Analysis of zero inflated dichotomous variables from a Bayesian perspective : application to occupational health

Background: Zero-inflated models are generally aimed to addressing the problem that arises from having two different sources that generate the zero values observed in a distribution. In practice, this is due to the fact that the population studied actually consists of two subpopulations: one in which the value zero is by default (structural zero) and the other is circumstantial (sample zero). Methods: This work proposes a new methodology to fit zero inflated Bernoulli data from a Bayesian approach, able to distinguish between two potential sources of zeros (structural and non-structural). Results: The proposed methodology performance has been evaluated through a comprehensive simulation study, and it has been compiled as an R package freely available to the community. Its usage is illustrated by means of a real example from the field of occupational health as the phenomenon of sickness presenteeism, in which it is reasonable to think that some individuals will never be at risk of suffering it because they have not been sick in the period of study (structural zeros). Without separating structural and non-structural zeros one would be studying jointly the general health status and the presenteeism itself, and therefore obtaining potentially biased estimates as the phenomenon is being implicitly underestimated by diluting it into the general health status. Conclusions: The proposed methodology is able to distinguish two different sources of zeros (structural and non-structural) from dichotomous data with or without covariates in a Bayesian framework, and has been made available to any interested researcher in the form of the bayesZIB R package (https://cran.r-project.org/package=bayesZIB)

Occupational health, frontline workers and COVID-19 lockdown : new gender-related inequalities?

The abrupt onset of COVID-19, with its rapid spread, has had brutal consequences in all areas of society, including the workplace. In this paper, we report the working conditions, health, and tranquilisers and opioid analgesics use of workers during the first months of the ensuing pandemic, according to whether they were frontline workers or not and also according to sex. Our analysis is based on cross-sectional survey data (collected during April and May 2020) from the wage-earning population in Spain (n=15 070). We estimate prevalences, adjusted prevalence differences and adjusted prevalence ratios by sex and according to whether the worker is a frontline worker or not. Employment and working conditions, exposure to psychosocial risks, as well as health status and the consumption of tranquilisers and opioid analgesics all showed sex and sectoral (frontline vs non-frontline) inequalities, which placed essential women workers in a particularly vulnerable position. Moreover, the consumption of tranquilisers and opioid analgesics increased during the pandemic and health worsened significantly among frontline women workers. The exceptional situation caused by the COVID-19 pandemic provides an opportunity to revalue essential sectors and to dignify such employment and working conditions, especially among women. There is an urgent need to improve working conditions and reduce occupational risk, particularly among frontline workers. In addition, this study highlights the public health problem posed by tranquilisers and opioid analgesics consumption, especially among frontline women

Correction : Analysis of zero inflated dichotomous variables from a Bayesian perspective: application to occupational health

Zero-inflated models are generally aimed to addressing the problem that arises from having two different sources that generate the zero values observed in a distribution. In practice, this is due to the fact that the population studied actually consists of two subpopulations: one in which the value zero is by default (structural zero) and the other is circumstantial (sample zero). This work proposes a new methodology to fit zero inflated Bernoulli data from a Bayesian approach, able to distinguish between two potential sources of zeros (structural and non-structural). The proposed methodology performance has been evaluated through a comprehensive simulation study, and it has been compiled as an R package freely available to the community. Its usage is illustrated by means of a real example from the field of occupational health as the phenomenon of sickness presenteeism, in which it is reasonable to think that some individuals will never be at risk of suffering it because they have not been sick in the period of study (structural zeros). Without separating structural and non-structural zeros one would be studying jointly the general health status and the presenteeism itself, and therefore obtaining potentially biased estimates as the phenomenon is being implicitly underestimated by diluting it into the general health status. The proposed methodology is able to distinguish two different sources of zeros (structural and non-structural) from dichotomous data with or without covariates in a Bayesian framework, and has been made available to any interested researcher in the form of the bayesZIB R package (https://cran.r-project.org/package=bayesZIB)

