Left-censored recurrent event analysis in epidemiological studies: a proposal for when the number of previous episodes is unknown.

BACKGROUND: When dealing with recurrent events in observational studies it is common to include subjects who became at risk before follow-up. This phenomenon is known as left censoring, and simply ignoring these prior episodes can lead to biased and inefficient estimates. We aimed to propose a statistical method that performs well in this setting. METHODS: Our proposal was based on the use of models with specific baseline hazards. In this, the number of prior episodes were imputed when unknown and stratified according to whether the subject had been at risk of presenting the event before t = 0. A frailty term was also used. Two formulations were used for this "Specific Hazard Frailty Model Imputed" based on the "counting process" and "gap time." Performance was then examined in different scenarios through a comprehensive simulation study. RESULTS: The proposed method performed well even when the percentage of subjects at risk before follow-up was very high. Biases were often below 10% and coverages were around 95%, being somewhat conservative. The gap time approach performed better with constant baseline hazards, whereas the counting process performed better with non-constant baseline hazards. CONCLUSIONS: The use of common baseline methods is not advised when knowledge of prior episodes experienced by a participant is lacking. The approach in this study performed acceptably in most scenarios in which it was evaluated and should be considered an alternative in this context. It has been made freely available to interested researchers as R package miRecSurv.

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 ).

Sickness presenteeism: Are we sure about what we are studying? A research based on a literature review and an empirical illustration.

BACKGROUND: There has been an increasing interest in studying sickness presenteeism (SP). An ever-increasing amount of scientific literature is published using this term, yet there appears to be considerable heterogeneity in how it is assessed, which could result in substantial differences in the definition and interpretation of the phenomenon really being studied. We aim to discuss what really is being studied, depending on how the phenomenon is operationalized, measured, and analyzed. METHODS: A study based on a literature review and an empirical illustration using data of the third Spanish Psychosocial Risks Survey (2016). RESULTS: Differences are observed based on the population in which SP is measured, the cut-off points used to define a worker as presenteeist, the reasons for an SP episode and even an analysis of the phenomenon treated as a count or as a dichotomous. CONCLUSIONS: Without being completely exclusive, it seems that restricting the population of analysis to only those workers who consider that they should not have gone to work due to their health, and/or establishing low cut-off points to define someone as presenteeist, would more clearly delimit the study of SP to the exercise of a right to sick leave. In contrast, working with the entire population or using high cut-off points appears to relate the study of SP more with health status and less with the exercise of rights. On the other hand, taking the reasons for SP into account would probably help to improve interpretation of the phenomenon.

A step-down protocol for omalizumab treatment in oral corticosteroid-dependent allergic asthma patients.

AIMS: There are no specific criteria for a step-down or withdrawal dose of omalizumab (OMA). Our purpose was to evaluate the viability of a protocol for OMAlizumab DOse REduction (the OMADORE study) in severe allergic asthma (SAA). METHODS: The study population included 35 SAA patients treated during a minimum period of 1 year with oral corticosteroids (OC) equivalent to a mean daily dose of 4 mg of methyl-prednisolone. To qualify for the protocol, the patients had to have received treatment with OMA for at least one and a half years, OC dose had to have reached the lowest tolerated dose and spirometry had to be greater than or equal to that at entry. The interventions were (a) OMA dose was reduced by half; (b) if patients were clinically stable after 6 months, the dose was halved again; (c) if repeated OC boosters were needed and/or spirometry worsened by more than 10%, OMA dose was raised to the previous figure until stabilization. RESULTS: Mean age was 52.5 (17) years, median monthly OC dose was 120 (IQR: 225) mg. Pulmonary function: FVC: 79.7 (20.2)%; FEV1 : 64.8 (21.7)%; FEV1 / FVC: 61.7(13.8)%. OMA could be withdrawn in 34.3% of the patients; 22.9% tolerated a reduction, and in 42.9% the dose could not be modified. Follow-up time after reduction or withdrawal ranged from 12 to 30 months. There were no severe exacerbations requiring emergency assistance or admission. CONCLUSIONS: The OMADORE study found that in more than 50% of SAA patients on OC, OMA dose can be safely reduced or withdrawn based on a progressive dose reduction protocol.

Specific psychosocial exposures for workers' mental health: A population-based study.

