The effect of multimorbidity on sickness absence by specific diagnoses.

BACKGROUND: As the world's population ages, the prevalence of multiple chronic and non-chronic health-related conditions is increasing. Research on multimorbidity, the co-occurrence of two or more health-related conditions, has mainly involved patient and older populations. Its effect in working populations, presumably younger and healthier, is not well known but could conceivably affect sickness absence (SA) and ability to return to work. AIMS: To examine the effect of multimorbidity on the incidence and duration of SA episodes by frequent diagnostic groups. METHODS: A prospective study (in 2006-2008) of workers in Spain. Information on health-related conditions was gathered with a standardized questionnaire and used to construct a sex-specific multidimensional multimorbidity score (MDMS). In order to estimate the effect of MDMS on incidence and duration of SA episodes due to cardiovascular diseases (CVD), musculoskeletal disorders (MSD) and mental health disorders (MHD), we fitted Cox models adjusted by age, occupational social class and number of prior SA episodes for both sexes. RESULTS: The study population was 372370. Men with high MDMS showed a trend towards higher incidence risk for SA due to CVD and MSD [adjusted hazard ratio (aHR) = 2.03; 95% confidence interval (CI) 1.48-2.78 and aHR = 1.20; 95% CI 1.01-1.43, respectively]. Women showed a similar trend for MSD, but MHD had the strongest association (aHR = 4.78; 95% CI 1.97-11.62) for high MDMS. In both sexes, the effect of MDMS was strongest among those without a prior SA. No consistent associations with SA duration were observed. CONCLUSIONS: Multimorbidity increased the risk of incident musculoskeletal, mental and cardiovascular SA episodes but not their duration.

Effect of working conditions on non-work-related sickness absence.

BACKGROUND: There is limited evidence of the role of working conditions as prognostic factors for non-work-related sickness absence (i.e. absence due to injuries or diseases of non-occupational origin). AIMS: To analyse the association between working conditions and time to return to work (RTW) in workers with long-term (>15 days) non-work-related sickness absence. METHODS: We followed up a total of 655 workers, who completed a baseline questionnaire including physical and psychosocial work factors, until their non-work-related long-term sickness absence ended. Time to RTW was determined based on the health insurance company register. Cox proportional hazard models were constructed to evaluate the associations between working conditions and time to RTW. RESULTS: A self-perceived high level of physical activity at work and work with back twisted or bent were related to longer duration of sickness absence. We did not find any strong evidence of associations between psychosocial work factors and time to RTW, although higher job insecurity and low reward showed marginal statistical significance. CONCLUSIONS: Hazardous physical working conditions are associated with longer duration of non-work-related sickness absence. Workplace ergonomic interventions could conceivably shorten the length of sickness absence that has not originated at work.

Does return to work occur earlier after work-related sick leave episodes than after non-work-related sick leave episodes? A retrospective cohort study in Spain.

OBJECTIVE: In Spain, sick pay benefits for work-related sick leave episodes are higher than for non-work-related episodes. Our aim is to assess whether time to return to work is longer for higher paid sick leave episodes than for lower paid episodes. METHODS: We used data from 62,376 work-related and 76,932 non-work-related sick leave episodes occurring among 338,226 workers from 56,099 companies in Spain in 2002. All episodes were followed for up to 18 months. Episodes were classified by a physician as being work- or non-work-related according to medico-legal judgments. The median episode duration and the 25th and 75th percentiles were calculated. The probability of remaining absent from work was estimated by a non-parametric estimator of the marginal survival function. The time ratio between both types of sick leave was estimated by a log-logistic regression model, using non-work-related episodes as the reference. RESULTS: Median episode duration (25th-75th percentiles) was 11 (6-21) days for work-related episodes and 9 (4-29) days for non-work-related episodes. Time to return to work was longer for work-related episodes than for non-work-related episodes of less than 16 days (time ratio: 1.19 in men and 1.08 in women), while the opposite was observed for episodes of more than 15 days (0.58 in men and 0.40 in women). CONCLUSIONS: Sick pay benefits have a limited effect on time to return to work after a sick leave episode.

