Military and demographic predictors of mental ill-health and socioeconomic hardship among UK veterans.

BACKGROUND: Around 8% of the UK Armed Forces leave in any given year, and must navigate unfamiliar civilian systems to acquire employment, healthcare, and other necessities. This paper determines longer-term prevalences of mental ill health and socioeconomic outcomes in UK Service leavers, and how they are related to demographic factors, military history, and pre-enlistment adversity. METHODS: This study utilised data from a longitudinal sample of a cohort study UK Armed Forces personnel since 2003. A range of self-reported military and sociodemographic factors were analysed as predictors of probable Post-Traumatic Stress Disorder, common mental disorders, alcohol misuse, unemployment and financial hardship. Prevalences and odds ratios of associations between predictors and outcomes were estimated for regular veterans in this cohort. RESULTS: Veteran hardship was mostly associated with factors linked to socio-economic status: age, education, and childhood adversity. Few military-specific factors predicted mental health or socio-economic hardship, except method of leaving (where those leaving due to medical or unplanned discharge were more likely to encounter most forms of hardship as veterans), and rank which is itself related to socioeconomic status. CONCLUSION: Transition and resettlement provisions become increasingly generous with longer service, yet this paper shows the need for those services becomes progressively less necessary as personnel acquire seniority and skills, and instead could be best targeted at unplanned leavers, taking socioeconomic status into consideration. Many will agree that longer service should be more rewarded, but the opposite is true if provision instead reflects need rather than length of service. This is a social, political and ethical dilemma.

Are common mental disorders more prevalent in the UK serving military compared to the general working population?

BACKGROUND: Although the military is considered to be a stressful occupation, there are remarkably few studies that compare the prevalence of common mental disorder (CMD) between the military and the general population. This study examined the prevalence of probable CMD in a serving UK military sample compared to a general population sample of employed individuals. METHOD: Data for the general population was from the 2003 and 2008 collections for the Health Survey for England (HSE) and for the serving military from phases 1 (2004-2006) and 2 (2007-2009) of the King's Centre for Military Health Research (KCMHR) cohort study. Probable CMD was assessed by the General Health Questionnaire (GHQ-12). The datasets were appended to calculate the odds of CMD in the military compared to the general population. RESULTS: The odds of probable CMD was approximately double in the military, when comparing phase 1 of the military study to the 2003 HSE [odds ratio (OR) 2.4, 95% confidence interval (CI) 2.1-2.7], and phase 2 to the 2008 HSE (OR 2.3, 95% CI 2.0-2.6) after adjustment for sex, age, social class, education and marital status. CONCLUSIONS: Serving military personnel are more likely to endorse symptoms of CMD compared to those selected from a general population study as employed in other occupations, even after accounting for demographic characteristics. This difference may be partly explained by the context of the military study, with evidence from previous research for higher reports of symptoms from the GHQ in occupational compared to population studies, in addition to the role of predisposing characteristics.

What explains post-traumatic stress disorder (PTSD) in UK service personnel: deployment or something else?

BACKGROUND: In previous studies an association between deployment to Iraq or Afghanistan and an overall increased risk for post-traumatic stress disorder (PTSD) in UK armed forces has not been found. The lack of a deployment effect might be explained by including, in the comparison group, personnel deployed on other operations or who have experienced traumatic stressors unrelated to deployment. METHODS: The sample comprised 8261 regular UK armed forces personnel who deployed to Iraq, Afghanistan or other operational areas or were not deployed. Participants completed the PTSD CheckList-Civilian Version (PCL-C) and provided information about deployment history, demographic and service factors, serious accidents and childhood experiences. RESULTS: Deployment to Iraq or Afghanistan [odds ratio (OR) 1.2, 95% confidence interval (CI) 0.6-2.2] or elsewhere (OR 1.1, 95% CI 0.6-2.0) was unrelated to PTSD although holding a combat role was associated with PTSD if deployed to Iraq or Afghanistan (OR 2.7, 95% CI 1.9-3.9). Childhood adversity (OR 3.3, 95% CI 2.1-5.0), having left service (OR 2.7, 95% CI 1.9-4.0) and serious accident (OR 2.1, 95% CI 1.4-3.0) were associated with PTSD whereas higher rank was protective (OR 0.3, 95% CI 0.12-0.76). CONCLUSIONS: For the majority of UK armed forces personnel, deployment whether to Iraq, Afghanistan or elsewhere confers no greater risk for PTSD than service in the armed forces per se but holding a combat role in those deployed to Iraq or Afghanistan is associated with PTSD. Vulnerability factors such as lower rank, childhood adversity and leaving service, and having had a serious accident, may be at least as important as holding a combat role in predicting PTSD in UK armed forces personnel.

