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OBJECTIVE: The purpose of this study was to assess cancer risk among agricultural workers compared to the general population. METHODS: The study utilized data from Farmers’ Health Insurance (FHI) in Taiwan, which enrolled agricultural workers (N=1 175 149). The enrolled workers were matched to a general population (N=1 175 149) of the same age, gender, township, and enrollment year. The study population was linked to the National Cancer Registry to identify new cancer cases between 2000 and 2018. The Cox proportional hazards model was used to estimate the hazard ratio and 95% confidence interval for outcomes. RESULTS: During the study period, 136 913 new cancers among agricultural workers were identified. The study found that male farmers had an increased cancer risk, including lymphocytic leukemia, chronic myelogenous leukemia, non-Hodgkin’s lymphoma (NHL), oral cancer, lip cancer, esophagus cancer, rectum and rectosigmoid junction cancer, liver and intrahepatic bile duct cancer, lung cancer, trachea and bronchi cancer, and other non-melanoma skin cancer, even when considering the latency period. Female farmers had an elevated risk of multiple myeloma and other non-melanoma skin cancer. Moreover, only lymphoma, NHL, other lymphoid, and multiple myeloma, were both found to occur at different insurance periods. CONCLUSIONS: This study provides farmer cancer patterns and risk, adding to the evidence that farmers are at increased risk of certain types of cancer, especially for hematological cancers. As exposure varies by farm operation type, individual farmer exposure may vary widely. Further understanding of the complex relationship between occupational exposure, environmental factors, and lifestyle factors is needed.

OBJECTIVES: It is still not well established how occupational air pollutants affect the prognosis of asthma or chronic obstructive pulmonary disease (COPD). This study uses nationwide Danish registers and quantitative dust industry exposure matrices (IEM) for the farming and wood industries to estimate whether previous year dust exposure level impacts hospital readmissions for workers diagnosed with asthma or COPD. METHODS: We identified all individuals with a first diagnosis of either asthma (769 individuals) or COPD (342 individuals) between 1997 and 2007 and followed them until the next hospital admission for asthma or COPD, emigration, death or 31 December 2007. We included only individuals who worked in either the wood or farming industries at least one year during follow-up. We used logistic regression analysis to investigate associations between dust exposure level in the previous year and hospital readmission, adjusting for sex, age, time since first diagnosis, socioeconomic status, and labor force participation. RESULTS: Asthma readmissions for individuals with low and high dust exposure were increased [adjusted rate ratio (RR_adj) 2.52, 95% confidence interval (CI) 1.45–4.40] and RR_adj 2.64 (95% CI 1.52–4.60), respectively. For COPD readmission, the risk estimates were RR_adj 1.36 (95% CI 0.57–3.23) for low and RR_adj 1.20 (95% CI 0.49–2.95) for high exposure level in the previous year. For asthma readmission, stratified analyses by type of dust exposure during follow-up showed increased risks for both wood dust [RR_adj 2.67 (95% CI 1.35–5.26) high exposure level] and farming dust [RR_adj 3.59 (95% CI 1.11–11.59) high exposure level]. No clear associations were seen for COPD readmissions. CONCLUSIONS: This study indicates that exposure to wood or farm dust in the previous year increases the risk of hospital readmission for individuals with asthma but not for those with COPD.