BACKGROUND: In order to plan interventions it is important to obtain evidence on the relation between a health outcome and specific exposures. However, there are few studies that identify the effect of specific psychosocial work exposures on poor mental health. This is the aim of this study. METHODS: Population-based cross-sectional study in Catalonia. We estimated prevalence ratios (PR) of minor psychiatric disorder associated with several psychosocial work exposures. RESULTS: The items with highest PR were "Are there times when you need to be at work and at home at the same time?" (PR = 1.81), "Are you worried about a variation in your salary?" (PR = 1.77), "Is your work emotionally demanding?" (PR = 1.65) and "Are you worried about it being difficult for you to find another job if you became unemployed?" (PR = 1.51). CONCLUSIONS: This study could be useful in order to begin planning interventions on specific psychosocial exposures to protect mental health in the workplace.

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%; FEV1: 62%; seasonal: FVC: 79%; FEV1: 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.

Is the worsening of psychosocial exposures associated with mental health? Comparing two population-based cross-sectional studies in Spain, 2005-2010.

AIMS: To analyze whether associations between workplace psychosocial exposures and the mental health of the working population in Spain changed between 2005 and 2010. METHODS: Two representative samples of the Spanish working population have been analyzed, 2005 (n = 5073) and 2010 (n = 3544). RESULTS: In 2010 there was a significant association between poor mental health and exposure to high Demands, low Social Support and high Insecurity over working conditions, and exposure to high Insecurity over losing the job only for men. In 2005 there was a significant association with exposure to high Demands and low Social Support. CONCLUSION: Changes in the associations between psychosocial risks and mental health may be related to the socioeconomic context marked by the rise in unemployment and the destruction of jobs as a result of the 2008 economic crisis.

The changing patterns of psychosocial exposures at work in the south of Europe: Spain as a labor market laboratory.

AIMS: To examine the pattern of psychosocial risk exposures at work among wage-earners in Spain in 2005 and 2010, and to analyze changes in exposure inequalities by gender and job category. METHODS: Psychosocial exposures were compared using the COPSOQ-ISTAS21 method, based on two surveys representative of the Spanish wage-earning population (2005 and 2010). Statistical analysis was conducted using correspondence analysis. RESULTS: There was an increase in exposure to high Double Presence, low Social Support, high Work Pace, and high Insecurity about finding a job; and reduction in exposure to high Insecurity about losing a job, and to high Insecurity over worsening of employment conditions. A gender- and occupation-related gradient was maintained. CONCLUSION: Although this study analyzes wage-earner "survivors" after the outbreak of the current economic crisis, it shows a worsening of harmful exposures to some psychosocial risks. In a context of job destruction, concerns about worsening working conditions appear to be subordinate to insecurity about job loss.

The copenhagen psychosocial questionnaire II (COPSOQ II) in Spain--a tool for psychosocial risk assessment at the workplace.

AIMS: To describe the second version of the Spanish Copenhagen Psychosocial Questionnaire and to present evidence of its validity and reliability. METHODS: The original Danish long COPSOQ II questionnaire was adapted to the labor market, cultural, and linguistic setting of Spain and included in the 2010 Spanish Psychosocial Risks Survey. Analysis involved the assessment of psychometric characteristics and associations among psychosocial scales and health scales. Medium and short versions were derived from the long one. RESULTS: The long questionnaire was configured with 24 dimensions (92 items); medium-length questionnaire with 20 dimensions (69 items); and short questionnaire with 14 dimensions (28 items). All scales showed acceptable reliability and concordance between versions. Most associations among psychosocial scales and Mental Health, Stress, and Burnout scales were in the expected direction, except the scale of Influence, that showed some incongruent associations. CONCLUSION: Results support the validity and reliability of Spanish COPSOQ II questionnaires as tools for psychosocial risk assessment at the workplace, however, better scales should be developed specially for the dimension of Influence.

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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Relationship between psychosocial risks exposure and health: a cohort study using the COPSOQ-Istas21]. / Relación entre exposición a riesgos psicosociales y salud: un estudio de cohorte mediante el COPSOQ-Istas21.

OBJECTIVE: To estimate the prospective relationships between exposure to psychosocial risks dimensions included in the COPSOQ-Istas21 and the deterioration of general and mental health and sleep problems among workers residing in Spain. METHOD: Cohort whose baseline corresponds to the 2016 Psychosocial Risks Survey with a new measurement after one year. RESULTS: Social capital and interpersonal relations and leadership dimensions, as well as work̶life conflict, were related to all health variables. Dimensions of work organization and job contents did it especially with the mental health, the quantitative demands with the general health and the emotional ones with the mental health. The dimensions related to job insecurity did not show relationships with health. CONCLUSIONS: The results obtained reinforce the role of the COPSOQ-Istas21 as a useful instrument for the evaluation and prevention of psychosocial risks at work.