Do Junior Entrants to the UK Armed Forces have worse outcomes than Standard Entrants?

INTRODUCTION: The UK is the only permanent member of the UN Security Council that has a policy of recruiting 16 and 17 year old individuals into its regular Armed Forces. Little is known about the consequences of enlisting as a Junior Entrant (JE), although concerns have been expressed. We compare the mental health, deployment history, and pre-enlistment and post-enlistment experiences of personnel who had enlisted as JEs with personnel who joined as Standard Entrants (SEs). METHOD: Participants from a large UK military cohort study completed a self-report questionnaire between 2014 and 2016 that included symptoms of probable post-traumatic stress disorder (PTSD), common mental disorders, alcohol consumption, physical symptoms and lifetime self-harm. Data from regular non-officer participants (n=4447) from all service branches were used in the analysis. JEs were defined as having enlisted before the age of 17.5 years. A subgroup analysis of participants who had joined or commenced adult service after April 2003 was carried out. RESULTS: JEs were not more likely to deploy to Iraq or Afghanistan but were more likely to hold a combat role when they did (OR 1.25, 95% CI 1.00 to 1.56). There was no evidence of an increase in symptoms of common mental disorders, PTSD, multiple somatic symptoms (MSS), alcohol misuse or self-harm in JEs in the full sample, but there was an increase in alcohol misuse (OR 1.84, 95% CI 1.18 to 2.87), MSS (OR 1.51, 95% CI 1.04 to 2.20) and self-harm (OR 2.13, 95% CI 1.15 to 3.95) in JEs who had commenced adult service after April 2003. JEs remain in adult service for longer and do not have more difficulties when they leave service. CONCLUSIONS: JEs do not have worse mental health than SEs, but there is uncertainty in relation to alcohol misuse, MSS and self-harm in more recent joiners. Monitoring these concerns is advisable.

Birth weight, current body mass index, and insulin sensitivity and secretion in young adults in two Latin American populations.

BACKGROUND AND AIMS: Although studies have shown association of birth weight (BW) and adult body mass index (BMI) with insulin sensitivity in adults, there is limited evidence that BW is associated with insulin secretion. We assessed the associations between BW and current BMI with insulin sensitivity and secretion in young Latin American adults. METHODS AND RESULTS: Two birth cohorts, one from Ribeirao Preto, Brazil, based on 1984 participants aged 23-25 years, and another from Limache, Chile, based on 965 participants aged 22-28 years were studied. Weight and height at birth, and current fasting plasma glucose and insulin levels were measured. Insulin sensitivity (HOMA%S) and secretion (HOMA%ß) were estimated using the Homeostatic Model Assessment (HOMA2). Multiple linear regression analyses were carried out to test the associations between BW and adult BMI z-scores on log HOMA%S and log HOMA%ß. BW z-score was associated with HOMA%S in the two populations and HOMA%ß in Ribeirao Preto when adult BMI z-score was included in the model. BW z-score was associated with decreasing insulin secretion even without adjusting for adult BMI, but only in Ribeirao Preto. BMI z-score was associated with low HOMA%S and high HOMA%ß. No interactions between BW and BMI z-scores on insulin sensitivity were shown. CONCLUSIONS: This study supports the finding that BW may affect insulin sensitivity and secretion in young adults. The effect size of BW on insulin status is small in comparison to current BMI.

Application of scientific criteria to food allergens of public health importance.