Objectives It is still not well established how occupational air pollutants affect the prognosis of asthma or chronic obstructive pulmonary disease (COPD). This study uses nationwide Danish registers and quantitative dust industry exposure matrices (IEM) for the farming and wood industries to estimate whether previous year dust exposure level impacts hospital readmissions for workers diagnosed with asthma or COPD. Methods We identified all individuals with a first diagnosis of either asthma (769 individuals) or COPD (342 individuals) between 1997 and 2007 and followed them until the next hospital admission for asthma or COPD, emigration, death or 31 December 2007. We included only individuals who worked in either the wood or farming industries at least one year during follow-up. We used logistic regression analysis to investigate associations between dust exposure level in the previous year and hospital readmission, adjusting for sex, age, time since first diagnosis, socioeconomic status, and labor force participation. Results Asthma readmissions for individuals with low and high dust exposure were increased [adjusted rate ratio (RRadj) 2.52, 95% confidence interval (CI) 1.45-4.40] and RRadj 2.64 (95% CI 1.52-4.60), respectively. For COPD readmission, the risk estimates were RRadj 1.36 (95% CI 0.57-3.23) for low and RRadj 1.20 (95% CI 0.49-2.95) for high exposure level in the previous year. For asthma readmission, stratified analyses by type of dust exposure during follow-up showed increased risks for both wood dust [RRadj 2.67 (95% CI 1.35-5.26) high exposure level] and farming dust [RRadj 3.59 (95% CI 1.11-11.59) high exposure level]. No clear associations were seen for COPD readmissions. Conclusions This study indicates that exposure to wood or farm dust in the previous year increases the risk of hospital readmission for individuals with asthma but not for those with COPD. [ABSTRACT FROM AUTHOR]

OBJECTIVES: This review aimed to quantify suicide risk among agricultural, forestry, and fishery workers and study potential variations of risk within this population. METHODS: We conducted a systematic literature review and meta-analysis from 1995 to 2016 using MEDLINE and following the PRISMA guidelines. A pooled effect size of suicide risk among the population of interest was calculated using meta-analysis. Subgroup analyses were conducted to investigate whether effect size differed according to population or study characteristics. Meta-regression was used to identify sources of heterogeneity. RESULTS: The systematic review identified 65 studies, of which 32 were included in the meta-analysis. Pooled effect size was 1.48 [95% confidence interval (CI) 1.30–1.68] representing an excess of suicide risk among the population of interest. Subgroup analysis showed that this effect size varied according to geographic area, with a higher effect size in Japan. The following study characteristics were found to contribute to the between-study variance: reference group, measure of effect size, and study design. CONCLUSIONS: Our findings suggest an excess of suicide risk among agricultural, forestry, and fishery workers and demonstrated that this excess may be even higher for these groups in Japan. This review highlights the need for suicide prevention policies focusing on this specific population of workers. More research is also needed to better understand the underlying factors that may increase suicide risk in this population.

OBJECTIVE: Studies of the mental health of farmers have been largely cross-sectional and possibly confounded. We performed a prospective cohort study as well as a sibling comparison to control for unmeasured confounding. METHODS: Our study included 76 583 participants aged ≥19 years from the Nord-Trøndelag Health Study [HUNT1 (1984–1986), HUNT2 (1995–1997) and HUNT3 (2006–2008)]. We used the Anxiety and Depression Index (ADI) and the Hospital Anxiety and Depression Scale (HADS) to measure symptoms of mental distress. We used logistic regression to investigate the association between occupation at baseline and symptoms of mental distress 11 years later and fixed effects conditional logistic regression to compare farmers with their siblings working in other occupations. RESULTS: In the prospective cohort study, farmers had similar odds of having symptoms of psychological distress and anxiety as other manual occupational groups. Among all the occupational groups in the study, farmers had the highest odds of having symptoms of depression [odds ratio (OR) 1.99, 95% confidence interval (CI) 1.55–2.55, reference group: higher grade professionals]. Compared with their farming brothers and sisters, siblings in other occupations had lower odds of having high depression (OR 0.70, 95% CI 0.55–0.89) and anxiety (OR 0.79, 95% CI 0.63–1.00) scores in 2006–2008. CONCLUSION: Farmers had higher odds of having high depression scores compared to both other occupational groups and their siblings who were not working as farmers, suggesting that working in agriculture may impact mental health.

OBJECTIVES: Prostate cancer is one of the most frequent cancers among men worldwide. Its etiology is largely unknown, but an increased risk has been repeatedly observed among farmers. Our aim was to identify occupational risk factors for prostate cancer among farmers in the prospective cohort study AGRICAN. METHODS: Data on lifetime agricultural exposures (type of crops, livestock and tasks including pesticide use, re-entry and harvesting) were collected from the enrolment questionnaire. During the period from enrolment (2005–2007) to 31 December 2009, 1672 incident prostate cancers were identified. Hazard ratios (HR) were estimated using Cox regression analysis. RESULTS: We found an increased risk for cattle breeders using insecticides [HR 1.20, 95% confidence interval (95% CI) 1.01–1.42] with a significant dose–response relationship with number of cattle treated (P for trend 0.01). A dose–response relationship was also observed with the number of hogs (P for trend 0.06). We found an excess of prostate cancer risk among people involved in grassland activities, mainly in haymaking (HR 1.18, 95% CI 1.02–1.36). Pesticide use and harvesting among fruit growers were associated with an elevated prostate cancer risk, with a two-fold increased risk for the largest area. For potato and tobacco producers, an elevated prostate cancer risk was observed for almost all tasks, suggesting a link with pesticide exposure since all of them potentially involved pesticide exposure. CONCLUSIONS: Our analysis suggests that the risk of prostate cancer is increased in several farming activities (cattle and hog breeding, grassland and fruit-growing) and for some tasks including pesticide use.

