even after diagnosis, this supports the need for multidisciplinary health care to help women adjust to their diagnosis and treatment regimens and facilitate positive, long-term mental health outcomes. Future research that examines medical and psychosocial sources of distress for young women with PCOS and endometriosis is needed. STUDY FUNDING/COMPETING INTERESTS: I.J.R. was supported by an Australian National Health and Medical Research Council Centre for Research Excellence (grant number: APP1000986). G.D.M. is funded by the Australian Research Council Future Fellowship (FT120100812). The Australian Longitudinal Study on Women's Health is funded by the Australian Government Department of Health. H.T. is supported by an Australian National Health and Medical Research Council Practitioner Fellowship. The authors declare that no competing interests exist. TRIAL REGISTRATION NUMBER: N/A.

Unit cohesion, traumatic exposure and mental health of military personnel.

BACKGROUND: The benefit of military unit cohesion to morale and psychological resilience is well established. But it remains unclear whether unit cohesion modifies the association between deployment-related traumatic exposure and mental health problems. AIMS: To examine the association between unit cohesion, traumatic exposure and poor mental health [symptoms of post-traumatic stress disorder (PTSD), psychological distress and alcohol dependency] and assess whether the relationship between traumatic exposure and poor mental health differs by level of unit cohesion. METHODS: A self-reported cross-sectional survey of Australian military personnel deployed to Iraq or Afghanistan between 2001 and 2009. RESULTS: Among 11411 participants, those with low levels of unit cohesion had higher odds of PTSD symptoms [aOR (95% CI): 2.54 (1.88, 3.42)], very high psychological distress [aOR (95% CI): 4.28 (3.04, 6.02)] and a high level of alcohol problems [aOR (95% CI): 1.71 (1.32, 2.22)] compared with those reporting high unit cohesion on deployment. Higher exposure to traumatic events on deployment was associated with greater risk of PTSD symptoms, very high levels of psychological distress and high levels of alcohol problems in this cohort. However, there was no evidence of a statistically significant interaction between unit cohesion and traumatic exposures in influencing poor mental health. CONCLUSIONS: Our findings suggest that both unit cohesion and traumatic exposure are independently associated with poor mental health. Efforts to improve military unit cohesion may help to improve the mental health resilience of military personnel, regardless of their level of traumatic exposure.

Factors associated with low unit cohesion in Australian Defence Force members who deployed to the Middle East (2001-2009).

INTRODUCTION: Unit cohesion has been shown to bolster the mental health of military personnel; hence, it is important to identify the characteristics that are associated with low unit cohesion, so that interventions to improve unit cohesion can be targeted and implemented. Little is known about the factors associated with low unit cohesion. This research aims to identify demographic, military service and deployment factors associated with low unit cohesion. METHODS: Data from a self-reported cross-sectional study of 11 411 current or ex-serving Australian military personnel deployed to Iraq or Afghanistan between 2001 and 2009 were used. Multivariable logistic regression was used to investigate the research aims. RESULTS: Being female (adjusted OR (aOR) (95% CI) 1.35 (1.21 to 1.51)), non-commissioned officer (aOR (95% CI) 1.50 (1.39 to 1.62)), lower ranked (aOR (95% CI) 1.74 (1.51 to 2.01)) or having left military service (aOR (95% CI) 1.71 (1.46 to 2.02)) was associated with reporting low unit cohesion. Potentially modifiable factors such as performing logistic roles on deployment (aOR (95% CI) 1.13 (1.01 to 1.27)), dissatisfaction with work experience on deployment such as working with colleagues who did not do what was expected of them (aOR (95% CI) 4.09 (3.61 to 4.64)), and major problems at home while deployed (aOR (95% CI) 1.50 (1.38 to 1.63)) were also associated with reporting low unit cohesion. CONCLUSIONS: This is the first study to identify demographic, military service and deployment factors associated with low unit cohesion. The modifiable nature of unit cohesion means that military leaders could use this information to identify subgroups for targeted resilience interventions that may reduce vulnerabilities to mental health problems and improve the job satisfaction, preparedness and deployment experiences of serving members.

Time-course of PTSD symptoms in the Australian Defence Force: a retrospective cohort study.