Scientific criteria for identifying allergenic foods of public health importance (Björkstén, B., Crevel, R., Hischenhuber, C., Løvik, M., Samuels, F., Strobel, S., Taylor, S.L., Wal, J.-M., Ward, R., 2008. Criteria for identifying allergenic foods of public health importance. Regulatory Toxicology and Pharmacology 51(1), 42-52) have been further refined to incorporate an assessment of the strength of available scientific evidence (van Bilsen, J.H., Ronsmans, S., Crevel, R.W., Rona, R.J., Przyrembel, H., Penninks, A.H., Contor, L., Houben, G.F., 2011. Evaluation of scientific criteria for identifying allergenic food of public health importance. Regulatory Toxicology and Pharmacology 60, 281-289). A multi-disciplinary group was invited to critically test the refined approach. They independently evaluated selected publications on coconut, soy and/or peanut allergy, scored them using the newly developed level of evidence criteria, and debated proposed approaches for combining and utilising the scores to measure the overall impact of an allergen in public health impact assessments. The evaluation of selected publications using the modified criteria produced a relatively consistent result across the experts. These refined criteria were judged to be a way forward for the identification of allergenic foods of public health importance, and for prioritisation of allergen risk management and future data gathering. The debate to combine available evidence when assessing whether an allergenic food is of sufficient public health importance to warrant active management led to proposals on how to weight and combine evidence on allergen severity, potency and prevalence. The refined criteria facilitate a debate to find a meaningful sequence of steps to summarise the available information in relation to a food allergen.

Mental health and health service use among post-national service veterans: results from the 2007 Adult Psychiatric Morbidity Survey of England.

BACKGROUND: There is concern surrounding the psychological health and uptake of treatment services among veterans of the UK Armed Forces. METHOD: Data from a cross-sectional, nationally representative sample were used to compare health outcomes and treatment seeking among 257 post-national service veterans aged 16-64 years and 504 age and sex frequency-matched non-veterans living in the community in England. Early leavers (<4 years service) were compared with longer serving veterans. RESULTS: Male veterans reported more childhood adversity and were more likely to have experienced a major trauma in adulthood than non-veterans. There was no association between any measure of mental health and veteran status in males, except reporting more violent behaviours [adjusted odds ratio (aOR) 1.44, 95% confidence interval (CI) 1.01-2.06]. In females, a significant association was found between veteran status and ever having suicidal thoughts (aOR 2.82, 95% CI 1.13-7.03). No differences in treatment-seeking behaviour were identified between veterans and non-veterans with any mental disorder. Early service leavers were more likely to be heavy drinkers (aOR 4.16, 95% CI 1.08-16.00), to have had suicidal thoughts (aOR 2.37, 95% CI 1.21-4.66) and to have self-harmed (aOR 12.36, 95% CI 1.61-94.68) than longer serving veterans. CONCLUSIONS: The findings of this study do not suggest that being a veteran is associated with adversity in terms of mental health, social disadvantage or reluctance to seek treatment compared with the general population. Some evidence implies that early service leavers may experience more mental health problems than longer-serving veterans.

Evaluation of scientific criteria for identifying allergenic foods of public health importance.

Identification of allergenic foods of public health importance should be based on well-defined criteria. Björkstén et al. (2008) proposed that the criteria should assess the evidence for an IgE mechanism, the reaction, the potency and the severity of the effect of the food and its prevalence. This study evaluated the application of the proposed criteria based on published reports. Publications were selected from two databases to test whether the descriptions for ranking the level of evidence for each criterion were unambiguous and covered the full range of levels of evidence regarding seven foods, five known to be allergenic and two negative controls. The options available to rank the quality of evidence were appropriate but needed refinement to improve clarity and conceptual value. The criteria were helpful to assess known IgE-dependent allergens, and to exclude the non-allergenic substances. The criteria framework discriminated between papers with high, moderate and low quality of evidence. The advantage of using the proposed criteria is to make the decision-making process and rationale explicit. The framework helps to identify gaps in knowledge and to uncover the level of heterogeneity of the evidence thus guiding research and providing a basis for sound risk management decisions.

PTSD after deployment to Iraq: conflicting rates, conflicting claims.