Mesothelioma mortality in men: trends during 1977-2001 and projections for 2002-2016 in Spain.

OBJECTIVES: To evaluate mesothelioma death trends in Spain and to predict the number of future cases of mesothelioma. METHODS: After descriptive analysis of mesothelioma mortality data, an age-period-cohort model was applied to estimate future mesothelioma deaths. RESULTS: From 1977 to 2001, 1928 men over 35 years of age died of mesothelioma in Spain. Projections indicate that 1321 men are expected to die from mesothelioma between 2007 and 2016. CONCLUSION: It is expected that mesothelioma deaths will increase at least until 2016. Available data do not allow prediction of the year when mortality will start to decrease.

Work in the textile industry in Spain and bladder cancer.

BACKGROUND/OBJECTIVE: Textile manufacturing is a complex industry that has frequently been associated with bladder cancer. However, results have not been consistent. This study investigated the risk of bladder cancer in Spanish textile workers. METHODS: We analysed data from a multicentre hospital-based case-control study carried out in Spain (1998-2001) including 1219 cases of bladder cancer and 1271 controls. Of those, 126 cases and 122 controls reported a history of employment in the textile industry. Lifetime occupational history was obtained using a computer-assisted personal interview. Occupations, locations and materials used in the textile industry were assessed using a detailed questionnaire and expert assessment. RESULTS: Overall, no increased risk of bladder cancer was found for textile workers, including duration of employment analysis. Increased risks were observed for weavers (OR = 1.82, 95% CI 0.95 to 3.47), for workers in winding/warping/sizing (OR 4.11, 95% CI 1.58 to 10.71) and for those exposed to synthetic materials (OR 1.89, 95% CI 1.00 to 3.56). Working for more than 10 years appeared to be associated with an increased risk for weavers (OR 2.27, 95% CI 0.97 to 5.34), for those who had ever worked in winding/warping/sizing (OR 11.03, 95% CI 1.37, 88.89), for workers in the weaving room (OR 2.94, 95% CI 1.24 to 7.01) and for those exposed to synthetic (OR 2.62, 95% CI 1.14 to 6.01) or cotton (OR 2.00, 95% CI 1.04 to 3.87) materials. Statistically significant higher risks were also found for specific combinations of occupations or locations with exposure to synthetics and cotton. CONCLUSIONS: There was no overall increased risk for textile workers, but increased risks were found for specific groups of workers. Our findings indicate that observed risks in previous studies may be better evaluated by analysis of materials used or section worked within the industry and occupation.

Associations between temporary employment and occupational injury: what are the mechanisms?

OBJECTIVE: To determine whether observed higher risks of occupational injury among temporary workers are due to exposure to hazardous working conditions and/or to lack of job experience level. METHODS: Data systematically recorded for 2000 and 2001 by the Spanish Ministry of Labour and Social Affairs on fatal and non-fatal traumatic occupational injuries were examined by type of employment and type of accident, while adjusting for gender, age, occupation, and length of employment in the company. In the study period there were 1500 fatal and 1 806 532 non-fatal traumatic occupational injuries that occurred at the workplace. Incidence rates and rate ratios (RR) were estimated using Poisson regression models. RESULTS: Temporary workers showed a rate ratio of 2.94 for non-fatal occupational injuries (95% CI 2.40 to 3.61) and 2.54 for fatal occupational injuries (95% CI 1.88 to 3.42). When these associations were adjusted by gender, age, occupation, and especially length of employment, they loose statistic significance: 1.05 (95% CI 0.97 to 1.12) for non-fatal and 1.07 (95% CI 0.91 to 1.26) for fatal. CONCLUSIONS: Lower job experience and knowledge of workplace hazards, measured by length of employment, is a possible mechanism to explain the consistent association between temporary workers and occupational injury. The role of working conditions associated with temporary jobs should be assessed more specifically.