We thank Dr Rahman Shiri (1) for his careful reading of our systematic review and meta-analysis on suicide among agricultural, forestry, and fishery workers (2). Our paper had the objective of providing a pooled effect size of suicide for this occupational group. Suicide is a crucial issue in public and occupational health. Suicide has a multifactorial etiology and recent systematic reviews and meta-analyses have pointed out the role of occupational exposures, mainly psychosocial work stressors, as risk factors for suicide (3, 4). Suicide is a very rare event in the general population and still more seldom in the working population. Indeed, unemployed and economically inactive people have a higher risk of suicide compared to employed people (5, 6). However, the total number of suicides is greater in the employed population than among the economically inactive or unemployed (6). Shiri’s letter (1) questioned several aspects of our review and meta-analysis. One comment related to the single reference database used in our review and a suggestion that our review could not be considered to be systematic. The review was based on Medline because our main interest was in quantitative epidemiologic studies. This is the largest database for biomedical literature and we would argue the most pertinent. Furthermore, we checked the reference lists of the most recent papers and literature reviews, and Shiri did not report any paper that was missing. No review, whether searching one or more databases, can expect to be totally exhaustive. There may always be missing studies, especially if we consider grey literature. Thus we assert that our review was systematic, while acknowledging that it may not be perfectly comprehensive. Shiri suggested an absence of quality assessment of the studies included in our meta-analysis. First, quality was considered in the context of our comments in the discussion section. Second, as suggested by Rothman et al (7), quality assessment was replaced by regression analyses of the effect of each quality item (study characteristics, ie, study design, effect measure, reference group, and adjustment). Third, because most studies included in this review were based on objective data (census, administrative, or register data), they were free of many of the sources of bias that exist in studies where information on exposure and outcome must be collected from participants. Consequently, many of the items related to quality were not pertinent, such as response and follow-up rates, coverage and representativeness of the sample, selection, etc. Contrary to what Shiri suggested, all study designs can be informative in this topic because all of them are able to provide an unbiased estimate of the effect size. In addition, the prospective and case–control studies may have shortcomings. For example, we excluded five studies including three prospective and case–control studies in the sensibility analysis because the group of interest was defined on the basis of the exposure to chemicals (pesticides) rather than job title. Our choice to retain the least adjusted models was justified because aggregated data were used for the meta-analysis. Therefore, unless all included studies adjusted for the same covariates measured in the same way, adjusted estimates cannot be meaningfully provided in an aggregate data meta-analysis. In addition, as the objective was above all descriptive and not etiological or explanatory, and as it is the norm in the exploration of social inequalities in health (8), the results from the least (gender- and age-) adjusted models were in line with the objective. Indeed, including more adjustment variables could lead to overadjustment as they may be intermediate variables on the causal pathways between occupation and suicide. Our strategy was in line with previous meta-analyses on similar topics (9–11). Consequently, we would argue that our results are not likely to be largely due to confounding, contrary to the comment by Shiri. Indeed, the study of the contribution of underlying factors in explaining social inequalities in health outcomes is a fully-fledged topic of research (12–15), but this is relevant research to conduct after demonstrating that inequalities exist between social or occupational groups. Several of Shiri’s comments were about statistical aspects of our analyses. First, it was suggested that we did not correctly extract the confidence intervals for the estimates of several studies. We disagree. We used the STATA metan suite of commands using log-transformed effect sizes and standard errors. Our figure 1 and the values of effect sizes and confidence intervals were provided by STATA, this explains why there may be small differences in these values compared with the results published in some studies. Using log-transformed effect sizes and confidence intervals, the analysis provided the same results. Second, our subgroup comparison was based on subsamples that were independent. As not all studies provided information for these subgroups, each subgroup was treated as a unit of analysis. This strategy allows the use of all relevant subgroups and comparisons between them (16). Third, we were