BACKGROUND: Post-traumatic stress disorder (PTSD) has been called one of the signature injuries of the Iraq War. In this review prevalence estimates of PTSD are summarized and discrepancies are discussed in relation to methodological differences between studies. METHOD: We searched for population-based studies with a minimum sample size of 300. Studies based on help-seeking samples were excluded. We identified 60 possible papers, of which 19 fulfilled the inclusion criteria. Prevalence estimates and study characteristics were examined graphically with forest plots, but because of high levels of heterogeneity between studies, overall estimates of PTSD prevalence were not discussed. RESULTS: The prevalence of PTSD in personnel deployed to Iraq varied between 1.4% and 31%. Stratifying studies by PTSD measure only slightly reduced the variability in prevalence. Anonymous surveys of line infantry units reported higher levels of PTSD compared to studies that are representative of the entire deployed population. UK studies tend to report lower prevalence of PTSD compared with many US studies; however, when comparisons are restricted to studies with random samples, prevalences are similar. US studies that have assessed personnel more than once since return from deployment have shown that PTSD prevalence increases over the 12 months following deployment. CONCLUSIONS: Differences in methodologies and samples used should be considered when making comparisons of PTSD prevalence between studies. Further studies based on longitudinal samples are needed to understand how the prevalence of PTSD changes over time.

Smoking among males in the UK Armed Forces: changes over a seven year period.

OBJECTIVES: We assessed socio-demographic and military factors associated with smoking among males in the UK Armed Forces; made comparisons with the general population; and, tested the hypothesis that smoking has declined in the Armed Forces. METHODS: Using data from two cross-sectional studies (conducted in 1998 and 2004), we examined the patterns of smoking among regular male UK Service personnel aged 20-49 years and made comparisons with general population data from England, Scotland and Wales. RESULTS: In 2004, the prevalence of smoking among military males aged 20-49 years was 30% (n=2276), compared to 33% within the general population. Among current smokers, the mean number of cigarettes smoked per day was 15 for the military and 14 for the general population. The prevalence of smoking has decreased in lower ranks between 1998 and 2004 by 5.1% in 20-24 year olds to 6.3% in 35-49 year olds. These decreases are similar to those seen within those in the routine, manual or intermediate socio-economic group. CONCLUSIONS: Smoking among males in the UK military is associated with similar factors to those in the general population. As these factors are clustered in younger personnel, policies to decrease smoking should be targeted at younger recruits.

Mental health among commando, airborne and other UK infantry personnel.

BACKGROUND: Despite having high levels of combat exposure, commando and airborne forces may be at less risk of mental ill-health than other troops. AIMS: To examine differences in mental health outcomes and occupational risk factors between Royal Marines Commandos (RMCs), paratroopers (PARAs) and other army infantry (INF). METHODS: Three groups of personnel (275 RMCs, 202 PARAs and 572 INF) were generated from a UK military cohort study of personnel serving at the time of the 2003 Iraq war. Participants completed a questionnaire about their mental health and experiences on deployment. Differences in mental health outcomes between the groups were examined with logistic regression and negative binomial regression analyses. RESULTS: Both RMCs and PARAs were less likely to have multiple physical symptoms or to be fatigued, and RMCs also had lower levels of general mental health problems and lower scores on the Post-traumatic Checklist than INF personnel. Differences were not explained by the level of unit cohesion. CONCLUSIONS: The effect of warfare on troops' well-being is not universal across occupational groups. A possible explanation for this difference is that the high level of preparedness in RMCs and PARAs may lessen the psychological impact of war-zone deployment experiences.

Relationship between oxidative stress-related biomarkers and antioxidant status with asthma and atopy in young adults: a population-based study.

BACKGROUND AND AIM: Enhanced oxidative stress has been described in adults who suffer from symptoms of asthma and poor lung function. This study assessed the relation between markers of oxidative stress and antioxidant status and lung function, symptoms of asthma, atopy and bronchial hyperresponsiveness (BHR) in young adults. METHODS: A sub-sample of 589 individuals aged 22-28 years, selected from a total of 1232 included in a survey assessing early and current risk factors for chronic diseases, participated in the study. Participants were from an agricultural area of Chile, responded to a Spanish version of the European Community Respiratory Health Survey questionnaire, were skin tested to eight allergens, and challenged with methacholine to assess BHR. Five hundred and eighty-five individuals had measures of plasma biomarkers ferric reducing ability of plasma, uric acid, protein carbonyls and 564 had 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) assessed. RESULTS: All participants had detectable plasma 8-iso-PGF(2alpha) and carbonyl levels. There was no indication for an association between markers of antioxidant status or oxidative stress with any of the outcomes studied. CONCLUSION: The levels of oxidative stress-related biomarkers and antioxidant status in plasma may not be related to asthma in the general population in the absence of more severe symptoms or exacerbations.

Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adults.

BACKGROUND: The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries. OBJECTIVE: To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings. METHODS: We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata. RESULTS: The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma. CONCLUSION: The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.

Nutritional status, especially body mass index, from birth to adulthood and lung function in young adulthood.

OBJECTIVE: The study assessed the impact of body mass index (BMI) at birth, infancy, and adulthood, and waist circumference on lung function. METHODS: Using a longitudinal design 1221 Chilean young adults were studied. A standardized respiratory questionnaire was used. Forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), height, weight and waist circumference were measured. Data at birth and at 1 year were obtained from clinical notes. RESULTS: Males with a BMI > or = 30 and women with a BMI < 20 had a lower FEV(1) (-230 mL, 95% CI -363 to -98; -106 mL, 95% CI -211 to -0.18, respectively). In both sexes those with a BMI 20-25 had the highest FEV(1) and FVC. In males there was a negative association between waist circumference and FEV(1) and FVC while in women the middle tertile had the highest FEV(1) and FVC. There was an association between birthweight and BMI at birth, and FEV(1) in men, when unadjusted for other measurements. CONCLUSIONS: BMI and waist circumference in adulthood make a greater impact on lung function in adulthood than anthropometric measurements at birth and infancy. Proxy measures of fatness in adulthood reduce lung function, but the pattern between fatness and lung function by sex may be different.

Trajectories of alcohol use in the UK military and associations with mental health.

INTRODUCTION: There are higher levels of alcohol misuse in the military compared to the general population. Yet there is a dearth of research in military populations on the longitudinal patterns of alcohol use. This study aims to identify group trajectories of alcohol consumption in the UK military and to identify associations with childhood adversity, deployment history and mental disorder. METHODS: Data on weekly alcohol consumption across an eight year period and three phases of a UK military cohort study (n=667) were examined using growth mixture modelling. RESULTS: Five alcohol trajectory classes were identified: mid-average drinkers (55%), abstainers (4%), low level drinkers (19%), decreasing drinkers (3%) and heavy drinkers (19%). Alcohol consumption remained stable over the three periods in all classes, other than in the small decreasing trajectory class. Individuals in the heavy drinking class were more likely to have deployed to Iraq. Abstainers and heavy drinkers were more likely to report post-traumatic stress disorders at baseline compared to average drinkers. CONCLUSIONS: Heavy drinkers in the UK military did not change their drinking pattern over a period of eight years. This highlights the need to develop effective preventive programmes to lessen the physical and psychological consequences of long-term heavy alcohol use. Individuals with a mental health problem appeared more likely to either be drinking at a high level or to be abstaining from use.

Respiratory consequences of light and moderate smoking in young adults in Chile.

OBJECTIVE: To assess the association between smoking and respiratory symptoms, lung function and bronchial hyperresponsiveness (BHR) in young adults in Chile. SETTING: Selected sample of 1232 subjects aged 22-28 years. DESIGN: In this cross-sectional study, the outcome measures were: respiratory symptoms, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% (FEF25-75), FEV1/FVC and BHR. RESULTS: Among the 1232 subjects, 67.7% of the men and 49.4% of the women were smokers; the median cigarettes smoked per day was four for men and three for women. Smoking was associated with wheezing, waking up with a cough, breathlessness following exercise and persistent cough, with odds ratios (OR) between 1.94 (95% CI 1.41-2.66) and 3.12 (95% CI 2.21-4.40) among those smoking > or = 5 cigarettes per day, compared to non-smokers. Smoking < 5 cigarettes was significantly associated with wheezing and waking up with a cough. Smokers had a lower FEV1/FVC than non-smokers by approximately 0.8%. Smoking was not associated with FEV1, FEF25-75 or BHR status. CONCLUSIONS: This study highlights the early effects of smoking on respiratory symptoms. It could help governments in Latin America take vigorous action to deter young people from starting smoking.

Medical downgrading, self-perception of health, and psychological symptoms in the British Armed Forces.