Validation of an asthma questionnaire for use in healthcare workers.

BACKGROUND: Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group. AIMS: To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers. METHODS: An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens. RESULTS: The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals. CONCLUSIONS: Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Occupation and pancreatic cancer in Spain: a case-control study based on job titles. PANKRAS II Study Group.

BACKGROUND: Occupational exposures may increase the risk of exocrine pancreatic cancer. This study aimed to identify occupations that in Spain may be associated with such risk. METHODS: Incident cases of pancreatic cancer and hospital controls were prospectively identified and interviewed during their hospital stay. Occupational history was obtained by direct interview with the patient and was available for 164 (89%) of 185 pancreatic cancer cases and for 238 (90%) of 264 controls. Occupations were coded according to the Spanish version of the International Standard Classification of Occupations 1988. RESULTS: A significant increased odds ratio (OR) was observed in men for 'physical, chemistry and engineering science technicians'. Elevated risks were also found for 'metal moulders, sheet-metal workers, structural metal workers, welders and related workers', 'painters and varnishers' and 'machinery mechanics and fitters'. 'Agricultural workers' did not present an increased risk for pancreas cancer in men. In women, however, high OR were observed for 'agricultural workers' and for 'textile and garment workers'. Most associations remained unchanged after considering long duration of the exposure and the period 5-15 years before diagnosis. CONCLUSIONS: Few occupations were at increased risk for pancreatic cancer, and the associations observed are in accordance with previous studies. The increases in risk observed for women in agricultural and textile jobs, and for men in the manufacture of dyes and pigments may deserve further attention.

Adding years to life: effect of avoidable mortality on life expectancy at birth.

STUDY OBJECTIVE: The aim was to determine the number of years that could be gained by preventing avoidable deaths. DESIGN: The study arose from the concept of avoidable causes of death and life expectancy at birth. Four abbreviated life tables were computed. The first included all causes of death; the second excluded all avoidable causes of death; the third and fourth excluded respectively primary and secondary avoidable causes of death. SETTING: Mortality and population data were taken from Mortality Statistics Offices in Valencia Region, Spain. MAIN RESULTS: Life expectancy at birth (LEB) was 75.7 years. After removing all avoidable deaths, LEB increased by 1.74 years. This improvement is attributed to avoidable deaths by primary prevention (1.09 years) and avoidable death by secondary prevention (0.37 year). CONCLUSIONS: According to these results the greatest improvement in LEB would be gained by primary prevention.

How do types of employment relate to health indicators? Findings from the second European survey on working conditions.

STUDY OBJECTIVE: To investigate the associations of various types of employment with six self reported health indicators, taking into account the part played by demographic variables, individual working conditions and four ecological indicators at the country level. DESIGN: Cross sectional survey (structured interview) of a sample of the active population of 15 European countries aged 15 years or over. Main independent variables were nine types of employment categorised as follows: small employers, full and part time permanent employees, full and part time fixed term employees, full and part time sole traders and full and part time temporary contracts. Main outcome measures were three self reported health related outcomes (job satisfaction, health related absenteeism, and stress) and three self reported health problems (overall fatigue, backache, and muscular pains). Logistic regression and multilevel models were used in the analyses. SETTING: 15 countries of the European Union. PARTICIPANTS: 15 146 employed persons aged 15 or over. MAIN RESULTS: Precarious employment was consistently and positively associated with job dissatisfaction but negatively associated with absenteeism and stress (as compared with full time permanent workers). Fatigue, backache and muscular pains also tended to be positively associated with precarious employment, particularly with full time precarious employment. Small employers reported high percentages of stress and fatigue, but absenteeism was relatively low. Sole traders generally reported high percentages of all outcomes, except for absenteeism, which was low. For each type of employment (except temporary contracts), full time workers tended to report worse health outcomes than part time workers. Patterns were generally consistent across countries. Associations persisted after adjustment for individual level working conditions and were not modified by country level variables. CONCLUSIONS: This study is the first to examine the relations between various types of employment and six health related indicators for all 15 member states of the European Union. Suggestive patterns worthy of further exploration have been found. Standardised definitions of types of underemployment and health related outcomes, more potent epidemiological designs and the inclusion of socioeconomic information (for example, social security systems, incapacity benefit schemes) at the regional level are proposed for inclusion in further research.