AIMS: Understanding the time-course of post-traumatic stress disorder (PTSD), and the underlying events, may help to identify those most at risk, and anticipate the number of individuals likely to be diagnosed after exposure to traumatic events. METHOD: Data from two health surveys were combined to create a cohort of 1119 Australian military personnel who deployed to the Middle East between 2000 and 2009. Changes in PTSD Checklist Civilian Version (PCL-C) scores and the reporting of stressful events between the two self-reported surveys were assessed. Logistic regression was used to examine the association between the number of stressful events reported and PTSD symptoms, and assess whether those who reported new stressful events between the two surveys, were also more likely to report older events. We also assessed, using linear regression, whether higher scores on the Kessler Psychological Distress Scale or the Alcohol Use Disorder Identification Test were associated with subsequent increases in the PCL-C in those who had experienced a stressful event, but who initially had few PTSD symptoms. RESULTS: Overall, the mean PCL-C scores in the two surveys were similar, and 78% of responders stayed in the same PCL-C category. Only a small percentage moved from having few symptoms of PTSD (PCL-C < 30) in Survey 1 to meeting the criteria for PTSD (PCL-C ≥ 50) at Survey 2 (1% of all responders, 16% of those with PCL-C ≥ 50 at Survey 2). Personnel who reported more stressful lifetime events were more likely to score higher on the PCL-C. Only 51% reported the same stressful event on both surveys. People who reported events occurring between the two surveys were more likely to record events from before the first survey which they had not previously mentioned (OR 1.48, 95% CI (1.17, 1.88), p < 0.001), than those who did not. In people who initially had few PTSD symptoms, a higher level of psychological distress, was significantly associated with higher PCL-C scores a few years later. CONCLUSIONS: The reporting of stressful events varied over time indicating that while the impact of some stressors endure, others may increase or decline in importance. When screening for PTSD, it is important to consider both traumatic experiences on deployment and other stressful life events, as well as other mental health problems among military personnel, even if individuals do not exhibit symptoms of PTSD on an initial assessment.

Fruit and vegetable consumption and prevalence and incidence of depressive symptoms in mid-age women: results from the Australian longitudinal study on women's health.

BACKGROUND/OBJECTIVES: There is continued interest in the associations between diet and depression and several studies have focused on individual dietary factors or diet patterns to investigate the relationship. We investigated the association between fruit and vegetables and symptoms of depression in the mid-age cohort of the Australian Longitudinal Study on Women's Health. SUBJECTS/METHODS: A total of 6271 women with a mean age of 55.45 (1.45 s.d.) years were followed up at three surveys over 6 years. A score of ⩾ 10 on the Center for Epidemiological Studies Depression-10 scale indicated depressive symptoms. Fruit and vegetable intake was assessed using short questions. RESULTS: A total of 381 women (6.1%) were depressed at all three surveys over the 6-year survey period. Cross-sectional logistic regression analysis using general estimating equations showed a reduced odds of depressive symptoms (odds ratio (OR) 0.86 (95% confidence interval (CI) 0.79-0.95, P=0.001)) among women who ate ⩾ 2 of fruit/day even after adjustment for several factors including smoking, alcohol, body mass index, physical activity, marital status, education, energy, fish intake and comorbidities. The predictive model also showed a reduced odds of depressive symptoms (OR 0.82 (95% CI 0.70-0.96, P=0.012)) among women who ate ⩾ 2 pieces of fruit/day. There was also an association between vegetable intake and prevalence of depressive symptoms at higher levels of intake. CONCLUSIONS: Increasing fruit consumption may be one important factor for reducing both the prevalence and incidence of depressive symptoms in mid-age women.

Weight Gain, Overweight, and Obesity: Determinants and Health Outcomes from the Australian Longitudinal Study on Women's Health.

Recent estimates suggest that 35.3 % of adult Australians are overweight and a further 27.5 % are obese. The Australian Longitudinal Study on Women's Health (ALSWH) is a prospective study of women's health that commenced in Australia in 1996. The study recruited approximately 40,000 women in three birth cohorts, 1973-1978, 1946-1951 and 1921-1926, who have since been followed up approximately every three years using self-report surveys. Six surveys have been completed to date. This review aims to describe the changes in weight and weight status over time in the three ALSWH cohorts, and to review and summarise the published findings to date relating to the determinants and health consequences of weight gain, overweight and obesity. Future plans for the ALSWH include on-going surveys for all cohorts, with a seventh survey in 2013-2015, and establishment of a new cohort of women born in 1990-1995, which is currently being recruited.

Validity of self-reported osteoporosis in mid-age and older women.

