Background: It is often difficult to discern whether a disease is an occupational or common disease, especially in a primary care setting.
Methods: From a randomly selected sample of 322 workers attending a Primary Health Care Center, 207 workers (response rate of 64.3%) agreed to participate. An occupational questionnaire was administered. General practitioners provided medical records for each worker. Medical records and occupational questionnaires were independently reviewed by three professionals. They assessed whether a relationship between disease and working conditions was probable or improbable.
Results: Thirty-three of the 207 cases (15.9%) were considered probably related to working conditions according to the expert's opinion. The most frequent were musculoskeletal diseases (20 cases). Of the 207 workers, 74 (35.7%) judged that their diseases could be related to their working conditions.
Conclusions: A significant proportion of diseases attended in primary care setting was not recognized as occupational, and they were hence not reflected in official statistics.