Distribution of sickness absence in the European Union countries.

AIMS: To determine the sickness absence frequency in European Union (EU) countries. METHODS: Sickness absence was measured by questionnaire using the Third European Survey on Working Conditions. Employees were considered to have sickness absence if they reported to be absent at least one day in the past 12 months because of an accident at work, work related problems, or by other health problems. RESULTS: Sickness absence percentages were lower in Southern European countries compared with Central and Northern European countries, and, in general, slightly higher in men than in women. CONCLUSION: This is the first description of sickness absence in each of the 15 EU countries. Examination of the sickness absence patterning between EU countries could indicate countries where important lessons to reduce sickness absence are to be learned and diffused across the EU.

Paternal exposure to pesticides and congenital malformations.

OBJECTIVES: A case-referent study with 261 matched pairs was carried out in 8 hospitals of Comunidad Valenciana, Spain, to assess the relation between occupational exposure to pesticides and selected congenital malformations. In this paper, the results concerning paternal exposure are presented. METHODS: The parents of the case patients and the referents were interviewed to collect information about exposure to pesticides and potential confounding variables. Detailed information on direct involvement in the handling of pesticides was collected for the interviewees involved in agricultural activities during a previously defined period in relation to conception and pregnancy. Exposure data were reviewed by 2 experts who assigned ordinal scores for the probability and intensity of exposure to pesticide classes and active ingredients. RESULTS: The dichotomous analysis of exposure (absent, present) yielded some increased risks, although not statistically significant, for aliphatic hydrocarbons [adjusted odds ratio (adjusted OR) 2.05, 95% confidence interval (95% CI) 0.62-6.80], inorganic compounds (adjusted OR 2.02, 95% CI 0.53-7.72), and glufosinate (adjusted OR 2.45, 95% CI 0.78-7.70), and a significant association for pyridil derivatives (adjusted OR 2.77, 95% CI 1.19-6.44). The analysis based on the experts' scores (2 levels of exposure) showed some consistent associations for these compounds. CONCLUSIONS: This research indicates a possible risk of congenital malformations for paternal exposure to some pesticides, notably, pyridils, aliphatic hydrocarbons, inorganic compounds, and glufosinate. It did not find an increased risk for paternal exposure to pesticides in the classes of organophosphates, carbamates, organochlorines, chloroalkylthio fungicides and organosulfurs. These findings warrant further investigation.

[Preventable mortality in Andalusian hospitals, 1982-1985]. / Mortalidad evitable ocurrida en hospitales andaluces, 1982-1985.

BACKGROUND: The hospital mortality has been proposed as an indicator of the quality of care, particularly the mortality defined as premature, which is considered as preventable with health care. METHODS: In the hospitals from Andalusia 2.364.934 disease episodes were cared for 1982 to 1985, with a death rate of 2.27%, as estimated in the Hospital Morbidity Survey published by the Instituto Nacional de Estadística. RESULTS: 2.8% of these deaths were caused by some of the diseases considered as preventable. Of these, hypertension and cerebrovascular disease accounted for 60% and tuberculosis for 16%. Lethality due to these conditions has increased from 0.25 in 1982 to 0.46. In addition, in the Málaga and Huelva provinces the lethality rates (0.63 and 0.61, respectively) and the standardized mortality ratios (225.6 and 174.2, respectively) corresponding to the above mentioned conditions were significantly higher than the mean values in Andalusia. CONCLUSIONS: The preventable mortality in hospitals could be used to evaluate the quality of hospital care from a double standpoint: a) the occurrence of one of these deaths could warrant an inquiry of its reasons; b) the comparison of the preventable mortality rates could identify hospital areas where health care may be provided with some inefficiencies.