also criticized for the use of random-effects models. Random-effects models are generally more plausible for meta-analysis based on studies from the published literature, because the fixed-effect model assumed that the entire corpus of literature has been obtained, ie, that every study has been or ever will be written on the topic has been included, which is an implausible assumption. We also assumed differences in effect size between studies and between subgroups, and the use of random-effects models was consistent with such an assumption. However, random-effects models produce wider confidence intervals compared to fixed-effect models (16). These models are thus more conservative, making our results all the more robust. One of Shiri’s comments related to the reference group used in the studies for the comparison of agricultural, forestry, and fishery workers. Although we reported that the studies using a specific occupational group as reference group provided a higher effect size than the studies using other reference groups, we did not explicitly recognize and state in the paper that the results for Japan were based on two studies using a specific occupational group as reference; we concede that this may explain why we found a much more elevated effect size for Japan. Shiri’s results (1) allow to conclude that the difference between Japan and the other geographic areas could be explained by the choice of reference group—we are grateful to him for raising this point. However, we would note that the effect size of suicide was still elevated and significant for agricultural, forestry, and fishery workers even after this change in the reference group for these two studies. Nevertheless, the choice of the optimal reference group is not obvious. If we consider the general population as the reference group, as unemployed people and economically inactive people (including people who may not be working due to illness or disability) are part of it and have a higher risk of suicide than employed people, the effect size provided by the nine studies using the general population as the reference is likely to be underestimated, which may contribute to an underestimation of the observed effect size of suicide among agricultural, forestry, and fishery workers in our study. The comparison was made in our paper with the other occupational groups (ie, the working population except the group of interest) as the reference, which was used by nine other studies, but this did not allow to determine the exact rank of the group of interest in the occupational hierarchy. Another relevant choice would have been to retain the group with the lowest suicide risk (for example, the high-skilled occupational group) as the reference, which would have led to a much higher effect size of suicide for agricultural, forestry, and fishery workers. To conclude, as statistical power in detecting differences between subgroups may be low in subgroup analyses and meta-regression, the absence of significant results according to subgroups found in our results cannot be interpreted as evidence that the effect size is the same across subgroups. Consequently, our meta-analysis reporting a significant excess of risk of suicide among agricultural, forestry, and fishery workers may also be a good incentive for more research among this group of workers to (i) confirm this observed excess of risk using differing methodological approaches to meta-analysis and (ii) explore the potential differences within this group and the underlying factors that may explain this excess of risk. References 1. Shiri R. Suicide among agricultural, forestry, and fishery workers. Scand J Work Environ Health – online first. https://doi.org/10.5271/sjweh.3697 2. Klingelschmidt J, Milner A, Khireddine-Medouni I, Witt K, Alexopoulos EC, Toivanen S, et al. Suicide among agricultural, forestry, and fishery workers: a systematic literature review and meta-analysis. Scand J Work Environ Health – online first. https://doi.org/10.5271/sjweh.3682 3. Milner A, Witt K, LaMontagne AD, Niedhammer I. Psychosocial job stressors and suicidality: a meta-analysis and systematic review. Occup Environ Med – online first. https://doi.org/10.1136/oemed-2017-104531 4. Leach LS, Poyser C, Butterworth P. Workplace bullying and the association with suicidal ideation/thoughts and behaviour: a systematic review. Occup Environ Med. 2017;74(1):72-9. https://doi.org/10.1136/oemed-2016-103726 5. Milner A, Page A, LaMontagne AD. Long-term unemployment and suicide: a systematic review and meta-analysis. PLoS One. 2013;8(1):e51333. https://doi.org/10.1371/journal.pone.0051333 6. Milner A, Morrell S, Lamontagne AD. Economically inactive, unemployed and employed suicides in Australia by age and sex over a 10-year period: what was the impact of the 2007 economic recession? Int J Epidemiol. 2014;43(5):1500-7. https://doi.org/10.1093/ije/dyu148 7. Rothman KJ, Greenland S, Lash TL. Modern Epidemiology - Third Edition. Philadelphia: Wolters Kluwer Health - Lippincott Williams & Wilkins; 2008. 8. Lundberg I, Hemmingsson T, Hogstedt C. Work and social inequalities in health in Europe. Brussels: P.I.E. Peter Lang SA; 2007. 