UNLABELLED: The validity of self-reported osteoporosis is often questioned, but validation studies are lacking. We validated self-reported prevalence and incidence of osteoporosis against self-reported and administrative data on medications. The concurrent validity was moderate to good for self-reported prevalent osteoporosis, but only poor to moderate for self-reported incident osteoporosis in mid-age and older women, respectively. Construct validity was acceptable for self-reported prevalent but not for incident osteoporosis. INTRODUCTION: The validity of self-reported osteoporosis is often questioned, but validation studies are lacking. The aim was to examine the validity of self-reported prevalence and incidence of osteoporosis against self-reported and administrative data on medications. METHODS: Data were from mid-age (56-61 years in 2007) and older (79-84 years in 2005) participants in the Australian Longitudinal Study on Women's Health. Self-reported diagnosis was compared with medication information from (1) self-report (n(mid) = 10,509 and n(old) = 7,072), and (2) pharmaceutical prescription reimbursement claims (n(mid) = 6,632 and n(old) = 4,668). Concurrent validity of self-report was examined by calculating agreement, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Construct validity was tested by examining associations of self-reported diagnosis with osteoporosis-related characteristics (fracture, weight, bodily pain, back pain, and physical functioning). RESULTS: Agreement, sensitivity and PPV of self-reported prevalent diagnosis were higher when compared with medication claims (mid-age women: kappa = 0.51, 95% confidence interval [CI] = 0.46-0.56; older women: kappa = 0.65, 95% CI = 0.63-0.68) than with self-reported medication (mid-age women: kappa = 0.41, 95% CI = 0.37-0.45; older women: kappa = 0.57, 95% CI = 0.55-0.59). Sensitivity, PPV and agreement were lower for self-reported incident diagnosis (mid-age women: kappa = 0.39, 95% CI = 0.32-0.47; older women: kappa = 0.55, 95% CI = 0.51-0.61). Statistically significant associations between self-reported diagnosis and at least four of five characteristics were found for prevalent diagnosis in both age groups and for incident diagnosis in older women. CONCLUSIONS: The concurrent validity was moderate to good for self-reported prevalent osteoporosis, but only poor to moderate for self-reported incident osteoporosis in mid-age and older women, respectively. Construct validity was acceptable for self-reported prevalent but not for incident osteoporosis.

Mediterranean dietary pattern and prevalence and incidence of depressive symptoms in mid-aged women: results from a large community-based prospective study.

BACKGROUND/OBJECTIVES: To investigate the association between dietary patterns and prevalence and incidence 3 years later of depressive symptoms using data from the mid-aged cohort in the Australian Longitudinal Study on Women's Health. SUBJECTS/METHODS: Participants (aged 50-55 years) completed a food frequency questionnaire in 2001. Depressive symptoms were measured in 2001 and 2004 using the validated 10-item Centre for Epidemiologic Studies Depression scale. Multiple logistic regression was used for cross-sectional analysis (8369 women) and longitudinal analysis (7588) to assess the associations between dietary patterns and prevalence of depressive symptoms, and then for longitudinal analysis (6060) on their associations with the incidence of depressive symptoms in 2004, while adjusting for sociodemographic and lifestyle factors. RESULTS: Six dietary patterns were identified from factor analysis: cooked vegetables, fruit, Mediterranean style, meat and processed meat, dairy, and high fat and sugar. A higher consumption of the Mediterranean-style diet had a cross-sectional association with lower prevalence of depressive symptoms in 2001, adjusted odds ratio 0.82 (95% confidence interval 0.77-0.88); and longitudinally with lower incidence of depressive symptoms in 2004, adjusted odds ratio 0.83 (0.75-0.91). None of the associations found for other dietary patterns remained statistically significant after adjustment for confounders. A dose-response relationship was found cross-sectionally when women were grouped according to quintiles of Mediterranean-style diet (P-value for trend <0.001). CONCLUSIONS: Consumption of a 'Mediterranean-style' dietary pattern by mid-aged women may have a protective influence against the onset of depressive symptoms. These findings suggest that dietary patterns have a potential role in the prevention and management of depressive symptoms.

Major dietary patterns of young and middle aged women: results from a prospective Australian cohort study.