[The incidence of occupational diseases: a study of medical evaluations for work incapacity in Barcelona (1987-1991)]. / Incidencia de enfermedades profesionales: estudio de las valoraciones médicas por incapacidad laboral en Barcelona (1987-1991).

BACKGROUND: The number of professional diseases (PD) declared in Spain is low. The existence of diseases of labor etiology treated as a common disease is recognized, thus disregarding important labor health risks. METHODS: The incidence of PD in the province of Barcelona from 1987-1991 was prospectively studied by the Units of Medical Evaluation of Incapacities (UMEI). The sociodemographic, medical and administrative data of the cases of PD were reported by a protocol of data collection. The cases of PD are described and the annual incidence in relation with the active working population calculated. RESULTS: The UMEI of Barcelona confirmed 554 cases of PD of which 331 were evaluated as permanent invalidity over the five years of the study. The most frequent diagnoses of PD were pneumoconiosis, skin diseases, diseases causing tendinous fatigue and hypoacusis or deafness. Eleven neoplasms were reported, 9 being caused by asbestos. During the five years the incidence of PD increased from 76 cases to 144 per 100,000 active workers. The procedure of information probably underreported the incidence of PD. CONCLUSIONS: A low incidence of professional disease was observed. The clinical-labor history is generally not carried out. The way in which the Units of Medical Evaluation of Incapacities report data concerning incidence may contribute to greater detection of professional diseases on registration being integrated into a system of epidemiologic surveillance in which all the health care, labor and administrative centers were effectively coordinated.

[Emotional disorders in the working population: an emerging problem in occupational health?]. / Trastornos afectivos en la población laboral: un problema emergente en salud laboral?

BACKGROUND: To know the prevalence of emotional disorders in a working population. SUBJECTS AND METHOD: Workers in four companies: construction (A), automobile components (B), electrical and electronic systems (C) and management services (D). The design of the study was cross-sectional with the GHQ-28 questionnaire. RESULTS: The prevalence fluctuated between 8,4% (A) and 24,0% (D). Sex, age, educational level and occupation showed significance differences in some companies. CONCLUSIONS: The results suggest an important prevalence of emotional disorders that likely increase as there will be more firms of services.

[Validity of the municipality of residence in mortality statistics: findings based on municipality census update in 2 municipalities of the Valencian community]. / La validez del municipio de residencia en las estadísticas de mortalidad: hallazgos a partir de la actualización de los padrones municipales en dos municipios de la comunidad Valenciana.

This study was designed to assess the validity of the variable "city of residence" in mortality statistics in relation to the information available in municipal census. Monthly record-linkages between mortality register and two municipal population census corresponding to the period 1991-1992 have been studied. The population census belong to Benidorm, an important Spanish coastal tourist centre, and Alcoi, a traditional industrial city. Results show that of those listed in the Alcoi mortality statistics (602 deaths), 83% were registered in its municipal population census. In Benidorm (282 deaths), this percentage was 54%; in this last city, having a private address (in contrast with hotel, apartment or clinic address...) was positively related with being registered (66.2% versus 8.8%). Likewise, deceased with Spanish names were in more likely to be registered names in municipal population census: 70.2% versus 11.9%, respectively. The evidence obtained shows that tourist area mortality statistics could be unreliable due to the incorrect reporting of the city of residence on the death certificate, and suggests actions to improve it, which should take into account the town authorities and funeral services.

[Changing the epidemiological surveillance into the public health surveillance. Work Group on Information Systems in Public Health]. / La reconversíon de la vigilancia epidemiológica en vigilancia de Salud Pública. Grupo de Trabajo sobre Sistemas de Información en Salud Púbplica.