9. Milner A, Spittal MJ, Pirkis J, Lamontagne AD. Suicide by occupation: systematic review and meta-analysis. Br J Psychiatry. 2013;203(6):409-16. https://doi.org/10.1192/bjp.bp.113.128405 10. Lorant V, Deliege D, Eaton W, Robert A, Philippot P, Ansseau M. Socioeconomic inequalities in depression: a meta-analysis. Am J Epidemiol. 2003;157(2):98-112. https://doi.org/10.1093/aje/kwf182 11. Grittner U, Kuntsche S, Gmel G, Bloomfield K. Alcohol consumption and social inequality at the individual and country levels--results from an international study. Eur J Public Health. 2013;23(2):332-9. https://doi.org/10.1093/eurpub/cks044 12. Niedhammer I, Bourgkard E, Chau N. Occupational and behavioural factors in the explanation of social inequalities in premature and total mortality: a 12.5-year follow-up in the Lorhandicap study. Eur J Epidemiol. 2011;26(1):1-12. https://doi.org/10.1007/s10654-010-9506-9 13. Niedhammer I, Chastang JF, David S, Kelleher C. The contribution of occupational factors to social inequalities in health: findings from the national French SUMER survey. Soc Sci Med. 2008;67(11):1870-81. https://doi.org/10.1016/j.socscimed.2008.09.007 14. Chazelle E, Lemogne C, Morgan K, Kelleher CC, Chastang JF, Niedhammer I. Explanations of educational differences in major depression and generalised anxiety disorder in the Irish population. J Affect Disord. 2011;134(1-3):304-14. https://doi.org/10.1016/j.jad.2011.05.049 15. Niedhammer I, Lesuffleur T, Coutrot T, Chastang JF. Contribution of working conditions to occupational inequalities in depressive symptoms: results from the national French SUMER survey. Int Arch Occup Environ Health. 2016;89(6):1025-37.https://doi.org/10.1007/s00420-016-1142-6 16. Borenstein M, Hedges LV, Higgins JPT, Rothstein HR. Introduction to meta-analysis: John Wiley & Sons, Ltd. ISBN: 978-0-470-05724-7; 2009. https://doi.org/10.1002/9780470743386

OBJECTIVE: Farming is a hazardous occupation, with high rates of injury and death. FarmSafe, a whole-country approach, sought to address work-related injury on New Zealand sheep, beef, and dairy farms. More than 10 000 farmers participated in 630 workshops held over two years. This short communication presents the results of an impact evaluation of the FarmSafe Awareness Workshop (FSAW) in its first two years of operation. METHODS: All FSAW participants completed, and received credit for, formal educational assessments. Pass rates were used to assess safety knowledge, and a quasi-experimental design with intervention and comparison groups was applied to assess attitudes, safety behaviors, and environmental determinants of injury. RESULTS: An intervention (N=111) and two comparison groups (C1, N=409, and C2, N=78) completed before and after questionnaires. At follow-up, the intervention group (IG) showed a small improvement in attitudes toward safety (IG=79.3, C1=77.4; C2=77.4, P=0.035), but there were no differences between groups for personal safety practice or the safety environment of the farm. However, if a respondent registered their interest in the workshop, but a different person from the same farm attended, there was some improvement in the safety of the farm environment score. CONCLUSION: Well-conducted safety training tailored to farmers was still not enough to change safety practice. Future interventions may be more likely to achieve progress if they are comprehensive, include environmental and enforcement features, and target more than one participant per farm.

OBJECTIVES: Previous studies indicate an increased risk of cryptorchidism, incomplete testicular descent, among sons of women working with pesticides. This study assessed the risk of cryptorchidism among boys of parents employed as horticultural workers and farmers using nationwide registers on occupation and cryptorchidism. METHODS: The cohort consisted of >600 000 boys born in Denmark from 1980–2007 with a parent in employment during pregnancy. These boys were followed for cryptorchidism from 1980–2009 comparing risks among sons of horticultural workers and farmers with sons of parents in other occupations. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox regression adjusting for parental age, birth years, parity, and geographical region. RESULTS: Sons of maternal farmers were at increased risk of cryptorchidism (157 cases; HR 1.31, 95% CI 1.12–1.53) compared to boys of mothers in other occupations (15 511 cases). Paternal occupation as farmer was unrelated to the risk among sons. Maternal occupation as a horticultural worker was associated with a non-significantly increased risk (72 cases; HR 1.20, 95% CI 0.95–1.52). A similar association was found for paternal horticultural workers. Sons of maternal farmers or horticultural workers who likely worked in the first trimester were not at increased risk of cryptorchidism. CONCLUSIONS: This nationwide cohort study found a slightly increased risk of cryptorchidism in sons of maternal horticultural workers and farmers. However, subgroup analyses indicated similar findings for paternal horticultural workers, and no association for women likely working in the first trimester. The main findings should therefore be interpreted with caution.

