Association Between education and walking speed: counterfactual mediation analysis in favor of a motor reserve hypothesis.

We quantified the extent to which the association between education and fast walking speed (FWS) is explained by 17 mediators (cardiovascular risk factors/diseases, comorbidities, health behaviours, socio-professional characteristics, cognition), and examined whether mediators interact with education, in favor of a reserve hypothesis. Cross-sectional analyses are based on Constances (population-based study of French adults 45-69y). 3m-FWS was measured using photoelectric cells. Education was categorized as lower/higher. After multiple imputation of missing values, we used counterfactual mediation models for multiple mediators allowing for education×mediator interactions, to estimate the total effect (TE), total indirect effect (TIE), and mediated interaction (IMD) of lower education on FWS. Analyses are based on 71,222 participants (52.6% women; mean age=57.2y; 27.2% higher education; mean FWS=180.2cm/s). In joint mediation analyses, the TE of lower education was -8.19cm/s (95% confidence interval [CI]=-8.87;-7.51), with a TIE of -5.76cm/s (95%CI=-6.10;-5.41; proportion mediated=70.3%, 95%CI=65.6;75.0). The IMD was negative (-2.52, 95%CI=-3.31;-1.72); 30.8% of the TE and 43.8% of the TIE were attributable to the IMD. Several mediators explain a large part of the association between lower education and slower FWS. The detrimental effect of mediators was more pronounced in participants with lower than in those with higher education, in agreement with a reserve hypothesis.

Long-term health in individuals born preterm or with low birth weight: A cohort study.

BACKGROUND: To measure the association of prematurity and non-preterm low birth weight (LBW) with several long-term health outcomes. METHODS: We selected adult participants from the Constances cohort. Associations between preterm birth (<37 weeks versus ≥37 weeks) and outcomes were measured using modified Poisson regression with adjustment for participant age and parental history. We used the same modeling methods to measure the association between LBW (i.e.,

Chronic occupational exposures to irritants and asthma in the CONSTANCES cohort.

OBJECTIVES: The impact of chronic occupational exposures to irritants on asthma remains discussed. We studied the associations between occupational exposures and asthma, with specific interest for chronic exposure to irritants, including disinfectants and cleaning products (DCPs) and solvents. METHODS: Cross-sectional analyses included 115 540 adults (55% women, mean age 43 years, 10% current asthma) working at inclusion in the French population-based CONSTANCES cohort (2012-2020). Current asthma was defined by ever asthma with symptoms, medication or asthma attacks (past 12 months), and the asthma symptom score by the sum of 5 respiratory symptoms (past 12 months). Both lifetime and current occupational exposures were assessed by the Occupational Asthma-specific Job-Exposure Matrix. Associations were evaluated by gender using logistic and binomial negative regressions adjusted for age, smoking status and body mass index. RESULTS: In women, associations were observed between current asthma and lifetime exposure to irritants (OR 1.05, 95% CI 1.00 to 1.11), DCPs (1.06, 95% CI 1.00 to 1.12) and solvents (1.06, 95% CI 0.98 to 1.14). In men, only lifetime exposure to DCPs (1.10, 95% CI 1.01 to 1.20) was associated with current asthma. Lifetime exposure to irritants was associated with higher asthma symptom score both in women (mean score ratio: 1.08, 95% CI 1.05 to 1.11) and men (1.11, 95% CI 1.07 to 1.15), especially for DCPs (women: 1.09, 95% CI 1.06 to 1.13, men: 1.21, 95% CI 1.15 to 1.27) and solvents (women 1.14, 95% CI 1.10 to 1.19, men: 1.10, 95% CI 1.05 to 1.15). For current exposures, no consistent associations were observed with current asthma and asthma symptom score. CONCLUSIONS: Lifetime occupational exposures to irritants were associated with current asthma and higher asthma symptom score. These exposures should be carefully considered in asthma management.

Relationship between night work and health-related quality of life: an analysis based on profiles and cumulative duration of exposure to night work among French workers in the CONSTANCES cohort.