Although epidemiological surveillance include originally a strategic function, beyond epidemic control, in Spain the communicable diseases control system has been the only surveillance scheme. This system suffer a severe crisis, probably due to the scarce uses of the information and/or because the system produce exclusively information about communicable diseases or outbreaks. In the last few years, information sources and procedure have been developed out of the official surveillance, such as cancer register, traffic accidents or air contamination statistics and so on. Moreover, national and regional health plans which signify specific health objectives entail information tools with ability to rank and evaluate the interventions. The principal health information system useful to surveillance has been described. We conclude that the expression public health surveillance define much better the functions of a) monitoring and evaluation of the health policy and b) detection and research of epidemics. Finally, we identify some elements for the change, such as: a) to include information related to adverse effects of the sanitary interventions, and environmental and occupational hazards; b) to facilitate the access of information by means of self-operating database and c) to make comparable the different information sources.

[Problems of the use of the trend test as a dose-response measurement in epidemiology]. / Problemas del uso del test de tendencia como medición de la relación dosis respuesta en epidemiología.

BACKGROUND: The objective of the dose-response analysis is to reveal the presence of a progressively response to an increased dose. One of the usual ways of doing so is the carrying out of the so-called trend test. However, the fact that this test may show statistical significance does not necessarily indicate that there is a uniform response between dose and response. This study aims to examine the various situations in which the use of the trend test is not always appropriate as well as given an overview of the use of potential alternatives. METHODS: Five theoretical dose-response scenarios have been created using for supposed case-control studies, in which the relationship was not always linear. The results-tables obtained have been analysed, leading to the attainment of the Chi-squared trent test, as well as the calculation of the linear component by means of the logistical regression. Subsequently, other alternative methods of trends analysis, such as categorical analysis, the transformation of the findings within the logistical model and the use of risk incrementals have been employed. RESULTS: The test of trends invariably proved to be significant, despite the fact that in four of the theoretical models there did not exist a clear relationship between dose and response. This significant result could lull its readers into proposing a linear dose-response relationship which, in fact, proves false. The alternative use of incremental risk models, or categorical analysis, permits the identification of situations in which there is no relationship. CONCLUSIONS: The trend test should only be employed in cases where the data demonstrates the existence of monotonous, lineal relationship that can be deduced from the results of categorical analysis, the use of incremental risk or the adjustment of various no linear models, although, in this cases, the significance of the test may bring forward no new information.

[Causality in occupational health: the Ardystil case]. / Causalidad en salud laboral: el caso ardystil.

Establishing causal relationships has been and is today a matter of debate in epidemiology. The observational nature of epidemiological research rends difficult the proving of these relationships. Related to this, different models and causal criteria have been proposed in order to explain health and disease determinants, from pure determinism in Koch postulates, accepting unicausal explanation for diseases, to more realistic multicausal models. In occupational health it is necessary to formulate causal models and criteria to assess causality, and frequently causal assessment in this field has important social, economic and juridical relevance. This paper deal with evaluation of causal relationships in epidemiology and this evaluation is illustrated with a recent example of an occupational health problem in our milieu: the Ardystil case.

[Avoidable years of life lost ratio: an indicator to identify excess mortality in health areas. Mortality workshop of the Valencia region]. / Razón de años de vida perdidos evitables: un indicador para identificar exceso de mortalidad en áreas de salud. Col.lectiu d'Estudis de Mortalitat del País Valencià.

Avoidable mortality has been proposed as an outcome indicator of health services. Until now the Standardized Mortality Ratio (SMR) has been the effect measure most used to detect excesses in avoidable mortality. We propose the use, as a complementary measure, of the Avoidable Years of Life Lost Ratio (AYLLR). We show that for tuberculosis, hypertension and for all avoidable deaths both measures provide complementary information, since in some areas where observed deaths are below the expected number (SMR less than 100) we detect an observed number of years of life lost higher than expected (AYLLR greater than 100), due to the occurrence of these deaths at younger ages. The AYLLR is a standardized effect measure that puts a higher weight to premature deaths.