OBJECTIVE: To investigate the contribution of psychological symptoms to limited employability for medical reasons in the British Armed Forces. METHODS: A sample of 4500 military personnel was randomly selected to receive either a full or an abridged questionnaire. The questionnaires asked whether the participant was medically downgraded and if yes, the reason for it. The full questionnaire included the General Health Questionnaire-12 (GHQ-12), the post-traumatic stress disorder (PTSD) checklist, 15 symptoms to assess somatisation, and selected items of the quality of life SF-36 questionnaire. The abridged questionnaire included the GHQ-4, a 14 item PTSD checklist, five symptoms, and the item on self-perception of health from the SF-36. Subjects above a threshold score for GHQ, PTSD, and symptoms were considered to have psychological symptoms. RESULTS: 12.4% of the participants were medically downgraded. The majority (70.4%) had social or work limitations. Medically downgraded personnel had higher odds ratios in comparison to non-downgraded personnel for psychological distress 1.84 (95% CI 1.43 to 2.37), PTSD 3.06 (95% CI 1.82 to 5.15), and number of symptoms 2.37 (95% CI 2.37 1.62 to 3.47). GHQ, PTSD, and symptoms scores were mainly, but not exclusively, related to chronic physical injury. CONCLUSIONS: Psychological symptoms are common among medically downgraded personnel. Although the mechanisms involved are unclear, tackling issues of psychological symptoms among these subjects could contribute to faster restitution to full employability in the Armed Forces.

Prevalence of asthma, atopy and bronchial hyperresponsiveness and their interrelation in a semi-rural area of Chile.

OBJECTIVE: To assess the prevalence of asthma symptoms and their association with sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine. SETTING: A random sample of 1232 adults, aged 22 to 28 years, studied in a Chilean semi-rural area. DESIGN: A cross-sectional design for the purpose of this analysis. RESULTS: The prevalence of wheeze was 27.4% (95%CI 24.9-29.9) and waking with breathlessness 13.7% (95%CI 11.8-15.6), higher than the results of a multi-centre European study. Only 7.8% (95%CI 6.3-9.3) had a positive BHR (< or =8 mg/ml) and 26.3% (95%CI 23.8-28.8) were atopic. The Youden index of asthma symptoms in non-atopic subjects varied from 0.184 to 0.259 when using BHR as gold standard for asthma, and increased from 0.379 to 0.504 among those with positive atopy. Only 4.5% reported asthma, and the Youden index was slightly higher in comparison to the asthma symptom groups. CONCLUSION: The prevalence of asthma symptoms in young adults was high, but only a small proportion of these were sensitised or had a positive BHR. We believe that aetiological studies of asthma should analyse subjects with asthma symptoms separately from those with positive atopic status or positive BHR.

The National Study of Health and Growth (NSHG): 23 years on the road.

This paper aims to give a record of the National Study of Health and Growth (NSHG) in terms of structure, process, its scientific contribution, outcome measurements, and the commissioning and funding of the study. The NSHG is a nutritional monitoring system of primary school children. The study included three samples: representative English and Scottish samples, and an inner city sample. There were 56 study areas and 50% were surveyed every year. The study was started in 1972 and ran without interruption for 23 years. Measurements were taken for height, weight and skinfold thickness for more than 95% of the children and the response rate to the questionnaire was approximately 85%. This level of collaboration did not diminish over time. More than 80 papers have been published on the study. Results from the study have documented an increase of height and obesity in England and Scotland, and an increase in asthma. The NSHG has shown that research units in a university environment can marry the scientific and administrative tasks of a large survey carried out over a long-term period.

Validity and repeatability of self-reported occupational and industrial history from patients in EEC countries.

The results of a study to assess the feasibility and acceptability of a questionnaire designed to ascertain occupational history and the repeatability of coding occupational and industrial status using an abbreviated version of the coding status are presented for EEC countries. The study demonstrates the difficulty of recruiting cancer patients below age 65. The percentage of useful information among patients who completed a self-administered questionnaire was slightly lower than those who completed an administered questionnaire but in general the response rate for most items in the questionnaires in any group was above 90%. The repeatability of coding occupational status and industrial status for current or last job was satisfactory with Kappa values of 65% and 76% respectively. The within-individual repeatability for these variables had similar Kappa values. The validity of coding occupational status with an abbreviated version of coding status compared to the full instructions was satisfactory for current or last occupation. However, observer variability may be fairly large for the abbreviated version. An increase in the coding repeatability could probably be achieved with few modifications to the description of occupation status groups and clearer headings for each division of the Industrial Occupation Classification and greater training of coders.