OBJECTIVE: The aim of this study was to assess the major dietary patterns of two age cohorts of women, to determine to the extent to which the dietary patterns differ between the cohorts and to assess whether they vary according to sociodemographic and behavioural characteristics and patterns of nutrient intake. METHOD: Dietary intake was assessed using an 80-item food frequency questionnaire for women aged 50-55 years (n=10 150; 'middle age') in 2001 and aged 25-30 years (n=7371; 'young') in 2003, from the Australian Longitudinal Study on Women's Health. Factor analysis using principal component extraction was used to identify dietary patterns, and a pattern score was calculated from the consumption of the food items identified with each dietary pattern. Associations between the dietary pattern scores and sociodemographic and behavioural characteristics and nutrient intakes were investigated using regression analysis. RESULTS: Six dietary patterns were identified and were labelled: cooked vegetables; fruit; Mediterranean-style; processed meat, meat and takeaway; reduced fat dairy; and high-fat and sugar foods. Regression analysis revealed that healthier dietary patterns were significantly associated with other favourable health-related behaviours, higher socioeconomic status and living in urban areas (P-values <0.05). CONCLUSIONS: In spite of differences in the level of consumption of individual food items, the similarity in dietary patterns across two generations of women suggests that policies and interventions to improve diet should focus on social and economic factors and general health-related behaviour rather than different age groups.

From partying to parenthood: young women's perceptions of cigarette smoking across life transitions.

This study explored influences on adoption, maintenance and cessation of smoking among young women as they experienced life transitions: leaving home, gaining employment or attending college/university, marriage and parenthood. Standardized, open-ended telephone interviews were conducted with 80 women (including never smokers, continuing smokers, recent adopters and quitters) aged 24-29 years, recruited from participants in the Australian Longitudinal Study on Women's Health. The social context of smoking (socializing with other smokers, drinking alcohol and going to pubs and clubs) was perceived to be a predominant influence on smoking from the time young women left home until they settled into a committed relationship or started their own family. Stress was identified as an important factor as they experienced lifestyle changes. An increased sensitivity to the negative aspects of smoking after turning 21 was reported, and around the mid-20s the women became concerned about the addictive nature of cigarettes. Motherhood was seen to carry increased responsibilities to protect children from passive smoking and there was a perceived importance of positive role modelling to protect children from becoming smokers themselves. This study highlights the need for public health campaigns to address the social role that smoking plays in young women's lives, and the perceived use of cigarettes for stress relief. Life changes such as settling down with a partner and the contemplation of motherhood provide opportunities for targeted interventions to promote quitting.

Estimating trends and seasonality in coronary heart disease.

We present two methods of estimating the trend, seasonality and noise in time series of coronary heart disease events. In contrast to previous work we use a non-linear trend, allow multiple seasonal components, and carefully examine the residuals from the fitted model. We show the importance of estimating these three aspects of the observed data to aid insight of the underlying process, although our major focus is on the seasonal components. For one method we allow the seasonal effects to vary over time and show how this helps the understanding of the association between coronary heart disease and varying temperature patterns.

Current smoking and the risk of non-fatal myocardial infarction in the WHO MONICA Project populations.

BACKGROUND: Cohort studies have shown that smoking has a substantial influence on coronary heart disease mortality in young people. Population based data on non-fatal events have been sparse, however. OBJECTIVE: To study the impact of smoking on the risk of non-fatal acute myocardial infarction (MI) in young middle age people. METHODS: From 1985 to 1994 all non-fatal MI events in the age group 35-64 were registered in men and women in the WHO MONICA (multinational monitoring of trends and determinants in cardiovascular disease) project populations (18,762 events in men and 4047 in women from 32 populations from 21 countries). In the same populations and age groups 65,741 men and 66,717 women participated in the surveys of risk factors (overall response rate 72%). The relative risk of non-fatal MI for current smokers was compared with non-smokers, by sex and five year age group. RESULTS: The prevalence of smoking in people aged 35-39 years who experienced non-fatal MI events was 81% in men and 77% in women. It declined with increasing age to 45% in men aged 60-64 years and 36% in women, respectively. In the 35-39 years age group the relative risk of non-fatal MI for smokers was 4.9 (95% confidence interval (CI) 3.9 to 6.1) in men and 5.3 (95% CI 3.2 to 8.7) in women, and the population attributable fractions were 65% and 55%, respectively. CONCLUSIONS: During the study period more than half of the non-fatal MIs occurring in young middle age people can be attributed to smoking.

Impact numbers in health policy decisions.