Health outcomes and psychosocial risk exposures among healthcare workers during the first wave of the COVID-19 outbreak.

The aim is to describe the health and psychosocial risk factors of Spanish healthcare workers during the COVID-19 pandemic. METHODS: A cross-sectional study by means of an online questionnaire (April-May 2020). The data comes from the database resulting from the COTS project "Working conditions, insecurity, and health in the context of the COVID-19 pandemic". The sample consisted of 1989 health care workers. RESULTS: Women, young people (doctors and nurses) and the middle-aged (assistants) had poorer health and greater exposure to psychosocial risks. Geriatric assistants were the most-affected occupational group. CONCLUSIONS: gender, occupation, and age are focuses of inequality in the exposure of health care workers to psychosocial risks.

Pulmonary tuberculosis infection among workers in the informal public transport sector in Lima, Peru.

BACKGROUND: Because a strong association was observed between pulmonary tuberculosis (TB) and the use of public transport, increasing with duration of journey, a study was carried out to assess infection by Mycobacterium tuberculosis and working conditions among workers in this sector. METHODS: A cross-sectional study was conducted between June and September 2008. A total of 104 workers from two public transport minibus ('combi') cooperatives covering marginal areas of the Ate-Vitarte district in Lima were interviewed. Demographic and occupational details were collected as well as prior family and personal history of TB and BCG vaccination. The tuberculin skin test (TST) was administered to each study subject and an induration of ≥ 10 mm was considered positive. Statistical analysis was based on logistic models, ORs and their 95% CIs. RESULTS: TST results were obtained for 70.2% (n=73), of whom 76.6% (n=56) were positive. Positivity was significantly associated with those who had worked for more than 2 years (crude OR 11.04; 95% CI 3.17 to 38.43) and more than 60 h/week (crude OR 9.8; 95% CI 2.85 to 33.72). These associations remained significant in a multivariate model as well. CONCLUSION: The association observed between years of working and weekly work burden among minibus workers suggests an occupational risk in service jobs in low-income countries with high TB prevalence. Consequently, other types of users are at increased risk for TB infection, with a causal relationship between effect and duration of exposure.

Previous sick leaves as predictor of subsequent ones.

PURPOSE: There is evidence that a history of sick leave (SL) increases the risk of suffering a new episode. However, little is known about the effect of the number of previous SL on subsequent ones. The aim of this paper was to quantify the effect of prior episodes on the risk of experiencing a new one and the effect on the duration of episodes, by diagnosis. METHODS: Prospective study. Sample comprises 1,542 workers from a university hospital, whose first contract started during 2000-2007. RESULTS: The studied workers accumulated 5,138 episodes, 21,250 days of absence and 45,324.2 months of follow-up. For all the causes, recurrence density was higher than incidence density. The higher the number of prior SL, the greater is the hazard of presenting a new episode. This is particularly true for episodes due to mental and behavioral disorders, diseases of the skin and subcutaneous tissue, and diseases related to nervous system. The adjusted hazard of suffering an SL episode due to mood disorders was increased 21.44 times when the worker had previously had one SL. The corresponding figures were 14.58 and 13.92 for SL due to skin and mucous membrane diseases and due to neurotic or stress-related disorders, respectively. CONCLUSIONS: The results obtained provide evidence that having suffered previous SL episodes implies a significant increase in the risk of experiencing a new one. High recurrence density of certain diagnoses should be interpreted as a general indication that something is wrong in the occupational setting.

Psychosocial risk exposures and labour management practices. An exploratory approach.

AIM: The purpose was to explore the relationship between psychosocial risk exposures and labour management practices (LMP), as indicators of work organization and pertinent features for primary preventive intervention. METHODS: Cross-sectional study of a representative sample of salaried working population in Spain (n = 7,612). Information was obtained in 2004-2005 using a standardized questionnaire administered through personal interviews at the household. Questions on working conditions were used to establish LMP indicators and the psychosocial exposures data were obtained on the basis of the Copenhagen Psychosocial Questionnaire (COPSOQ) I (ISTAS21). A multivariate description was performed through multiple correspondence analysis, and associations between LMPs and psychosocial exposures were assessed by ordinal logistic analysis adjusting for age and sex. RESULTS: Correspondence analysis showed a good-bad coherent pattern regarding both psychosocial dimension and LMPs, though several LMPs categories were placed in the centre. Among the 14 possible associations of each psychosocial scale with LMP variables, several scales showed significant associations with more than eight LMP variables. Most relevant results referred to the LMP variable ''Consultative and delegative participation in methods''. CONCLUSIONS: In line with previous research, psychosocial exposures were associated with LMP. LMP may constitute a step on a pathway from work organization to health. Our exploratory work suggested that good psychosocial exposures were related to participatory working methods, being hired with a permanent labour contract, not being made to feel easily replaceable, having superiors with non-authoritarian and non-aggressive manners, not being threatened with dismissal, upward functional mobility, being paid according to the number of working hours and occupation, working between 31 and 40 hours per week and in regular morning shifts. Hence, the more these features became part of LMP in the workplace, the better the psychosocial work environment would be.