Incapacidades laborales : problemas en la reinserción al trabajo

En este estudio transversal se evalúan los factores asociados con la probabilidad de reincorporación al trabajo de los trabajadores incapacitados permanentes para la profesión habitual por accidente de trabajo. La muestra la forman los casos atendidos por el Centro de Rehabilitación Profesional (CRP) de Belo Horizonte, Brasil, en 1995. Se analiza el hecho del trabajador ser aceptado o no en el programa, así como la posterior reinserción laboral mediante modelos logit. Respecto al primer, los factores más influyentes fueron la edad, la presencia de Lesiones por Esfuerzo Repetitivo (LER) y el nivel de estudios. Analizado el resultado del programa, se observa que los hombres jóvenes de alta escolarización son los que tienen mayor probabilidad de reinserción laboral (90,9%). Existe una incongruencia respecto a la admisión de los trabajadores y el resultado del programa: para su admisión, el trabajador debe cumplir un perfil exigido por el mercado en lo que se refiere a la edad y al nivel de estudios; los portadores de LER cumplen estos criterios y, sin embargo, son los que con mayor dificultad se reincorporan al trabajo. Se observa, así mismo, una discriminación laboral clara hacia las mujeres, a pesar del hecho que las mismas presentan iguales condiciones de edad o de nivel educativo que los hombresThis cross-sectional study was conducted on permanently disabled workers assisted by the Center for Occupational Rehabilitation (CRP) in Belo Horizonte, Minas Gerais, Brazil, to evaluate factors associated with their chances of readmission into the labor market. A logistic model was used to investigate workers' acceptance into the professional rehabilitation program and their return into the market. The most decisive factors for their acceptance were age, presence of repetitive strain injury (RSI), and educational level. The most favorable situation was that of workers with RSI under 40 years of age and with average schooling (75.6%). Results showed that young male workers with high educational levels were the ones with the best chances of rejoining the market (90.9%). A controversial issue relates to workers' acceptance and program results. In order to be accepted, the worker had to display a given age and educational profile. Workers with RSI had this profile, but once accepted they were the ones with the greatest difficulty in rejoining the work force. In addition, discrimination against female workers was observed, despite their characteristics being similar to those of male

Prevalence, associated factors and reasons for sickness presenteeism : a cross-sectional nationally representative study of salaried workers in Spain, 2016

The aim of this study was to estimate the prevalence of sickness presenteeism (SP), its associated factors and the reasons given for SP episodes, among the overall salaried population and excluding the 'healthy' workers. Population-based cross-sectional study. Salaried population in Spain. Data were obtained from the third Spanish Psychosocial Risks Survey (2016), carried out between October and December 2016, n=1615. Self-reported episodes of SP and their reasons. 23.0% (95% CI 19.2 to 26.8) of the workers exhibit SP, whereas among those manifesting having had some health problem in the preceding year, the figure was 53.0% (95% CI 46.9 to 59.1). The factors associated with SP when we study all workers are age, seniority, salary structure, working more than 48 hours, the contribution of worker's wage to the total household income and downsizing; factors among the 'unhealthy' workers are working more than 48 hours and not having a contract. The most common reason for SP is 'did not want to burden my colleagues', 45.7% (95% CI 37.3 to 54.4), whereas 'I could not afford it for economic reasons' ranked third, 35.9% (29.4% to 42.9%), and 27.5% (21.3% to 34.6%) of the workers report 'worried about being laid off' as a reason for going to work despite being ill. The estimated frequency of SP in Spain is lower than certain other countries, such as the Scandinavian countries. The factors associated vary depending on the population analysed (all workers or excluding 'healthy' workers). The reason 'I was worried about being laid off' was much more common than the estimates for Sweden or Norway

Socioeconomic status in childhood and obesity in adults : a population-based study

Altres ajuts: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - Process 485327/2007-4 and 477061/20109).To test whether there is an association between socioeconomic status in childhood and measures of body mass index, waist circumference and the presence of overall and abdominal obesity in adult life. A cross-sectional analysis of a population-based cohort study, including a sample of adults (22-63 years old) living in Florianópolis, Southern Brazil. The socioeconomic status in childhood was analyzed through the education level of the participant's parents. Height, weight and waist circumference were measured by previously trained interviewers. Linear and logistic regressions with adjustment for confounding factors and stratification of data according to gender were used. Of the 1,222 adults evaluated, 20.4% (95%CI 18.1-22.8) presented overall obesity and 24.8% (95%CI 22.4-27.4), abdominal obesity. The body mass index and waist circumference averages among women were, respectively, 1.2 kg/m 2 (95%CI -2.3- -0.04) and 2.8 cm (95%CI -5.3- -0.2) lower among those with higher socioeconomic status in childhood. Among men, waist circumference was 3.9 cm (95%CI 1.0-6.8) higher in individuals with higher socioeconomic status in childhood. Regarding obesity, women of higher socioeconomic status in childhood had lower odds of abdominal obesity (OR = 0.56, 95%CI 0.34-0.90), and no such association was observed among men. The socioeconomic status in childhood influences body mass index, waist circumference and obesity in adults, with a difference in the direction of association according to gender. The higher socioeconomic status among men and the lower socioeconomic status among women were associated with higher adiposity indicators

