[Difficulties of a longitudinal epidemiological follow-up study in French occupational medicine]. / Les difficultés d'un suivi epidémiologique longitudinal dans les services de santé au travail.

INTRODUCTION: This study was designed to describe the difficulties of epidemiological follow-up of employees by occupational health services. METHODS: This study was based on two transverse studies conducted by the Pays de la Loire musculoskeletal disorders (MSD) surveillance network. Eighty-three occupational health physicians included 3,710 employees between 2002 and 2005 and had to review them between 2007 and 2009. Thirteen of these physicians changed jobs and 7 changed geographical sector in the same occupational health service. RESULTS: Another 94 physicians were contacted and 85 agreed to participate in the network. The follow-up rate was 43%: 1,044 employees were reviewed by the physician who saw them on inclusion and 567 employees were reviewed by another physician of the network. The other employees were distributed as follows: 25% were lost to follow-up and their occupational status remained unknown; 23% were still employed with an identified occupational health physician but had not attended a medical visit during the follow-up study; 5% had left the occupational health surveillance system. Only 23 employees refused to participate in the follow-up and 105 employees had a physician who refused to participate. DISCUSSION: There is therefore a considerable mobility of occupational health physicians, which interfered with follow-up despite their good mobilization and a high percentage of employee are lost to follow-up after having left their jobs. More appropriate systems must be set up to follow populations of employees, such as new collaborations with general practitioners.

[MSDs and job security of employees aged 50 years and over: a challenge for occupational health and public health]. / Les TMS et le maintien en emploi des salariés de 50 ans et plus: un défi pour la santé au travail et la santé publique.

Work-related musculoskeletal disorders of the upper limbs (MSDs) are the first cause of occupational illness in France, as in Europe. A pilot network for epidemiological surveillance system of MSDs has been implemented in France's Loire Valley region to assess the prevalence of MSDs and their risk factors in the working population, namely the ageing workforce. The surveillance was based on a network of occupational physicians and used the recommendations of a group of European experts ('Saltsa Criteria document' consensus). Between 2002 and 2004, 3710 men and women (aged 20-59) representative of the regional workforce were randomly selected. Exposure to risk factors of MSDs was evaluated by the use of a self-administered questionnaire which aimed to assess bio-mechanical and psychosocial risk factors. With at least one of the six primary MSDs of the upper limbs having been clinically diagnosed using a rigorous protocol, the prevalence of clinically-diagnosed MSDs was high: about 11% of male and 15% of female workers suffered from at least one of the MSDs studied. After age fifty, about 19% of male and 27% of female workers suffered from at least one MSD and 4% of male and 6% of female workers from at least two disorders. Blue-collar workers were the most affected, regardless of age or gender, followed by office employees. Exposure to MSD risk factors of remained high after age fifty: 77% of male and 72% of female blue-collar workers were exposed to at least two MSD risk factors. The implications for the prevention of MSDs and job security of workers are discussed. The high prevalence of specific MSDs of the upper limb combined with a high exposure to risk factors of MSDs in ageing workers emphasizes the need to implement comprehensive prevention programs in most sectors to reduce the exposure to risk, the prevalence of MSDs and ensure the capacity to keep employees suffering from MSDs working, or at least to quickly return to work after recovery.