Psychosocial work environment and its association with socioeconomic status. A comparison of Spain and Denmark.

AIMS: The purpose of this study was to describe psychosocial work environment inequalities among wage earners in Spain and Denmark. METHODS: Data came from the Spanish COPSOQ (ISTAS 21) and the Danish COPSOQ II surveys both performed in 2004-05 and based on national representative samples of employees with a 60% response rate. Study population was 3,359 Danish and 6,685 Spanish women and men. Only identical items from both surveys were included to construct 18 psychosocial scales. Socioeconomic status was categorized according to the European Socioeconomic Classification System. Analysis included ordinal logistic regression and multiple correspondence analysis after categorizing all scales. RESULTS: A relationship between socioeconomic status and psychosocial work environment in both Denmark and Spain was observed, with wider social inequalities in Spain for many scales, describing a strong interaction effect between socioeconomic status and country. CONCLUSIONS: Socioeconomic status is related to psychosocial work environment and some adverse psychosocial conditions tend to cluster in lower socioeconomic status groups in both Spain and Denmark. This effect could be modified by a country's characteristics, such as economic and labour market structures, normative regulations and industrial relations including work organization. Hence, preventive strategies to reduce social inequalities in working conditions should consider the combination of actions at the macro and micro levels.

[Design and validation of a satisfaction and quality of life scale for users of residential and social care centres]. / Diseño y validación de una escala de satisfacción y calidad de vida para usuarios de centros residenciales y sociosanitarios.

BACKGROUND: In a comprehensive approach to ageing care, the promotion of personal and emotional well-being is fundamental, as well as the development of tools to evaluate outcomes. This approach needs to take into account the subjective perception of the elderly by gathering evidence using indicators that express impacts and satisfaction. Thus, the SAR Foundation's Satisfaction and Quality of Life Scale (SyCV-FSAR) has been developed and validated to assess well-being in residential care settings. METHODS: Bibliographical reviews, interviews and focal groups with professionals (doctors, nurses, social workers, quality managers, etc.) were conducted to define the questionnaire that was first piloted and then applied in a final survey. Test of validity was carried out by factorial analysis (FA), principal axis factoring and Oblimin rotation. The sampling adequacy was measured by Kaiser-Meyer-Olkin test and Bartlett's sphericity. Test of reliability was carried out by internal consistency analysis (Cronbach's alpha). RESULTS: A total of 475 users took part in the survey, 69.1% of those who fulfilled the criteria. Of these 60.0% were women, an average age 82.1, 47.2% of them between 75 and 84 years old, with a MMSE of 27. The FA identified three factors ("Residential service and geriatric care", "Personal framework" and "Social relationships") that explained 27.5% of the total variability. The measure of sampling adequacy by Kaiser-Meyer-Olkin test was 0.80, and the Bartlett's sphericity test was significant (P<0.001). The global α Cronbach was 0.82. CONCLUSIONS: According to the results obtained in the study we can conclude that the SyCV-FSAR Scale is a reliable, simple and easy-to-apply tool, which gathers the users' perception on key aspects of daily life in residential and social care centres.

A comparison between cognitive and affective job insecurities.

BACKGROUND: Cognitive and affective job insecurity are compared in six aspects related to employment: job loss, worsening of tasks, schedule, salary and workplace, and difficulties over finding an alternative job (also known as labor market insecurity). Methods: Cross-sectional study. Data comes from the third Spanish Psychosocial Risks Survey (2016) which is a representative sample of the Spanish salaried population. Results: Affective responses are more variable than cognitive ones resulting in a low degree of answer concordance (IC95% Kappa = 0.08-0.13 to 0.18-0.23). There is a significant percentage of workers (22.5-50.3%) highly concerned about their future despite perceiving low probabilities of experiencing the specific insecurity threat, except for the labor market insecurity question. Conclusion: The differences observed in the degree of insecurity between the affective and the cognitive forms confirm that they are measuring different components of the insecurity construct. These differences are partly due to the economic situation of their households.