Objectives This review aimed to quantify suicide risk among agricultural, forestry, and fishery workers and study potential variations of risk within this population. Methods We conducted a systematic literature review and meta-analysis from 1995 to 2016 using MEDLINE and following the PRISMA guidelines. A pooled effect size of suicide risk among the population of interest was calculated using meta-analysis. Subgroup analyses were conducted to investigate whether effect size differed according to population or study characteristics. Meta-regression was used to identify sources of heterogeneity. Results The systematic review identified 65 studies, of which 32 were included in the meta-analysis. Pooled effect size was 1.48 [95% confidence interval (CI) 1.30-1.68] representing an excess of suicide risk among the population of interest. Subgroup analysis showed that this effect size varied according to geographic area, with a higher effect size in Japan. The following study characteristics were found to contribute to the between-study variance: reference group, measure of effect size, and study design. Conclusions Our findings suggest an excess of suicide risk among agricultural, forestry, and fishery workers and demonstrated that this excess may be even higher for these groups in Japan. This review highlights the need for suicide prevention policies focusing on this specific population of workers. More research is also needed to better understand the underlying factors that may increase suicide risk in this population. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) of unknown etiology (CKDu) was first reported in El Salvador and Nicaragua in Central America, where it has very high prevalence and mortality. However, CKDu is now an epidemic in countries around the equator: Central America and Mexico, India and Sri Lanka, and Egypt. Unlike the more common kind of CKD, seen mostly among the elderly in urban areas, CKDu appears to be a rural disease, affecting farm workers, mostly men aged 30–50 years. This disease has substantial mortality, and as it prevents sick men and women from participating in the workforce and limits their role in home life, CKDu also severely affects society. CKDu is so fatal in part because it is hard to detect. In the early stages of the disease, the patients show no symptoms; by the time a diagnosis is made, the damage to the kidneys is irreversible, leading to high blood pressure, weakness, sleep problems, nausea and vomiting, and weight loss. Access to dialysis or kidney transplant is often very limited and costly in the areas where the disease is prevalent. Many patients do not survive a long time between diagnosis and death. In Central America, which has been hit the hardest, the leading hypothesis is that CKDu is an occupational disease, caused by long hours of work in the heat with too little drinking water, leading to chronic dehydration, such as may occur during work in the cane fields. Sugarcane cutting is a repetitive high-intensity work, and workers spend the majority of their work day above 50% of their maximal heart rate (1). An animal study showed that recurrent dehydration can induce renal injury (2), and a human pilot study indicated a possible mechanism behind chronic dehydration and kidney damage: high levels of uric acid crystals were found in cane cutters’ urine, especially at the ends of their shifts (3). Those crystals may injure the kidneys. However, other causal factors have been debated, such as metals and silica in the drinking water or pesticides used in farming (4, 5). It is possible that the disease is multifactorial, depending on the region. However, a recent review of CDKu and use of pesticides did not find strong evidence for an association (6). In this issue of the Scandinavian Journal of Work, Environment & Health, Wegman et al (7) present the results of an intervention study where they assessed the potential to reduce kidney damage, as measured by biomarkers of dehydration, kidney function, and muscle-tissue breakdown in serum and urine. They studied the implementation of a water, rest, shade, and efficiency intervention program among sugarcane workers in El Salvador. The program began two months into the 5-month harvest: one of two groups of sugarcane workers was provided with portable water reservoirs, mobile shaded tents, and scheduled rest periods (10–15 minutes of rest every 1–1.5 hours). Health data, blood, and urine samples were collected at baseline and at three subsequent times over the course of the harvest. The intervention study found that over the course of the working day, urine osmolality increased, indicating dehydration, and the estimated glomerular filtration rate (eGFR), reflecting kidney function, decreased. The decrease in eGFR across the day was present in both groups, but smaller for the intervention group. Decreased eGFR over the 5-month harvest was also seen in both groups, but