OBJECTIVE: The aim of this study is to estimate the association between night work and health-related quality of life (HRQoL) among French workers. The association between cumulative duration of night work and HRQoL was also investigated. METHODS: Three career-long night work exposure groups were defined at inclusion in the CONSTANCES cohort: permanent night workers, rotating night workers and former night workers. Day workers with no experience of night work were the reference group. HRQoL was assessed using the Short Form Health Survey (SF-12), in particular the physical component summary (PCS) and mental component summary (MCS) scores, with a higher score indicating better HRQoL. Several linear regression models were built to test the association between night work exposure and HRQoL. The relationship between cumulative duration of night work and HRQoL scores was analyzed using generalised additive models. RESULTS: The sample consisted of 10,372 participants. Former night workers had a significantly lower PCS score than day workers (ß [95% CI]: - 1.09 [- 1.73; - 0.45], p = 0.001), whereas permanent night workers had a significantly higher MCS score (ß [95% CI]: 1.19 [0.009; 2.36], p = 0.048). A significant decrease in PCS score from 5 to 20 years of cumulative night work was observed among former night workers. CONCLUSIONS: Former night workers had poorer physical HRQoL in contrast to permanent and rotating night workers who had similar or even better HRQoL than day workers, suggesting the well-known healthy worker survivor effect. Consequently, both current and former night workers require regular and specific follow-up focused on the physical components of their health.

Electronic cigarette use and respiratory symptoms in the French population-based Constances cohort.

BACKGROUND: Knowledge about the consequences of electronic cigarette (EC) use on respiratory health is still limited. We aimed to assess whether EC use is associated with the occurrence of asthma symptoms and chronic bronchitis among the French adult population, with a specific focus on never combustible cigarettes (CC) smokers. We further investigated whether the association differed in men and women. METHODS: Constances is a population-based cohort of adults aged 18-69 years at inception. We analyzed baseline data collected in 136,276 participants recruited in 2015-2019. Associations of current and former EC use with respiratory symptoms (asthma symptom score and chronic bronchitis) were assessed, controlling for CC smoking, cannabis use, demographics, education and body mass index (BMI). RESULTS: Increased frequencies of respiratory symptoms were observed in both current and former EC users (for the asthma symptom score, adjusted mean score ratio (aMSR): 1.34 [95 % confidence interval: 1.28-1.41] and 1.39 [1.33-1.45], respectively; for chronic bronchitis, adjusted prevalence ratio (aPR): 1.27 [1.19-1.36] and 1.40 [1.32-1.48], respectively). Among never CC smokers, ever EC use was associated with an increased asthma symptom score in both men and women (aMSR = 1.44 [1.09-1.90] and 1.36 [1.01-1.83], respectively), and with a higher prevalence of chronic bronchitis only in women (aPR = 1.97 [1.27-3.05]). CONCLUSION: EC use is associated with symptoms of asthma and chronic bronchitis, independently of CC smoking and cannabis use. The fact that these associations are observed among individuals who have never smoked tobacco adds further evidence of the deleterious effects of EC on respiratory health.

Development of a crosswalk to convert French PCS2003 into international ISCO88 occupational classifications. Application to the Occupational Asthma-specific Job-Exposure Matrix (OAsJEM).

INTRODUCTION: The problem of transcoding is recurrent when researchers wish to link occupational data from cohorts to Job-Exposure Matrices (JEMs) which were not set up in the same classifications. The Occupational Asthma-specific JEM (OAsJEM) is a JEM developed for assessing exposure to agents known at risk for asthma for jobs coded with ISCO88 occupation classification. To apply the OAsJEM in the CONSTANCES cohort, in which jobs and industries were coded with French PCS2003 and NAF2008 classifications respectively, we developed a crosswalk to convert jobs from PCS2003 into ISCO88 classification. METHODS: This work was carried out by 2 skilled coders and 1 novice coder who have worked independently by using different tools and transcoding strategies defined a priori. Consensus meetings were organized with skilled coders to define the final crosswalk. This work was elaborated in 2 steps: (i) for 38 ISCO88 codes classified as potentially exposed to cleaning and disinfection products by the OAsJEM, and (ii) for all jobs from the ISCO88 classification. A comparison between the 3 initial coder's crosswalk proposals and the final crosswalk was made for the 38 ISCO codes in step (i). RESULTS: The final crosswalk provided 998 matches between the 482 4-digit PCS2003 codes, 308 4-digit ISCO88 codes, and 31 3-digit ISCO88 codes. Information regarding the NAF2008 industry classification was also used in some cases to improve the final crosswalk. For the selected 38 ISCO88 codes, the final crosswalk provided 110 combinations, but the number of proposed ISCO88-PCS2003 couples by each of the 3 coders varied greatly from 68 to 153. In addition, an important variability between the 3 coders were observed among the number of common combinations between the initial coder's proposals and the final crosswalk (from 47% to 78%). DISCUSSION: We have developed a crosswalk specifically for an application of the OAsJEM in population-based surveys using the PCS2003 occupation classification. The development of this crosswalk is of great interest for the use of OAsJEM on the data of the CONSTANCES cohort and on any other survey with occupational data coded according to the French classifications. This OAsJEM crosswalk could be used by other teams to evaluate occupational exposures known to be at risk of asthma from occupational calendars coded with French classifications.