La tercera versión de COPSOQ-Istas21. Un instrumento internacional actualizado para la prevención de riesgos psicosociales en el trabajo

Fundamentos: El Copenhagen Psychosocial Questionnaire (COPSOQ) es uno de los más utilizados en investigación y evaluación de riesgos psicosociales en el trabajo. En este artículo se describió la adaptación de la tercera versión internacional a España y se presentaron las pruebas de su validez y fiabilidad. Métodos: La mayoría de los ítems ya formaban parte de las versiones anteriores I y II. La traducción de los nuevos ítems fue realizada mediante traducción/traducción inversa. El cuestionario se incluyó en la Encuesta de Riesgos Psicosociales de 2016, estudio transversal de una muestra representativa de la población asalariada en España (N=1.807). Se analizaron los estadísticos descriptivos, consistencia interna, efectos suelo y techo y estructura factorial. Se calcularon las Razones de Prevalencia ajustadas por edad, sexo y clase ocupacional (aRP) con salud mental, salud general y satisfacción laboral. Finalmente, se calcularon los valores de referencia poblacionales para todas las dimensiones del instrumento. Resultados: El cuestionario mostró una excelente estructura factorial. Todas las escalas, excepto una, mostraron α de CronbachBackground: The Copenhagen Psychosocial Questionnaire (COPSOQ) is one of the most widely used in research and psychosocial risk assessment in the workplace. The adaptation of the third international COPSOQ version to Spain is described and the evidence of its validity and reliability presented. Methods: Most of the items were already part of the previous versions I and II. The translation of the new items was done by means of translation/reverse translation. The questionnaire was included in the Psychosocial Risk Survey 2016, a cross-sectional study of a representative sample of the wage-earning population in Spain (N=1,807). Descriptive statistics, internal consistency, floor and ceiling effects and factor structure were analysed. Prevalence Ratios adjusted by age, sex and occupational class (aPR) to mental health, general health and job satisfaction were calculated. Finally, population reference values were calculated for all dimensions of the instrument. Results: The questionnaire showed an excellent factorial structure. All scales, except one, showed α of Cronbac

Omalizumab is equally effective in persistent allergic oral corticosteroid-dependent asthma caused by either seasonal or perennial allergens : A pilot study

Omalizumab is marketed for chronic severe asthma patients who are allergic to perennial allergens. Our purpose was to investigate whether omalizumab is also effective in persistent severe asthma due to seasonal allergens. Thirty patients with oral corticosteroid-dependent asthma were treated with Omalizumab according to the dosing table. For each patient with asthma due to seasonal allergens, we recruited the next two consecutive patients with asthma due to perennial allergens. The dose of oral methyl prednisolone was tapered at a rate of 2 mg every two weeks after the start of treatment with omalizumab depending on tolerance. At each monthly visit, a forced spirometry and fractional exhaled nitric oxide (FeNO) measurement were performed and the accumulated monthly methyl prednisolone dose was calculated. At entry, there were no differences between groups in terms of gender, body mass index or obesity, year exacerbation rate, monthly dose of methyl-prednisolone (MP), FeNO and blood immunoglobuline E (IgE) MP, FeNO and IgE values, or spirometry (perennial: FVC: 76%; FEV: 62%; seasonal: FVC: 79%; FEV: 70%). The follow-up lasted 76 weeks. One patient in each group was considered a non-responder. Spirometry did not worsen in either group. There was a significant intragroup reduction in annual exacerbation rate and methyl prednisolone consumption but no differences were detected in the intergroup comparison. Omalizumab offered the same clinical benefits in the two cohorts regardless of whether the asthma was caused by a seasonal or a perennial allergen. These results strongly suggest that allergens are the trigger in chronic asthma but that it is the persistent exposure to IgE that causes the chronicity

La tercera versión de COPSOQ-ISTAS21. Un instrumento internacional actualizado para la prevención de riesgos psicosociales en el trabajo

El Copenhagen Psychosocial Questionnaire (COPSOQ) es uno de los más utilizados en investigación y evaluación de riesgos psicosociales en el trabajo. En este artículo se describió la adaptación de la tercera versión internacional a España y se presentaron las pruebas de su validez y fiabilidad