was 56% higher in the group not receiving the intervention (-5.3 versus -3.4 mL/min/1.73 m2). Moreover, the decrease in eGFR seemed to cease after the start of the intervention in the group receiving the program. No long-term effects on the other biomarkers were found. Theo Bodin, the senior author of the study (7) explains the study’s biggest challenge was to recruit the cane workers and to plan and coordinate the study with the employers and the workers. Security was also a major issue in performing such a study as El Salvador is considered one of the 20 most dangerous countries in the world. The authors should be applauded for collecting and handling biological samples under these conditions, as the measurement of biomarkers in serum and urine provides solid data on positive effects of the intervention. Furthermore, the study gives additional support to the notion that heat stress and/or repeated dehydration causes the disease in this region. The study has limitations that reflect the difficulties in performing such a study in this region. A limited numbers of individuals participated, there were dropouts during the study, and there are possible confounders and unmeasured risk factors that need to be considered. Still, the effects of the intervention on kidney function and damage were evident, suggesting a clear effect of the apparently simple actions of providing shade, rest, and access to water. Whether these actions can prevent CKDu in El Salvador, or elsewhere, is not yet clear and needs further research. This intervention study has received a lot of attention in El Salvador, and as a result, the sugarcane industry has started to improve the work environment for cane workers in different countries. The intervention program is continuing in El Salvador and intervention studies have started in other Central American countries, such as Nicaragua, says Theo Bodin. Obviously, there is a desperate need to identify the causes for this fatal occupational disease and find ways to prevent it. This study by Wegman and co-authors provides evidence for how further actions should be taken.

In their meta-analysis, Klingelschmidt and her associates (1) found that agricultural, forestry, and fishery workers are at 48% higher risk of suicide than the working-age population. Moreover, they found that the excess risk is even greater among Japanese agricultural workers than workers from other high-income countries. There are several concerns regarding this meta-analysis. It appears that the excess risk has been overestimated for these workers. Furthermore, the excess risk in Japan is not different than other high-income countries. First, in a systematic review, a literature search is comprehensive. A search of a single database is unlikely to identify most of relevant studies, and these types of reviews are not therefore considered as systematic reviews (2). In this review, a specialized database (­PsycINFO) or a European database (EMBASE or ­Scopus) was not searched. Second, following the PRISMA guidelines, the critical appraisal of included studies (quality assessment) is a requirement for a systematic review. In a meta-analysis of observational studies, selection bias and confounding should be ruled out. Third, the reviewers did not correctly extract confidence intervals (CI) for the estimates of several studies such as Hassler 2004, Fleming 1999, and Fragar 2011. Moreover, some studies reported both the least- and maximally adjusted risk estimates. The reviewers, however, extracted age- or the least-adjusted risk estimate. A confounder-adjusted estimate is a more appropriate estimate of the true association. In some studies [eg, Kposowa (3) Agerbo (4)], the excess risk dropped by 52–71% after adjustment for confounders. As a sensitivity analysis, the reviewers could limit their meta-analysis to a subgroup of studies controlled for confounders. Fourth, the reviewers did not estimate an overall risk estimate for each study. They included the estimates of 2–6 subgroups for 22 studies in forest and funnel plots. A fixed-effect meta-analysis is a more appropriate model to combine the subgroups of a single study. Moreover, for the assessment of publication bias, it is not appropriate to include several subsamples of a single study in a funnel plot. Using estimates of subgroups can change a large study into several smaller studies. Fifth, some of the included studies compared agricultural, forestry, and fishery workers with a specific occupational group. The reviewers could calculate a risk estimate using all other occupational groups as a comparison group and exclude those studies that did not provide sufficient data for estimating such a risk estimate. In some studies, the excess risk for agricultural, forestry, and fishery workers disappears after comparing with other occupational groups [eg, adjusted risk ratios (RR) for Kposowa (3) = 1.02, 95% CI 0.41–2.54]. This is a