OBJECTIVE: To outline the major methodological issues appropriate to the use of the population impact number (PIN) and the disease impact number (DIN) in health policy decision making. DESIGN: Review of literature and calculation of PIN and DIN statistics in different settings. SETTING: Previously proposed extensions to the number needed to treat (NNT): the DIN and the PIN, which give a population perspective to this measure. MAIN RESULTS: The PIN and DIN allow us to compare the population impact of different interventions either within the same disease or in different diseases or conditions. The primary studies used for relative risk estimates should have outcomes, time periods and comparison groups that are congruent and relevant to the local setting. These need to be combined with local data on disease rates and population size. Depending on the particular problem, the target may be disease incidence or prevalence and the effects of interest may be either the incremental impact or the total impact of each intervention. For practical application, it will be important to use sensitivity analyses to determine plausible intervals for the impact numbers. CONCLUSIONS: Attention to various methodological issues will permit the DIN and PIN to be used to assist health policy makers assign a population perspective to measures of risk.

Impact numbers: measures of risk factor impact on the whole population from case-control and cohort studies.

OBJECTIVE: To describe new measures of risk from case-control and cohort studies, which are simple to understand and relate to numbers of the population at risk. DESIGN: Theoretical development of new measures of risk. SETTING: Review of literature and previously described measures. MAIN RESULTS: The new measures are: (1) the population impact number (PIN), the number of those in the whole population among whom one case is attributable to the exposure or risk factor (this is equivalent to the reciprocal of the population attributable risk); (2) the case impact number (CIN) the number of people with the disease or outcome for whom one case will be attributable to the exposure or risk factor (this is equivalent to the reciprocal of the population attributable fraction); (3) the exposure impact number (EIN) the number of people with the exposure among whom one excess case is attributable to the exposure (this is equivalent to the reciprocal of the attributable risk); (4) the exposed cases impact number (ECIN) the number of exposed cases among whom one case is attributable to the exposure (this is equivalent to the reciprocal of the aetiological fraction). The impact number reflects the number of people in each population (the whole population, the cases, all those exposed, and the exposed cases) among whom one case is attributable to the particular risk factor. CONCLUSIONS: These new measures should help communicate the impact on a population, of estimates of risk derived from cohort or case-control studies.

Health services research using linked records: who consents and what is the gain?

OBJECTIVE: To assess consent to record linkage, describe the characteristics of consenters and compare self-report versus Medicare records of general practitioner use. METHOD: Almost 40,000 women in the Australian Longitudinal Study on Women's Health were sent a request by mail for permission to link their Medicare records and survey data. RESULTS: 19,700 women consented: 37% of young (18-23 years), 59% of mid-age (45-50 years) and 53% of older women (70-75 years). Consenters tended to have higher levels of education and, among the older cohort, were in better health than non-consenters. Women tended to under-report the number of visits to general practitioners. CONCLUSIONS: Record linkage of survey and Medicare data on a large scale is feasible. The linked data provide information on health and socio-economic status which are valuable for understanding health service utilisation. IMPLICATIONS: Linked records provide a powerful tool for health care research, particularly in longitudinal studies.

Underuse of beta-blockers following myocardial infarction: a tale of two cities.

AIMS: To measure factors associated with underuse of beta-blocker therapy after myocardial infarction (MI). METHODS: The Newcastle and Perth collaborating centres of the World Health Organization (WHO) MONICA project (to MONItor trends and determinants of Cardiovascular disease) systematically evaluated all patients admitted to hospital in their respective regions with possible MI. A total of 1766 patients in Newcastle and 4,503 patients in Perth, discharged from hospital after confirmed MI from 1985 to 1993, were studied. Rates of beta-blocker use before and after hospital discharge were evaluated and correlates of beta-blocker use determined. RESULTS: Beta-blocker use was similar in Newcastle and Perth before MI (21% of patients in each centre). During hospital admission, beta-blocker therapy was initiated nearly twice as frequently in Perth compared with Newcastle (66 vs 36%, respectively) and more patients were discharged from hospital on beta-blockers in Perth (68%) than in Newcastle (45%). The main factors associated with underuse of beta-blockers in multivariate analysis were geographical centre (odds ratio (OR) for Newcastle compared with Perth 0.3; 95% confidence interval (CI) 0.3-0.3), a history of previous MI (OR 0.6, 95% CI 0.5-0.7), admission to hospital in earlier years (OR 0.4, 95% CI 0.3-0.4 for years 1985-87 compared with years 1991-93), diabetes (OR 0.6, 95% CI 0.5-0.8) and the concomitant use of diuretics (OR 0.5, 95% CI 0.4-0.6) and calcium antagonists (OR 0.6, 95% CI 0.5-0.8). CONCLUSIONS: Underuse of beta-blockers after MI was strongly related to hospital prescribing patterns and not to community use of beta-blockers. Underuse occurred in patients with diabetes and in patients with left ventricular dysfunction, patients who stand to benefit most from beta-blocker use following MI.