main reason for observed higher excess risk in Japanese workers. Wada et al (5) compared Japanese agricultural workers with sales workers and Suzuki et al (6) compared Japanese agricultural, forestry, and fishery workers with production process and related workers. Using all other occupational groups as a reference group, age-adjusted RR dropped from 3.53 (95% CI 2.84–4.38) to 2.61 (95% CI 2.10–3.25) for Wada et al (5) and from 3.24 (CI 2.95–3.57, both sexes combined) to 1.31 (CI 1.27–1.35 age-adjusted OR after excluding unemployed people) for Suzuki et al (6). The pooled estimate of these two register-based studies was 1.33 (95% CI 1.29–1.37) using a fixed model and 1.83 (95% CI 0.93–3.60) using a random model. Sixth, most of the included studies used register data, which had little information on the background characteristics of the participants. A majority of these studies controlled the estimates for age and sex only. Moreover, in this review, prospective cohort studies did not support the observed association. A meta-analysis of 11 case–control and prospective cohort studies shows no significant excess risk of suicide for agricultural, forestry, and fishery workers (pooled estimate = 1.02, 95% CI 0.71-1.47 for 6 cohort studies and 1.13, 95% CI 0.92–1.39, I2 = 91% for 11 case control and cohort studies, combining maximally adjusted risk estimates and comparing agricultural, forestry, and fishery workers with all other occupational groups where possible). The excess risk found in this review (1) can thus largely be due to confounding. References 1. Klingelschmidt J, Milner A, Khireddine-Medouni I, Witt K, Alexopoulos EC, Toivanen S, LaMontagne AD, Chastang JF, Niedhammer I. Suicide among agricultural, forestry, and fishery workers: a systematic literature review and meta-analysis. Scand J Work Environ Health. 2018;44(1):3–15. https://doi.org/10.5271/sjweh.3682. 2. Puljak L. If there is only one author or only one database was searched, a study should not be called a systematic review. J Clin Epidemiol. 2017;91:4–5. https://doi.org/10.1016/j.jclinepi.2017.08.002. 3. Kposowa AJ. Suicide mortality in the United States: differentials by industrial and occupational groups. Am J Ind Med. 1999;36:645–52. https://doi.org/10.1002/(SICI)1097-0274(199912)36:63.0.CO;2-T. 4. Agerbo E, Gunnell D, Bonde JP, Mortensen PB, Nordentoft M. Suicide and occupation: the impact of socio-economic, demographic and psychiatric differences. Psychol Med. 2007;37:1131–40. https://doi.org/10.1017/S0033291707000487. 5. Wada K, Gilmour S. Inequality in mortality by occupation related to economic crisis from 1980 to 2010 among working-age Japanese males. Sci Rep. 2016;6:22255. https://doi.org/10.1038/srep22255. 6. Suzuki E, Kashima S, Kawachi I, Subramanian SV. Social and geographical inequalities in suicide in Japan from 1975 through 2005: a census-based longitudinal analysis. PLoS One. 2013;8:e63443. https://doi.org/10.1371/journal.pone.0063443.

Objective Farming is a hazardous occupation, with high rates of injury and death. FarmSafe, a whole-country approach, sought to address work-related injury on New Zealand sheep, beef, and dairy farms. More than 10 000 farmers participated in 630 workshops held over two years. This short communication presents the results of an impact evaluation of the FarmSafe Awareness Workshop (FSAW) in its first two years of operation. Methods All FSAW participants completed, and received credit for, formal educational assessments. Pass rates were used to assess safety knowledge, and a quasi-experimental design with intervention and comparison groups was applied to assess attitudes, safety behaviors, and environmental determinants of injury. Results An intervention (N=111) and two comparison groups (C1, N=409, and C2, N=78) completed before and after questionnaires. At follow-up, the intervention group (IG) showed a small improvement in attitudes toward safety (IG=79.3, C1=77.4; C2=77.4, P=0.035), but there were no differences between groups for personal safety practice or the safety environment of the farm. However, if a respondent registered their interest in the workshop, but a different person from the same farm attended, there was some improvement in the safety of the farm environment score. Conclusion Well-conducted safety training tailored to farmers was still not enough to change safety practice. Future interventions may be more likely to achieve progress if they are comprehensive, include environmental and enforcement features, and target more than one participant per farm. [ABSTRACT FROM AUTHOR]

The article determines whether people with different forms of professional contact with animals are at risk of methicillin-resistant Staphylococcus aureus (MRSA) carriage in Denmark. Standard microbiological techniques were utilized for the study as to screen about one-tenth of the reference population of veterinary practitioners in Denmark for MRSA carriage.